US20020158285A1 - Nonvolatile floating-gate memory devices, and process of fabrication - Google Patents
Nonvolatile floating-gate memory devices, and process of fabrication Download PDFInfo
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- US20020158285A1 US20020158285A1 US10/165,010 US16501002A US2002158285A1 US 20020158285 A1 US20020158285 A1 US 20020158285A1 US 16501002 A US16501002 A US 16501002A US 2002158285 A1 US2002158285 A1 US 2002158285A1
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- 238000004519 manufacturing process Methods 0.000 title description 7
- 239000000758 substrate Substances 0.000 claims description 21
- 230000015654 memory Effects 0.000 claims description 17
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims description 14
- 239000004065 semiconductor Substances 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 6
- 229920005591 polysilicon Polymers 0.000 claims 9
- 229910021332 silicide Inorganic materials 0.000 claims 2
- FVBUAEGBCNSCDD-UHFFFAOYSA-N silicide(4-) Chemical compound [Si-4] FVBUAEGBCNSCDD-UHFFFAOYSA-N 0.000 claims 2
- 239000003989 dielectric material Substances 0.000 claims 1
- 238000010405 reoxidation reaction Methods 0.000 abstract description 14
- 230000014759 maintenance of location Effects 0.000 abstract description 4
- 238000005530 etching Methods 0.000 abstract 1
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000009413 insulation Methods 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- WQJQOUPTWCFRMM-UHFFFAOYSA-N tungsten disilicide Chemical compound [Si]#[W]#[Si] WQJQOUPTWCFRMM-UHFFFAOYSA-N 0.000 description 3
- 229910021342 tungsten silicide Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 2
- 238000005121 nitriding Methods 0.000 description 2
- 238000002161 passivation Methods 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910020781 SixOy Inorganic materials 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007943 implant Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- RJCRUVXAWQRZKQ-UHFFFAOYSA-N oxosilicon;silicon Chemical compound [Si].[Si]=O RJCRUVXAWQRZKQ-UHFFFAOYSA-N 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 150000003376 silicon Chemical class 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
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- 230000000087 stabilizing effect Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
- H01L29/423—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions not carrying the current to be rectified, amplified or switched
- H01L29/42312—Gate electrodes for field effect devices
- H01L29/42316—Gate electrodes for field effect devices for field-effect transistors
- H01L29/4232—Gate electrodes for field effect devices for field-effect transistors with insulated gate
- H01L29/42324—Gate electrodes for transistors with a floating gate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
- H01L29/423—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions not carrying the current to be rectified, amplified or switched
- H01L29/42312—Gate electrodes for field effect devices
- H01L29/42316—Gate electrodes for field effect devices for field-effect transistors
- H01L29/4232—Gate electrodes for field effect devices for field-effect transistors with insulated gate
- H01L29/42324—Gate electrodes for transistors with a floating gate
- H01L29/42328—Gate electrodes for transistors with a floating gate with at least one additional gate other than the floating gate and the control gate, e.g. program gate, erase gate or select gate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66409—Unipolar field-effect transistors
- H01L29/66477—Unipolar field-effect transistors with an insulated gate, i.e. MISFET
- H01L29/66825—Unipolar field-effect transistors with an insulated gate, i.e. MISFET with a floating gate
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B41/00—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates
- H10B41/30—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates characterised by the memory core region
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B41/00—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates
- H10B41/30—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates characterised by the memory core region
- H10B41/35—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates characterised by the memory core region with a cell select transistor, e.g. NAND
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B69/00—Erasable-and-programmable ROM [EPROM] devices not provided for in groups H10B41/00 - H10B63/00, e.g. ultraviolet erasable-and-programmable ROM [UVEPROM] devices
Definitions
- the present invention relates to a process of fabricating floating-gate memory devices, and to a memory device fabricated thereby.
- nonvolatile floating-gate memory devices comprises a sequence of steps commencing with a substrate of semiconductor material (monocrystalline silicon). More specifically, according to a typical fabrication process, a gate oxide layer is grown on the substrate, in which the active areas and any P- and N-wells required according to the process are already defined. A thin tunnel oxide region is possibly grown in the gate oxide layer (as in the case of EEPROM memories). A first polycrystalline silicon layer (poly1) is deposited and patterned to define it in a first, channel width direction on the oxide layers. An intermediate dielectric layer of silicon oxide or ONO—an acronym of silicon Oxide-silicon Nitride-silicon Oxide, is deposited or grown thermally on poly1.
