WO2022137563A1 - 半導体素子を用いたメモリ装置 - Google Patents
半導体素子を用いたメモリ装置 Download PDFInfo
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Definitions
- the present invention relates to a memory device using a semiconductor element.
- the channel In a normal planar type MOS transistor, the channel extends in the horizontal direction along the upper surface of the semiconductor substrate.
- the SGT channel extends in a direction perpendicular to the upper surface of the semiconductor substrate (see, for example, Patent Document 1 and Non-Patent Document 1). Therefore, the SGT can increase the density of the semiconductor device as compared with the planar type MOS transistor.
- DRAM Dynamic Random Access Memory
- PCM Phase Change Memory
- Non-Patent Document 7 RRAM (Resistive Random Access Memory, for example, Non-Patent Document 4), MRAM (Magneto-resistive Random Access Memory, for example, Non-Patent Document 5) that changes the direction of magnetic spin by a current to change the resistance. It is possible to achieve high integration such as). Further, there is a DRAM memory cell (see Non-Patent Document 7) composed of one MOS transistor having no capacitor. The present application relates to a dynamic flash memory that does not have a resistance changing element or a capacitor and can be configured only by a MOS transistor.
- FIGS. 15 (A) to 15 (D) show the write operation of the DRAM memory cell composed of one MOS transistor having no capacitor
- FIGS. 16 (A) and 16 (B) show the operation. Problems and reading operations are shown in FIGS. 17 (A) to 17 (C) (see Non-Patent Documents 7 to 10).
- FIG. 15A shows a “1” writing state.
- the memory cell is formed on the SOI substrate 1101, the source line SL is connected to the source N + layer 1103, the bit line BL is connected to the drain N + 1104, and the word line WL is connected to the gate conductive layer 1105.
- Is connected and is composed of a floating body 1102 of a MOS transistor 1110a, has no capacitor, and has one MOS transistor 1110a to form a DRAM memory cell.
- the SiO 2 layer 1101 of the SOI substrate is in contact with the floating body 1102 directly below.
- the MOS transistor 1110a is operated in the linear region. That is, the electron channel 1107 extending from the source N + layer 1103 has a pinch-off point 1108, and has not reached the drain N + layer 1104 to which the bit line is connected.
- the bit wire BL connected to the drain N + layer and the word wire WL connected to the gate conductive layer 1105 are both set to a high voltage
- the gate voltage is about 1/2 of the drain voltage
- the MOS transistor 1110a is set.
- the electric field strength becomes maximum at the pinch-off point 1108 near the drain N + 1104.
- the accelerated electrons flowing from the source N + layer 1103 toward the drain N + layer 1104 collide with the Si lattice, and the kinetic energy lost at that time generates electron-hole pairs.
- Most of the generated electrons (not shown) reach the drain N + layer 1104.
- a small portion of the very hot electrons jump over the gate oxide film 1109 and reach the gate conductive layer 1105.
- the holes 1106 generated at the same time charge the floating body 1102.
- the generated holes contribute as an increment of a large number of carriers because the floating body 1102 is P-type Si.
- the floating body 1102 is filled with the generated holes 1106, and when the voltage of the floating body 1102 becomes higher than Vb above the source N + layer 1103, the further generated holes are discharged to the source N + 1103.
- Vb is the built-in voltage of the PN junction between the source N + layer 1103 and the floating body 1102 of the P layer, and is about 0.7V.
- FIG. 15B shows a state in which the floating body 1102 is saturated and charged with the generated holes 1106.
- FIG. 15C shows how the “1” writing state is rewritten to the “0” writing state.
- the voltage of the bit line BL is negatively biased, and the PN junction between the drain N + layer 1104 and the floating body 1102 of the P layer is forward biased.
- the holes 1106 previously generated in the floating body 1102 in the previous cycle flow to the drain N + layer 1104 connected to the bit line BL.
- the capacity C FB of the floating body includes the capacity C WL between the gate connected by the word line and the floating body, the source N + layer 1103 connected by the source line, and the floating body.
- C FB C WL + C BL + C SL (1) It is represented by.
- the voltage of the floating body 1102 which is a storage node (contact) of the memory cell, is also affected by the amplitude.
- FIG. 16 (B) When the word line voltage V WL rises from 0 V to V Prog WL during writing, the voltage V FB of the floating body 1102 is capacitively coupled to the word line from the initial voltage V FB1 to V FB2 before the word line voltage changes. Rise by.
- FIG. 17 (A) and 7 (B) show the read operation
- FIG. 17 (A) shows the “1” write state
- FIG. 17 (B) shows the “0” write state.
- Vb is written to the floating body 1102 by "1” writing
- the word line returns to 0V at the end of writing
- the floating body 1102 is lowered to a negative bias.
- the negative bias becomes deeper, and the potential difference margin between "1” and "0” cannot be made sufficiently large at the time of writing, so that the capacitor is not actually provided. It was difficult to commercialize a DRAM memory cell.
- the capacitive coupling coupling between the word line and the floating SGT body is large, and the potential of the word line is oscillated when reading or writing data. There was a problem that it was directly transmitted as noise to the SGT body. As a result, problems of erroneous reading and erroneous rewriting of stored data are caused, and it is difficult to put a 1-transis type DRAM (gain cell) without a capacitor into practical use.
- the semiconductor memory device is On the substrate, a semiconductor base that stands perpendicular to the substrate or extends horizontally, and The first impurity layer and the second impurity layer at both ends of the semiconductor base, A first gate insulating layer that encloses a part or all of the side surface of the semiconductor base between the first impurity layer and the second impurity layer and is in contact with or in close proximity to the first impurity layer. , A second gate insulating layer that surrounds a part or all of the side surface of the semiconductor base, is connected to the first gate insulating layer, and is in contact with or adjacent to the second impurity layer (ibid.).
- the semiconductor base has a channel semiconductor layer composed of a first channel semiconductor layer covered with the first gate insulating layer and a second channel semiconductor layer covered with the second gate insulating layer.
- the entire side surface of the channel semiconductor layer is an insulating material layer including the first gate insulating layer and the second gate insulating layer, or the first gate insulating layer and the second gate insulating layer.
- Surrounded by The first channel semiconductor layer and the first channel semiconductor layer are controlled by controlling the voltage applied to the first wiring conductor layer, the second wiring conductor layer, the third wiring conductor layer, and the fourth wiring conductor layer.
- the operation of generating an impact ionization phenomenon by the current flowing between the first impurity layer and the second impurity layer, and among the generated electron group and hole group, the above-mentioned The operation of removing the electron group from the first impurity layer or the second impurity layer, and a part or all of the hole group are removed from the first channel semiconductor layer and the second channel semiconductor.
- Perform a memory write operation by performing an operation of remaining on one or both of the layers, and then performing a memory write operation.
- the voltage applied to the first wiring conductor layer, the second wiring conductor layer, the third wiring conductor layer, and the fourth wiring conductor layer is controlled to control the first impurity layer. It is characterized in that the residual hole group among the hole groups is extracted from one or both of the second impurity layer and the second impurity layer, and a memory erasing operation is performed.
- the first PN junction between the first impurity layer and the first channel semiconductor layer, the second impurity layer, and the second channel semiconductor layer are performed. It is characterized in that the second PN junction with and from is held in a reverse bias state.
- the first wiring conductor layer is a source wire
- the second wiring conductor layer is a bit wire
- one of the third wiring conductor layer and the fourth wiring conductor layer is a word wire. If so, the other is the first drive control line, It is characterized in that the memory erasing operation and the memory writing operation are selectively performed by the voltage applied to the source line, the bit line, the first drive control line, and the word line.
- the second wiring conductor layer is characterized in that it is orthogonal to the third wiring conductor layer and the fourth wiring conductor layer.
- the first gate capacitance between the first gate conductor layer and the first channel semiconductor layer is the second gate capacitance between the second gate conductor layer and the second channel semiconductor layer. Greater than It is characterized by that.
- the first channel length of the first gate conductor layer is longer than the second channel length of the second gate conductor layer, or the first gate insulating layer is more than the second gate insulating layer. Is thin, or the relative dielectric constant of the first gate insulating layer is larger than the relative dielectric constant of the second gate insulating layer, or a combination thereof.
- the first gate capacity is larger than the second gate capacity.
- the first impurity layer and the second impurity layer are N-type semiconductor layers, and the first channel semiconductor layer and the second channel semiconductor layer are P-type semiconductor layers or neutral semiconductor layers.
- the second impurity layer has a lower voltage than the second channel semiconductor layer, and between the second impurity layer and the second channel semiconductor layer.
- the PN junction between the second impurity layer and the second channel semiconductor layer becomes a forward bias, and the hole group is pulled from the second channel semiconductor layer to the second impurity layer. Removal operation and Subsequently, the second impurity layer has a higher voltage than the second channel semiconductor layer, the second PN junction becomes a reverse bias, and the removal of the hole group is stopped. It is characterized in that the memory erasing operation is performed by the operation.
- the hole group generated by the impact ionization phenomenon accumulates in the first channel semiconductor layer and the second channel semiconductor layer, so that the first gate conductor layer
- the first gate in accordance with the decrease of the first threshold voltage of the first MOS transistor and the second threshold voltage of the second MOS transistor of the second gate conductor layer. It is characterized in that the voltage of either the conductor layer or the second gate conductor layer is reduced.
- the hole group generated by the impact ionization phenomenon accumulates in the first channel semiconductor layer and the second channel semiconductor layer, so that the first gate conductor layer From the drain electrode layer to the said by lowering the first threshold voltage of the first MOS transistor and the second threshold voltage of the second MOS transistor of the second gate conductor layer. It is characterized in that positive feedback is generated in the memory writing operation due to the effect of increasing the current to the source electrode layer to perform writing.
- the first channel conductor layer surrounded by the first gate conductor layer or the second gate conductor layer connected to the drive control line during the memory write operation and the memory read operation. It is characterized in that an inversion layer is formed on the outer peripheral portion of the second channel conductor layer.
- the semiconductor base is formed perpendicular to the substrate, and the semiconductor base is formed. In the vertical direction, with the first impurity layer on the substrate, The first channel semiconductor layer on the first impurity layer and The second channel semiconductor layer on the first channel semiconductor layer and With the second impurity layer on the second channel semiconductor layer, The first gate insulating layer surrounding the first channel semiconductor layer and The second gate insulating layer surrounding the second channel semiconductor layer and The first gate conductor layer surrounding the first gate insulating layer and the first gate conductor layer. The second gate conductor layer surrounding the second gate insulating layer and the second gate conductor layer It is characterized by having the first insulating layer between the first gate conductor layer and the second gate conductor layer.
- the first gate insulating layer and the second gate insulating layer are made of the same material.
- the first gate insulating layer and the second gate insulating layer are made of different material layers, and the first insulating layer is made of the same material layer as the second gate insulating layer. And.
- a first insulating material layer having a first hole or not containing the first hole Adjacent to the first gate conductor layer and the second gate conductor layer, a first insulating material layer having a first hole or not containing the first hole is provided on the substrate. On the other hand, it is characterized in that it is extended in the vertical direction.
- the first insulating material layer is made of a low dielectric constant material.
- a second insulating material that is adjacent to one or both of the first wiring conductor layer or the second wiring conductor layer and contains a second hole or does not contain the second hole. It is characterized by having layers.
- the first insulating material layer is made of a low dielectric constant material.
- a first conductor layer is provided at the bottom of the first insulating material layer, and the first conductor layer is connected to the first impurity layer and extends in the horizontal direction.
- a first impurity well layer formed on the substrate and a second impurity well layer formed in the first impurity well layer are further provided.
- the semiconductor base is characterized in that it stands vertically on the substrate or extends horizontally on the second impurity well layer.
- the substrate is a P-type semiconductor
- the first impurity well layer is an N-type semiconductor
- the second impurity well layer is a P-type semiconductor. It is characterized in that a negative bias is applied to the P-type second impurity well layer during the erasing operation.
- 9 is a circuit block diagram and a timing operation waveform diagram for explaining a page erasing operation of a memory device having an SGT according to a ninth embodiment.
- 9 is a circuit block diagram and a timing operation waveform diagram for explaining a page erasing operation of a memory device having an SGT according to a ninth embodiment.
- FIG. 9 is a circuit block diagram and a timing operation waveform diagram for explaining a page erasing operation of a memory device having an SGT according to a ninth embodiment. It is a top view and the cross-sectional structure view for demonstrating the manufacturing method of the memory apparatus which has SGT which concerns on 10th Embodiment. It is a top view and the cross-sectional structure view for demonstrating the manufacturing method of the memory apparatus which has SGT which concerns on 10th Embodiment. It is a top view and the cross-sectional structure view for demonstrating the manufacturing method of the memory apparatus which has SGT which concerns on 10th Embodiment.
- FIG. 1 shows the structure of the dynamic flash memory cell according to the first embodiment of the present invention.
- Si pillar 100 having a P-type or i-type (intrinsic type) conductive type formed on a substrate Sub (an example of a “base” in the claims)
- a silicon semiconductor pillar is referred to as a "Si pillar”
- N + layers 101a and 101b hereinafter referred to as donor impurities
- one is a source and the other is a drain at the upper and lower positions in (an example of a "semiconductor base” in the claims).
- a semiconductor region containing a high concentration is referred to as an "N + layer" (an example of a "first impurity layer” and a “second impurity layer” in the claims) is formed.
- the portion of the Si column 100 between the N + layers 101a and 101b serving as the source and drain is the channel region 102.
- An example of the "2 gate insulating layer” is formed.
- the first gate insulating layer 103a and the second gate insulating layer 103b are in contact with or in close proximity to the N + layers 101a and 101b serving as sources and drains, respectively.
- a first gate conductor layer 104a (an example of the "first gate conductor layer” in the claims), a second gate conductor layer 104a so as to surround the first gate insulating layer 103a and the second gate insulating layer 103b.
- Each of the gate conductor layers 104b (which is an example of the "second gate conductor layer” in the claims) is formed.
- the first gate conductor layer 104a and the second gate conductor layer 104b are separated by an insulating layer 105 (which is an example of the "first insulating layer” in the claims).
- the portion of the Si column 100 between the N + layers 101a and 101b is the channel region 102 (an example of the "channel semiconductor layer” in the scope of the patent claim) is the first gate insulating layer 103a.
