This application is based upon and claims the benefit of Japanese Patent Application No. 2022-046554, filed on Mar. 23, 2022, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a semiconductor memory device.
There has been known a semiconductor memory device in which a plurality of memory cells are stacked in a direction intersecting with a surface of a substrate.
A semiconductor memory device according to one embodiment comprises: a substrate; and a plurality of first memory layers and a plurality of second memory layers arranged in alternation in a first direction intersecting with a surface of the substrate. The substrate includes: a plurality of local block regions arranged in a second direction intersecting with the first direction; and a hook-up region aligned in the second direction with respect to the plurality of local block regions. In the plurality of local block regions, each of the plurality of first memory layers and the plurality of second memory layers includes: a plurality of memory strings extending in the second direction and arranged in a third direction intersecting with the first direction and the second direction; and a first wiring extending in the third direction and connected to the plurality of memory strings in common. In the hook-up region, each of the plurality of first memory layers and the plurality of second memory layers includes: a signal amplifier circuit electrically connected to the first wiring; a second wiring connected to the signal amplifier circuit; a first switch transistor connected to the second wiring; a third wiring electrically connected to the second wiring via the first switch transistor; and a fourth wiring electrically connected to the second wiring without via the first switch transistor. The hook-up region includes: a plurality of first via-contact electrodes extending in the first direction and connected to the third wirings in the plurality of first memory layers; and a plurality of second via-contact electrodes extending in the first direction and connected to the fourth wirings in the plurality of second memory layers.
Next, the semiconductor memory devices according to embodiments are described in detail with reference to the drawings. The following embodiments are only examples, and not described for the purpose of limiting the present invention. The following drawings are schematic, and for convenience of description, a part of a configuration and the like is sometimes omitted. Parts common in a plurality of embodiments are attached by same reference numerals and their descriptions may be omitted.
In this specification, when referring to a “semiconductor memory device”, it may mean a memory die and may mean a memory system including a controller die, such as a memory chip, a memory card, and a Solid State Drive (SSD). Further, it may mean a configuration including a host computer, such as a smartphone, a tablet terminal, and a personal computer.
In this specification, when it is referred that a first configuration “is electrically connected” to a second configuration, the first configuration may be directly connected to the second configuration, and the first configuration may be connected to the second configuration via a wiring, a semiconductor member, a transistor, or the like. For example, when three transistors are connected in series, even when the second transistor is in OFF state, the first transistor is “electrically connected” to the third transistor.
In this specification, when it is referred that the first configuration “is connected between” the second configuration and a third configuration, it may mean that the first configuration, the second configuration, and the third configuration are connected in series and the second configuration is connected to the third configuration via the first configuration.
In this specification, when it is referred that a circuit or the like “electrically conducts” two wirings or the like, it may mean, for example, that this circuit or the like includes a transistor or the like, this transistor or the like is disposed in a current path between the two wirings, and this transistor or the like is turned ON.
In this specification, a direction parallel to an upper surface of the substrate is referred to as an X-direction, a direction parallel to the upper surface of the substrate and perpendicular to the X-direction is referred to as a Y-direction, and a direction perpendicular to the upper surface of the substrate is referred to as a Z-direction.
In this specification, a direction along a predetermined plane may be referred to as a first direction, a direction along this predetermined plane and intersecting with the first direction may be referred to as a second direction, and a direction intersecting with this predetermined plane may be referred to as a third direction. These first direction, second direction, and third direction may each correspond to any of the X-direction, the Y-direction, and the Z-direction and need not correspond to these directions.
Expressions such as “above” and “below” in this specification are based on the substrate. For example, a direction away from the substrate along the Z-direction is referred to as above and a direction approaching the substrate along the Z-direction is referred to as below. A lower surface and a lower end of a certain configuration mean a surface and an end portion at the substrate side of this configuration. An upper surface and an upper end of a certain configuration mean a surface and an end portion at a side opposite to the substrate of this configuration. A surface intersecting with the X-direction or the Y-direction is referred to as a side surface and the like.
[Configuration]
The semiconductor substrate Sub is, for example, a semiconductor substrate, such as silicon (Si), containing P-type impurities, such as boron (B). On the upper surface of the semiconductor substrate Sub, a part of a peripheral circuit that controls a configuration in the memory cell array layer LMCA may be disposed.
