Patent Application
20170222133
This patent document relates to memory circuits or devices and their applications in electronic devices or systems.
Recently, as electronic appliances trend toward miniaturization, low power consumption, high performance, multi-functionality, and so on, semiconductor devices capable of storing information in various electronic appliances such as a computer, a portable communication device, and so on have been demanded in the art, and research has been conducted for the semiconductor devices. Such semiconductor devices include semiconductor devices which can store data using a characteristic that they are switched between different resistant states according to an applied voltage or current, for example, an RRAM (resistive random access memory), a PRAM (phase change random access memory), an FRAM (ferroelectric random access memory), an MRAM (magnetic random access memory), an E-fuse, etc.
The disclosed technology in this patent document includes memory circuits or devices and their applications in electronic devices or systems and various implementations of an electronic device including a variable resistance element of which the performance is improved.
In an implementation, there is provided a method for fabricating an electronic device including a variable resistance element which includes a free layer formed over a substrate and having a changeable magnetization direction, a pinned layer having a pinned magnetization direction, a tunnel barrier layer interposed between the free layer and the pinned layer, and a magnetic correction layer suitable for reducing the influence of a stray field generated by the pinned layer. The method may include cooling the substrate, before forming the magnetic correction layer such that the magnetic correction layer is formed over the cooled substrate.
The cooling of the substrate may include cooling the substrate at a temperature of at least 75K or less. The cooling of the substrate may include cooling the substrate at a temperature of 50K. The forming of the magnetic correction layer may include a unit cycle of forming a first layer containing a magnetic material and successively forming a second layer containing a non-magnetic material over the first layer, and a plurality of unit cycles are performed to form the magnetic correction layer. The magnetic material may include Co, Fe, or Ni. The non-magnetic material may include Pt or Pd.
The forming of the magnetic correction layer may further include recooling the substrate at every (N/M)th unit cycle, when the unit cycle is performed a total number of N times in order to form the magnetic correction layer, where N and M are natural numbers excluding 0. N may be larger than M (N>M), and N may be an integer multiple of M. M may be equal to or more than at least 4. The recooling of the substrate may include cooling the substrate at a temperature of at least 75K or less. The recooling of the substrate may include cooling the substrate at a temperature of 50K. The cooling of the substrate and the recooling of the substrate may be performed at the same temperature.
In an implementation, there is provided a method for fabricating an electronic device having a multilayer thin film which is formed over a substrate and in which a plurality of first layers containing a magnetic material and a plurality of second layers containing a non-magnetic material are alternately stacked. The method may include: cooling the substrate; and forming the multilayer thin film over the cooled substrate. The forming of the multilayer thin film may include: performing a unit cycle a total number of N times, the unit cycle including forming the first layer over the cooled substrate and successively forming the second layer over the first layer; and recooling the substrate at every (N/M)th unit cycle, where N and M are natural numbers excluding 0.
N may be larger than M (N>M), and N may be an integer multiple of M. M may be equal to or more than at least 4. The cooling of the substrate and the recooling of the substrate may include cooling the substrate at a temperature of at least 75K or less. The cooling of the substrate and the recooling of the substrate may include cooling the substrate at a temperature of 50K. The cooling of the substrate and the recooling of the substrate may be performed at the same temperature. The magnetic material may include Co, Fe, or Ni. The non-magnetic material may include Pt or Pd.
In an implementation, there is provided an electronic device including a semiconductor memory. The semiconductor memory may include: a free layer having a changeable magnetization direction; a pinned layer having a magnetization direction pinned to a first direction; a tunnel barrier layer interposed between the free layer and the pinned layer; a magnetic correction layer having a magnetization direction pinned to a second direction which is the opposite direction of the first direction; and a spacer layer interposed between the pinned layer and the magnetic correction layer so as to provide exchange coupling. The interface between the magnetic correction layer and the spacer layer may have lower roughness than the other interfaces.
A mixing layer at the interface between the magnetic correction layer and the spacer layer may have a smaller thickness than mixing layers at the other interfaces. The magnetic correction layer may include a multilayer thin film in which a plurality of first layers containing a magnetic material and a plurality of second layers containing a non-magnetic material are alternately stacked. The magnetic material may include Co, Fe, or Ni. The non-magnetic material may include Pt or Pd.
The electronic device may further comprising a microprocessor which includes: a control unit configured to receive a signal including a command from an outside of the microprocessor, and performs extracting, decoding of the command, or controlling input or output of a signal of the microprocessor; an operation unit configured to perform an operation based on a result that the control unit decodes the command; and a memory unit configured to store data for performing the operation, data corresponding to a result of performing the operation, or an address of data for which the operation is performed, wherein the semiconductor memory is part of the memory unit in the microprocessor.
The electronic device may further comprising a processor which includes: a core unit configured to perform, based on a command inputted from an outside of the processor, an operation corresponding to the command, by using data; a cache memory unit configured to store data for performing the operation, data corresponding to a result of performing the operation, or an address of data for which the operation is performed; and a bus interface connected between the core unit and the cache memory unit, and configured to transmit data between the core unit and the cache memory unit, wherein the semiconductor memory is part of the cache memory unit in the processor.