- Channel Si layer 102a an example of the "first channel semiconductor layer” in the scope of the patent claim
- the second channel Si layer 102b in the scope of the patent claim
- the channel region 102 As a result, from the N + layers 101a and 101b serving as sources and drains, the channel region 102, the first gate insulating layer 103a, the second gate insulating layer 103b, the first gate conductor layer 104a, and the second gate conductor layer 104b.
- Dynamic flash memory cell 110 is formed.
- the source N + layer 101a is the source line SL (an example of the "source line” in the claims)
- the drain N + layer 101b is the bit line BL (the "bit line” in the claims).
- the first gate conductor layer 104a is a plate wire PL (an example of the "first drive control line” in the claims)
- the second gate conductor layer 104b is a word wire.
- the gate capacitance of the first gate conductor layer 104a to which the plate wire PL is connected may have a structure that is larger than the gate capacitance of the second gate conductor layer 104b to which the word wire WL is connected. desirable.
- the gate capacitance of the first gate conductor layer 104a connected to the plate wire PL is larger than the gate capacitance of the second gate conductor layer 104b to which the word wire WL is connected.
- the gate length of the first gate conductor layer 104a is made longer than the gate length of the second gate conductor layer 104b.
- the gate length of the first gate conductor layer 104a is not made longer than the gate length of the second gate conductor layer 104b, and the film thickness of each gate insulating layer is changed to change the film thickness of the first.
- the film thickness of the gate insulating film of the gate insulating layer 103a may be thinner than the film thickness of the gate insulating film of the second gate insulating layer 103b.
- the dielectric constant of the gate insulating film of the first gate insulating layer 103a is made higher than the dielectric constant of the gate insulating film of the second gate insulating layer 103b. You may.
- the channel region 102 between the N + layers 101a and 101b is electrically separated from the substrate to form a floating body.
- FIG. 2A shows a state in which the hole group 106 generated by impact ionization in the previous cycle is stored in the channel region 102 before the erasing operation. and.
- the voltage of the source line SL is set to the negative voltage V ERA during the erasing operation.
- V ERA is, for example, -3V.
- the PN junction between the N + layer 101a, which is the source to which the source line SL is connected, and the channel region 102 becomes a forward bias regardless of the value of the initial potential of the channel region 102.
- the hole group 106 stored in the channel region 102 generated by impact ionization in the previous cycle is sucked into the N + layer 101a of the source portion, and the potential V FB of the channel region 102 becomes V.
- FB V ERA + Vb.
- FIG. 2C shows an example of the voltage condition of each main node contact during the erasing operation.
- 3 (A) to 3 (C) show the writing operation of the dynamic flash memory cell according to the first embodiment of the present invention.
- 0V is input to the N + layer 101a to which the source line SL is connected
- 3V is input to the N + layer 101b to which the bit line BL is connected.
- 2V is input to the connected first gate conductor layer 104a
- 5V is input to the connected second gate conductor layer 104b of the word line WL.
- an annular inversion layer 107a is formed on the inner circumference of the first gate conductor layer 104a to which the plate wire PL is connected, and the first gate conductor layer 104a is formed.
- the first N-channel MOS transistor with is operated in the linear region.
- the pinch-off point 108 exists in the inverted layer 107a on the inner circumference of the first gate conductor layer 104a to which the plate wire PL is connected.
- the second N-channel MOS transistor having the second gate conductor layer 104b to which the word line WL is connected is operated in the saturation region.
- the inverted layer 107b is formed on the entire surface of the inner circumference of the second gate conductor layer 104b to which the word line WL is connected without the pinch-off point.
- the inversion layer 407b formed on the entire inner circumference of the second gate conductor layer 104b to which the word line WL is connected is a substantial drain of the second N-channel MOS transistor having the second gate conductor layer 104b.
- Work as. As a result, the boundary of the channel region 102 between the first N-channel MOS transistor having the first gate conductor layer 104a connected in series and the second N-channel MOS transistor having the second gate conductor layer 104b.
- the electric field is maximized in a region (an example of the "first boundary region" in the claims), and an impact ionization phenomenon occurs in this region.
- this region is the region on the source side as seen from the second N-channel MOS transistor having the second gate conductor layer 104b to which the word line WL is connected, this phenomenon is called the source side impact ionization phenomenon. Due to this source-side impact ionization phenomenon, electrons flow from the N + layer 101a to which the source line SL is connected toward the N + layer 101b to which the bit line is connected. Accelerated electrons collide with lattice Si atoms, and their kinetic energy creates electron-hole pairs. Some of the generated electrons flow to the first gate conductor layer 104a and the second gate conductor layer 104b, but most of them flow to the N + layer 101b to which the bit line BL is connected (not shown).
- the generated hole group 106 is a majority carrier of the channel region 102 and charges the channel region 102 with a positive bias (FIG. 3 (B)). Since the connected N + layer 101a of the source line SL is 0V, the channel region 102 has a built-in voltage Vb (about 0) of the PN junction between the connected N + layer 101a of the source line SL and the channel region 102. It is charged to .7V). When the channel region 102 is charged to the positive bias, the threshold voltages of the first N-channel MOS transistor and the second N-channel MOS transistor become lower due to the substrate bias effect. As a result, as shown in FIG. 3C, the threshold voltage of the second N-channel MOS transistor to which the word line WL is connected becomes low. The write state of the channel area 102 is assigned to the logical storage data “1”.
- the second boundary region between the first impurity layer and the first channel semiconductor layer, or the second impurity layer and the second channel semiconductor layer are used.
- an electron-hole pair may be generated by an impact ionization phenomenon, and the channel region 102 may be charged by the generated hole group 106.
- FIG. 3D shows a diagram for explaining the electric field strength during the writing operation of the dynamic flash memory cell according to the first embodiment of the present invention. Due to the impact ionization phenomenon on the source side, the electric field strength is the first gate conductor layer 104a to which the plate wire PL is connected, which is two gate conductor layers connected in series, and the second gate conductor to which the ward wire WL is connected. It shows how to maximize between the layer 104b and the layer 104b. At this time, although the amount is very small, the electric field becomes large even in the vicinity of the N + layer 101b of the drain portion to which the bit line BL is connected.
- FIG. 3 (E) shows how the channel region 102, which is a floating body, is charged at the time of writing and the voltage rises. Since the channel area 102 is erased before writing, its initial value is (V ERA + Vb). When writing is started, the voltage in the channel region 102 rises to Vb according to the writing time. However, when the voltage of the channel region 102 becomes Vb or higher, the PN junction between the N + layer 101a to which the source line SL is connected and the channel region 102 of the P layer becomes a forward bias, and the source side impact ionization phenomenon occurs. The generated hole group 106 is emitted from the channel region 102 of the P layer to the source line SL connected to the N + layer 101a.
- Vb is a built-in voltage of the PN junction between the N + layer 101a to which the source line SL is connected and the channel region 102 of the P layer, and is about 0.7V.
- the word line WL is connected as the potential of the channel region 102 changes during the writing operation of the dynamic flash memory cell according to the first embodiment of the present invention shown in FIG. 3E. It is a figure for demonstrating the threshold voltage change of both the 2nd N-channel MOS transistor and the 1st N-channel MOS transistor to which a plate wire PL is connected. As the channel region 102 rises, the threshold voltage of the second N-channel MOS transistor having the second gate conductor layer 104b to which the word line WL is connected decreases. Further, as shown in FIG. 3A, holes generated in the channel region 102 in the process of gradually changing the state of the floating body of the channel region 102 from the erased state “0” to the writing state “1”.
- the group accumulates. That is, the threshold voltages of both the second N-channel MOS transistor to which the word line WL is connected and the first N-channel MOS transistor to which the plate line PL is connected decrease. Then, as shown in FIG. 3 (F), the word line WL voltage at the time of writing can be lowered as the threshold voltage is lowered. Then, as shown in FIG. 3 (G), the hole group 106 is accumulated in the channel region 102 for writing “1”, and along with this, the second N-channel MOS transistor to which the word line WL is connected is connected. The threshold voltage of both of the first N-channel MOS transistors to which the plate wire PL is connected decreases. As a result, positive feedback is applied, the current flowing from the bit line BL to the source line SL increases, the impact ionization phenomenon becomes more remarkable, and the page writing operation is accelerated.
- the inversion layer is formed on the outer peripheral portion of the channel region 102 during the writing operation as the potential of the channel region 102 changes during the writing operation of the dynamic flash memory cell according to the first embodiment of the present invention. Is formed in. As a result, the electric field from the connected first gate conductor layer 104a of the plate wire PL to which the fixed voltage is constantly applied is shielded, and the retention characteristic of the hole group in the channel region 102 is improved.
- the voltage of the word line WL becomes the second N channel MOS having the second gate conductor layer 104b.
- the voltage is as high as 5V at the beginning of writing, but decreases to about 2V as the writing progresses. Can be done.
- FIG. 3 (I) summarizes an example of the voltage condition of each main node contact during the writing operation.
- photons are generated in addition to the electron / hole pair.
- the generated photons repeatedly reflect with the first gate conductor layer 104a and the second gate conductor layer 104b of the Si pillar 100, and proceed in the vertical direction of the Si pillar 100.
- the generated photons are generated in the first gate conductor layer 104a to which the plate wire PL is connected and the second gate conductor layer 104b to which the word wire WL is connected, using the Si column 100 as a waveguide.
- the reflection is repeated and the Si column 100 travels in the vertical direction.
- the first gate conductor layer 104a and the second gate conductor layer 104b also have a light shielding effect on the photons so that the photons generated at the time of writing do not destroy the data in the adjacent memory cells.
- FIG. 4 (A) to 4 (D) are diagrams for explaining the reading operation of the dynamic flash memory cell according to the first embodiment of the present invention.
- FIG. 4A when the channel region 102 is charged to the built-in voltage Vb (about 0.7V), the threshold voltage of the N-channel MOS transistor is lowered by the substrate bias effect. This state is assigned to the logical storage data "1".
- FIG. 4B when the memory block selected before writing is in the erase state “0” in advance, the channel area 102 has a floating voltage V FB and V ERA + Vb. The writing state "1" is randomly stored by the writing operation. As a result, logical storage data of logic "0" and "1” is created for the word line WL.
- FIG. 4C reading is performed by a sense amplifier by utilizing the height difference between the two threshold voltages with respect to the word line WL.
- FIG. 4D summarizes an example of the voltage condition of each main node contact during the read operation.
- FIG. 4 (E) to 4 (H) show the gate capacitances of the two first gate conductor layers 104a and the second gate conductor layer 104b during the read operation of the dynamic flash memory cell according to the first embodiment of the present invention. It is a structural diagram explaining the magnitude relation of. It is desirable that the gate capacitance of the second gate conductor layer 104b to which the ward wire WL is connected is designed to be smaller than the gate capacitance of the first gate conductor layer 104a to which the plate wire PL is connected. As shown in FIG. 4 (E), the vertical length of the first gate conductor layer 104a to which the plate wire PL is connected is larger than the vertical length of the second gate conductor layer 104b to which the word wire WL is connected.
- FIG. 4 (F) shows an equivalent circuit of one cell of the dynamic flash memory of FIG. 4 (E).
- FIG. 4 (G) shows the combined capacity relationship of the dynamic flash memory.
- C WL is the capacitance of the second gate conductor layer 104b
- C PL is the capacitance of the first gate conductor layer 104a
- C BL is the drain N + layer 101b and the second channel region 102b.
- the capacitance of the PN junction between and C SL is the capacitance of the PN junction between the source N + layer 101a and the first channel region 102a.
- V Read WL is the amplitude potential at the time of reading the word line WL.
- the vertical length of the first gate conductor layer 104a to which the plate wire PL is connected is made longer than the vertical length of the first gate conductor layer 104b to which the word wire WL is connected, and C PL > C. It is desirable to use WL . However, only by adding the plate line PL, the coupling ratio of the capacitive coupling (C WL / (C PL + C WL + C BL + C SL )) with respect to the channel region 102 of the word line WL becomes small. As a result, the potential fluctuation ⁇ V FB in the channel region 102 of the floating body becomes small.
- V ErasePL of the plate wire PL for example, a fixed voltage of 2V may be applied regardless of each operation mode, and for the voltage V ErasePL of the plate wire PL, for example, 0V is applied only at the time of erasing. You may.
- the dynamic flash memory operation described in the present embodiment can be performed.
- circular, elliptical, and rectangular dynamic flash memory cells may be mixed on the same chip.
- a dynamic flash memory is formed on a Si pillar 100 standing vertically on a substrate Sub.
- this dynamic flash memory does not stand in the vertical direction on the substrate Sub, for example, GAA (Gate All Around: for example, which is one of the SGTs].
- GAA Gate All Around: for example, which is one of the SGTs.
- Non-Patent Document 10] The above-mentioned dynamic flash memory operation can be performed even if it is formed horizontally with respect to the substrate Sub by using the technique and Nanosheet technology (see, for example, Reference [Non-Patent Document 11]). ..
- a first gate insulating layer 103a and a second gate insulating layer 103b are provided on the substrate Sub to surround the entire side surface of the Si pillar 100 standing in the vertical direction, and the first gate insulating layer 103a,
- the dynamic flash memory element has been described by taking an SGT having a first gate conductor layer 104a and a second gate conductor layer 104b surrounding the entire second gate insulating layer 103b as an example.
- the dynamic flash memory element may have a structure that satisfies the condition that the hole group 106 generated by the impact ionization phenomenon is held in the channel region 102.
- the channel region 102 may have a floating body structure separated from the substrate Sub.
- the semiconductor base in the channel region is used as a substrate Sub. Even if it is formed horizontally with respect to the above, the above-mentioned dynamic flash memory operation can be performed. Further, it may have a device structure using SOI (Silicon OnInsulator) (see, for example, Non-Patent Documents 7 to 10). In this device structure, the bottom of the channel region is in contact with the insulating layer of the SOI substrate, and the other channel region is surrounded by the gate insulating layer and the element separation insulating layer.
- SOI Silicon OnInsulator
- the channel region has a floating body structure.