The memory cell array layer LMCA includes memory cells MC described later. The transistor layer LT includes a control circuit that controls a configuration in the memory cell array layer LMC.
[Configuration in Memory Cell Array Layer LMCA]
In the example of
[Configuration in Local Block Region RLBLK]
As illustrated in
As illustrated in
The memory string MS includes a drain-side select transistor STD, the plurality of memory cells MC (memory transistors), and a source-side select transistor STS. The drain-side select transistor STD, the plurality of memory cells MC, and the source-side select transistor STS are connected in series between the local block connection lines LBI_a and the source line SL. Hereinafter, the drain-side select transistor STD and the source-side select transistor STS are simply referred to as select transistors (STD, STS) in some cases.
The memory cell MC is a field-effect type transistor. The memory cell MC includes a semiconductor layer, a gate insulating film, and a gate electrode. The semiconductor layer functions as a channel region. The gate insulating film includes an electric charge accumulating layer. A threshold voltage of the memory cell MC changes according to an electric charge amount in the electric charge accumulating layer. The memory cell MC stores one bit or a plurality of bits of data. Note that a word line WL is connected to each of gate electrodes of the plurality of memory cells MC included in one memory unit MU. Each of these word lines WL is connected to all of the memory units MU in one local block region RLBLK in common.
The select transistors (STD, STS) are field-effect type transistors. The select transistor (STD, STS) includes a semiconductor layer, a gate insulating film, and a gate electrode. The semiconductor layer functions as a channel region. Select gate lines (SGD, SGS) are connected to gate electrodes of the select transistors (STD, STS), respectively. Each of two drain-side select gate lines corresponding to the two memory strings MS is connected to all of the memory units MU in one string unit SU in common. Each of two source-side select gate lines SGS corresponding to the two memory strings MS is connected to all of the memory units MU in one string unit SU in common.
As illustrated in
As illustrated in
For example, as illustrated in
The via-electrodes 120, for example, function as gate electrodes of the plurality of memory cells MC, the word lines WL connected to them, and the like. For example, as illustrated in
The gate insulating layer 130 includes, for example, a tunnel insulating layer 131 disposed on a side surface in the X-direction of the semiconductor layer 110, an electric charge accumulating layer 132 disposed on the side surface in the X-direction of the tunnel insulating layer 131, and a block insulating layer 133 disposed on the side surface in the X-direction of the electric charge accumulating layer 132.
The tunnel insulating layer 131 may, for example, contain silicon oxide (SiO2).
The electric charge accumulating layer 132 may contain, for example, polycrystalline silicon (Si). The polycrystalline silicon (Si) may contain N-type impurities, such as phosphorus (P), or P-type impurities, such as boron (B), or need not contain these impurities.
The block insulating layer 133 may contain, for example, silicon oxide (SiO2). The block insulating layer 133 may include any insulating metal oxide film including aluminum oxide (AlO) and hafnium oxide (HfO).
In the select transistor region RSGD (
The conductive layer 140 functions as, for example, a contact electrode to form the hole channels in the semiconductor layer 110 and apply a voltage to the hole channels formed in the semiconductor layer 110. For example, as illustrated in
The via-electrodes 150, for example, function as gate electrodes of the plurality of drain-side select transistors STD, the drain-side select gate lines SGD connected to them, and the like. For example, as illustrated in
The semiconductor layer 160 may include a semiconductor layer of, for example, polycrystalline silicon (Si) containing N-type impurities, such as phosphorus (P). Between two semiconductor layers 160 adjacent in the X-direction, an insulating layer 161 is disposed. The insulating layer 161 may contain, for example, silicon oxide (SiO2). The insulating layer 161 passes through the plurality of memory layers ML and extends in the Z-direction.
In the ladder region RLD (
In the local block connection line region RLBIL (
The conductive layer 170 functions as, for example, the local block connection line LBI_a (
The insulating layer 171 may contain, for example, silicon oxide (SiO2). For example, as illustrated in
[Configuration in Local Block Connection Line Region RLBIG]
In the local block connection line region RLBIG, the memory layer ML includes a pair of conductive layers 180 extending in the Y-direction. In the local block connection line region RLBIG, a plurality of insulating layers 181 positioned between two conductive layers 180 adjacent in the X-direction and arranged in the Y-direction are disposed.