The electronic device may further comprising a processing system which includes: a processor configured to decode a command received by the processor and control an operation for information based on a result of decoding the command; an auxiliary memory device configured to store a program for decoding the command and the information; a main memory device configured to call and store the program and the information from the auxiliary memory device such that the processor can perform the operation using the program and the information when executing the program; and an interface device configured to perform communication between at least one of the processor, the auxiliary memory device and the main memory device and the outside, wherein the semiconductor memory is part of the auxiliary memory device or the main memory device in the processing system.
The electronic device may further comprising a data storage system which includes: a storage device configured to store data and conserve stored data regardless of power supply; a controller configured to control input and output of data to and from the storage device according to a command inputted form an outside; a temporary storage device configured to temporarily store data exchanged between the storage device and the outside; and an interface configured to perform communication between at least one of the storage device, the controller and the temporary storage device and the outside, wherein the semiconductor memory is part of the storage device or the temporary storage device in the data storage system.
The electronic device may further comprising a memory system which includes: a memory configured to store data and conserve stored data regardless of power supply; a memory controller configured to control input and output of data to and from the memory according to a command inputted form an outside; a buffer memory configured to buffer data exchanged between the memory and the outside; and an interface configured to perform communication between at least one of the memory, the memory controller and the buffer memory and the outside, wherein the semiconductor memory is part of the memory or the buffer memory in the memory system.
In accordance with the present implementations, the substrate may be cooled when the magnetic correction layer is formed, which makes it possible to improve the characteristic of the variable resistance element without a structural change of the variable resistance element.
Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention. The drawings are not necessarily to scale and in some instances, proportions may have been exaggerated in order to clearly illustrate features of the embodiments. When a first layer is referred to as being “on” a second layer or “on” a substrate, it not only refers to a case where the first layer is formed directly on the second layer or the substrate but also a case where a third layer exists between the first layer and the second layer or the substrate.
As illustrated in
In the MTJ structure, the free layer 120 may store data according to the magnetization direction thereof, because the magnetization direction is changeable. Thus, the free layer 120 may be referred to as a storage layer. The magnetization direction of the free layer 120 may be changed by spin transfer torque. The pinned layer 140 having the pinned magnetization direction may be referred to as a reference layer of which the magnetization direction can be compared to the magnetization direction of the free layer 120. The tunnel barrier layer 130 may change the magnetization direction of the free layer 120 through electron tunneling. The free layer 120 and the pinned layer 140 may have a magnetization direction perpendicular to the surfaces of the respective layers. For example, as indicated by arrows of
According to a voltage or current applied to the variable resistance element 100, the magnetization direction of the free layer 120 may be changed to be parallel or anti-parallel to the magnetization direction of the pinned layer 140. Thus, the variable resistance element 100 may switch between a low-resistance state in which the magnetization direction is parallel and a high-resistance state in which the magnetization direction is anti-parallel, and store different data through the switching operation. That is, the variable resistance element 100 may function as a memory cell.
Each of the free layer 120 and the pinned layer 140 may have a single-layer or multilayer structure including a ferromagnetic material. For example, each of the free layer 120 and the pinned layer 140 may include an alloy based on Fe, Ni, or Co, such as Co—Fe—B alloy, Co—Fe—B—X alloy, Fe—Pt alloy, Fe—Pd alloy, Co—Pd alloy, Co—Pt alloy, Fe—Ni—Pt alloy, Co—Fe—Pt alloy, Co—Ni—Pt alloy, Fe—Pd alloy, Co—Pd alloy, Co—Pt alloy, Fe—Ni—Pt alloy, Co—Fe—Pt alloy, or Co—Ni—Pt alloy, where X represents Al, Si, Ti, V, Cr, Ni, Ga, Ge, Zr, Nb, Mo, Pd, Ag, Hf, Ta, W, or Pt. Each of the free layer 120 and the pinned layer 140 may include a stacked structure such as Co/Pt or Co/Pd. Furthermore, each of the free layer 120 and the pinned layer 140 may have a stacked structure in which a magnetic substance and a non-magnetic substance are alternately stacked. The tunnel barrier layer 130 may include an insulating oxide such as MgO, CaO, SrO, TiO, VO, or NbO.
The variable resistance element 100 may further include various functional layers for improving characteristics required by the MTJ structure. In the present implementation, the various functional layers may include the bottom layer 110, the spacer layer 150, the magnetic correction layer 160, and the capping layer 170. However, the present implementation is not limited thereto.
The bottom layer 110 may be used to improve the perpendicular magnetic anisotropy or crystallinity of the layer positioned thereon, for example, the free layer 120. The bottom layer 110 may have a single-layer or multilayer structure including various conductive materials such as metal and metal nitride.