- a second polycrystalline silicon layer (poly2) is deposited on the dielectric layer.
- a tungsten silicide layer is possibly deposited on poly2.
- the stack of poly2, ONO and poly1 layers is self-align etched to define the stacked floating and control gate regions in a second, channel-length direction perpendicular to the first direction.
- the source/drain regions of the cell are implanted.
- a “reoxidation” heat treatment is performed to seal the floating gate region.
- the source and drain regions of peripheral circuit transistors are formed and reoxidized.
- the contacts and interconnecting layer are formed and a passivation layer is deposited.
- the reoxidation step provides for sealing the floating gate region of the cells to prevent direct contact with the outside environment, ensure long-term retention of the charge stored in the region, and so ensure good quality of the memory even in the event of prolonged operation.
- the reoxidation step may also serve other purposes. First, this step helps in stabilizing the tungsten silicide layer which may form part of the control gates of the devices, including both the cells and the circuit transistors. Second, the reoxidation step provides for diffusing in the substrate the normally implanted dopant that determines the electric characteristics of the devices.
- the reoxidation step be made as effective as possible to insure the insulation and charge retention of nonvolatile memories.
- oxinitriding is aimed at eliminating the reverse short channel effect (i.e., the increase in the threshold voltage of short channel MOSFET transistors) generally attributed to an uneven lateral channel profile caused, among other things, by reoxidation resulting in the formation of supersaturated silicon interstitial.
- a process of fabricating floating-gate memory devices More specifically, on a substrate, an insulated control gate region is formed on a floating gate region. Next, an insulating layer of oxynitride is formed on the side of the floating gate region.
- FIG. 1 shows a cross section of a wafer of semiconductor material, in which is formed a memory cell in accordance with the present invention.
- the fabrication process according to the present invention comprises the same initial steps as in known processes. More specifically, the process steps include forming P/N wells in the monocrystalline silicon substrate; growing the field oxide to define the active areas; and forming the isolation regions and/or channel stoppers. Next, an electric continuity region is formed in the substrate and a gate oxide layer is grown. A thin tunnel oxide region is grown in the gate oxide layer.
- a first polycrystalline silicon layer (poly1) is deposited on the oxide structure and is patterned to define it widthwise. Over the patterned poly1 layer, an intermediate dielectric layer of oxide or ONO is deposited or grown.
- a second polycrystalline silicon layer (poly2) is deposited and a tungsten silicide layer is possibly deposited. With this structure, the poly2, ONO and poly1 layers are self-align etched to define, lengthwise, the stacked floating and control gate regions and two sides of the floating gate region (defining it lengthwise) and of the control gate region are exposed.
- the source/drain is implanted in a conventional manner, and reoxidation is performed to seal the floating gate region.
- reoxidation is performed by heat treating the wafer of semiconductor material in an oven or RTP (rapid thermal processing) facility.
- the RTP facility exposes the wafer to batteries of lamps for generating a rapid rise and fall in temperature ranging from 800 to 1000° C., in an environment containing N 2 O, NO or NH 3 , and for a time ranging from a few tens of seconds (RTP treatment) to a few hours (oven treatment).
- the selection transistor relative to the cell.
- the gate regions of the peripheral circuit transistors are formed.
- the source and drain of the transistors are implanted, possibly preceded by a light implant and the formation of oxide spacers, in the case of Light Doped Drain LDD devices.
- a surface reoxidate step is provided which may also be performed in nitrided manner, as described above, to improve the electric characteristics as indicated in the above article by Tsui et al.
- the contacts and the interconnecting layer are formed, and the passivation layer is deposited.
- a P-type substrate 10 contains an N-type source region 11 of the cell, an implanted N-type electric continuity region 12 , an N-type drain/source region 13 defining the drain region of cell 2 and the source region of selection transistor 3 , and an N-type drain region 14 for selection transistor 3 .
- the substrate region 31 between source region 11 and electric continuity region 12 forms the channel of cell 2 , and regions 11 - 14 all face the surface 15 of substrate 10 .
- a gate oxide region 18 of cell 2 incorporating a thin tunnel oxide region 19 is stacked on surface 15 .
- a floating gate region 20 of cell 2 , an interpoly dielectric layer 21 ; and a control gate region 22 of cell 2 are sequentially stacked on the oxide regions 18 and 19 .