The conductive layer 180 functions as, for example, the local block connection line LBI_b (
The insulating layer 181 may contain, for example, silicon oxide (SiO2). The insulating layer 181 passes through the plurality of memory layers ML and extends in the Z-direction. Between two insulating layers 181 adjacent in the Y-direction, an insulating layer 182 of, for example, silicon oxide (SiO2) is disposed. A width in the X-direction of the insulating layer 181 may be larger than a width in the X-direction of the insulating layer 182.
[Configuration in Hook-Up Region RHU]
[Configuration of Hook-Up]
As illustrated in
In the lead line regions RLLE, RLLO, the memory layer ML includes a conductive layer 190 extending in the X-direction. The lead line regions RLLE, RLLO include a plurality of insulating layers 191 arranged in the X-direction along the conductive layer 190.
The conductive layer 190 functions as the local block connection line LBI_c (
The insulating layer 191 may include an insulating layer of, for example, silicon oxide (SiO2). For example, as illustrated in
For example, as illustrated in
For example, as illustrated in
The part 192 may include a barrier conductive layer 194 of, for example, titanium nitride (TiN) and a conductive layer 195 of, for example, tungsten (W). The part 192 passes through the plurality of memory layers ML and extends in the Z-direction. An insulating layer 196 of, for example, silicon oxide (SiO2) may be disposed on an outer peripheral surface of the part 192. A part of the outer peripheral surface of the insulating layer 196 is in contact with the insulating layers 101. A part of an outer peripheral surface of the insulating layer 196 is in contact with the insulating layers 102. A thickness in a radial direction of the part in contact with the insulating layer 102 of the insulating layer 196 may be larger than a thickness in a radial direction of the part in contact with the insulating layer 101 of the insulating layer 196.
The part 193 may include the barrier conductive layer 194 of, for example, titanium nitride (TiN). The part 193 is included in any of the memory layers ML and connected to a side surface in the X-direction of the conductive layer 190 included in any of the memory layers ML. In the hook-up region RHU, the via-contact electrodes CC corresponding to all of the memory layers ML may be disposed. In this case, the number of via-contact electrodes CC may match the number of memory layers ML, or may be larger than the number of memory layers ML.
For example, as illustrated in
As illustrated in
In the memory layer ML_E, the conductive layer 190 disposed in the lead line region RLLO is not connected to the via-contact electrode CC. Additionally, in the memory layer ML_E, the conductive layer 190 disposed in the lead line region RLLE is connected to the via-contact electrode CC.
[Configurations of Pre-Amplifier Circuit PA and Switch Circuit ES_SW]
Note that
As illustrated in
As illustrated in
The pre-amplifier circuit PA includes a transistor Tr1, which is connected between the nodes N1 and N2, transistors Tr2 and Tr3, which are connected in series between the nodes N2 and N3, and a transistor Tr4, which is connected between the nodes N1, N3. The transistors Tr1 to Tr4 are, for example, N-channel type field effect transistors.
A source electrode of the transistor Tr1 is connected to the node N2. A drain electrode of the transistor Tr1 is connected to the node N1. A gate electrode of the transistor Tr1 is connected to a signal line Pre_WE.
A source electrode of the transistor Tr2 is connected to a drain electrode of the transistor Tr3. A drain electrode of the transistor Tr2 is connected to the node N2. A gate electrode of the transistor Tr2 is connected to a signal line Pre_RE.
A source electrode of the transistor Tr3 is connected to the node N3. A drain electrode of the transistor Tr3 is connected to the source electrode of the transistor Tr2. A gate electrode of the transistor Tr3 is connected to the node N1.
A source electrode of the transistor Tr4 is connected to the node N3. A drain electrode of the transistor Tr4 is connected to the node N1. A gate electrode of the transistor Tr4 is connected to a signal line Pre_reset.
The switch circuit ES_SW includes a transistor Tr5. A source electrode of the transistor Tr5 is connected to the local block connection line LBI_ce. A drain electrode of the transistor Tr5 is connected to the node N2. A gate electrode of the transistor Tr5 is connected to a signal line EO_selector.