The magnetic correction layer 160 may offset or reduce the influence of a stray field generated by the pinned layer 140. In this case, the influence on the free layer 120 by the stray field of the pinned layer 140 may be decreased to reduce a bias magnetic field in the free layer 120. The magnetic correction layer 160 may be formed over a cooled substrate, and have a stacked structure in which a magnetic substance and a non-magnetic substance are alternately stacked. Specifically, the magnetic correction layer 160 may have a multilayer structure in which a first layer including a magnetic material and a second layer including a non-magnetic material are alternately stacked. The magnetic material may include Co, Fe, and Ni, and the non-magnetic material may include Pt and Pd. Since the magnetic correction layer 160 is formed over the cooled substrate, the formation of a mixing layer may be suppressed at the interface between the magnetic correction layer 160 and a layer connected to the magnetic correction layer 160, for example, the spacer layer 150 and the interface between the magnetic correction layer 160 and the capping layer 170, 1.3 compared to other interfaces in the MTJ structure, for example, the interface between the pinned layer 140 and the spacer layer 150. Furthermore, the magnetic correction layer 160 may have low roughness. Such a structure can improve the characteristics of the magnetic correction layer 160.
The magnetic correction layer 160 may have a magnetization direction anti-parallel to the magnetization direction of the pinned layer 140. In the present implementation, when the pinned layer 140 has a magnetization direction from bottom to top, the magnetic correction layer 160 may have a magnetization direction from top to bottom. On the other hand, when the pinned layer 140 has the magnetization direction from top to bottom, the magnetic correction layer 160 may have the magnetization direction from bottom to top.
The spacer layer 150 may be interposed between the magnetic correction layer 160 and the pinned layer 140, and used to provide exchange coupling therebetween. The spacer layer 150 may include a metallic non-magnetic material, for example, Cr, Ru, Ir, or Rh.
The capping layer 170 may function as a hard mask when the variable resistance element 100 is patterned. The capping layer 170 may include various conductive materials such as metal.
In the variable resistance element 100 including the above-described MTJ structure, the stray field of the pinned layer 140 may disturb normal switching (magnetization switching) of the free layer 120. Thus, as the stray field of the pinned layer 140 is offset by the magnetic correction layer 160, the characteristics of the variable resistance element 100 can be improved. For this operation, a variety of methods have been proposed, which includes a method using a material with a large magnetic moment as the magnetic correction layer 160, a method of increasing the thickness of the magnetic correction layer 160, or a method of decreasing the thickness of the pinned layer 140 to reduce a stray field generated in the pinned layer 140.
However, since the above-described methods cause the following problems, the methods cannot be applied. Specifically, the material with a large magnetic moment may have poor perpendicular magnetic anisotropy or low stability. The method of increasing the thickness of the magnetic correction layer 160 may make it difficult to pattern the variable resistance element 100. The method of decreasing the thickness of the pinned layer 140 may reduce the perpendicular magnetic anisotropy of the pinned layer 140.
Thus, it is the most ideal to improve the characteristic of the magnetic correction layer 160 while maintaining the shape of the variable resistance element 100. The shape of the variable resistance element 100 may indicate the applied materials and the stacked structure. In the present implementation, the applied materials and the stacked structure will be described in detail.
The present implementation may provide a method capable of increasing the anisotropy field (Hk) of the magnetic correction layer 160, while maintaining the magnetic moment (Ms*t) of the magnetic correction layer 160. For this method, the magnetic correction layer 160 may be formed in an ultra-low temperature state. The ultra low temperature may indicate a temperature of 75K or less. Specifically, the ultra low temperature may be set to 50K. Hereafter, the method will be described in more detail with reference to
Referring to
Each of the free layer 120 and the pinned layer 140 which include a ferromagnetic material may be formed through PVD (Physical Vapor Deposition). Since the ferromagnetic material is composed of various elements, various targets with small sizes may be used during the PVD process for forming the free layer 120 and the pinned layer 140, and the free layer 120 and the pinned layer 140 may be deposited while the substrate is rotated.
The substrate over which the bottom layer 110, the free layer 120, the tunnel barrier layer 130, the pinned layer 140, and the spacer layer 150 are formed may be moved to a stage chamber at an ultra low temperature of 75K or less and then cooled down, at step S202. At this time, the substrate may be cooled to a temperature of 50K.
Then, the magnetic correction layer 160 may be formed over the cooled substrate. The forming of the magnetic correction layer 160 may include performing a plurality of unit cycles to form a part of the magnetic correction layer 160 at step S203, recooling the substrate at step S204, and determining the completion of the magnetic correction layer 160 at step S205. The unit cycle for forming the magnetic correction layer 160 may include forming a first layer containing a magnetic material over the cooled substrate and successively forming a second layer containing a non-magnetic material over the first layer. The first and second layers may be formed through a rotation deposition method using the PVD process, for example, a sputtering process. The magnetic material may include Co, Fe, and Ni, and the non-magnetic material may include Pt and Pd. The magnetic correction layer 160 may be formed through a total number of N unit cycles.
When the magnetic correction layer 160 is formed through the total number of N unit cycles, the forming of the part of the magnetic correction layer 160 at step S203 may include repeating the unit cycle N/M times at a time. That is, the forming of the part of the magnetic correction layer 160 at step S203 may be repeated until the unit cycle is performed the total number of N times. At each step, the unit cycle may be repeated N/M times. Here, N and M represent natural numbers excluding 0, N is larger than M (N>M), and N is an integer multiple of M. Furthermore, M may be equal to or larger than 4. Thus, the magnetic correction layer 160 formed at each of the steps S203 of forming the part of the magnetic correction layer 160 may have the same thickness.