- the dynamic flash memory element provided by the present embodiment, it is sufficient to satisfy the condition that the channel region has a floating body structure. Further, even in a structure in which a Fin transistor (see, for example, Non-Patent Document 13) is formed on an SOI substrate, this dynamic flash operation can be performed if the channel region has a floating body structure.
- the potential distributions of the first channel region 102a and the second channel region 102b are connected and formed. ..
- the channel regions of the first channel region 102a and the second channel region 102b are connected by a region surrounded by the insulating layer 105, which is the first insulating layer, in the vertical direction.
- FIGS. 2 (A) to 2 (D) show an example of erasing operation conditions.
- the source line SL, the plate line PL, and the bit line BL can be realized.
- the voltage applied to the word line WL may be changed.
- the present embodiment provides the following features.
- the N + layers 101a and 101b serving as sources and drains, the channel region 102, the first gate insulating layer 103a, the second gate insulating layer 103b, and the first gate conductor layer 104a
- the second gate conductor layer 104b is formed in a columnar shape as a whole.
- the source N + layer 101a is used for the source line SL
- the drain N + layer 101b is used for the bit line BL
- the first gate conductor layer 104a is used for the plate line PL
- the second gate conductor layer 104b is used for the word.
- Each is connected to the wire WL.
- the gate capacitance of the first gate conductor layer 104a to which the plate wire PL is connected is characterized by a structure that is larger than the gate capacitance of the second gate conductor layer 104b to which the word wire WL is connected. ..
- a first gate conductor layer and a second gate conductor layer are laminated in the vertical direction. Therefore, the gate capacitance of the first gate conductor layer 104a to which the plate wire PL is connected is larger than the gate capacitance of the second gate conductor layer 104b to which the word wire WL is connected.
- the memory cell area is not increased in a plan view. As a result, high performance and high integration of dynamic flash memory cells can be realized at the same time.
- the first N-channel MOS transistor having the first gate conductor layer 104a connected to the plate wire PL on the source wire SL side is operated in the linear region and drained.
- the second N-channel MOS transistor having the second gate conductor layer 104b to which the word line WL is connected, which is arranged on the N + layer 101b side, is operated in the saturation region.
- the inversion layer 407b formed on the entire surface directly under the second gate conductor layer 104b to which the word line WL is connected is substantially the second N-channel MOS transistor having the second gate conductor layer 104b. It becomes a drain.
- the electric field between the first N-channel MOS transistor having the first gate conductor layer 104a connected in series and the second N-channel MOS transistor having the second gate conductor layer 104b becomes maximum. Impact ionization occurs in this region and electron-hole pairs are generated. In this way, the channel between the first N-channel MOS transistor having the first gate conductor layer 104a connected in series with the impact ionization generation location and the second N-channel MOS transistor having the second gate conductor layer 104b. Can be set to.
- the first N-channel MOS transistor having the first gate conductor layer 104a to which the plate wire PL is connected, which is arranged on the N + layer 101a side as the source, is operated in the linear region and is operated in the linear region with the drain.
- the second N-channel MOS transistor having the second gate conductor layer 104b to which the word line WL is connected, which is arranged on the N + layer 101b side, is operated in the saturation region, whereby the inverted layer 107b is generated. Acts as a substantial drain portion extending from the N + layer 101b that serves as a drain.
- the electric field strength due to the impact ionization phenomenon on the source side is the connected first gate conductor layer 104a of the plate wire PL, which is two gate conductor layers connected in series, and the connected second gate conductor layer of the word wire WL. It is maximized between the gate conductor layer 104b and the gate conductor layer 104b.
- a second gate conductor layer 104b having a second gate conductor layer 104b to which a word line WL is connected is provided as the potential of the channel region 102 during the writing operation of the dynamic flash memory cell according to the first embodiment of the present invention increases.
- the threshold voltage of the two N-channel MOS transistors and the first N-channel MOS transistor having the first gate conductor layer 104a to which the plate wire PL is connected is lowered. Therefore, as the threshold voltage decreases, the voltage of the word line WL at the time of writing can be decreased. Further, as the holes generated in the channel region 102 during writing are accumulated, positive feedback is applied and the page writing operation is accelerated. As a result, the data writing time can be shortened.
- the inversion layer is formed on the outer peripheral portion of the channel region 102 of the Si column 100 during the write operation. It is formed. As a result, the electric field from the plate wire PL to which a fixed voltage is constantly applied is shielded. This improves the retention characteristics of the hole group in the channel region 102.
- a second N-channel MOS transistor having a second gate conductor layer 104b is provided as the potential of the channel region 102 during the write operation of the dynamic flash memory cell according to the first embodiment of the present invention increases.
- the initial voltage of the word line WL at the start of writing can be reduced while maintaining operation in the saturation region.
- the effect of reducing the potential of the floating body 100, which is capacitively coupled to the second gate conductor layer 104b is reduced. This leads to stable operation by expanding the operation margin of the dynamic flash memory cell.
- Photons are generated in addition to electron-hole pairs by the impact ionization phenomenon caused during the writing operation of the dynamic flash memory cell according to the first embodiment of the present invention.
- the generated photons are repeatedly reflected by the first gate conductor layer 104a and the second gate conductor layer 104b of the Si column 100, and proceed in the vertical direction of the Si column 100.
- the first gate conductor layer 104a to which the plate wire PL is connected has a shielding effect on the photons so that the photons generated at the time of writing do not destroy the data of the adjacent memory cells in the horizontal direction. ..
- 5 (A) and 5 (B) show the writing operation.
- 0V is input to the N + layer 101a which is the connected source of the source line SL
- 3V is input to the N + layer 101b which is the connected drain of the bit line BL.
- 5V is input to the first gate conductor layer 104a to which the plate wire PL is connected
- 2V is input to the second gate conductor layer 104b to which the word wire WL is connected.
- an inverted layer 107a is formed on the entire surface immediately below the first gate conductor layer 104a to which the plate wire PL is connected, and has the first gate conductor layer 104a.
- the first N-channel MOS transistor operates in the saturation region.
- the inversion layer 107a directly below the first gate conductor layer 104a to which the plate wire PL is connected has no pinch-off point and has a second gate conductor layer 104b.
- the second N-channel MOS transistor having the second gate conductor layer 104b to which the word line WL is connected operates in the linear region.
- the pinch-off point 108 exists in the formed inversion layer 107b directly below the second gate conductor layer 104b to which the word line WL is connected.
- the electric field becomes maximum in the vicinity of the N + layer 101b, which is the drain of the second N-channel MOS transistor having the second gate conductor layer 104b to which the word line WL is connected, and impact ionization occurs in this region. Due to the impact ionization phenomenon, the floating body 100 is charged to Vb and becomes the writing state "1".
- FIG. 5B summarizes an example of the voltage condition of each main node contact during this writing operation.
- the voltage of the plate line PL can be set as high as 5V
- the voltage of the word line WL can be set to be lower than that and fixed at 2V.
- impact ionization occurs in the vicinity of the N + layer 101b, which is the drain of the second N-channel MOS transistor having the second gate conductor layer 104b to which the word line WL is connected.
- the dynamic flash memory operation can be performed as in the first embodiment.
- connection positional relationship between the word line WL and the plate line PL with respect to the Si pillar 100 is upside down with respect to the structure shown in FIG.
- the portion of the Si column 100 between the N + layers 101a and 101b that serve as the source and drain becomes the channel region 102.
- a first gate insulating layer 103a2 and a second gate insulating layer 103b2 are formed so as to surround the channel region 102.
- a first gate conductor layer 104a2 and a second gate conductor layer 104b2 are formed so as to surround the first gate insulating layer 103a2 and the second gate insulating layer 103b2, respectively.
- the conductor layer 104b2 is formed in a columnar shape as a whole.
- An insulating layer 105 for separating the first and second gate conductor layers is formed between the first gate conductor layer 104a2 and the second gate conductor layer 104b2.
- the source N + layer 101a is used for the source line SL
- the drain N + layer 101b is used for the bit line BL
- the first gate conductor layer 104a2 is used for the word line WL
- the second gate conductor layer 104b2 is used for the plate.
- Each is connected to the line PL.
- the gate capacitance of the second gate conductor layer 104b2 to which the plate wire PL is connected is larger than the gate capacitance of the first gate conductor layer 104a2 to which the word wire WL is connected. It is characterized by a structure that makes it larger.
- the gate length of the first gate conductor layer 104a2 is made longer than the gate length of the second gate conductor layer 104b2 by changing the respective gate lengths.
- a first N-channel MOS transistor having a first gate conductor layer 104a to which a plate wire PL is connected is arranged on the N + layer 101a side as a source.
- a second N-channel MOS transistor having a second gate conductor layer 104b to which the word line WL is connected, which is arranged on the N + layer 101b side as a drain, are connected in series.
- the connection positional relationship between the word line WL and the plate line PL with respect to the Si pillar 100 is upside down with respect to the structure shown in FIG. Further, as shown in FIG.
- the gate length of the first gate conductor layer 104a2 is made longer than the gate length of the second gate conductor layer 104b2 by changing the respective gate lengths, and the plate wire PL is connected.
- the gate capacitance of the second gate conductor layer 104b2 is characterized by a structure that is larger than the gate capacitance of the first gate conductor layer 104a2 to which the word line WL is connected.
- FIGS. 7 (A) to 7 (M) A method for manufacturing the dynamic flash memory according to the fourth embodiment will be described with reference to FIGS. 7 (A) to 7 (M).
- (a) is a plan view
- (b) is a cross-sectional structure diagram along the XX'line of (a)
- (c) is a cross-sectional structure diagram along the YY'line.
- a case of forming a memory cell area consisting of nine memory cells of 3 rows ⁇ 3 columns will be described.
- the P layer substrate 1 is prepared.
- the N + layer 2 is formed on the upper part of the P layer substrate 1.
- the P layer 3 is formed by the epitaxial growth method.
- an N + layer 4 is formed on the upper portion of the epitaxially grown P layer 3.
- a mask material layer (not shown) was deposited on the upper part of the N + layer 4, and the mask material layers 5 11 to 5 33 patterned in the region forming the Si column were formed. leave.
- it may be formed by etching by the RIE (Reactive Ion Etching) method.
- the region covered with the mask material layers 5 11 to 5 33 is left, and the epitaxially grown P layer 3 is etched by, for example, the RIE (Reactive Ion Etching) method, and N + Layers 4 11 to 4 33 are formed at the top of the P layer Si columns 3 11 to 3 33 .
- RIE Reactive Ion Etching
- a hafnium oxide (HfO 2 ) layer 6 11 to 6 33 which is a gate insulating layer by the ALD (Atomic Layer Deposition) method, is surrounded by Si columns 3 11 to 3 33 .
- the HfO 2 layers 6 11 to 6 33 may be formed by being connected to the N + layer 2 on the outer peripheral portion of the P layer Si columns 3 11 to 3 33 .
- a TiN layer (not shown) to be a gate conductor layer is formed by covering the HfO 2 layers 6 11 to 6 33 after covering the SiO 2 layer 7. Then, the TiN layer is etched by the RIE method to form the TiN layers 81, 8 2 and 83 which are the first gate conductor layers.
- the TiN layers 81, 8 2 and 83 which are the first gate conductor layers, are plate wire PLs.
- the SiO 2 layer 9 serves as an insulating material between the plate wire PL and the word wire WL.
- a TiN layer (not shown) to be a second gate conductor layer is formed by covering the HfO 2 layers 6 11 to 6 33 . Then, the TiN layer is etched by the RIE method to form the TiN layers 10 1 , 10 2 , 10 3 which are the second gate conductor layers. The TiN layers 10 1 , 10 2 , 10 3 which are the second gate conductor layers are word line WLs. Then, the SiO 2 layer 11 is covered. Next, the mask material layers 5 11 to 5 33 are removed by etching to form pores 12 11 to 12 33 .
- a conductor layer for example, tungsten W13 11 to 13 33 is embedded in the holes 12 11 to 12 33 by a damascene process.
- a conductor layer (not shown) of a copper CU is formed.
- the copper CU layer is etched by the RIE method to form, for example, copper CU layers 141 , 142 , and 14 3 which are wiring conductor layers.
- the copper CU layers 141, 142, and 14 3 which are the wiring conductor layers are bit wires BL.
- the SiO 2 layer 15 serving as a protective film is covered to complete the dynamic flash memory cell region.
- the area of the 1-cell region UC surrounded by the dotted line is 4F 2 when the length between the Si pillars 3 11 to 3 33 and the length between the Si pillars 3 11 to 3 33 is F.
- an N + layer 2 is formed on the upper part of the P layer substrate 1, and then the P layer 3 is formed by an epitaxial growth method and is epitaxially grown.
- An N + layer 4 is formed on the upper part of the P layer 3, a mask material layer is deposited on the upper part of the N + layer 4, and the patterned mask material layers 5 11 to 5 33 are left in the region forming the Si column, and RIE (Reactive) is left. Etching is performed by the Ion Etching) method to form Si columns.
- the region covered with the mask material layers 5 11 to 5 33 is left, and the epitaxially grown P layer 3 is etched by, for example, the RIE (Reactive Ion Etching) method, and the N + layers 4 11 to 4 33 are placed on the upper part.
- the P layer Si column 3 11 to 3 33 to be formed is formed.
- P-layer Si columns 3 11 to 3 33 including N + layers 2, 4 11 to 4 33 can be formed at the same time on the upper and lower sides. This leads to simplification of manufacturing of this dynamic flash memory.
- a hafnium oxide (HfO 2 ) layer 6 11 to 6 33 to be a gate insulating layer is formed by surrounding the Si columns 3 11 to 3 33 by the ALD (Atomic Layer Deposition) method.
- the HfO 2 layers 6 11 to 6 33 are covered to form a TiN layer to be the first gate conductor layer.
- the TiN layer is etched by the RIE method to form the TiN layers 81, 8 2 and 83 which are the first gate conductor layers.
- the TiN layers 81, 8 2 and 83 which are the first gate conductor layers, are plate wire PLs.
- FIG. 8A shows a memory block circuit diagram selected for block erasure.
- the memory cells show a total of 9 CL 11 to CL 33 of 3 rows ⁇ 3 columns, but the actual memory block is larger than this matrix.
