Aspects of the present disclosure relate generally to the field of isolation structure formation for devices such as complimentary metal-oxide semiconductor (CMOS) and, more particularly to single diffusion breaks. Decisions regarding integrate circuits are progressively being driven not only by manufacturing costs and efficiency, but also by device density and scalability. Single diffusion breaks are often used to reduce the circuit area consumed and to enable the formation high density integrated circuits. Unfortunately, single diffusion breaks are often challenging to manufacture while still consuming a significant amount of chip space.
A first aspect of the present disclosure provides a reduced diffusion break structure (RDB) structure including: a first sidewall spacer positioned between a first gate terminal and a first source/drain terminal of a first active device, wherein the first sidewall spacer includes a first L-shaped spacer and a first outer spacer, the L-shaped spacer having a base portion horizontally extended from the first gate terminal to the first source/drain terminal and a vertical portion vertically extended, parallel to the first outer spacer, to a top portion of a first inter dielectric layer (IDL); a RDB dielectric, having a first reduced width less than a width of the first gate terminal, vertically extended from the top portion of the first IDL into a substrate, wherein the RDB dielectric is separated from the first source/drain terminal by a first RDB spacer, the first RDB spacer having a first upper spacer, wherein the first RDB spacer has a second reduced width less that a width of the first sidewall spacer.
A second aspect of the present disclosure provides a method of forming a RDB structure, the method including: forming a first dummy gate and a second dummy gate on a substrate, wherein an exposed portion of substrate is between the first dummy gate and the second dummy gate; depositing a first spacer liner over the first dummy gate, the second dummy gate, and the exposed portion of substrate between the first dummy gate and the second dummy gate; forming a RDB dielectric structure between the first dummy gate and the second dummy gate; depositing a second spacer liner vertically along the RDB dielectric structure, the first dummy gate, and the second dummy gate; forming a set of source/drain terminals for each of the first dummy gate and the second dummy gate, wherein the set of source/drain terminals are embedded adjacent to the first dummy gate and the second dummy gate, respectively; and replacing each the first dummy gate and the second dummy gate with a metal gate terminal.
A third aspect of the present disclosure provides a semiconductor structure, the semiconductor structure including: a reduced diffusion break (RDB) structure having a RDB dielectric structure vertically extended into a substrate from a top portion of the inter dielectric layer (IDL), wherein the RDB dielectric structure is configured between a first RDB spacer and a second RDB spacer; a first sidewall spacer positioned between a first gate terminal and a first source/drain terminal of a first active device, wherein the first sidewall spacer includes a first L-shaped spacer and a first outer spacer, the L-shaped spacer having a base portion horizontally extended from the first gate terminal to the first source/drain terminal and a vertical portion vertically extended parallel to the first outer spacer a top portion of an inter dielectric layer (IDL); and a second sidewall spacer positioned between a second gate terminal and a second source/drain terminal of a second active device, wherein the second sidewall spacer includes a second L-shaped spacer and a second outer spacer, the second L-shaped spacer having a base portion horizontally extended from the second gate terminal to the second source/drain terminal and a vertical portion vertically extended parallel to the second outer spacer to a top portion of a second IDL.
The drawings included in the present disclosure are incorporated into, and form part of, the specification. They illustrate embodiments of the present disclosure and, along with the description, serve to explain the principles of the disclosure. The drawings are only illustrative of certain embodiments and do not limit the disclosure.
While the embodiments described herein are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the particular embodiments described are not to be taken in a limiting sense. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.
Aspects of the present disclosure relate generally to the field of isolation structure formation for devices such as complimentary metal-oxide semiconductor (CMOS) and, more particularly to single diffusion break (SDB) structure.