The recooling of the substrate at step S204 may include moving the substrate, over which the bottom layer 110, the free layer 120, the tunnel barrier layer 130, the pinned layer 140, the spacer layer 150, and the part of the magnetic correction layer 160 are formed, to the stage chamber at an ultra low temperature of 75K or less, for example, and cooling down the substrate. At this time, the substrate may be cooled to a temperature of 50K. That is, the cooling of the substrate at step S202 and the recooling of the substrate at step S204 may be performed at the same temperature. The recooling of the substrate at step S204 is in order to prevent an increase in temperature of the substrate and maintain a predetermined level of temperature, during the process for forming the magnetic correction layer 160, thereby improving the characteristic of the magnetic correction layer 160 or particularly the anisotropy field. The recooling of the substrate at step S204 may be performed at every (N/M)-th unit cycle, when the unit cycle is repeated a total number of N times to form the magnetic correction layer 160. That is, M may represent the total number of times by which the recooling of the substrate at step S204 is performed. In order to increase the characteristic, M may be equal to or larger than 4. For example, when the unit cycle is a total number of 12 times to form the magnetic correction layer 160, the unit cycle for the forming of the part of the magnetic correction layer 160 at step S203 may be repeated three times at each step. Furthermore, the recooling of the substrate at step S204 may be performed once after the unit cycle is repeated three times. Thus, the recooling of the substrate at step S204 may be performed a total number of four times.
The determining of the completion of the magnetic correction layer 160 at step S205 may include counting how many times the unit cycle was repeated, in order to determine the completion of the magnetic correction layer 160.
Then, the capping layer 170 may be formed over the magnetic correction layer 160 at step S206. The capping layer 170 may be formed at a temperature of 0° C. or more, for example, room temperature.
The bottom layer 110, the free layer 120, the tunnel barrier layer 130, the pinned layer 140, the spacer layer 150, the magnetic correction layer 160, and the capping layer 170 may be patterned to form the pillar-shaped variable resistance element 100 as illustrated in
As described above, when the magnetic correction layer 160 is formed over the cooled substrate, exchange coupling between the magnetic correction layer 160 and the pinned layer 140 may be strengthened. This is because, since the heat energy at the surface of the spacer layer 150 is lowered by the cooled substrate when the magnetic correction layer 160 is deposited, the formation of a mixing layer between the spacer layer 150 and the magnetic correction layer 160 can be suppressed, and the roughness can be reduced to prevent magnetic deterioration of the magnetic correction layer 160, which may be caused by the mixing layer and the roughness. Furthermore, when the magnetic correction layer 160 is formed over the cooled substrate, the characteristic of the magnetic correction layer 160 can be improved while the shape of the variable resistance element 100 is maintained. Specifically, as the magnetic correction layer 160 is formed at a temperature of 75K or less, or particularly an ultra low temperature of 50K, the anisotropy field (Hk) of the magnetic correction layer 160 can be increased, while the magnetic moment (Ms*t) of the magnetic correction layer 160 is maintained. This was experimentally confirmed, and will be described in detail with reference to
In
Referring to
In
Referring to
As illustrated in
The bottom layer 410, the free layer 420, the tunnel barrier layer 430, the pinned layer 440, the spacer layer 450, the magnetic correction layer 460, and the capping layer 470 include the same material as the bottom layer 110, the free layer 120, the tunnel barrier layer 130, the pinned layer 140, the spacer layer 150, the magnetic correction layer 160, and the capping layer 170 in
In accordance with implementation, it is possible to improve characteristics of the variable resistance element and thus, improve characteristics of the semiconductor memory including the variable resistance element and the electronic device including the semiconductor device.
The variable resistance element in accordance with the implementations of the present disclosure, for example, the variable resistance element 100 of
Referring to
The above memory device may be fabricated by following processes.
First, the substrate 500 in which the transistor is formed may be provided, and then, a first interlayer dielectric layer 510 may be formed over the substrate 500. Subsequently, the lower contact 520 may be formed by selectively etching the first interlayer dielectric layer 510 to form a hole exposing a portion of the substrate 500 and filling the hole with a conductive material. Then, the variable resistance element 100 may be formed by forming material layers for the variable resistance element 100 over the first interlayer dielectric layer 510 and the lower contact 520, and selectively etching the material layers. A second interlayer dielectric layer 530 may be formed by filling spaces among the variable resistance elements 100 with an insulating material. Then, a third interlayer dielectric layer 340 may be formed over the variable resistance element 100 and the second interlayer dielectric layer 530, and then, the upper contact 550 penetrating through the third interlayer dielectric layer 530 and coupled to the upper end of the variable resistance element 100 may be formed.
In the memory device of this implementation, all layers included in the variable resistance element 100 may have sidewalls aligned with each other. This is because the variable resistance element 100 may be formed by an etching process using a single mask.
However, unlike the implementation of
Referring to
The above memory device may be fabricated by following processes.