- Source lines SL 1 to SL 3 , bit lines BL 1 to BL 3 , plate lines PL 1 to PL 3 , and word lines WL 1 to WL 3 are connected to each memory cell.
- an erasing voltage V ERA is applied to the source lines SL 1 to SL 3 of the memory block selected for block erasing.
- the bit lines BL 1 to BL 3 are VSS
- the word lines WL 1 to WL 3 are VSS .
- VSS is 0V.
- V ErasePL is applied to the plate lines PL 1 to PL 3 regardless of whether or not the block erasure is selected, but V Erase PL is applied to the plate lines PL 1 to PL 3 of the selected block . Is applied, and VSS may be applied to the plate lines PL 1 to PL 3 of the non-selective block.
- the potential of the channel region 102 of the floating body in the erased state “0” is V ERA + Vb.
- the potential of the channel region 102 of the floating body is -2.3V.
- Vb is a built-in voltage of the PN junction between the N + layer which is the source line SL and the channel region 102 of the floating body, and is about 0.7V.
- a cache memory for temporarily storing the data in the memory block and a logical address physical address conversion table for the memory block are required. These are stored in the dynamic flash memory device. It may be provided or it may be provided in the system that handles it.
- An erasing voltage V ERA is applied to the source lines SL 1 to SL 3 of the memory block selected for block erasing.
- V ERA + Vb The potential of the channel region 102 in the erased state “0” is V ERA + Vb.
- Vb is the built-in voltage of the PN junction between the N + layer, which is the source line SL, and the channel region 102.
- FIG. 9A shows a memory block circuit diagram selected for page writing.
- V Prog BL is applied to the bit line BL 2 for writing “1”
- VSS is applied to the bit lines BL 1 and BL 3 that do not write and maintain the erased state “0”.
- V ProgBL is 3V and VSS is 0V.
- V Prog WL is applied to the word line WL 2 for which page writing is performed
- VSS is applied to the word lines WL 1 and WL 3 for which page writing is not performed.
- V ProgWL is 5V and VSS is 0V.
- V Prog PL is applied to the plate lines PL 1 to PL 3 regardless of whether page writing is selected or not.
- V ProgPL is 2V.
- the bit line BL 2 connected to the memory cell CL 22 is V Prog BL
- the word line WL 2 is V Prog WL
- the plate line PL 2 is V Prog PL, so that the word line WL 2 is connected.
- the source side impact ionization phenomenon occurs between 2 and the input two-layer gate of the plate wire PL 2 .
- Vb is a PN junction between the source N + layer to which the source line SL is connected and the channel region 102, and is, for example, 0.7V.
- VSS is applied to the bit lines BL 1 and BL 3 connected to the memory cells CL 21 and CL 23 that do not write "1" on the same selection page and keep the erased state
- the memory cell CL In 21 and CL 23 the current from the drain to the source does not flow, the source side impact ionization phenomenon does not occur, and the logical storage data in the erased state “0” is maintained.
- V ProgBL is applied to the bit line BL 2 for writing "1"
- the bit lines BL 1 and BL 3 that do not write and maintain the erased state "0" are used.
- VSS is applied.
- the bit line BL 2 connected to the memory cell CL 22 is V Prog BL
- the word line WL 2 is V Prog WL
- the plate line PL 2 is V Prog PL, so that the word line WL 2 is connected.
- the source side impact ionization phenomenon occurs between 2 and the input two-layer gate of the plate wire PL 2 .
- Vb is a PN junction between the N + layer, which is the source to which the source line SL is connected, and the channel region 102.
- the back bias effect lowers the threshold voltage of the second N-channel MOS transistor input by the word line WL.
- VSS is applied to the bit lines BL 1 and BL 3 connected to the memory cells CL 21 and CL 23 that do not write “1” on the same selection page and keep the erased state, respectively.
- the current from the drain to the source does not flow, the source side impact ionization phenomenon does not occur, and the logical storage data in the erased state “0” is maintained.
- VSS is applied to the source lines SL 1 to SL 3
- V Read BL is applied to the bit lines BL 1 to BL 3
- VSS is 0V
- V ReadBL is 1V
- V Read WL is applied to the selection word line WL 2 for page reading.
- V Read WL is 2V
- V Read PL is applied to the plate lines PL 1 to PL 3 regardless of whether page writing is selected or not.
- V ReadPL is 2V.
- the threshold voltage is high, so that the memory cell current does not flow and the bit line BL does not discharge and maintains V Read BL.
- the threshold voltage is low, so that the memory cell current flows, the bit line BL is discharged, and the V Read BL is changed to VSS. do.
- the potential states of these two bit lines BL are read by a sense amplifier, and "1" and "0" of the logical storage data in the memory cell are determined (not shown).
- the threshold voltage is high, so the memory cell current does not flow and the bit line is discharged. Keep V Read BL without.
- the threshold voltage is low, so that the memory cell current flows, the bit line is discharged, and the V Read BL changes to VSS. ..
- VSS is applied to the source lines SL 1 to SL 3 of the selection memory block to be refreshed
- V is applied to the bit lines BL 1 to BL 3 .
- Refresh BL is applied.
- VSS is 0V
- V RefreshBL is 3V.
- a fixed voltage V RefreshPL is applied to the plate lines PL 1 to PL 3 regardless of whether or not block erasure is selected, but V Refresh PL is applied to the plate lines PL 1 to PL 3 of the selected block.
- VSS may be applied to the plate lines PL 1 to PL 3 of the non-selection block.
- V Refresh WL is applied to the word lines WL 1 to WL 3 of the memory block for refreshing.
- V RefreshPL is 2V and V RefreshWL is 3V.
- FIG. 11C summarizes an example of the voltage condition of each main node contact at the time of block refresh.
- the memory block data is temporarily stored in the cache in the memory chip or in the system, and the memory block is erased in blocks. It is refreshed by rewriting the logical storage data.
- the conversion table of the logical block address and the physical block address may be stored in the memory chip or the system, and the refreshed data may be stored in the physical block address different from the previous one.
- the following features are provided.
- the first N-channel MOS transistor and word line WL to which the plate line PL is connected are placed in the logical storage data “1” stored in the channel area 102 of the floating body of the memory cell. Since the threshold voltage of the second N-channel MOS transistor to which is connected is low, memory cell current flows even if the applied voltage is V RefreshWL and V RefreshPL , which are lower than the page write voltage. A source-side impact ionization phenomenon occurs between the two gates, and the generated holes are accumulated in the channel region 102 of the floating body. As a result, the memory cell in the write state "1" is refreshed in units of memory blocks.
- V PageErase PL is applied only to the plate line PL 2 connected to the memory cell whose page is erased.
- V PageErasePL is, for example, 2V.
- V PageErase WL is applied to the word line WL 2 connected to the memory cell whose page is erased, and V PageErase WL is VSS , for example, 0V.
- V ERA Page is applied to the source lines SL 1 to SL 3 .
- V ERA Page is set at a voltage higher than the block erasing bit line applied voltage V ERA . For example, V ERA is -3V , while V ERA Page is -1V. This is protection so that the data in the memory cell that has already been written to "1" and maintained to be erased by "0" in the same block for page erasure is not rewritten by page erasure.
- FIG. 12C summarizes an example of the voltage condition of each main node contact when the page is erased.
- the plate wire PL other than the plate wire PL connected to the memory cell for page erasing drops from the constantly applied fixed voltage to VSS. Since the gate capacitance to which the plate wire PL is connected is large, the floating body FB of the memory cell storing the data of “1” and “0” is lowered by the capacitive coupling. As a result, page erasure protects the already written "1" data from being rewritten. Then, V PageErase PL is applied only to the plate line PL 2 connected to the memory cell whose page is erased. Further, V ERA Page is applied to the bit lines BL 1 to BL 3 . This makes it possible to reliably erase the page.
- FIGS. 13 (A) to 13 (E) A method for manufacturing the dynamic flash memory according to the tenth embodiment will be described with reference to FIGS. 13 (A) to 13 (E).
- (a) is a plan view
- (b) is a cross-sectional structure diagram along the XX'line of (a)
- (c) is a cross-sectional structure diagram along the YY'line.
- a case of forming a memory cell area consisting of nine memory cells of 3 rows ⁇ 3 columns will be described.
- FIGS. 7 (A) to 7 (F) are performed.
- the SiO 2 layer 7 is formed, the entire HfO 2 layer 6 is covered with the HfO 2 layer 6 by, for example, the ALD method.
- the HfO 2 layer 6 is surrounded and the TiN layers 8 1 , 8 2 and 83, which are the first gate conductor layers extended in the XX'line direction , are formed. do.
- the HfO 2 layer 6 above the upper ends of the TiN layers 81, 8 2, and 8 3 is removed to form the second gate insulating layer, the HfO 2 layer 61. Form. Then, the entire surface is covered with the HfO 2 layer 18. Then, in the same manner as in the process shown in FIG. 7 (J), the TiN layers 10 1 , 10 2 , 10 3 which are the second gate conductor layers extended in the XX'line direction are formed.
- CVD Chemical Vapor Deposition
- CMP Chemical Mechanical Polish
- the W layers 201 and 202 are formed in contact with the N + layer 2 at the bottom of the contact holes 19 1 and 19 2 . Then, on the W layers 201 and 202, the SiO 2 layers 22 1 and 222 including the pores 21 1 and 211 extending in the XX'direction are formed.
- FIG. 13 (E) SiO 2 surrounding the TiN layers 10 1 , 10 2 , 10 3 is performed.
- the layer 11 1 and the SiO 2 layer 112 covering the N + layers 4 11 to 4 33 are formed.
- the W layers 13 11 to 13 33 are formed on the N + layers 4 11 to 4 33 .
- the damascene method for example, Cu layers 141 , 142, and 14 3 to be bit wire BL are formed.
- the SiO 2 layer 15 is formed.
- the SiO 2 layers 22 1 and 222 including the pores 21 1 and 211 may be formed of a low dielectric constant material layer containing the pores 21 1 and 211 . Further, the SiO 2 layers 22 1 and 222 may be formed from other insulating material layers.
- the upper end positions of the holes 21 1 and 211 in the vertical direction are lower than the upper end positions of the TiN layers 10 1 , 10 2 , 10 3 of the second gate conductor layer. Further, the upper end positions of the holes 21 1 and 211 in the vertical direction may be lower than the upper end positions of the TiN layers 81, 8 2 and 8 3 of the first gate conductor layer.
- the holes 16 1 and 16 2 are formed on the N + layer 4 11 to 4 33 , on the side surface of any one of the W layer 13 11 to 13 33 , the Cu layer 14 11 to 14 3 , or two consecutive layers. May be formed.
- This embodiment has the following features.
- the HfO 2 layers 6 11 to 6 33 serving as the gate insulating layer are the N + layers on the tops of the Si columns 3 11 to 3 33 . It is formed by connecting 4 11 to 4 33 and N + layer 2 at the bottom.
- the gate insulating layer of the PL line gate TiN layers 8 1 , 8 2 , 8 3 and the WL line gate TiN layers 10 1 , 10 2 , 10 3 is formed by the same HfO 2 layers 3 11 to 33 3. Has been done.
- the PL line gate conductor layers 8 1 , 8 2 , 8 3 and the WL line gate conductor layers 10 1 , 10 2 , 10 3 and the gate insulating layers 6 and 18 are separately separated. It is formed.
- the film thickness and the material of the gate insulating layer 6 and the gate insulating layer 18 are separately selected, and the PL line and the floating body capacitance C PL can be more effectively obtained, and the WL wire and the floating body capacitance C can be obtained more effectively. It can be larger than the WL . This contributes to more stable dynamic flash memory operation.
- (Feature 2) In the fourth embodiment, as shown in FIG. 7 (I), as an interlayer insulating layer between the PL line gate TiN layers 8 1 , 8 2 , 8 3 and the WL line gate TiN layers 10 1 , 10 2 , 10 3 .
- the SiO 2 layer 9 is formed. The formation of the SiO 2 layer 9 is performed, for example, after the formation of the TiN layers 81, 82, and 8 3 in FIG . 7 (H), the entire SiO 2 layer is covered, and then the upper surface position thereof is determined by the CMP method.
- the mask material layer 5 11 to 5 33 is polished to the upper surface position and then etched back by RIE to form.
- FIG. 7 (I) As an interlayer insulating layer between the PL line gate TiN layers 8 1 , 8 2 , 8 3 and the WL line gate TiN layers 10 1 , 10 2 , 10 3 .
- the SiO 2 layer 9 is formed. The formation of the SiO 2 layer 9 is performed, for example, after the formation
- the interlayer insulating layer corresponding to the SiO 2 layer 9 is formed, and the HfO 2 layer 18 is formed as the second gate insulating layer, and at the same time, the SiO is formed. It is formed as an interlayer insulating layer corresponding to the two layers 9. This simplifies the manufacturing process.
- the contact holes 191 and 192 have holes 21 1 and 221 and W layers 201 and 202 formed therein.
- the holes 21 1 and 211 and the W layers 201 and 202 2 are formed by self-alignment.
- the W layers 21 and 202 reduce the resistance of the N + layer 2 region of the SL line to contribute to more stable dynamic flash memory operation.
- the holes 21 1 and 211 can reduce the parasitic capacitance between the WL line TiN layers 81, 82 , 83 and the PL line TiN layers 10 1 , 10 2 , 10 3 . This reduction in parasitic capacitance can contribute to the expansion of the operating margin of dynamic flash memory.
- the formation of the holes 21 1 and 211 and the W layers 21 and 202 by self - alignment contributes to high integration of the dynamic flash memory.
- the W layers 21 and 202 may not be formed in the memory cell region, but the SL wire metal wiring portion connected to the N + layer 2 may be formed in the peripheral portion of the memory cell region.
- the SL line resistance is larger than that in the case where the W layers 201 and 2022 are present, but the WL line TiN layers 81, 8 2 , 83 , and the PL line TiN layers 10 1 , 10 2 are present.
- the effect of reducing the parasitic capacitance between 10 and 3 remains the same, and there is no need to improve the precision of the manufacturing process in order to reliably connect the W layers 21 and 202 to the N + layer 2 .
- the presence or absence of the formation of the W layers 201 and 202 can be selected in consideration of the low resistance of the SL line and the facilitation of the manufacturing process.