Note that
Similarly,
As illustrated in
The conductive layer 210 functions as the node N1, which has been described with reference to
The insulating layer 211 may contain, for example, silicon oxide (SiO2). For example, as illustrated in
As illustrated in
The conductive layer 220 functions as the node N2, which has been described with reference to
The insulating layer 221 may contain, for example, silicon oxide (SiO2). The insulating layer 221 passes through the plurality of memory layers ML and extends in the Z-direction.
As illustrated in
The semiconductor layers 230 function as source regions of the transistors Tr3, Tr4, which have been described with reference to
The via-electrode 231 functions as the node N3, which has been described with reference to
As illustrated in
The semiconductor layers 240 function as channel regions of the transistors Tr1, Tr2, Tr4, Try, which have been described with reference to
The via-electrodes 241 function as gate electrodes of the transistors Tr1, Tr2, Tr4, Tr5, which have been described with reference to
The insulating layers 242 function as gate insulating films of the transistors Tr1, Tr2, Tr4, Tr5, which have been described with reference to
As illustrated in
The semiconductor layer 250 functions as a channel region of the transistor Tr3, which has been described with reference to
The insulating layer 251 functions as a gate insulating film of the transistor Tr3, which has been described with reference to
The insulating layer 252 may contain, for example, silicon oxide (SiO2). The insulating layer 252 passes through the plurality of memory layers ML and extends in the Z-direction.
The semiconductor layer 253 reduces a leak current in the transistor Tr3 configured of the semiconductor layer 250 and the like. The semiconductor layer 253 may contain, for example, polycrystalline silicon (Si) containing P-type impurities, such as boron (B). A concentration of the impurities contained in the semiconductor layer 253 is larger than a concentration of the impurities contained in the semiconductor layer 250. The semiconductor layer 253 passes through the plurality of memory layers ML and extends in the Z-direction.
As illustrated in
A part of the plurality of semiconductor layers 260 is connected to the conductive layer 210 and the semiconductor layer 240. The semiconductor layers 260 function as the drain regions of the transistors Tr1, Tr4, which have been described with reference to
A part of the plurality of semiconductor layers 260 is connected to the two semiconductor layers 240 and the conductive layer 220. The semiconductor layers 260 function as the source region of the transistor Tr1 and the drain region of the transistor Tr2, which have been described with reference to
A part of the plurality of semiconductor layers 260 is connected to the semiconductor layer 240 and the semiconductor layer 250. The semiconductor layers 260 function as the source region of the transistor Tr2 and the drain region of the transistor Tr3, which have been described with reference to
A part of the plurality of semiconductor layers 260 is connected to the conductive layer 220 and the semiconductor layer 240. The semiconductor layer 260 functions as the drain region of the transistor Tr5, which has been described with reference to
A part of the plurality of semiconductor layers 260 is connected to the conductive layer 190 and the conductive layer 240. The semiconductor layer 260 functions as the source region of the transistor Tr5, which has been described with reference to
The semiconductor layer 260 may contain, for example, polycrystalline silicon (Si) containing N-type impurities, such as phosphorus (P).
The insulating layer 261 may contain, for example, silicon oxide (SiO2). For example, as illustrated in
As illustrated in
The semiconductor layer 270 functions as the gate electrode of the transistor Tr3, which has been described with reference to
[Configuration in Transistor Layer LT]
The transistor layer LT includes a plurality of sense amplifier circuits SA_O disposed corresponding to the plurality of memory layers ML_O and a plurality of sense amplifier circuits SA_E disposed corresponding to the plurality of memory layers ML_E.
As illustrated in
The sense amplifier circuit SA_O includes transistors Tr11, Tr12 connected in series between the bit line BL and a voltage node Vss, transistors Tr13, Tr14 connected in series between the bit line BL and a voltage node Vdd, a transistor Tr15 connected between a voltage node Vpre and the via-contact electrode CC, and a transistor Tr16 connected between the bit line BL and the via-contact electrode CC. The transistors Tr11, Tr12, Tr15, Tr16, for example, are N-channel type field effect transistors. The transistors Tr13, Tr14, for example, are P-channel type field effect transistors.
A source electrode of the transistor Tr11 is connected to a drain electrode of the transistor Tr12. A drain electrode of the transistor Tr11 is connected to the bit line BL. A gate electrode of the transistor Tr11 is connected to a signal line amp_RE. A source electrode of the transistor Tr12 is connected to the voltage node Vss. A gate electrode of the transistor Tr12 is connected to the via-contact electrode CC.