First, a first interlayer dielectric layer 610 may be formed over a substrate 600, and then, a hole H exposing a portion of the substrate 600 may be formed by selectively etching the first interlayer dielectric layer 610. Then, the lower contact 620 filled in a lower portion of the hole H may be formed. Specifically, the lower contact 620 may be formed by forming a conductive material covering a resultant structure in which the hole H is formed, and removing a portion of the conductive material by an etch back process, etc, until the conductive material has a target height. Then, the under layer 110 filled in a remaining space of the hole H in which the lower contact 620 is formed may be formed. For example, the under layer 110 may be formed by forming a material layer which includes a light metal and covers a resultant structure in which the lower contact 620 is formed, and performing a planarization process, for example, a CMP (Chemical Mechanical Polishing) process until a top surface of the first interlayer dielectric layer 610 is exposed. Then, the remaining portion of the variable resistance element 100 may be formed by forming material layers for the remaining layers of the variable resistance element 100, except for the under layer 110, and selectively etching the material layers. Following processes are substantially same as the implementation of
In this implementation, since a thickness to be etched for forming the variable resistance element 100 decreases, a difficulty of an etching process can be reduced.
Also, in this implementation, a case that the under layer 110 is filled in the hole H is described. However, other implementations are also possible. For example, another portion of the variable resistance element 100 can be further filled in the hole H.
The semiconductor memory in accordance with the implementation of the present disclosure may be applied to diverse electronic devices or systems.
Referring to
The memory unit 1010 is a part which stores data in the microprocessor 1000, as a processor register, register or the like. The memory unit 1010 may include a data register, an address register, a floating point register and so on. Besides, the memory unit 1010 may include various registers. The memory unit 1010 may perform the function of temporarily storing data for which operations are to be performed by the operation unit 1020, result data of performing the operations and addresses where data for performing of the operations are stored.
The memory unit 1010 may include one or more of the above-described semiconductor devices in accordance with the implementations. The memory unit 1010 may include a variable resistance element. The variable resistance element may include a free layer having a changeable magnetization direction; a pinned layer having a pinned magnetization direction; a tunnel barrier layer interposed between the free layer and the pinned layer; a magnetic correction layer that decreases the influence of a stray field generated by the pinned layer. The magnetic correction layer may be formed through a fabrication method that includes a process of cooling the substrate before the magnetic correction layer is formed. Also, the magnetic correction layer may reduce roughness on the interface contacting the magnetic correction layer and suppress the formation of a mixing layer. In this way, it is possible to improve the characteristic of the variable resistance element without a structural change of the variable resistance element. Therefore, the semiconductor memory with improved operation characteristics may be provided. Through this, the memory unit 1010 and the microprocessor 1000 may have improved reliability.
The operation unit 1020 may perform four arithmetical operations or logical operations according to results that the control unit 1030 decodes commands. The operation unit 1020 may include at least one arithmetic logic unit (ALU) and so on.
The control unit 1030 may receive signals from the memory unit 1010, the operation unit 1020 and an external device of the microprocessor 1000, perform extraction, decoding of commands, and controlling input and output of signals of the microprocessor 1000, and execute processing represented by programs.
The microprocessor 1000 according to the present implementation may additionally include a cache memory unit 1040 which can temporarily store data to be inputted from an external device other than the memory unit 1010 or to be outputted to an external device. In this case, the cache memory unit 1040 may exchange data with the memory unit 1010, the operation unit 1020 and the control unit 1030 through a bus interface 1050.
Referring to
The core unit 1110 of the present implementation is a part which performs arithmetic logic operations for data inputted from an external device, and may include a memory unit 1111, an operation unit 1112 and a control unit 1113.
The memory unit 1111 is a part which stores data in the processor 1100, as a processor register, a register or the like. The memory unit 1111 may include a data register, an address register, a floating point register and so on. Besides, the memory unit 1111 may include various registers. The memory unit 1111 may perform the function of temporarily storing data for which operations are to be performed by the operation unit 1112, result data of performing the operations and addresses where data for performing of the operations are stored. The operation unit 1112 is a part which performs operations in the processor 1100. The operation unit 1112 may perform four arithmetical operations, logical operations, according to results that the control unit 1113 decodes commands, or the like. The operation unit 1112 may include at least one arithmetic logic unit (ALU) and so on. The control unit 1113 may receive signals from the memory unit 1111, the operation unit 1112 and an external device of the processor 1100, perform extraction, decoding of commands, controlling input and output of signals of processor 1100, and execute processing represented by programs.