- the holes 16 1 , 16 2 formed between the side surfaces of the N + layers 4 11 to 4 33 , the W layers 13 11 to 13 33 , and the Cu layers 14 11 to 14 33 shown in FIG. 13 (E) are bit wires BL.
- the parasitic capacitance between can be reduced. This contributes to more stable dynamic flash memory operation.
- phosphorus P and arsenic As are ion-implanted into the P layer substrate 1 to provide an N-well (N-Well) layer 1A.
- boron B is ion-implanted into the N-well (N-Well) layer 1A to provide the P-well (P-Well) layer 1B.
- This two-layer well structure is a measure for enabling the dynamic flash memory of the present application to apply a negative bias to the source line SL during the erasing operation. By adopting such a double-layer well structure, the negative bias of the source line SL does not affect the PN junction of other peripheral circuits and the transistor circuit.
- the erasing operation of the dynamic flash memory of the present application makes the source line SL a negative bias.
- the double-layer well structure in the P-layer substrate 1 in the memory cell region By providing the double-layer well structure in the P-layer substrate 1 in the memory cell region, other circuits can be shielded from this negative bias.
- the Si pillar is formed in the present invention
- the semiconductor pillar may be made of a semiconductor material other than the Si pillar. This also applies to the other embodiments according to the present invention.
- the N + layers 101a and 101b serving as sources and drains in the first embodiment may be formed of Si containing donor impurities or other semiconductor material layers. Further, the N + layers 101a and 101b serving as sources and drains may be formed of different semiconductor material layers. This also applies to the other embodiments according to the present invention.
- the N + layer 4 is formed on the upper part of the P layer 3 epitaxially grown in FIG. 7D by the epitaxial crystal growth method.
- the formed N + layer may be used.
- the N + layer may be formed by another method. This also applies to the other embodiments according to the present invention.
- a hafnium oxide (HfO 2 ) layer 6 11 to 6 33 to be a gate insulating layer is formed by surrounding the Si columns 3 11 to 3 33 .
- the hafnium oxide (HfO 2 ) layer 6 11 to 6 33 uses a single layer or another material layer including an organic material or an inorganic material, if it is a material suitable for the object of the present invention. May be good. This also applies to the other embodiments according to the present invention.
- the mask material layers 5 11 to 5 33 deposited on the upper part of the N + layer 4 and patterned in the region forming the Si column are left.
- the mask material layer is an organic material or an inorganic material consisting of a SiO 2 layer, an aluminum oxide (Al 2 O 3 ; also referred to as AlO) layer, a SiO 2 layer, and a single layer or a plurality of layers as long as the material meets the object of the present invention.
- AlO aluminum oxide
- SiO 2 layer silicon oxide
- Other material layers containing the material may be used. This also applies to the other embodiments according to the present invention.
- the upper surface of each of the mask material layers 5 11 to 5 33 and the position of the bottom in the vertical direction are formed in the same manner.
- the positions of the surface and the bottom may be different in the vertical direction. This also applies to the other embodiments according to the present invention. This also applies to the other embodiments according to the present invention.
- the thickness and shape of the mask material layers 5 11 to 5 33 are changed by polishing by CMP, RIE etching, and washing. There is no problem if this change is within the range that meets the object of the present invention. This also applies to the other embodiments according to the present invention.
- the materials of the various wiring metal layers WL, PL, BL, SL may be not only metals but also conductive material layers such as alloys, acceptors, or semiconductor layers containing a large amount of donor impurities. Well, they may be configured in a single layer or in combination of multiple layers. This also applies to the other embodiments according to the present invention.
- a TiN layer was used as the gate conductor layer.
- the TiN layer a material layer composed of a single layer or a plurality of layers can be used as long as it is a material that meets the object of the present invention.
- the TiN layer can be formed from a conductor layer such as a single layer or a plurality of metal layers having at least a desired work function.
- another conductive layer such as a W layer may be formed.
- a single layer or a plurality of metal layers may be used.
- the W layer acts as a metal wiring layer connecting the gate metal layers.
- a single layer or a plurality of metal layers may be used.
- the hafnium oxide (HfO 2 ) layers 6 11 to 6 33 which are the gate insulating layers are formed by surrounding the Si columns 3 11 to 33 3, but each of them is made of a single layer or a plurality of layers. Other material layers may be used. This also applies to the other embodiments according to the present invention.
- the shape of the Si pillars 3 11 to 33 3 in a plan view was a circular shape.
- the shape of a part or all of the Si columns 3 11 to 33 3 in a plan view may be a circle, an ellipse, a shape elongated in one direction, or the like.
- Si columns having different planar views can be mixedly formed in the logic circuit region according to the logic circuit design. This also applies to the other embodiments of the present invention.
- an alloy layer such as metal or silicide may be formed on the upper surface of the bottom N + layer 2.
- a metal layer or an alloy layer that is in contact with and stretched in contact with these P + layers and N + layers may be provided. This also applies to the other embodiments according to the present invention.
- the dynamic flash memory cell is formed on the P layer substrate 1, but an SOI (Silicon On Insulator) substrate may be used instead of the P layer substrate 1.
- SOI Silicon On Insulator
- a substrate made of another material may be used as long as it serves as a substrate. This also applies to the other embodiments according to the present invention.
- a dynamic flash memory cell constituting a source and a drain using N + layers 101a and 101b having the same polarity of conductivity above and below the Si column 100 has been described, but the polarities are different.
- the present invention can also be applied to a tunnel type device having a source and a drain. This also applies to the other embodiments according to the present invention.
- the hafnium oxide (HfO 2 ) layers 6 11 to 6 33 to be the gate insulating layer are formed. It is formed by surrounding the Si columns 3 11 to 3 33 , and the TiN layer is etched by the RIE method to form the TiN layers 8 1 , 8 2 , 8 3 which are the first gate conductor layers, and the TiN is formed by the RIE method. The layers were etched to form the TiN layers 10 1 , 10 2 , 10 3 , which are the second gate conductor layers.
- hafnium oxide (HfO 2 ) layers 6 11 to 6 33 which are gate insulating layers, are formed surrounding Si columns 3 11 to 3 33 , and the TiN layer is etched by the RIE method to form the first gate conductor layer.
- the TiN layers 8 1 , 8 2 , 8 3 are formed, and the TiN layers 10 1 , 10 2 , 10 3 which are the second gate conductor layers are formed, and then the N + layers 4 11 to 4 33 are formed. You may. This also applies to the other embodiments according to the present invention.
- the P layer 3 was formed by the epitaxial growth method.
- a P + layer containing acceptor impurities may be formed by the epitaxial crystal growth method.
- the thin single crystal Si layer is a material layer for obtaining the P layer 3 having good crystallinity. As long as it is a material layer for obtaining the P layer 3 having good crystallinity, it may be another single layer or a plurality of material layers.
- the HfO 2 layer is used as the gate insulating layer, but another material layer composed of a single layer or a plurality of layers may be used for each. This also applies to the other embodiments according to the present invention.
- the shape of the Si pillar in a plan view was a circular shape.
- the shape of these Si columns in a plan view may be not only a circular shape and a rectangular shape but also an elliptical shape. This also applies to the other embodiments according to the present invention.
- the source line SL is negatively biased during the erasing operation to extract the hole group in the floating body FB, but the bit line BL is negative instead of the source line SL.