- a gate oxide region 25 and a gate region 26 of selection transistor 3 are also stacked on surface 15 .
- An intermediate dielectric layer 30 covers the resultant structure and insulates the various layers.
- thin oxynitride layers 35 are formed on either side of floating gate region 20 and control gate region 22 .
- Layers 35 seal the sides of regions 20 and 22 extending in the channel width direction, i.e., perpendicularly to the plane of the drawing and to the channel length, and as measured between source region 11 and electric continuity region 12 .
- Similar oxynitride layers 36 may be formed in selection transistor 3 and in the circuit transistors (not shown).
- oxinitriding of the floating gate region as described above may be applied to any process of fabricating nonvolatile floating-gate memories, including all EPROM, EEPROM and flash-EEPROM processes.
Abstract
A process of fabricating a floating-gate memory device, the process including the steps of: forming a stack of superimposed layers including a floating gate region, a dielectric region, and a control gate region; and forming an insulating layer of oxynitride to the side of the floating gate region to completely seal the floating gate region outwards and improve the retention characteristics of the memory device. The insulating layer is formed during reoxidation of the sides of the floating gate region, after self-align etching the stack of layers and implanting the source/drain of the cell.
Description
- This application is a division of U.S. patent application Ser. No. 09/548,782, filed Apr. 13, 2000, now pending, which application is incorporated herein by reference in its entirety, and which is a continuation of U.S. patent application Ser. No. 08/792,621, filed Jan. 31, 1997, now abandoned, which application is incorporated herein by reference in its entirety.
- 1. Field of the Invention
- The present invention relates to a process of fabricating floating-gate memory devices, and to a memory device fabricated thereby.
- 2. Description of the Related Art
- As is known, the fabrication of nonvolatile floating-gate memory devices comprises a sequence of steps commencing with a substrate of semiconductor material (monocrystalline silicon). More specifically, according to a typical fabrication process, a gate oxide layer is grown on the substrate, in which the active areas and any P- and N-wells required according to the process are already defined. A thin tunnel oxide region is possibly grown in the gate oxide layer (as in the case of EEPROM memories). A first polycrystalline silicon layer (poly1) is deposited and patterned to define it in a first, channel width direction on the oxide layers. An intermediate dielectric layer of silicon oxide or ONO—an acronym of silicon Oxide-silicon Nitride-silicon Oxide, is deposited or grown thermally on poly1. A second polycrystalline silicon layer (poly2) is deposited on the dielectric layer. A tungsten silicide layer is possibly deposited on poly2. The stack of poly2, ONO and poly1 layers is self-align etched to define the stacked floating and control gate regions in a second, channel-length direction perpendicular to the first direction. Next, the source/drain regions of the cell are implanted. A “reoxidation” heat treatment is performed to seal the floating gate region. Now, the source and drain regions of peripheral circuit transistors are formed and reoxidized. And finally, the contacts and interconnecting layer are formed and a passivation layer is deposited.
- One of the most critical steps in the above process, regardless of the architecture being formed, is the reoxidation step. The reoxidation step, as stated, provides for sealing the floating gate region of the cells to prevent direct contact with the outside environment, ensure long-term retention of the charge stored in the region, and so ensure good quality of the memory even in the event of prolonged operation.
- The reoxidation step may also serve other purposes. First, this step helps in stabilizing the tungsten silicide layer which may form part of the control gates of the devices, including both the cells and the circuit transistors. Second, the reoxidation step provides for diffusing in the substrate the normally implanted dopant that determines the electric characteristics of the devices.
- It is desired that the reoxidation step be made as effective as possible to insure the insulation and charge retention of nonvolatile memories.
- To improve the electric characteristics of transistors, an article entitled “Suppression of MOSFET Reverse Short Channel Effect by N2O Gate Poly Reoxidation Process” by P. G. Y. Tsui, S. H. Tseng, M. Orlowski, S. W. Sun, P. J. Tobin, K. Reid and W. J. Taylor, IEDM 94, 19.5.1, proposes, during final reoxidation of the gate region, to use a gas for nitriding the interface between the silicon substrate and gate oxide, at least in the areas closest to the exposed sides of the transistor. In particular, oxinitriding is aimed at eliminating the reverse short channel effect (i.e., the increase in the threshold voltage of short channel MOSFET transistors) generally attributed to an uneven lateral channel profile caused, among other things, by reoxidation resulting in the formation of supersaturated silicon interstitial.