A source electrode of the transistor Tr13 is connected to the drain electrode of the transistor Tr14. A drain electrode of the transistor Tr13 is connected to the bit line BL. A gate electrode of the transistor Tr13 is connected to a signal line/amp_RE. A source electrode of the transistor Tr14 is connected to the voltage node Vdd. A gate electrode of the transistor Tr14 is connected to the via-contact electrode CC.
A source electrode of the transistor Tr15 is connected to the via-contact electrode CC. A drain electrode of the transistor Tr15 is connected to the voltage node Vpre. A gate electrode of the transistor Tr15 is connected to a signal line amp_pre.
A source electrode of the transistor Tr16 is connected to the via-contact electrode CC. A drain electrode of the transistor Tr16 is connected to the bit line BL. A gate electrode of the transistor Tr16 is connected to a signal line amp_WE.
As illustrated in
Note that the sense amplifier circuit SA_O and the sense amplifier circuit SA_E are controllable independently from one another. That is, each of the signal lines amp_RE, /amp_RE, amp_pre, amp_WE corresponding to the sense amplifier circuit SA_E is electrically independent from the signal lines amp_RE, /amp_RE, amp_pre, amp_WE corresponding to the sense amplifier circuit SA_O, and different signals can be input.
[Read Operation]
Note that
In
Similarly, in
At a timing of starting the read operation, as illustrated in
Additionally, the voltages of the signal lines Pre_WE, Pre_RE, Pre_reset corresponding to the pre-amplifier circuit PA are set to “L, L, L”.
The voltage of the signal line EO_selector corresponding to the switch circuit ES_SW is set to “L”.
The voltages of the signal lines amp_RE, /amp_RE, amp_pre, amp_WE corresponding to the sense amplifier circuit SA_E, SA_O are set to “L, H, L, L”.
At timing t101 in the read operation, the local block connection line LBI_a in the memory layer ML_E, ML_O is discharged. For example, as illustrated in
At timing t102 in the read operation, the voltage of the word line WL is adjusted. For example, the voltage of the selected word line WL is set to a predetermined read voltage. The read voltage is a voltage having a magnitude around the memory cell MC entering the ON state or the OFF state according to data stored in the memory cell MC. Additionally, the voltage of the unselected word line WL is set to a read pass voltage. The read pass voltage is a voltage having a magnitude around the memory cell MC entering the ON state regardless of the data stored in the memory cell MC.
At timing t103 in the read operation, for example, as illustrated in
At timing t104 in the read operation, for example, as illustrated in
At timing t105 in the read operation, discharge of the local block connection line LBI_a in the memory layer ML_E, ML_O ends. For example, as illustrated in
At timing t106 in the read operation, a precharge operation is performed. For example, as illustrated in
At timing t107 in the read operation, the precharge operation ends. For example, as illustrated in
At timing t107 in the read operation, a discharge operation is performed. For example, as illustrated in
Here, in the memory layer ML_E, read data R is read. That is, in the memory layer ML_E, the voltages in the local block connection line LBI_a and the memory string MS are “H”. Therefore, when a threshold voltage of the selected memory cell MC is smaller than the read voltage, electric charges in the local block connection line LBI_a and the memory string MS are discharged, and these voltages become “L”. In this case, the transistor Tr3 enters the OFF state. Moreover, when the threshold voltage of the selected memory cell MC is larger than the read voltage, the electric charge in the local block connection line LBI_a or the memory string MS is not discharged and these voltages are maintained to be “H”. In this case, the transistor Tr3 enters the ON state.
On the other hand, in the memory layer ML_O, the voltages in the local block connection line LBI_a and the memory string MS are “L”. Accordingly, regardless of the threshold voltage of the selected memory cell MC, the voltages of the local block connection line LBI_a and the memory string MS are maintained to be “L”. Accordingly, the transistor Tr3 enters the OFF state.