The cache memory unit 1120 is a part which temporarily stores data to compensate for a difference in data processing speed between the core unit 1110 operating at a high speed and an external device operating at a low speed. The cache memory unit 1120 may include a primary storage section 1121, a secondary storage section 1122 and a tertiary storage section 1123. In general, the cache memory unit 1120 includes the primary and secondary storage sections 1121 and 1122, and may include the tertiary storage section 1123 in the case where high storage capacity is required. As the occasion demands, the cache memory unit 1120 may include an increased number of storage sections. That is to say, the number of storage sections which are included in the cache memory unit 1120 may be changed according to a design. The speeds at which the primary, secondary and tertiary storage sections 1121, 1122 and 1123 store and discriminate data may be the same or different. In the case where the speeds of the respective storage sections 1121, 1122 and 1123 are different, the speed of the primary storage section 1121 may be largest. At least one storage section of the primary storage section 1121, the secondary storage section 1122 and the tertiary storage section 1123 of the cache memory unit 1120 may include one or more of the above-described semiconductor devices in accordance with the implementations. For example, the cache memory unit 1120 may include a variable resistance element. The variable resistance element may include a free layer having a changeable magnetization direction; a pinned layer having a pinned magnetization direction; a tunnel barrier layer interposed between the free layer and the pinned layer; a magnetic correction layer that decreases the influence of a stray field generated by the pinned layer. The magnetic correction layer may be formed through a fabrication method that includes a process of cooling the substrate before the magnetic correction layer is formed. Also, the magnetic correction layer may reduce roughness on the interface contacting the magnetic correction layer and suppress the formation of a mixing layer. In this way, it is possible to improve the characteristic of the variable resistance element without a structural change of the variable resistance element. Therefore, the semiconductor memory with improved operation characteristics may be provided. Through this, the cache memory unit 1120 and the processor 1100 may have improved reliability.
Although it was shown in
The bus interface 1130 is a part which connects the core unit 1110, the cache memory unit 1120 and external device and allows data to be efficiently transmitted.
The processor 1100 according to the present implementation may include a plurality of core units 1110, and the plurality of core units 1110 may share the cache memory unit 1120. The plurality of core units 1110 and the cache memory unit 1120 may be directly connected or be connected through the bus interface 1130. The plurality of core units 1110 may be configured in the same way as the above-described configuration of the core unit 1110. In the case where the processor 1100 includes the plurality of core unit 1110, the primary storage section 1121 of the cache memory unit 1120 may be configured in each core unit 1110 in correspondence to the number of the plurality of core units 1110, and the secondary storage section 1122 and the tertiary storage section 1123 may be configured outside the plurality of core units 1110 in such a way as to be shared through the bus interface 1130. The processing speed of the primary storage section 1121 may be larger than the processing speeds of the secondary and tertiary storage section 1122 and 1123. In another implementation, the primary storage section 1121 and the secondary storage section 1122 may be configured in each core unit 1110 in correspondence to the number of the plurality of core units 1110, and the tertiary storage section 1123 may be configured outside the plurality of core units 1110 in such a way as to be shared through the bus interface 1130.
The processor 1100 according to the present implementation may further include an embedded memory unit 1140 which stores data, a communication module unit 1150 which can transmit and receive data to and from an external device in a wired or wireless manner, a memory control unit 1160 which drives an external memory device, and a media processing unit 1170 which processes the data processed in the processor 1100 or the data inputted from an external input device and outputs the processed data to an external interface device and so on. Besides, the processor 1100 may include a plurality of various modules and devices. In this case, the plurality of modules which are added may exchange data with the core units 1110 and the cache memory unit 1120 and with one another, through the bus interface 1130.
The embedded memory unit 1140 may include not only a volatile memory but also a nonvolatile memory. The volatile memory may include a DRAM (dynamic random access memory), a mobile DRAM, an SRAM (static random access memory), and a memory with similar functions to above mentioned memories, and so on. The nonvolatile memory may include a ROM (read only memory), a NOR flash memory, a NAND flash memory, a phase change random access memory (PRAM), a resistive random access memory (RRAM), a spin transfer torque random access memory (STTRAM), a magnetic random access memory (MRAM), a memory with similar functions.
The communication module unit 1150 may include a module capable of being connected with a wired network, a module capable of being connected with a wireless network and both of them. The wired network module may include a local area network (LAN), a universal serial bus (USB), an Ethernet, power line communication (PLC) such as various devices which send and receive data through transmit lines, and so on. The wireless network module may include Infrared Data Association (IrDA), code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), a wireless LAN, Zigbee, a ubiquitous sensor network (USN), Bluetooth, radio frequency identification (RFID), long term evolution (LTE), near field communication (NFC), a wireless broadband Internet (Wibro), high speed downlink packet access (HSDPA), wideband CDMA (WCDMA), ultra wideband (UWB) such as various devices which send and receive data without transmit lines, and so on.
The memory control unit 1160 is to administrate and process data transmitted between the processor 1100 and an external storage device operating according to a different communication standard. The memory control unit 1160 may include various memory controllers, for example, devices which may control IDE (Integrated Device Electronics), SATA (Serial Advanced Technology Attachment), SCSI (Small Computer System Interface), RAID (Redundant Array of Independent Disks), an SSD (solid state disk), eSATA (External SATA), PCMCIA (Personal Computer Memory Card International Association), a USB (universal serial bus), a secure digital (SD) card, a mini secure digital (mSD) card, a micro secure digital (micro SD) card, a secure digital high capacity (SDRC) card, a memory stick card, a smart media (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), a compact flash (CF) card, and so on.
The media processing unit 1170 may process the data processed in the processor 1100 or the data inputted in the forms of image, voice and others from the external input device and output the data to the external interface device. The media processing unit 1170 may include a graphic processing unit (GPU), a digital signal processor (DSP), a high definition audio device (HD audio), a high definition multimedia interface (HDMI) controller, and so on.