- the erasing operation may be performed by using a bias or by setting the source line SL and the bit line BL to a negative bias. This also applies to the other embodiments according to the present invention.
- a dynamic flash memory which is a memory device using a high-density and high-performance SGT can be obtained.
- Dynamic flash memory cell 100 Si column 101a, 101b: N + layer 102 having a P-type or i-type (intrinsic type) conductive type: Channel regions 103a, 103b, 103a2, 103b2: Gate insulating layer 104a, 104b, 104a2, 104b2: Gate conductor layer 105: Insulation layer for separating two gate conductor layers BL: Bit line SL: Source line PL: Plate line WL: Word line FB: Floating body 1: P layer substrate 1A: N well 1B: P well 2, 4: N + layer 3: P layer 5 11 to 5 33 by the epitaxial growth method: Mask material layer 4 11 to 4 33 : N + layer 3 11 to 3 33 : P layer Si column 6 11 to 6 33 : Hafnium oxide (HfO 2 ) layer 7, 8, 11, 15: SiO 2 layer 8 1 , 8 2 , 8 3 , 10 1 , 10 2 , which is a gate insulating layer.
- HfO 2
- TiN layer which is a gate conductor layer 12 11 to 12 33 : Pore 13 11 to 13 33 : Conductor layer, for example, tungsten W 14 1 , 142 , 14 3 : Conductor layer, for example, copper CU layer.
- CL 11 to CL 33 Memory cell SL 1 to SL 3 : Source line BL 1 to BL 3 : Bit line PL 1 to PL 3 : Plate line WL 1 to WL 3 : Word line 1110a, 1110b: DRAM memory cell without capacitor 1100: SOI substrate 1101: SiO 2 film 1102 of SOI substrate: Floating Body 1103: Source N + Layer 1104: Drain N + 1105: Gate conductive layer 1106: Hole 1107: Inverted layer, electron channel 1108: Pinch-off point 1109: Gate oxide film
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Abstract
Description
CFB = CWL + CBL + CSL (1)
で表される。したがって、書込み時にワード線電圧VWLが振幅すると、メモリセルの記憶ノード(接点)となるフローティングボディ1102の電圧も、その影響を受ける。その様子を図16(B)に示している。書込み時にワード線電圧VWLが0VからVProgWLに上昇すると、フローティングボディ1102の電圧VFBは、ワード線電圧が変化する前の初期状態の電圧VFB1からVFB2へのワード線との容量結合によって上昇する。その電圧変化量ΔVFBは、
ΔVFB = VFB1 - VFB2
= CWL / (CWL + CBL + CSL) × CProgWL (2)
で表される。
ここで、
β= CWL / (CWL + CBL + CSL) (3)
で表され、βをカップリング率と呼ぶ。このようなメモリセルに置いて、CWLの寄与率が大きく、例えば、CWL:CBL:CSL=8:1:1である。この場合、β=0.8となる。ワード線が、例えば、書込み時の5Vから、書込み終了後に0Vになると、ワード線とフローティングボディ1102との容量結合によって、フローティングボディ1102が、5V×β=4Vも振幅ノイズを受ける。このため、書込み時のフローティングボディ1102“1”電位と“0”電位との電位差マージンを十分に取れない問題点があった。
基板上に、前記基板に対して、垂直方向に立つか、または水平方向に伸延する半導体母体と、
前記半導体母体の両端にある第1の不純物層と、第2の不純物層と、
前記第1の不純物層と前記第2の不純物層の間の前記半導体母体の側面の一部または全てを囲こみ、前記第1の不純物層に接する、または、近接した第1のゲート絶縁層と、
前記半導体母体の側面の一部または全てを囲み、前記第1のゲート絶縁層に繋がり、且つ前記第2の不純物層に接する、または、近接した第2のゲート絶縁層と、(同上)
前記第1のゲート絶縁層を覆う第1のゲート導体層と、
前記第2のゲート絶縁層を覆う第2のゲート導体層と、
前記第1のゲート導体層と、前記第2のゲート導体層との間にある第1の絶縁層と、
前記第1の不純物層に接続した第1の配線導体層と、
前記第2の不純物層に接続した第2の配線導体層と、
前記第1のゲート導体層に接続した第3の配線導体層と、
前記第2のゲート導体層に接続した第4の配線導体層と、を有し、
前記半導体母体が前記第1のゲート絶縁層で覆われた第1のチャネル半導体層と、前記第2のゲート絶縁層で覆われた第2のチャネル半導体層と、からなるチャネル半導体層を有し、
前記チャネル半導体層側面全体が、前記第1のゲート絶縁層と、前記第2のゲート絶縁層とにより、または、前記第1のゲート絶縁層と、前記第2のゲート絶縁層を含む絶縁材料層で囲まれており、
前記1の配線導体層と、前記2の配線導体層と、前記3の配線導体層と、前記4の配線導体層と、に印加する電圧を制御して、前記第1のチャネル半導体層と前記第2のチャネル半導体層との第1の境界領域、又は第1の不純物層と第1のチャネル半導体層との第2の境界領域、または、第2の不純物層と第2のチャネル半導体層との第3の境界領域で、前記第1の不純物層と前記第2の不純物層との間に流す電流でインパクトイオン化現象を発生させる動作と、発生させた電子群と正孔群の内、前記電子群を、前記第1の不純物層、または前記第2の不純物層から、除去する動作と、前記正孔群の一部または全てを、前記第1のチャネル半導体層と前記第2のチャネル半導体層との、いずれか、または両方に残存させる動作とを行って、メモリ書き込み動作を行い、
前記第1の配線導体層と、前記第2の配線導体層と、前記第3の配線導体層と、前記第4の配線導体層とに印加する電圧を制御して、前記第1の不純物層と、前記第2の不純物層との、片方、もしくは、両方から、前記正孔群のうちの残存正孔群を抜きとり、メモリ消去動作を行うことを特徴とする。
前記ソース線と、前記ビット線と、前記第1の駆動制御線と、前記ワード線とに印加する電圧により、選択的に前記メモリ消去動作および前記メモリ書き込み動作を行うことを特徴とする。
ことを特徴とする。
前記第1のゲート容量が、前記第2のゲート容量よりも大きいことを特徴とする。
前記メモリ消去動作が開始されると、前記第2の不純物層は、前記第2のチャネル半導体層よりも低電圧となり、前記第2の不純物層と、前記第2のチャネル半導体層との間の、前記第2の不純物層と、前記第2のチャネル半導体層とによるPN接合が順バイアスとなり、前記正孔群を前記第2のチャネル半導体層から前記第2の不純物層へ引き去る正孔群除去動作と、
続いて、前記第2の不純物層が、前記第2のチャネル半導体層よりも高電圧となり、前記第2のPN接合が逆バイアスとなり、前記正孔群の除去が停止する除去正孔群除去停止動作と、により、前記メモリ消去動作が行われることを特徴とする。
垂直方向において、前記基板上の前記第1の不純物層と、
前記第1の不純物層上の前記第1のチャネル半導体層と、
前記第1のチャネル半導体層上の前記第2のチャネル半導体層と、
前記第2のチャネル半導体層上の前記第2の不純物層と、
前記第1のチャネル半導体層を囲んだ前記第1のゲート絶縁層と、
前記第2のチャネル半導体層を囲んだ前記第2のゲート絶縁層と、
前記第1のゲート絶縁層を囲んだ前記第1のゲート導体層と、
前記第2のゲート絶縁層を囲んだ前記第2のゲート導体層と、
前記第1のゲート導体層と、前記第2のゲート導体層との間にある前記第1の絶縁層と、を有することを特徴とする。
前記半導体母体は前記第2の不純物ウェル層の上に基板に垂直に立つかまたは水平方向に延伸することを特徴とする。
前記消去動作時に前記P型第2の不純物ウェル層に負バイアスが印加することを特徴とする。
図1~図4を用いて、本発明の第1実施形態に係るダイナミック フラッシュ メモリセルの構造と動作メカニズムを説明する。図1を用いて、ダイナミック フラッシュ メモリセルの構造を説明する。そして、図2を用いてデータ消去メカニズムを、図3を用いてデータ書き込みメカニズムを、図4を用いてデータ書き込みメカニズムを説明する。
(特徴1)
本実施形態のダイナミック フラッシュ メモリセルでは、ソース、ドレインとなるN+層101a、101b、チャネル領域102、第1のゲート絶縁層103a、第2のゲート絶縁層103b、第1のゲート導体層104a、第2のゲート導体層104bが、全体として柱状に形成される。また、ソースとなるN+層101aはソース線SLに、ドレインとなるN+層101bはビット線BLに、第1のゲート導体層104aはプレート線PLに、第2のゲート導体層104bはワード線WLに、それぞれ接続している。プレート線PLが接続された、第1のゲート導体層104aのゲート容量は、ワード線WLが接続された、第2のゲート導体層104bのゲート容量よりも、大きくなるような構造を特徴としている。本ダイナミック フラッシュ メモリセルでは、垂直方向に第1のゲート導体層と、第2のゲート導体層が、積層されている。このため、プレート線PLが接続された、第1のゲート導体層104aのゲート容量が、ワード線WLが接続された、第2のゲート導体層104bのゲート容量よりも、大きくなるような構造にしても、平面視において、メモリセル面積を大きくさせない。これによりダイナミック フラッシュ メモリセルの高性能化と高集積化が同時に実現できる。
図3(D)に示すように、書込み動作時には、ソース線SL側のプレート線PLに接続された第1のゲート導体層104aを有する第1のNチャネルMOSトランジスタは線形領域で動作させ、ドレインとなるN+層101b側に配設された、ワード線WLの接続された第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタは飽和領域で動作させる。これにより、このワード線WLの接続された第2のゲート導体層104bの直下に全面に形成された反転層407bは、第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタの実質的なドレインとなる。これにより、直列接続された第1のゲート導体層104aを有する第1のNチャネルMOSトランジスタと、第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタとの間の電界は最大となり、この領域でインパクトイオン化が生じ、電子・正孔対が生成される。このように、インパクトイオン化発生場所を直列接続された第1のゲート導体層104aを有する第1のNチャネルMOSトランジスタと、第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタ間のチャネルに設定できる。
書込み動作時には、ソースとなるN+層101a側に配設された、プレート線PLの接続された第1のゲート導体層104aを有する第1のNチャネルMOSトランジスタは線形領域で動作させ、ドレインとなるN+層101b側に配設された、ワード線WLの接続された第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタは飽和領域で動作させ、それにより、発生する反転層107bは、ドレインとなるN+層101bから延びた実質的なドレイン部として働く。その結果、ソース側インパクトイオン化現象で電界強度が、直列接続された2つのゲート導体層である、プレート線PLの接続された第1のゲート導体層104aと、ワード線WLの接続された第2のゲート導体層104bとの間で、最大になる。この動作メカニズムを用いたソースサイドインジェクション型のフラッシュメモリはある。このフラッシュメモリの書込みには、インパクトイオン化現象で発生する熱電子として、酸化膜の障壁を乗り越えて、浮遊ゲートに電子を注入するための3.9eV以上のエネルギーが必要である。しかし、ダイナミック フラッシュ メモリの書込みに置いては、正孔群のみをチャネル領域102に蓄積すれば良いため、フラッシュメモリの書込みよりも低電界で良い。その結果、インパクトイオン化現象を書込みの動作メカニズムとして用いた、フラッシュメモリよりも、多ビット同時に書込みを行うことができ、より書込みの高速化と低消費電力化が実現できる。
本発明の第1実施形態に係るダイナミック フラッシュ メモリセルの書込み動作時のチャネル領域102の電位が上昇して行くのに伴って、ワード線WLの接続された第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタと、プレート線PLの接続された第1のゲート導体層104aを有する第1のNチャネルMOSトランジスタの、しきい値電圧が低下する。従って、このしきい値電圧の低下に伴い、書込み時ワード線WLの電圧を低下させて行くことができる。また、書込み時にチャネル領域102に発生した正孔が蓄積されて行くに従って、正帰還が掛かり、ページ書込み動作が加速される。これにより、データ書き込み時間の短縮化が図られる。
本発明の第1実施形態に係るダイナミック フラッシュ メモリセルの書込み動作時のチャネル領域102の電位が上昇して行くのに伴って、書込み動作時に反転層がSi柱100のチャネル領域102の外周部に形成される。これにより、常時固定電圧が印加されているプレート線PLからの電界は遮蔽される。これにより、チャネル領域102内の正孔群の保持特性が向上する。
本発明の第1実施形態に係るダイナミック フラッシュ メモリセルの書込み動作時のチャネル領域102の電位が上昇して行くのに伴って、第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタを飽和領域で動作させることを維持しながら、書込み開始時のワード線WLの初期電圧は、低下させることが出来る。この結果、書込み終了時にワード線WL電圧が、0Vにリセットされても、第2のゲート導体層104bが容量結合する、フローティングボディ100の電位を引き下げる影響が減少する。これは、ダイナミック フラッシュ メモリセルの動作マージンの拡大による、安定な動作に繋がる。
本発明の第1実施形態に係るダイナミック フラッシュ メモリセルの書込み動作時に引き起こさせる、インパクトイオン化現象で、電子・正孔対以外にフォトンが発生する。発生したフォトンは、Si柱100の第1のゲート導体層104aと第2のゲート導体層104bとで反射を繰り返し、Si柱100の垂直方向に進んで行く。この際に、プレート線PLの接続する第1のゲート導体層104aは、書込み時に発生したフォトンが、水平方向にある隣接メモリセルのデータを破壊しないように、フォトンに対して、遮蔽効果がある。
本発明の第1実施形態に係るダイナミック フラッシュ メモリセルのプレート線PLの接続する第1のゲート導体層104aの役割に注目すると、以下(1)~(5)の5つある。
(1) ダイナミック フラッシュ メモリセルが書込み、読出し動作をする際に、ワード線WLの電圧が上下に振幅する。この際に、プレート線PLは、ワード線WLとチャネル領域102との間の容量結合比を低減させる役目を担う。この結果、ワード線WLの電圧が上下に振幅する際の、チャネル領域102の電圧変化の影響を著しく抑えることができる。これにより、論理“0”と“1”を示すワード線WLのSGTトランジスタのしきい値電圧差を大きくすることが出来る。これは、ダイナミック フラッシュ メモリセルの動作マージンの拡大に繋がる。
(2) ダイナミック フラッシュ メモリセルが消去、書込み、読出し動作をする際に、プレート線PLが接続された、第1のゲート導体層104aと、ワード線WLが接続された第2のゲート電極104bと、の両者が、SGTトランジスタのゲートとして働く。ビット線BLからソース線SLに電流が流れる際に、SGTトランジスタの短チャネル効果(Short Channel Effect)を抑えることができる。このように、プレート線PLの接続された第1のゲート導体層104aにより、短チャネル効果が抑止される。これにより、データ保持特性の向上が図られる。
(3) ダイナミック フラッシュ メモリセルの書込み動作が開始されると、チャネル領域102へ徐々に正孔群が貯まり、プレート線PLを有する、第1のMOSトランジスタと、ワード線WLを有する、第2のMOSトランジスタのしきい値電圧は低下する。この際に、プレート線PLを有する、第1のMOSトランジスタのしきい値電圧が低下することによって、書込み動作時のインパクトイオン化現象を助長する。これにより、プレート線PLは、書込み時に正帰還を働かせて、書込み動作の高速化が図られる。
(4) “1”書込みを行った、ダイナミック フラッシュ メモリセルにおいて、プレート線PLを有する、第1のMOSトランジスタのしきい値電圧が低下している。この結果、プレート線PLに正バイアスを印加すると、常時、プレート線PLに繋がる第1のゲート導体層104a直下には、反転層が形成される。この結果、プレート線PLに繋がる第1のゲート導体層104a直下に形成された、反転層に溜まる電子層が、導体電波シールド層となる。これにより、“1”書込みを行った、ダイナミック フラッシュ メモリセルは、その周辺からの外乱ノイズから、遮蔽される。
(5) ダイナミック フラッシュ メモリセルの書込み動作時に、インパクトイオン化現象で、フォトンが発生する。発生したフォトンは、第1のゲート導体層104aと第2のゲート導体層104bとで反射を繰り返し、Si柱100の垂直方向に進んで行く。この際に、プレート線PLは、書込み時に発生したフォトンが、水平方向にある隣接メモリセルのデータを破壊しないように、フォトンに対して、光遮蔽効果がある。
図5(A)、図5(B)を用いて、第2実施形態を説明する。
第1実施形態では、図5(A)に示すように、インパクトイオン化がプレート線PLの接続された第1のゲート導体層104aを有する第1のNチャネルMOSトランジスタのワード線WLに隣接した領域で生じる。これに対し、本実施形態では、ワード線WLの接続された第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタのドレインとなるN+層101b近傍でインパクトイオン化が生じる。これにより、第1実施形態と同じく、ダイナミク フラッシュ メモリ動作ができる。