At timing t108 in the read operation, the discharge operation ends. For example, as illustrated in
Additionally, at timing t108 in the read operation, a pre-amplifier operation is performed. For example, as illustrated in
Here, the read data R corresponding to the memory layer ML_E is transferred to the sense amplifier circuit SA_E as inverted data/R. That is, in the memory layer ML_E, when the transistor Tr3 is in the ON state, a ground voltage is applied to the node N2. Accordingly, the voltage of the node N2 becomes “L”. In this case, the transistor Tr12 in the sense amplifier circuit SA_E enters the OFF state. Additionally, the transistor Tr14 in the sense amplifier circuit SA_E enters the ON state. On the other hand, when the transistor Tr3 is in the OFF state, the ground voltage is not applied to the node N2. Accordingly, the voltage of the node N2 is maintained to be “H”. In this case, the transistor Tr12 in the sense amplifier circuit SA_E enters the ON state. Additionally, the transistor Tr14 in the sense amplifier circuit SA_E enters the OFF state.
Note that, in the memory layer ML_O, the transistor Tr3 is in the OFF state. Additionally, the voltage of the node N2 is maintained to be “H”.
At timing t109 in the read operation, for example, as illustrated in
At timing t110 in the read operation, the local block connection line LBI_a in the memory layer ML_E, ML_O is discharged. For example, as illustrated in
At timing till in the read operation, an amplifier operation is performed. For example, as illustrated in
Here, the inverted data/R corresponding to the memory layer ML_E is transferred to the bit line BL as the read data R. That is, in the sense amplifier circuit SA_E, when the transistor Tr12 is in the OFF state and the transistor Tr14 is in the ON state, the voltage of the bit line BL becomes “H”. On the other hand, in the sense amplifier circuit SA_E, when the transistor Tr12 is in the ON state and the transistor Tr14 is in the OFF state, the voltage of the bit line BL becomes “L”. Note that the read data R transferred to the bit line BL is further transferred to a circuit (not illustrated).
Additionally, at timing till in the read operation, for example, as illustrated in
At timing t112 in the read operation, the amplifier operation ends. For example, as illustrated in
At timing t112 in the read operation, discharge of the local block connection line LBI_a in the memory layer ML_E, ML_O ends. For example, as illustrated in
At timing t113 in the read operation, a precharge operation is performed. For example, as illustrated in
At timing t114 in the read operation, the precharge operation ends. For example, as illustrated in
Additionally, at timing t114 in the read operation, for example, as illustrated in
At timing t115 in the read operation, a discharge operation is performed. For example, as illustrated in
Here, in the memory layer ML_O, the read data R is read.
On the other hand, in the memory layer ML_E, the voltages of the local block connection line LBI_a and the memory string MS are maintained to be “L”.
At timing t116 in the read operation, the discharge operation ends. For example, as illustrated in
Additionally, at timing t116 in the read operation, a pre-amplifier operation is performed. For example, as illustrated in
Here, the read data corresponding to the memory layer ML_O is transferred to the sense amplifier circuit SA_O as the inverted data/R.
Note that, in the memory layer ML_E, the transistor Tr3 is in the OFF state. Additionally, the voltage of the node N2 is maintained to be “L”.
At timing t117 in the read operation, an amplifier operation is performed. For example, as illustrated in
Here, the inverted data/R corresponding to the memory layer ML_O is transferred to the bit line BL as the read data R. The read data R transferred to the bit line BL is further transferred to a circuit (not illustrated).
At timing t118 in the read operation, the amplifier operation ends. For example, as illustrated in
Additionally, at timing t118 in the read operation, for example, as illustrated in
As described with reference to
Here, in the semiconductor memory device according to the embodiment, the local block connection line regions RLBIG are disposed as the regions to connect the plurality of local block regions RLBLK and the hook-up region RHU. As illustrated in
Here, for example, as described with reference to
For example, when the selected memory cells MC are in the ON state in the two memory layers ML arranged in the Z-direction, the times required for the discharge operation in these two memory layers ML are comparatively short. On the other hand, in a case where the selected memory cell MC is in the ON state only in one of the two memory layers ML arranged in the Z-direction, the times required for the discharge operation are comparatively long in these two memory layers ML.
Therefore, in the embodiment, the sense amplifier circuit SA_O and the sense amplifier circuit SA_E are controllable independently from one another.
In the embodiment, as described with reference to
With this method, the variation of the times required for the discharge operation in all of the memory layers ML can be substantially reduced. Thus, the data stored in the selected memory cell MC can be preferably read.