Referring to
The processor 1210 may decode inputted commands and processes operation, comparison, etc. for the data stored in the system 1200, and controls these operations. The processor 1210 may include a microprocessor unit (MPU), a central processing unit (CPU), a single/multi-core processor, a graphic processing unit (GPU), an application processor (AP), a digital signal processor (DSP), and so on.
The main memory device 1220 is a storage which can temporarily store, call and execute program codes or data from the auxiliary memory device 1230 when programs are executed and can conserve memorized contents even when power supply is cut off. The main memory device 1220 may include one or more of the above-described semiconductor devices in accordance with the implementations. For example, the main memory device 1220 may include a variable resistance element. The variable resistance element may include a free layer having a changeable magnetization direction; a pinned layer having a pinned magnetization direction; a tunnel barrier layer interposed between the free layer and the pinned layer; a magnetic correction layer that decreases the influence of a stray field generated by the pinned layer. The magnetic correction layer may be formed through a fabrication method that includes a process of cooling the substrate before the magnetic correction layer is formed. Also, the magnetic correction layer may reduce roughness on the interface contacting the magnetic correction layer and suppress the formation of a mixing layer. In this way, it is possible to improve the characteristic of the variable resistance element without a structural change of the variable resistance element. Therefore, the semiconductor memory with improved operation characteristics may be provided. Through this, the main memory device 1220 and the system 1200 may have improved reliability.
Also, the main memory device 1220 may further include a static random access memory (SRAM), a dynamic random access memory (DRAM), and so on, of a volatile memory type in which all contents are erased when power supply is cut off. Unlike this, the main memory device 1220 may not include the semiconductor devices according to the implementations, but may include a static random access memory (SRAM), a dynamic random access memory (DRAM), and so on, of a volatile memory type in which all contents are erased when power supply is cut off.
The auxiliary memory device 1230 is a memory device for storing program codes or data. While the speed of the auxiliary memory device 1230 is slower than the main memory device 1220, the auxiliary memory device 1230 can store a larger amount of data. The auxiliary memory device 1230 may include one or more of the above-described semiconductor devices in accordance with the implementations. For example, the auxiliary memory device 1230 may include a variable resistance element. The variable resistance element may include a free layer having a changeable magnetization direction; a pinned layer having a pinned magnetization direction; a tunnel barrier layer interposed between the free layer and the pinned layer; a magnetic correction layer that decreases the influence of a stray field generated by the pinned layer. The magnetic correction layer may be formed through a fabrication method that includes a process of cooling the substrate before the magnetic correction layer is formed. Also, the magnetic correction layer may reduce roughness on the interface contacting the magnetic correction layer and suppress the formation of a mixing layer. In this way, it is possible to improve the characteristic of the variable resistance element without a structural change of the variable resistance element. Therefore, the semiconductor memory with improved operation characteristics may be provided. Through this, the auxiliary memory device 1230 and the system 1200 may have improved reliability.
Also, the auxiliary memory device 1230 may further include a data storage system (see the reference numeral 1300 of
The interface device 1240 may be to perform exchange of commands and data between the system 1200 of the present implementation and an external device. The interface device 1240 may be a keypad, a keyboard, a mouse, a speaker, a mike, a display, various human interface devices (HIDs), a communication device, and so on. The communication device may include a module capable of being connected with a wired network, a module capable of being connected with a wireless network and both of them. The wired network module may include a local area network (LAN), a universal serial bus (USB), an Ethernet, power line communication (PLC), such as various devices which send and receive data through transmit lines, and so on. The wireless network module may include Infrared Data Association (IrDA), code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), a wireless LAN, Zigbee, a ubiquitous sensor network (USN), Bluetooth, radio frequency identification (RFID), long term evolution (LTE), near field communication (NFC), a wireless broadband Internet (Wibro), high speed downlink packet access (HSDPA), wideband CDMA (WCDMA), ultra wideband (UWB), such as various devices which send and receive data without transmit lines, and so on.
Referring to
The storage device 1310 may include a nonvolatile memory which stores data semi-permanently. The nonvolatile memory may include a ROM (read only memory), a NOR flash memory, a NAND flash memory, a phase change random access memory (PRAM), a resistive random access memory (RRAM), a magnetic random access memory (MRAM), and so on.
The controller 1320 may control exchange of data between the storage device 1310 and the interface 1330. To this end, the controller 1320 may include a processor 1321 for performing an operation for, processing commands inputted through the interface 1330 from an outside of the data storage system 1300 and so on.
The interface 1330 is to perform exchange of commands and data between the data storage system 1300 and the external device. In the case where the data storage system 1300 is a card type, the interface 1330 may be compatible with interfaces which are used in devices, such as a USB memory (universal serial bus memory), a secure digital (SD) card, a mini secure digital (mSD) card, a micro secure digital (micro SD) card, a secure digital high capacity (SDHC) card, a memory stick card, a smart media (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), a compact flash (CF) card, and so on, or be compatible with interfaces which are used in devices similar to the above mentioned devices. In the case where the data storage system 1300 is a disk type, the interface 1330 may be compatible with interfaces, such as IDE (Integrated Device Electronics), SATA (Serial Advanced Technology Attachment), SCSI (Small Computer System Interface), eSATA (External SATA), PCMCIA (Personal Computer Memory Card International Association), a USB (universal serial bus), and so on, or be compatible with the interfaces which are similar to the above mentioned interfaces. The interface 1330 may be compatible with one or more interfaces having a different type from each other.