- It is an object of the present invention to provide a fabrication process enabling improved insulation of the floating gate of nonvolatile floating-gate memory devices.
- According to the present invention, there is provided a process of fabricating floating-gate memory devices. More specifically, on a substrate, an insulated control gate region is formed on a floating gate region. Next, an insulating layer of oxynitride is formed on the side of the floating gate region.
- A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawing.
- FIG. 1 shows a cross section of a wafer of semiconductor material, in which is formed a memory cell in accordance with the present invention.
- In the following description, reference will be made, purely by way of example, to an embodiment of the present process for forming an EEPROM memory cell. Since, however, the oxinitriding step performed during reoxidation and characteristic of the present invention is not limited solely to the fabrication of EEPROM cells, but may also be applied to any process of fabricating memories with floating gate cells, the same also applies to the formation of EPROM and flash-EEPROM memory devices.
- Research and experiments by the present Applicant have now shown that the use of nitriding a gas when reoxidizing the floating gate region of nonvolatile memories provides for forming a thin oxynitride layer contacting the polycrystalline silicon forming the floating gate region. The oxynitride layer of the floating gate provides for improved insulation between the floating gate region of stacked-gate memory cells and the outside environment.
- The fabrication process according to the present invention comprises the same initial steps as in known processes. More specifically, the process steps include forming P/N wells in the monocrystalline silicon substrate; growing the field oxide to define the active areas; and forming the isolation regions and/or channel stoppers. Next, an electric continuity region is formed in the substrate and a gate oxide layer is grown. A thin tunnel oxide region is grown in the gate oxide layer. A first polycrystalline silicon layer (poly1) is deposited on the oxide structure and is patterned to define it widthwise. Over the patterned poly1 layer, an intermediate dielectric layer of oxide or ONO is deposited or grown. A second polycrystalline silicon layer (poly2) is deposited and a tungsten silicide layer is possibly deposited. With this structure, the poly2, ONO and poly1 layers are self-align etched to define, lengthwise, the stacked floating and control gate regions and two sides of the floating gate region (defining it lengthwise) and of the control gate region are exposed.
- At this point, the source/drain is implanted in a conventional manner, and reoxidation is performed to seal the floating gate region. According to one embodiment of the present invention, reoxidation is performed by heat treating the wafer of semiconductor material in an oven or RTP (rapid thermal processing) facility. The RTP facility exposes the wafer to batteries of lamps for generating a rapid rise and fall in temperature ranging from 800 to 1000° C., in an environment containing N2O, NO or NH3, and for a time ranging from a few tens of seconds (RTP treatment) to a few hours (oven treatment). This results in the formation, on the exposed sides of the floating gate and control gate, of a thin layer of oxynitride (SixOyNz), which, by virtue of its excellent insulating properties, provides for optimum sealing of the floating gate region.
- Then, conventional steps are performed for forming the selection transistor relative to the cell. First, the gate regions of the peripheral circuit transistors are formed. Second, the source and drain of the transistors are implanted, possibly preceded by a light implant and the formation of oxide spacers, in the case of Light Doped Drain LDD devices. Next, a surface reoxidate step is provided which may also be performed in nitrided manner, as described above, to improve the electric characteristics as indicated in the above article by Tsui et al. Finally, the contacts and the interconnecting layer are formed, and the passivation layer is deposited.
- The structure of the resulting memory device is illustrated in the accompanying drawing wherein the
memory device 1, the memory cell andrelative sensing transistor 2, and the selection transistor 3 are shown. More specifically, a P-type substrate 10 contains an N-type source region 11 of the cell, an implanted N-typeelectric continuity region 12, an N-type drain/source region 13 defining the drain region ofcell 2 and the source region of selection transistor 3, and an N-type drain region 14 for selection transistor 3. Thesubstrate region 31 betweensource region 11 andelectric continuity region 12 forms the channel ofcell 2, and regions 11-14 all face thesurface 15 ofsubstrate 10. - Now, a
gate oxide region 18 ofcell 2, incorporating a thintunnel oxide region 19 is stacked onsurface 15. Next, a floatinggate region 20 ofcell 2, aninterpoly dielectric layer 21; and a control gate region 22 ofcell 2 are sequentially stacked on theoxide regions gate oxide region 25 and agate region 26 of selection transistor 3 are also stacked onsurface 15. Anintermediate dielectric layer 30 covers the resultant structure and insulates the various layers. - As can be seen, according to the present invention, thin oxynitride layers35 are formed on either side of floating
gate region 20 and control gate region 22.Layers 35 seal the sides ofregions 20 and 22 extending in the channel width direction, i.e., perpendicularly to the plane of the drawing and to the channel length, and as measured betweensource region 11 andelectric continuity region 12. Similar oxynitride layers 36 (dotted line) may be formed in selection transistor 3 and in the circuit transistors (not shown). - The advantages of the process according to the present invention are clear from the above description. In particular, it provides for improved retention of the resulting memory by improving sealing of the floating gate region of the cells. Oxinitriding the floating gate region provides for exploiting the advantages afforded by the improvement of the electric parameters also in the cells. Forming the oxynitride layer also during reoxidation of the selection and circuit transistors, as described in the above-mentioned article, provides for also improving the electric characteristics of the transistors. The process involves no particular technical difficulties or additional fabrication steps, and therefore no appreciable increase in cost.