A SDB structure is an isolation structure in semiconductor technology that allows for the formation of high density integrated circuit technology by reducing the amount of circuit area consumed. Often the SDB acts as an isolation barrier between semiconductor components (e.g., between two transistors). Though traditional SDB structures have been effective, the size associated with traditional SDB structures has remained constant despite many the area reduction of many semiconductor devices. For example, traditional SDB structures are often designed with a width of the sum of the gate length and 2 times of the width of the gate spacer (e.g., if the gate length is 18 nm, and the gate spacer width is 6 nm, the SDB size is approximately 30 nm). As such, there is a desire for a reduced diffusion break that may continue to aid in scaling (e.g., CMOS scaling). The present disclosure provides solutions for the structure and formation of a reduced isolation structure (e.g., reduced diffusion break) that requires less area than traditional SBD structures while still isolating two active devices.
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First transistor device 102a and second device 102b may be electrically separated by a SDB structure 112. SDB structure 112 acts as an isolation area to block parasitic elements between first transistor device 102a and second transistor device 102b. This SDB structure 112 includes SDB dielectric 114, that extends into substrate 104, and SDB spacers 116. SDB spacers 116 separate source/drain regions 106a and 106b, respectively, from SDB dielectric 114.
Due to conventional formation of SDB structures, such as SDB structure 112, in semiconductor structures, SDB dielectric 114 is approximately the width of a gate structure. For example, a gate structure can be approximately 18 nm for advanced FINFET technology, and can be slightly smaller for nanowire or nanosheet technology (e.g., gate structures 108a and 108b). SDB spacers 116 are traditionally the same or approximately the same width and composition as spacers 110. The conventional SDB spacers 116 and spacers 110 depicted in
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RDB structure 202 may include a RDB dielectric structure 210 and first RDB spacer and second RDB spacer configured on either side of the RDB dielectric structure 210. RDB dielectric structure 210 may be centrally positioned between the first RDB spacer and the second RDB spacer. In some embodiments, RDB dielectric structure 210 may vertically extend from a predetermined depth within substrate 212 to a vertical height approximately the height of a top portion 214 of interlayer dielectric (IDL) layer 216. In embodiments, RDB dielectric structure 210 may have first reduced width that is less than the width of a gate terminal. For example, RDB dielectric structure 210 may have a width of approximately 9 nm while first gate terminal 226 associated with first active device 204 and second gate terminal 228 associated with second active device 206 respectively, may each have a gate width approaching 18 nm. While RDB dielectric structure 210 may be comprised of any available dielectric material, examples of possible dielectric material include SiN, SiC, and SiCO.
In embodiments, first and second RDB spacer may each vertically extend from the top of substrate 212 to a vertical height approximately the height of a top portion 214 of a first interlayer dielectric (IDL) layer 216 on either side of RDB dielectric structure 210. Based on the design parameters of semiconductor structure 200, the first and second RDB spacer may each have a reduced width (e.g., second reduced width) of approximately 3 nm. In some embodiments, each RDB spacer may include a upper spacer and/or a base spacer. For example, first RDB spacer may include first upper spacer 218 and first base spacer 220 and second RDB spacer may include second upper spacer 222 and second base spacer 224. First base spacer 220 may be positioned directly beneath first upper spacer 236 and directly above substrate 212. First base spacer may then extend horizontally from RDB dielectric structure 210 to first source/drain terminal 230a associated with first active device 204. While second base spacer 224 is similarly also positioned directly beneath second upper spacer 242 and directly above substrate 212, second base spacer 224 extends (e.g., in the opposite direction) horizontally toward second source/drain terminal 232a associated with second active device 206. To provide a complete illustration of first active device 204 and second active device 206, first and second active device 204 and 206 may each include a corresponding source/drain terminal (e.g., first corresponding source/drain terminal 230b and second corresponding source/drain terminal 232b). In embodiments, directly above each first source/drain terminal 230a and second source/drain terminal 232a (and the associated corresponding source/drain terminals 230b and 232b) is an ILD layer 216 (e.g., first ILD layer and second IDL layer) that extends from the top of the respective source/drain terminal and extends to the top of semiconductor structure 200 (e.g., to top portion 214).