The temporary storage device 1340 can store data temporarily for efficiently transferring data between the interface 1330 and the storage device 1310 according to diversifications and high performance of an interface with an external device, a controller and a system. The temporary storage device 1340 for temporarily storing data may include one or more of the above-described semiconductor devices in accordance with the implementations. For example, the temporary storage device 1340 may include a variable resistance element. The variable resistance element may include a free layer having a changeable magnetization direction; a pinned layer having a pinned magnetization direction; a tunnel barrier layer interposed between the free layer and the pinned layer; a magnetic correction layer that decreases the influence of a stray field generated by the pinned layer. The magnetic correction layer may be formed through a fabrication method that includes a process of cooling the substrate before the magnetic correction layer is formed. Also, the magnetic correction layer may reduce roughness on the interface contacting the magnetic correction layer and suppress the formation of a mixing layer. In this way, it is possible to improve the characteristic of the variable resistance element without a structural change of the variable resistance element. Therefore, the semiconductor memory with improved operation characteristics may be provided. Through this, the temporary storage device 1340 and the data storage system 1300 may have improved reliability.
Referring to
The memory 1410 for storing data may include one or more of the above-described semiconductor devices in accordance with the implementations. For example, the memory 1410 may include a variable resistance element. The variable resistance element may include a free layer having a changeable magnetization direction; a pinned layer having a pinned magnetization direction; a tunnel barrier layer interposed between the free layer and the pinned layer; a magnetic correction layer that decreases the influence of a stray field generated by the pinned layer. The magnetic correction layer may be formed through a fabrication method that includes a process of cooling the substrate before the magnetic correction layer is formed. Also, the magnetic correction layer may reduce roughness on the interface contacting the magnetic correction layer and suppress the formation of a mixing layer. In this way, it is possible to improve the characteristic of the variable resistance element without a structural change of the variable resistance element. Therefore, the semiconductor memory with improved operation characteristics may be provided. Through this, the memory 1410 and the memory system 1400 may have improved reliability.
Also, the memory 1410 according to the present implementation may further include a ROM (read only memory), a NOR flash memory, a NAND flash memory, a phase change random access memory (PRAM), a resistive random access memory (RRAM), a magnetic random access memory (MRAM), and so on, which have a nonvolatile characteristic.
The memory controller 1420 may control exchange of data between the memory 1410 and the interface 1430. To this end, the memory controller 1420 may include a processor 1421 for performing an operation for and processing commands inputted through the interface 1430 from an outside of the memory system 1400.
The interface 1430 is to perform exchange of commands and data between the memory system 1400 and the external device. The interface 1430 may be compatible with interfaces which are used in devices, such as a USB memory (universal serial bus memory), a secure digital (SD) card, a mini secure digital (mSD) card, a micro secure digital (micro SD) card, a secure digital high capacity (SDHC) card, a memory stick card, a smart media (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), a compact flash (CF) card, and so on, or be compatible with interfaces which are used in devices similar to the above mentioned devices. The interface 1430 may be compatible with one or more interfaces having a different type from each other.
The memory system 1400 according to the present implementation may further include a buffer memory 1440 for efficiently transferring data between the interface 1430 and the memory 1410 according to diversification and high performance of an interface with an external device, a memory controller and a memory system. For example, the buffer memory 1440 may include a variable resistance element. The variable resistance element may include a free layer having a changeable magnetization direction; a pinned layer having a pinned magnetization direction; a tunnel barrier layer interposed between the free layer and the pinned layer; a magnetic correction layer that decreases the influence of a stray field generated by the pinned layer. The magnetic correction layer may be formed through a fabrication method that includes a process of cooling the substrate before the magnetic correction layer is formed. Also, the magnetic correction layer may reduce roughness on the interface contacting the magnetic correction layer and suppress the formation of a mixing layer. In this way, it is possible to improve the characteristic of the variable resistance element without a structural change of the variable resistance element. Therefore, the semiconductor memory with improved operation characteristics may be provided. Through this, the buffer memory 1440 and the memory system 1400 may have improved reliability.
Moreover, the buffer memory 1440 according to the present implementation may further include an SRAM (static random access memory), a DRAM (dynamic random access memory), and so on, which have a volatile characteristic, and a phase change random access memory (PRAM), a resistive random access memory (RRAM), a spin transfer torque random access memory (STTRAM), a magnetic random access memory (MRAM), and so on, which have a nonvolatile characteristic. Unlike this, the buffer memory 1440 may not include the semiconductor devices according to the implementations, but may include an SRAM (static random access memory), a DRAM (dynamic random access memory), and so on, which have a volatile characteristic, and a phase change random access memory (PRAM), a resistive random access memory (RRAM), a spin transfer torque random access memory (STTRAM), a magnetic random access memory (MRAM), and so on, which have a nonvolatile characteristic.
While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
| Number | Date | Country | |
|---|---|---|---|
| 62288213 | Jan 2016 | US |