- Clearly, changes may be made to the process and memory device as described and illustrated herein without, however, departing from the scope of the present invention. In particular, oxinitriding of the floating gate region as described above may be applied to any process of fabricating nonvolatile floating-gate memories, including all EPROM, EEPROM and flash-EEPROM processes.
Claims (15)
1. A memory device comprising:
a floating gate region having sidewalls;
a dielectric region over said floating gate region;
a control gate region over said dielectric region; and
first oxynitride insulating layers on the sidewalls of said floating gate region.
2. The memory device of claim 1 , further comprising second oxynitride insulating layers on sidewalls of said control gate region.
3. The memory device of claim 1 , further comprising:
a substrate of semiconductor material; and
an insulating layer positioned on the substrate and directly below the floating gate region.
4. The memory device of claim 3 , further comprising a source region and a drain region formed in the substrate in areas lateral of a central area below the floating gate region.
5. The memory device of claim 1 wherein the floating gate, dielectric, and control gate regions are part of a memory transistor, the memory device further comprising a selection transistor positioned laterally adjacent to the memory transistor, the selection transistor including a control gate region with sidewalls, and second oxynitride insulating layers on the sidewalls of said control gate region of the selection transistor.
6. The memory device of claim 5 , further comprising:
a substrate of semiconductor material; and
an insulating layer positioned on the substrate and directly below the floating gate region and the control gate region of the selection transistor.
7. The memory device of claim 6 , further comprising first, second, and third doped regions formed in the substrate, the first doped region being positioned laterally adjacent to a first end of the floating gate region, the second doped region being positioned laterally adjacent to a second end of the floating gate region and a first end of the control gate region of the selection transistor, and the third doped region being positioned laterally adjacent to a second end of the control gate region of the selection transistor, the second doped region being shared by the memory and selection transistors.
8. The memory device of claim 1 wherein the control gate region includes a polysilicon layer and a silicide layer formed on the polysilicon layer.
9. A floating-gate memory device, comprising:
an insulating layer on a semiconductor substrate;
a first polysilicon layer positioned over said insulating layer;
a dielectric material layer positioned over said first polysilicon layer;
a second polysilicon layer positioned over said dielectric layer, wherein the first and second polysilicon layers and the dielectric layer are defined to form a gate stack; and
first oxynitride sidewalls positioned on lateral walls of said second polysilicon layer.
10. The memory device of claim 9 , further comprising second oxynitride insulating layers on sidewalls of said first polysilicon layer.
11. The memory device of claim 9 , further comprising:
a substrate of semiconductor material; and
an insulating layer positioned on the substrate and directly below the floating gate region.
12. The memory device of claim 9 , further comprising a source region and a drain region formed in the substrate in areas lateral of a central area below the gate stack.
13. The memory device of claim 9 wherein the gate stack is part of a memory transistor, the memory device further comprising a selection transistor positioned laterally adjacent to the memory transistor, the selection transistor including a control gate region with lateral walls, and second oxynitride sidewalls on the lateral walls of said control gate region of the selection transistor.
14. The memory device of claim 13 , further comprising first, second, and third doped regions formed in the substrate, the first doped region being positioned laterally adjacent to a first end of the gate stack, the second doped region being positioned laterally adjacent to a second end of the gate stack and a first end of the control gate region of the selection transistor, and the third doped region being positioned laterally adjacent to a second end of the control gate region of the selection transistor, the second doped region being shared by the memory and selection transistors.