In embodiments, semiconductor device 200 may also include first sidewall spacer positioned between first gate terminal 226 and a first source/drain terminal 230a of a first active device 204. First sidewall spacer may include a first L-shaped spacer 234 and first outer spacer 236. In embodiments, L-shaped spacer 234 may be configured to have a bottom portion 238 that horizontally extends from first gate terminal 226 to first source/drain terminal 230a. The vertical portion of L-shaped space 234 may vertically extended, parallel to first outer spacer 236, to a vertical height approximately the height a top portion 214 of a IDL layer 216 (e.g., a first IDL layer). In some embodiment, the first RDB spacer may have a reduced width (e.g., second reduced width) that is less than the width of the first sidewall spacer (e.g., the combined width of each the first outer spacer 236 and the L-shaped spacer 234).
In embodiments, semiconductor device 200 may also include a second sidewall spacer. The second sidewall spacer may be positioned between second gate terminal 228 and second source/drain terminal 232a of second active device 206. The second sidewall spacer may include a second L-shaped spacer 240 and second outer spacer 242. In embodiments, second L-shaped spacer 240 may have bottom portion 244 that horizontally extends from second gate terminal 228 to second source/drain terminal 232a and a vertical portion that extends vertically, parallel to second outer spacer 242 to a vertical height approximately the height a top portion 214 of a IDL layer 216 (e.g., a second IDL layer). In embodiments, second RDB spacers may have a reduced width (e.g., third reduced width) that is less than the width of second sidewall spacer (e.g., the combined width of each the second outer spacer 242 and the L-shaped spacer 240). In embodiments contemplated herein, the widths of RDB dielectric structure 210, the first RDB spacer, and the second RDB spacer, when combined, have a combined reduced width that is less than a combined width of either first gate terminal 226 or second gate terminal 228. Accordingly, the RDB structure, such as that contemplated herein, can have an isolation footprint of approximately 15 nm. The aforementioned structure of semiconductor structure 200 results in approximately a 50% reduction in area needed to form an isolation break than the amount of area needed to form traditional SDB structures.
In some embodiments, the material comprising the base spacers (e.g., first base spacer 220 and second base spacer 224) associated with the first and second RDB spacers, is the same material comprising the L-shaped spacers (e.g., first L-shaped spacer 234 and L-shaped spacer 244) of the first and second sidewall spacers. This material may be comprised of a variety of materials including, but not limited to, SiBCN, SiOCN, and SiCO. In some embodiments, the material comprising the outer spacers (e.g., first outer spacer 236 and second outer spacer 242) associated with first and second sidewall spacer is the same material of the upper spacers (e.g., first upper spacer 218 and second upper spacer 222) associated with the RDB spacers.
In embodiments, semiconductor structure 300 having a RDB structure may have a number of dummy gates 302 formed on substrate 304. In such embodiments, the dummy gates may be patterned with variable pitch. While semiconductor structure 300 may have any number of dummy gates 302 (e.g.,
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In embodiments, during the deposition of second space liner 328, one or more side wall spacers 334 (e.g., first side wall spacer and second side wall spacer discussed in
In embodiments, during the deposition of second space liner 328, first RDB spacer 342 and second RDB spacer 344 may be formed. Both first RDB spacer 342 and second RDB spacer 344 may extending vertically along the set of exposed walls of RDB dielectric structure 324 directly above the substrate 304. First RDB spacer 342 and second RDB spacer 344 may each include an upper spacer 346, composed of second spacer liner 328, and a base spacer 348, composed of first spacer liner 314. With the formation of first RDB spacer 342 and second RDB spacer 344 adjacent to RDB dielectric structure 324, RDB structure 350 is formed.