図6に示す構造図を用いて、第3実施形態を説明する。
第1実施形態では、図1に示すように、ソースとなるN+層101a側に配設された、プレート線PLの接続された第1のゲート導体層104aを有する第1のNチャネルMOSトランジスタと、ドレインとなるN+層101b側に配設された、ワード線WLの接続された第2のゲート導体層104bを有する第2のNチャネルMOSトランジスタとを直列接続していた。本実施形態によれば、図6に示すように、Si柱100に対して、ワード線WLとプレート線PLとの接続位置関係は図1に示す構造に対して上下逆になっている。また、図6に示したように、それぞれのゲート長を変えて、第1のゲート導体層104a2のゲート長を、第2のゲート導体層104b2のゲート長よりも長くし、プレート線PLが接続された、第2のゲート導体層104b2のゲート容量は、ワード線WLが接続された、第1のゲート導体層104a2のゲート容量よりも、大きくなるような構造を特徴としている。
図7(A)~図7(M)を参照して、第4実施形態に係るダイナミック フラッシュメモリの製造方法を説明する。それぞれの図において、(a)は平面図、(b)は(a)のX-X’線に沿う断面構造図、(c)はY-Y’線に沿う断面構造図を示す。なお、本実施形態では、3行×3列の9個のメモリセルよりなるメモリセル領域を形成する場合について説明する。
(特徴1)
本実施形態では、図7(A)~図7(F)に示すように、P層基板1上部にN+層2を形成し、次に、エピタキシャル成長法によりP層3を形成し、エピタキシャル成長したP層3上部にN+層4を形成し、N+層4の上部にマスク材料層を堆積し、Si柱を形成する領域にパターニングしたマスク材料層511~533を残し、RIE(Reactive Ion Etching)法によりエッチングして、Si柱を形成する。次に、マスク材料層511~533で覆われた領域を残し、エピタキシャル成長したP層3まで、例えばRIE(Reactive Ion Etching)法によりエッチングして、N+層411~433を上部に有するP層Si柱311~333を形成する。これにより、上下にN+層2、411~433を含むP層Si柱311~333を同時に形成することが出来る。これは、本ダイナミック フラッシュ メモリの製造の簡略化に繋がる。
本実施形態では、例えば、ALD(Atomic Layer Deposition)法によりゲート絶縁層となるハフニウム酸化(HfO2)層611~633をSi柱311~333を囲んで形成する。次に、SiO2層7を被覆した後にHfO2層611~633を覆って第1のゲート導体層となるTiN層を形成する。そして、RIE法によりTiN層をエッチングして第1のゲート導体層であるTiN層81、82、83を形成する。この第1のゲート導体層であるTiN層81、82、83は、プレート線PLとなる。これにより、Si柱311~333間の長さを最小加工寸法Fとすると4F2の1セル領域UCが形成される。
図8(A)~(E)を参照して、第5実施形態に係るダイナミック フラッシュ回路のブロック消去動作を説明する。
ブロック消去のために選択されたメモリブロックのソース線SL1~SL3には、消去電圧VERAが印加される。この結果、選択ブロック内の各メモリセルのフローティングボディのチャネル領域102に蓄積された論理記憶データ“1”および“0”が全て“0”となる。消去状態“0”のチャネル領域102の電位は、VERA+Vbとなる。ここで、Vbは、ソース線SLとなるN+層とチャネル領域102との間のPN接合のビルトイン電圧である。チャネル領域102が、負バイアスされると、バックバイアス効果によって、ワード線WLの入力している第2のNチャネルMOSトランジスタのしきい値電圧が上昇する。これにより、ブロック消去動作が容易に実現できる。
図9(A)~(C)を参照して、第6実施形態に係るダイナミック フラッシュ回路のページ書込み動作を説明する。
ページ書込み動作が開始されると、“1”を書込むビット線BL2には、VProgBLが印加され、書込みを行わず、消去状態“0”を維持するビット線BL1とBL3には、VSSが印加される。メモリセルCL22に置いて、その接続される、ビット線BL2は、VProgBLであり、ワード線WL2は、VProgWLであり、プレート線PL2は、VProgPLであるため、ワード線WL2とプレート線PL2の入力する2層ゲートの中間でソースサイドインパクトイオン化現象が起こる。その結果、メモリセルCL22のフローティングボディのチャネル領域102にソースサイドインパクトイオン化現象で発生した電子・正孔対の内、チャネル領域102の多数キャリアである正孔が蓄積され、チャネル領域102の電圧は、Vbまで上昇して、“1”書込みが行われる。ここで、Vbは、ソース線SLが接続されるソースとなるN+層とチャネル領域102間のPN接合である。チャネル領域102が、正バイアスされると、バックバイアス効果によって、ワード線WLが入力する第2のNチャネルMOSトランジスタのしきい値電圧が低下する。これにより、同一選択ページで“1”書込みを行わず、消去状態を保つメモリセルCL21とCL23に接続されるビット線BL1とBL3には、それぞれVSSが印加されているため、メモリセルCL21とCL23に置いて、そのドレインからソースへの電流が流れず、ソースサイドインパクトイオン化現象は起こらず、消去状態“0”の論理記憶データが維持される。
図10(A)~(C)を参照して、第7実施形態に係るダイナミック フラッシュ回路のページ読出し動作を説明する。
ソース線SL1~SL3には、VSSが印加され、ビット線BL1~BL3には、VReadBLが印加される。ここで、例えば、VSSは、0Vであり、VReadBLは、1Vである。また、ページ読出しを行う選択ワード線WL2には、VReadWLが、印加される。ここで、例えば、VReadWLは、2Vである。また、プレート線PL1~PL3には、ページ書込みの選択/非選択の如何に関わらず、VReadPLが印加される。ここで、例えば、VReadPLは、2Vである。このように信号線の電圧設定が制御されることにより、ページ読出しが行われる。チャネル領域102の電位が、VERA+Vbの消去状態“0”のメモリセルでは、しきい値電圧が高いため、メモリセル電流が流れず、ビット線BLは放電せずにVReadBLを保つ。一方、チャネル領域102の電位が、Vbの書込み状態“1”のメモリセルでは、しきい値電圧が低いため、メモリセル電流が流れ、ビット線BLは放電し、VReadBLからVSSへと変化する。この2つのビット線BLの電位状態をセンスアンプで読み取り、メモリセル内の論理記憶データの“1”と“0”を判定する(図示せず)。
ページ読出し動作が開始されると、フローティングボディFBの電位が、VERA+Vbの消去状態“0”のメモリセルでは、しきい値電圧が高いため、メモリセル電流が流れず、ビット線は放電せずにVReadBLを保つ。一方、フローティングボディFBの電位が、Vbの書込み状態“1”のメモリセルでは、しきい値電圧が低いため、メモリセル電流が流れ、ビット線は放電し、VReadBLからVSSへと変化する。この2つのビット線電位状態をセンスアンプで読み取る。これにより、メモリセル内の論理記憶データの“1”と“0”を判定することができる。
図11(A)~(C)を参照して、第8実施形態に係るダイナミック フラッシュ回路のブロックリフレッシュ動作を説明する。
図11(A)、図11(B)に示すように、リフレッシュを行う選択メモリブロックのソース線SL1~SL3には、VSSが印加され、ビット線BL1~BL3には、VRefreshBLが印加される。ここで、例えば、VSSは、0Vであり、VRefreshBLは、3Vである。プレート線PL1~PL3には、ブロック消去選択の有無に関わらず、固定の電圧VRefreshPLが印加されているが、選択されたブロックのプレート線PL1~PL3には、VRefreshPLが印加され、非選択ブロックのプレート線PL1~PL3には、VSSが印加されても良い。また、リフレッシュを行うメモリブロックのワード線WL1~WL3には、VRefreshWLが印加される。ここで、例えば、VRefreshPLは、2Vであり、VRefreshWLは、3Vである。このように信号線の電圧設定が制御されることにより、メモリセルのフローティングボディのチャネル領域102に蓄積された論理記憶データ“1”に置いて、プレート線PLが接続された第1のNチャネルMOSトランジスタおよびワード線WLが接続された第2のNチャネルMOSトランジスタのしきい値電圧が低いため、それぞれの印加電圧がページ書込み電圧よりも低い電圧のVRefreshWLとVRefreshPLであっても、メモリセル電流が流れ、2つのゲート間でソースサイドインパクトイオン化現象を起こし、発生された正孔をチャネル領域102に蓄積する。この結果、書込み状態“1”のメモリセルのメモリブロック単位のリフレッシュが行われる。図11(C)に、ブロックリフレッシュ時の各主要ノード接点の電圧条件例を纏めている。
ブロックリフレッシュ動作が開始されると、メモリセルのフローティングボディのチャネル領域102に蓄積された論理記憶データ“1”に置いて、プレート線PLが接続された第1のNチャネルMOSトランジスタおよびワード線WLが接続された第2のNチャネルMOSトランジスタのしきい値電圧が低いため、それぞれの印加電圧がページ書込み電圧よりも低い電圧のVRefreshWLとVRefreshPLであっても、メモリセル電流が流れ、2つのゲート間でソースサイドインパクトイオン化現象を起こし、発生された正孔をフローティングボディのチャネル領域102に蓄積する。この結果、書込み状態“1”のメモリセルのメモリブロック単位のリフレッシュが行われる。
図12(A)~(C)を参照して、第9実施形態に係るダイナミック フラッシュ回路のページ消去動作を説明する。
図12(A)、図12(B)に示すように、ページ消去動作が始まると、ページ消去するメモリセルに接続するプレート線PL以外のプレート線PLは、常時印加されている固定電圧からVSSに低下する。プレート線PLの接続されるゲート容量は大きいため、“1”と“0”のデータを記憶しているメモリセルのフローティングボディFBは、容量結合により、引き下げられる。この結果、ページ消去によって、既に書込みされている“1”データの書換えが起こらないように保護される。そして、ページ消去されるメモリセルに接続されるプレート線PL2のみにVPageErasePLが印加される。VPageErasePLは、例えば、2Vである。この時、ページ消去されるメモリセルに接続されるワード線WL2には、VPageEraseWLが印加されるが、VPageEraseWLは、VSSであり、例えば、0Vである。また、ソース線SL1~SL3には、VERAPageが印加される。VERAPageは、ブロック消去のビット線印加電圧VERAよりも、高い電圧で設定される。例えば、VERAは、-3Vであるのに対して、VERAPageは、-1Vである。これは、ページ消去を行う同一ブロック内で既に“1”書込みと“0”消去維持になっているメモリセルのデータがページ消去によって、書換えが起こらないための保護である。
ページ消去動作が開始されると、ページ消去するメモリセルに接続するプレート線PL以外のプレート線PLは、常時印加されている固定電圧からVSSに低下する。プレート線PLの接続されるゲート容量は大きいため、“1”と“0”のデータを記憶しているメモリセルのフローティングボディFBは、容量結合により、引き下げられる。この結果、ページ消去によって、既に書込みされている“1”データの書換えが起こらないように保護される。そして、ページ消去されるメモリセルに接続されるプレート線PL2のみにVPageErasePLが印加される。また、ビット線BL1~BL3には、VERAPageが印加される。これにより、ページ消去を確実に行うことができる。
図13(A)~図13(E)を参照して、第10実施形態に係るダイナミック フラッシュメモリの製造方法を説明する。それぞれの図において、(a)は平面図、(b)は(a)のX-X’線に沿う断面構造図、(c)はY-Y’線に沿う断面構造図を示す。なお、本実施形態では、3行×3列の9個のメモリセルよりなるメモリセル領域を形成する場合について説明する。
第4実施形態では、図7(G)~図7(J)に示すように、ゲート絶縁層になるHfO2層611~633が、Si柱311~333の頂部のN+層411~433と、底部のN+層2の間で繋がって形成されている。これにより、PL線ゲートTiN層81、82、83と、WL線ゲートTiN層101、102、103との、ゲート絶縁層が、同じHfO2層311~333で形成されている。これに対して、本実施形態では、PL線ゲート導体層81、82、83と、WL線ゲート導体層101、102、103と、ゲート絶縁層6、18が、別々に形成される。これにより、例えば、ゲート絶縁層6とゲート絶縁層18の、膜厚、材料を別々に選択して、より効果的にPL線とフローティングボディ間容量CPLを、WL線とフローティングボディ間容量CWLより大きくすることが出来る。これは、より安定なダイナミック フラッシュ メモリ動作に寄与する。
第4実施形態では、図7(I)に示すように、PL線ゲートTiN層81、82、83と、WL線ゲートTiN層101、102、103との層間絶縁層としてSiO2層9が形成される。このSiO2層9の形成は、例えば、図7(H)におけるTiN層81、82、83の形成後、SiO2層を全体に被覆した後、CMP法により、その上面位置が、マスク材料層511~533の上面位置になるまで研摩し、そしてRIEによりエッチバックして形成する。これに対して、本実施形態では、SiO2層9に対応する層間絶縁層を、図13(B)に示すように、HfO2層18を、第2のゲート絶縁層として形成すると同時に、SiO2層9に対応する層間絶縁層として形成している。これにより、製造工程の簡易化が図られる。
図13(C)、図13(D)に示すように、コンタクトホール191、192は内に空孔211、212と、W層201、202とが形成される。これにより、空孔211、212と、W層201、202とが、自己整合で形成される。W層201、202は、SL線のN+層2の領域を低抵抗化して、より安定なダイナミック フラッシュ メモリ動作に寄与する。そして、空孔211、212は、WL線TiN層81、82、83間、及びPL線TiN層101、102、103間の寄生容量を低減できる。この寄生容量の低減は、ダイナミック フラッシュ メモリの動作マージンの拡大に寄与できる。また、空孔211、212と、W層201、202とが、自己整合で形成されることは、ダイナミック フラッシュ メモリの高集積化に寄与する。なお、W層201、202をメモリセル領域に形成せず、メモリセル領域の周辺部にN+層2と接続するSL線金属配線部を形成してもよい。この場合は、W層201、202がある場合と比べて、SL線抵抗は大きくなるが、WL線TiN層81、82、83間、及びPL線TiN層101、102、103間の寄生容量の低減効果は変わらず、且つW層201、202を確実にN+層2に接続させるための製造工程の高精度化の必要がない。このように、W層201、202の形成の有無を、SL線低抵抗化と、製造工程の容易化とを勘案して、選択することができる。
図13(E)に示すN+層411~433、W層1311~1333、Cu層1411~1433の側面間に形成する空孔161、162、は、ビット線BL間の寄生容量を低減できる。これは、より安定なダイナミック フラッシュ メモリ動作に寄与する。
図14を参照して、第11実施形態に係るダイナミック フラッシュメモリのP層基板1内に設ける二層ウェル構造の製造方法を説明する。
本願のダイナミック フラッシュメモリの消去動作は、ソース線SLを負バイアスにする。メモリセル領域のP層基板1内に二層ウェル構造を設けることにより、その他の回路を、この負バイアスから遮蔽することができる。
なお、本発明では、Si柱を形成したが、これ以外の半導体材料よりなる半導体柱であってもよい。このことは、本発明に係るその他の実施形態においても同様である。
〔非特許文献14〕を参照したGIDL(Gate Induced Drain Leakage)電流を用いた、インパクトイオン化現象により、電子・正孔対を発生させ、生成された正孔群でフローティングボディFB内を満たしてもよい。このことは、本発明に係るその他の実施形態においても同様である。
100:P型又はi型(真性型)の導電型を有するSi柱
101a、101b:N+層
102:チャネル領域
103a、103b、103a2、103b2:ゲート絶縁層
104a、104b、104a2、104b2:ゲート導体層
105:2層のゲート導体層を分離するための絶縁層
BL:ビット線
SL:ソース線
PL:プレート線
WL:ワード線
FB:フローティングボディ
1:P層基板
1A:Nウェル
1B:Pウェル
2、4:N+層
3:エピタキシャル成長法によりP層
511~533:マスク材料層
411~433を:N+層
311~333:P層Si柱
611~633:ゲート絶縁層となるハフニウム酸化(HfO2)層
7、8、11、15:SiO2層
81、82、83、101、102、103:ゲート導体層であるTiN層
1211~1233:空孔
1311~1333:導体層、例えば、タングステンW
141、142、143:導体層である、例えば、銅CU層
CL11~CL33:メモリセル
SL1~SL3:ソース線
BL1~BL3:ビット線
PL1~PL3:プレート線
WL1~WL3:ワード線
1110a、1110b:キャパシタを有しない、DRAMメモリセル
1100:SOI基板
1101:SOI基板のSiO2膜
1102:フローティングボディ(Floating Body)
1103:ソースN+層
1104:ドレインN+
1105:ゲート導電層
1106:正孔
1107:反転層、電子のチャネル
1108:ピンチオフ点
1109:ゲート酸化膜
Claims (20)
- 基板上に、前記基板に対して、垂直方向に立つか、または水平方向に伸延する半導体母体と、
前記半導体母体の両端にある第1の不純物層と、第2の不純物層と、
前記第1の不純物層と前記第2の不純物層の間の前記半導体母体の側面の一部または全てを囲こみ、前記第1の不純物層に接する、または、近接した第1のゲート絶縁層と、
前記半導体母体の側面の一部または全てを囲み、前記第1のゲート絶縁層に繋がり、且つ前記第2の不純物層に接する、または、近接した第2のゲート絶縁層と、(同上)
前記第1のゲート絶縁層を覆う第1のゲート導体層と、
前記第2のゲート絶縁層を覆う第2のゲート導体層と、
前記第1のゲート導体層と、前記第2のゲート導体層との間にある第1の絶縁層と、
前記第1の不純物層に接続した第1の配線導体層と、
前記第2の不純物層に接続した第2の配線導体層と、
前記第1のゲート導体層に接続した第3の配線導体層と、
前記第2のゲート導体層に接続した第4の配線導体層と、を有し、
前記半導体母体が前記第1のゲート絶縁層で覆われた第1のチャネル半導体層と、前記第2のゲート絶縁層で覆われた第2のチャネル半導体層と、からなるチャネル半導体層を有し、
前記チャネル半導体層側面全体が、前記第1のゲート絶縁層と、前記第2のゲート絶縁層とにより、または、前記第1のゲート絶縁層と、前記第2のゲート絶縁層を含む絶縁材料層で囲まれており、
前記1の配線導体層と、前記2の配線導体層と、前記3の配線導体層と、前記4の配線導体層と、に印加する電圧を制御して、前記第1のチャネル半導体層と前記第2のチャネル半導体層との第1の境界領域、又は第1の不純物層と第1のチャネル半導体層との第2の境界領域、または、第2の不純物層と第2のチャネル半導体層との第3の境界領域で、前記第1の不純物層と前記第2の不純物層との間に流す電流でインパクトイオン化現象を発生させる動作と、発生させた電子群と正孔群の内、前記電子群を、前記第1の不純物層、または前記第2の不純物層から、除去する動作と、前記正孔群の一部または全てを、前記第1のチャネル半導体層と前記第2のチャネル半導体層との、いずれか、または両方に残存させる動作とを行って、メモリ書き込み動作を行い、