15. The memory device of claim 9 , further comprising a silicide layer formed on the second polysilicon layer.
Priority Applications (1)
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US10/165,010 US20020158285A1 (en) | 1996-01-31 | 2002-06-06 | Nonvolatile floating-gate memory devices, and process of fabrication |
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Application Number | Priority Date | Filing Date | Title |
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EP96830040A EP0788168A1 (en) | 1996-01-31 | 1996-01-31 | Process of fabricating non-volatile floating-gate memory devices, and memory device fabricated thereby |
EP96830040.0 | 1996-01-31 | ||
US79262197A | 1997-01-31 | 1997-01-31 | |
US09/548,782 US6448138B1 (en) | 1996-01-31 | 2000-04-13 | Nonvolatile floating-gate memory devices, and process of fabrication |
US10/165,010 US20020158285A1 (en) | 1996-01-31 | 2002-06-06 | Nonvolatile floating-gate memory devices, and process of fabrication |
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US09/548,782 Division US6448138B1 (en) | 1996-01-31 | 2000-04-13 | Nonvolatile floating-gate memory devices, and process of fabrication |
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US10/165,010 Abandoned US20020158285A1 (en) | 1996-01-31 | 2002-06-06 | Nonvolatile floating-gate memory devices, and process of fabrication |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US20020175382A1 (en) * | 1998-09-03 | 2002-11-28 | Li Li | Ion-assisted oxidation methods and the resulting structures |
US20060006452A1 (en) * | 2004-07-06 | 2006-01-12 | Samsung Electronics Co., Ltd. | EEPROM device and manufacturing method thereof |
US8320191B2 (en) | 2007-08-30 | 2012-11-27 | Infineon Technologies Ag | Memory cell arrangement, method for controlling a memory cell, memory array and electronic device |
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US11302827B2 (en) * | 2020-01-23 | 2022-04-12 | Nanya Technology Corp. | Semiconductor device with sidewall oxidized dielectric and method for fabricating the same |
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1996
- 1996-01-31 EP EP96830040A patent/EP0788168A1/en not_active Withdrawn
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- 2000-04-13 US US09/548,782 patent/US6448138B1/en not_active Expired - Fee Related
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2002
- 2002-06-06 US US10/165,010 patent/US20020158285A1/en not_active Abandoned
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
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US20020175382A1 (en) * | 1998-09-03 | 2002-11-28 | Li Li | Ion-assisted oxidation methods and the resulting structures |
US6770538B2 (en) | 1998-09-03 | 2004-08-03 | Micron Technology, Inc. | Ion-assisted oxidation methods and the resulting structures |
US20040266213A1 (en) * | 1998-09-03 | 2004-12-30 | Li Li | Ion-assisted oxidation methods and the resulting structures |
US7119033B2 (en) | 1998-09-03 | 2006-10-10 | Micron Technology, Inc. | Ion-assisted oxidation methods and the resulting structures |
US20070059943A1 (en) * | 1998-09-03 | 2007-03-15 | Li Li | Ion-assisted oxidation methods and the resulting structures |
US7371697B2 (en) | 1998-09-03 | 2008-05-13 | Micron Technology, Inc. | Ion-assisted oxidation methods and the resulting structures |
US8492851B2 (en) | 1998-09-03 | 2013-07-23 | Micron Technology, Inc. | Structures including an at least partially reoxidized oxide material |
US8790982B2 (en) | 1998-09-03 | 2014-07-29 | Micron Technology, Inc. | Methods for reoxidizing an oxide and for fabricating semiconductor devices |
US20060006452A1 (en) * | 2004-07-06 | 2006-01-12 | Samsung Electronics Co., Ltd. | EEPROM device and manufacturing method thereof |
US7408230B2 (en) * | 2004-07-06 | 2008-08-05 | Samsung Electronics Co., Ltd. | EEPROM device having first and second doped regions that increase an effective channel length |
US8320191B2 (en) | 2007-08-30 | 2012-11-27 | Infineon Technologies Ag | Memory cell arrangement, method for controlling a memory cell, memory array and electronic device |
US9030877B2 (en) | 2007-08-30 | 2015-05-12 | Infineon Technologies Ag | Memory cell arrangement, method for controlling a memory cell, memory array and electronic device |
Also Published As
Publication number | Publication date |
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EP0788168A1 (en) | 1997-08-06 |
US6448138B1 (en) | 2002-09-10 |
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