Additionally, to perform the operation, for example, it is considered to transfer the read data R corresponding to the memory layer ML_E to the bit line BL and further, after charging of the bit line BL ends, the voltage of the drain-side select gate line SGD is set to “H” to acquire the read data R corresponding to the memory layer ML_O. However, in this case, the time required for the read operation possibly increases to around double.
Therefore, in the embodiment, as described with reference to
With this configuration, for example, as described with reference to
For example, as described with reference to
Additionally, for example, as described with reference to
In the embodiment, the transistors Tr4, Tr5 are disposed, not in the transistor layer LT (
Next, a semiconductor memory device according to the second embodiment will be described. In the following description, parts similar to those of the semiconductor memory device according to the first embodiment are attached by the same reference numerals, thereby omitting the description.
The semiconductor memory device according to the second embodiment is configured basically similarly to the semiconductor memory device according to the first embodiment.
However, as described with reference to
The switch circuit OS_SW includes a transistor Tr6. A source electrode of the transistor Tr6 is connected to the local block connection line LBI_co. A drain electrode of the transistor Tr6 is connected to the node N2. A gate electrode of the transistor Tr6 is connected to a signal line EO_selector1.
Note that, in
As illustrated in
With this configuration, the capacitance in each of the wirings in the memory layer ML_E and the capacitance in each of the wirings in the memory layer ML_O can be matched. Thus, there may be a case where the read operation can be more preferably performed.
The semiconductor memory devices according to the first embodiment and the second embodiment have been described above. However, the configurations, the operations, and the like described above are merely examples, and the specific configurations, operations, and the like are appropriately adjustable.
For example, in the semiconductor memory device according to the second embodiment, the switch circuit ES_SW may be omitted.
Additionally, the read operation as described as an example in
For example, in the semiconductor memory device according to the first embodiment, as described with reference to
For example, the configuration of the pre-amplifier circuit PA described as an example above is merely an example, and the specific configuration is appropriately adjustable.
For example, in the example of
The semiconductor layer 350 is configured basically similarly to the semiconductor layer 250. However, one insulating layer 251 is disposed on the outer peripheral surface of the semiconductor layer 250, and the semiconductor layer 250 is opposed to one semiconductor layer 270 via the insulating layer 251. On the other hand, the two insulating layers 251 are disposed on the outer peripheral surface of the semiconductor layer 350, and the semiconductor layer 350 is opposed to the two semiconductor layers 270 via these insulating layers 251. In the configuration, a channel width of the transistor Tr3 configured by the semiconductor layer 350 can be increased to increase an ON current.
For example, in the example of
The semiconductor layer 450 is configured basically similarly to the semiconductor layer 250. However, a part of the outer peripheral surface of the semiconductor layer 250 is disposed along the circumference of one circle with the center position of one insulating layer 252 as its center. Additionally, the other part of the outer peripheral surface of the semiconductor layer 250 is disposed within the range of the circle. On the other hand, a part of an outer peripheral surface of the semiconductor layer 450 is disposed along circumferences of two circles with center positions of the two insulating layers 252 as their respective centers. The other part of the outer peripheral surface of the semiconductor layer 450 is disposed within a range of at least one of the two circles. An opposed area of the semiconductor layer 450 with the semiconductor layer 270 is larger than an opposed area of the semiconductor layer 250 with the semiconductor layer 270. This configuration allows increasing a channel length of the transistor Tr3 configured by the semiconductor layer 450 and reducing an off-leakage current.
Additionally, for example, as illustrated in
The semiconductor memory devices according to the first embodiment and the second embodiment include so-called NAND flash memories. However, the configurations described as examples in the first embodiment and the second embodiment are applicable to a semiconductor memory device not including the NAND flash memory. For example, the configurations as described in the first embodiment and the second embodiment as examples are applicable to a configuration that includes semiconductor layers extending in the Y-direction in the plurality of memory layer ML and one or a plurality of memory transistors treating the semiconductor layers as channel regions. The configurations as described in the first embodiment and the second embodiment as examples are applicable to a configuration including another memory transistor. Additionally, the configurations as described in the first embodiment and the second embodiment as examples are applicable to another memory.
Additionally, as described with reference to
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms: furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
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2022-046554 | Mar 2022 | JP | national |
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20230307359 A1 | Sep 2023 | US |