前記第1の配線導体層と、前記第2の配線導体層と、前記第3の配線導体層と、前記第4の配線導体層とに印加する電圧を制御して、前記第1の不純物層と、前記第2の不純物層との、片方、もしくは、両方から、前記正孔群のうちの残存正孔群を抜きとり、メモリ消去動作を行う、
ことを特徴とする半導体メモリ装置。 - 前記メモリ消去動作を行うことにより、前記第1の不純物層と前記第1のチャネル半導体層との間の、第1のPN接合と、前記第2の不純物層と、前記第2のチャネル半導体層との間の、第2のPN接合とを、逆バイアス状態に保持する、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記第1の配線導体層は、ソース線であり、前記第2の配線導体層は、ビット線であり、前記第3の配線導体層と、前記第4の配線導体層との一方がワード線であれば、他方が第1の駆動制御線であり、
前記ソース線と、前記ビット線と、前記第1の駆動制御線と、前記ワード線とに印加する電圧により、選択的に前記メモリ消去動作および前記メモリ書き込み動作を行う、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 平面視において、前記第2の配線導体層は、前記第3の配線導体層と前記第4の配線導体層とに直交している、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記第1のゲート導体層と前記第1のチャネル半導体層との間の第1のゲート容量は、前記第2のゲート導体層と前記第2のチャネル半導体層との間の第2のゲート容量よりも大きい、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記第1のゲート導体層の第1のチャネル長が、前記第2のゲート導体層の第2のチャネル長よりも長いか、前記第1のゲート絶縁層が、前記第2のゲート絶縁層よりも薄いか、前記第1のゲート絶縁層の比誘電率が、前記第2のゲート絶縁層の比誘電率よりも大きいか、の内いずれか、又はこれらを組み合わせて、
前記第1のゲート容量が、前記第2のゲート容量よりも大きい、
ことを特徴とする請求項5に記載の半導体メモリ装置。 - 前記第1の不純物層と前記第2の不純物層は、N型半導体層であり、前記第1のチャネル半導体層と前記第2のチャネル半導体層は、P型半導体層、または中性半導体層であり、
前記メモリ消去動作が開始されると、前記第2の不純物層は、前記第2のチャネル半導体層よりも低電圧となり、前記第2の不純物層と、前記第2のチャネル半導体層との間の、前記第2の不純物層と、前記第2のチャネル半導体層とによるPN接合が順バイアスとなり、前記正孔群を前記第2のチャネル半導体層から前記第2の不純物層へ引き去る正孔群除去動作と、
続いて、前記第2の不純物層が、前記第2のチャネル半導体層よりも高電圧となり、前記第2のPN接合が逆バイアスとなり、前記正孔群の除去が停止する除去正孔群除去停止動作と、により、前記メモリ消去動作が行われる、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記メモリ書き込み動作が開始されると、インパクトイオン化現象で発生した前記正孔群が、前記第1のチャネル半導体層と前記第2のチャネル半導体層に溜まることによる、前記第1のゲート導体層の第1のMOSトランジスタの第1のしきい値電圧と、前記第2のゲート導体層の、第2のMOSトランジスタの第2のしきい値電圧との、低下に合わせて、前記第1のゲート導体層と、前記第2のゲート導体層のいずれかの電圧を低下させる、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記メモリ書き込み動作が開始されると、インパクトイオン化現象で発生した前記正孔群が、前記第1のチャネル半導体層と前記第2のチャネル半導体層に溜まることによる、前記第1のゲート導体層の第1のMOSトランジスタの第1のしきい値電圧と、前記第2のゲート導体層の第2のMOSトランジスタの第2のしきい値電圧と、を低下させることによる、前記ドレイン電極層から前記ソース電極層への電流の増大効果により、前記メモリ書き込み動作に正帰還を発生させ、書き込みを行う、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記メモリ書き込み動作時と、前記メモリ読み出し動作時において、前記駆動制御線に繋がる前記第1のゲート導体層、または第2のゲート導体層とに囲まれた、前記第1のチャネル導体層、または前記第2のチャネル導体層との外周部に、反転層を形成する、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記半導体母体が基板に対して垂直に形成され、
垂直方向において、前記基板上の前記第1の不純物層と、
前記第1の不純物層上の前記第1のチャネル半導体層と、
前記第1のチャネル半導体層上の前記第2のチャネル半導体層と、
前記第2のチャネル半導体層上の前記第2の不純物層と、
前記第1のチャネル半導体層を囲んだ前記第1のゲート絶縁層と、
前記第2のチャネル半導体層を囲んだ前記第2のゲート絶縁層と、
前記第1のゲート絶縁層を囲んだ前記第1のゲート導体層と、
前記第2のゲート絶縁層を囲んだ前記第2のゲート導体層と、
前記第1のゲート導体層と、前記第2のゲート導体層との間にある前記第1の絶縁層と、を有する、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記第1のゲート絶縁層と、前記第2のゲート絶縁層と、が同じ材料よりなる、
ことを特徴とする請求項11に記載の半導体メモリ装置。 - 前記第1のゲート絶縁層と、前記第2のゲート絶縁層と、が異なる材料層よりなり、且つ、前記第1の絶縁層が前記第2のゲート絶縁層と同じ材料層よりなる、
ことを特徴とする請求項11に記載の半導体メモリ装置。 - 前記第1のゲート導体層と、前記第2のゲート導体層に隣接して、第1の空孔を含むか又は前記第1の空孔を含まない第1の絶縁材料層が、前記基板に対して垂直方向に伸延してある、
ことを特徴とする請求項11に記載の半導体メモリ装置。 - 前記第1の絶縁材料層が低誘電率材料よりなる、
ことを特徴とする請求項14に記載の半導体メモリ装置。 - 前記第1の配線導体層、又は前記第2の配線導体層と、の一方又は両方に隣接して、第2の空孔を含むか又は前記第2の空孔を含まない第2の絶縁材料層が、ある、
ことを特徴とする請求項11に記載の半導体メモリ装置。 - 前記第1の絶縁材料層が低誘電率材料よりなる、
ことを特徴とする請求項16に記載の半導体メモリ装置。 - 前記第1の絶縁材料層の底部に第1の導体層があり、前記第1の導体層が前記第1の不純物層に繋がり、水平方向に延びている、
ことを特徴とする請求項13に記載の半導体メモリ装置。 - 前記基板に形成された第1の不純物ウェル層と、前記第1の不純物ウェル層内に形成された第2の不純物ウェル層とをさらに備え、
前記半導体母体は前記第2の不純物ウェル層の上に基板に垂直に立つかまたは水平方向に延伸する、
ことを特徴とする請求項1に記載の半導体メモリ装置。 - 前記基板は、P型半導体であり、前記第1の不純物ウェル層は、N型半導体であり、前記第2の不純物ウェル層は、P型半導体であり、
前記消去動作時に前記P型第2の不純物ウェル層に負バイアスが印加する、
ことを特徴とする請求項19に記載の半導体メモリ装置。
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2024042609A1 (ja) * | 2022-08-23 | 2024-02-29 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置 |
WO2024062551A1 (ja) * | 2022-09-21 | 2024-03-28 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置 |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20220392900A1 (en) * | 2021-03-29 | 2022-12-08 | Unisantis Electronics Singapore Pte. Ltd. | Memory device using semiconductor element and method for manufacturing the same |
WO2023281613A1 (ja) * | 2021-07-06 | 2023-01-12 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置 |
WO2023238370A1 (ja) * | 2022-06-10 | 2023-12-14 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体メモリ装置 |
WO2023242956A1 (ja) * | 2022-06-14 | 2023-12-21 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置 |
WO2023248418A1 (ja) * | 2022-06-23 | 2023-12-28 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置 |
WO2023248415A1 (ja) * | 2022-06-23 | 2023-12-28 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置 |
EP4362623A1 (en) * | 2022-10-24 | 2024-05-01 | National Central University | Memory circuit, dynamic random access memory and operation method thereof |
WO2024089809A1 (ja) * | 2022-10-26 | 2024-05-02 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置の製造方法 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006080280A (ja) * | 2004-09-09 | 2006-03-23 | Toshiba Corp | 半導体装置およびその製造方法 |
JP2008218556A (ja) * | 2007-03-01 | 2008-09-18 | Toshiba Corp | 半導体記憶装置 |
Family Cites Families (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2703970B2 (ja) | 1989-01-17 | 1998-01-26 | 株式会社東芝 | Mos型半導体装置 |
JPH03171768A (ja) | 1989-11-30 | 1991-07-25 | Toshiba Corp | 半導体記憶装置 |
JP3957774B2 (ja) | 1995-06-23 | 2007-08-15 | 株式会社東芝 | 半導体装置 |
JP3808763B2 (ja) | 2001-12-14 | 2006-08-16 | 株式会社東芝 | 半導体メモリ装置およびその製造方法 |
DE10361695B3 (de) * | 2003-12-30 | 2005-02-03 | Infineon Technologies Ag | Transistorstruktur mit gekrümmtem Kanal, Speicherzelle und Speicherzellenfeld für DRAMs sowie Verfahren zur Herstellung eines DRAMs |
TWI333691B (en) * | 2006-05-23 | 2010-11-21 | Ememory Technology Inc | Nonvolatile memory with twin gate and method of operating the same |
JP5078338B2 (ja) | 2006-12-12 | 2012-11-21 | ルネサスエレクトロニクス株式会社 | 半導体記憶装置 |
US8058683B2 (en) * | 2007-01-18 | 2011-11-15 | Samsung Electronics Co., Ltd. | Access device having vertical channel and related semiconductor device and a method of fabricating the access device |
US8188537B2 (en) * | 2008-01-29 | 2012-05-29 | Unisantis Electronics Singapore Pte Ltd. | Semiconductor device and production method therefor |
JP2010283071A (ja) * | 2009-06-03 | 2010-12-16 | Elpida Memory Inc | 半導体装置および半導体装置の製造方法 |
KR102234799B1 (ko) * | 2014-08-14 | 2021-04-02 | 삼성전자주식회사 | 반도체 장치 |
US9831290B2 (en) * | 2016-03-10 | 2017-11-28 | Toshiba Memory Corporation | Semiconductor memory device having local bit line with insulation layer formed therein |
US10269800B2 (en) * | 2017-05-26 | 2019-04-23 | Taiwan Semiconductor Manufacturing Co., Ltd. | Vertical gate semiconductor device with steep subthreshold slope |
CN109461738B (zh) * | 2017-09-06 | 2021-03-26 | 中国科学院微电子研究所 | 半导体存储设备及其制造方法及包括存储设备的电子设备 |
KR102424557B1 (ko) * | 2018-06-08 | 2022-07-22 | 에스케이하이닉스 주식회사 | 반도체 소자, 및 이를 제조하는 방법 |
KR102132196B1 (ko) * | 2018-09-05 | 2020-07-09 | 고려대학교 산학협력단 | 피드백 루프 동작을 이용하는 피드백 전계효과 전자소자 및 이를 이용한 배열 회로 |
KR102118440B1 (ko) * | 2018-09-05 | 2020-06-03 | 고려대학교 산학협력단 | 휘발성 및 비휘발성 동작변환 가능한 피드백 전계효과 배열소자 및 이를 이용한 배열 회로 |
CN113939907A (zh) * | 2019-06-05 | 2022-01-14 | 新加坡优尼山帝斯电子私人有限公司 | 柱状半导体装置的制造方法 |
KR20210081735A (ko) * | 2019-12-24 | 2021-07-02 | 삼성전자주식회사 | 메모리 소자 및 이의 제조 방법 |
JP7433973B2 (ja) * | 2020-02-20 | 2024-02-20 | キオクシア株式会社 | 不揮発性半導体記憶装置及びその製造方法 |
US11985822B2 (en) * | 2020-09-02 | 2024-05-14 | Macronix International Co., Ltd. | Memory device |
US11875947B2 (en) * | 2021-04-12 | 2024-01-16 | Micron Technology, Inc. | Capacitive units and methods of forming capacitive units |
US20230107258A1 (en) * | 2021-10-01 | 2023-04-06 | Besang, Inc. | Structures for Three-Dimensional CMOS Integrated Circuit Formation |
US20230018059A1 (en) * | 2022-06-10 | 2023-01-19 | Changxin Memory Technologies, Inc. | Semiconductor structure and method for forming same |
-
2020
- 2020-12-25 WO PCT/JP2020/048952 patent/WO2022137563A1/ja active Application Filing
- 2020-12-25 CN CN202080108095.2A patent/CN116724354A/zh active Pending
- 2020-12-25 KR KR1020237025279A patent/KR20230124701A/ko unknown
- 2020-12-25 JP JP2021525268A patent/JP7057032B1/ja active Active
-
2021
- 2021-06-15 WO PCT/JP2021/022617 patent/WO2022137607A1/ja active Application Filing
- 2021-06-15 JP JP2022571019A patent/JP7335661B2/ja active Active
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- 2021-12-22 TW TW110148184A patent/TWI781028B/zh active
- 2021-12-24 TW TW110148707A patent/TWI787016B/zh active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006080280A (ja) * | 2004-09-09 | 2006-03-23 | Toshiba Corp | 半導体装置およびその製造方法 |
JP2008218556A (ja) * | 2007-03-01 | 2008-09-18 | Toshiba Corp | 半導体記憶装置 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2024042609A1 (ja) * | 2022-08-23 | 2024-02-29 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置 |
WO2024062551A1 (ja) * | 2022-09-21 | 2024-03-28 | ユニサンティス エレクトロニクス シンガポール プライベート リミテッド | 半導体素子を用いたメモリ装置 |
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