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In embodiments, an ILD layer 354 may be deposited over each of the source/drain terminals 332 that may extend to the top portion of the dummy gates 304 through CMP. Each dummy gate 304 (e.g., first dummy gate 306 and second dummy 308) may then be replaced with metal gate terminals 352. While one or more methods may be used replace dummy gates 304 with metal gate terminals 352, one such method may use an wet or RIE etch to remove the dummy gate, followed by depositing gate stack including gate dielectric and gate electrode to form the replacement metal gate process. In some embodiments, the replacement gate 352 is recessed, followed by an gate dielectric cap 366 formation.
In embodiments, RDB dielectric structure 324 may have a reduced width 356 (e.g., first reduced width) that is less than a width 358 of a gate terminal (e.g., first gate terminal). In such embodiments, first RDB spacer 342 and second RDB spacer 344 each have a reduced width 360 (e.g., second reduced width) that is less than the width 362 of the sidewall spacer (e.g., first sidewall spacer). Accordingly, semiconductor structure 300 has a RDB structure 350 having a total combined isolation footprint 364 that is approximately 15 nm (e.g., combining a 3 nm reduced width associated with first RDB spacer 342, a 3 nm reduced width associated with second RDB spacer 344, and a 9 nm reduced width associated with RDB dielectric structure 324). RDB structure 350's isolation footprint 364 is approximately half the total area of traditional SDB structures (e.g., SDB structure 112 of
The computer system 401 may contain one or more general-purpose programmable central processing units (CPUs) 402A, 402B, 402C, and 402D, herein generically referred to as the CPU 402. In some embodiments, the computer system 401 may contain multiple processors typical of a relatively large system; however, in other embodiments the computer system 401 may alternatively be a single CPU system. Each CPU 402 may execute instructions stored in the memory subsystem 404 and may include one or more levels of on-board cache.
System memory 404 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 422 or cache memory 424. Computer system 401 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 426 can be provided for reading from and writing to a non-removable, non-volatile magnetic media, such as a “hard drive.” Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), or an optical disk drive for reading from or writing to a removable, non-volatile optical disc such as a CD-ROM, DVD-ROM or other optical media can be provided. In addition, memory 404 can include flash memory, e.g., a flash memory stick drive or a flash drive. Memory devices can be connected to memory bus 409 by one or more data media interfaces. The memory 404 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of various embodiments.
One or more programs/utilities 428, each having at least one set of program modules 490 may be stored in memory 404. The programs/utilities 428 may include a hypervisor (also referred to as a virtual machine monitor), one or more operating systems, one or more application programs, other program modules, and program data. Each of the operating systems, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Programs 428 and/or program modules 440 generally perform the functions or methodologies of various embodiments.
Although the memory bus 409 is shown in
In some embodiments, the computer system 401 may be a multi-user mainframe computer system, a single-user system, or a server computer or similar device that has little or no direct user interface, but receives requests from other computer systems (clients). Further, in some embodiments, the computer system 401 may be implemented as a desktop computer, portable computer, laptop or notebook computer, tablet computer, pocket computer, telephone, smartphone, network switches or routers, or any other appropriate type of electronic device.
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As discussed in more detail herein, it is contemplated that some or all of the operations of some of the embodiments of methods described herein may be performed in alternative orders or may not be performed at all; furthermore, multiple operations may occur at the same time or as an internal part of a larger process.
The present disclosure may be a system, a method, and/or a computer program product at any possible technical detail level of integration. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present disclosure.
The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.
Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.
Computer readable program instructions for carrying out operations of the present disclosure may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++, or the like, and procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure.
Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.
These computer readable program instructions may be provided to a processor of a computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.
The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be accomplished as one step, executed concurrently, substantially concurrently, in a partially or wholly temporally overlapping manner, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.
The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Although the present disclosure has been described in terms of specific embodiments, it is anticipated that alterations and modification thereof will become apparent to the skilled in the art. Therefore, it is intended that the following claims be interpreted as covering all such alterations and modifications as fall within the true spirit and scope of the disclosure.