Methods of forming memory devices having protected gate electrodes
First Claim
1. A method of forming an integrated circuit memory device, comprising the steps of:
- patterning a field oxide isolation region at a face of a semiconductor substrate to define an active region therein;
forming a gate electrode of a memory device on the active region;
forming a word line on the field oxide isolation region and on the gate electrode;
forming a first protection layer on an upper surface of the word line;
implanting source and drain region dopants of first conductivity type into the active region, using the first protection layer as an implant mask;
thenetching the field oxide isolation region to expose the face of the substrate, using the first protection layer as an etching mask; and
implanting dopants of first conductivity type into the exposed face of the substrate to define a common source region therein which is electrically coupled to the memory device, using the first protection layer as an implant mask.
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Accused Products
Abstract
Methods of forming memory device having protected gate electrodes include the steps of forming protection layers on gate electrodes, word lines and related structures and then using these protected structures as etching and implantation masks to reliably form semiconductor regions in a substrate. In particular, methods of forming integrated circuit memory devices preferably include the steps of patterning a field oxide isolation region at a face of a semiconductor substrate to define an active region therein and then forming a gate electrode of a memory device on the active region. Word lines are also formed on the gate electrode and on the field oxide isolation region. A first protection layer, comprising a material which can preferably be used as a selective etching mask, is also formed on an upper surface of the word line to protect the word line. The field oxide isolation region, which may be a relatively thick silicon dioxide layer, is then preferably etched to expose the face of the substrate. Here, the etching step is performed using the protected word line as an etching mask.
60 Citations
30 Claims
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1. A method of forming an integrated circuit memory device, comprising the steps of:
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patterning a field oxide isolation region at a face of a semiconductor substrate to define an active region therein; forming a gate electrode of a memory device on the active region; forming a word line on the field oxide isolation region and on the gate electrode; forming a first protection layer on an upper surface of the word line; implanting source and drain region dopants of first conductivity type into the active region, using the first protection layer as an implant mask;
thenetching the field oxide isolation region to expose the face of the substrate, using the first protection layer as an etching mask; and implanting dopants of first conductivity type into the exposed face of the substrate to define a common source region therein which is electrically coupled to the memory device, using the first protection layer as an implant mask. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of forming nonvolatile memory device, comprising the steps of:
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patterning a field oxide isolation region at a face of a semiconductor substrate to define an active region therein; forming first and second floating gate electrodes of respective first and second EEPROM memory cells, on the active region; forming a word line on the field oxide isolation region and on the first and second floating gate electrodes; forming a first protection layer on an upper surface of the word line; implanting source and drain region dopants of first conductivity type into the active region, using the first protection layer as an implant mask;
thenetching the field oxide isolation region to expose the face of the substrate, using the first protection layer as an etching mask; and implanting dopants of first conductivity type into the exposed face of the substrate to define a common source region therein which is electrically coupled to the first and second EEPROM memory cells, using the first protection layer as an implant mask. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method of forming an integrated circuit memory device, comprising the steps of:
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forming a field oxide isolation region at a face of a semiconductor substrate to define an active region therein; forming a gate electrode of a memory device on the active region; forming a word line on the field oxide isolation region and on the gate electrode; forming a first protection layer comprising a material selected from the group consisting of silicon nitride and silicon oxynitride, on an upper surface of the word line; etching the field oxide isolation region to expose the face of the substrate, using the first protection layer as an etching mask that protects the word line; and implanting dopants of first conductivity type into the exposed face of the substrate to define a common source region therein which is electrically coupled to the memory device, using the first protection layer as an implant mask that protects the word line from implant damage. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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24. A method of forming nonvolatile memory device, comprising the steps of:
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forming a field oxide isolation region at a face of a semiconductor substrate to define an active region therein; forming first and second floating gate electrodes of respective first and second EEPROM memory cells, on the active region; forming a word line on the field oxide isolation region and on the first and second floating gate electrodes; forming a first protection layer comprising a material selected from the group consisting of silicon nitride and silicon oxynitride, on an upper surface of the word line; etching the field oxide isolation region to expose the face of the substrate, using the first protection layer as an etching mask that protects the word line; and implanting dopants of first conductivity type into the exposed face of the substrate to define a common source region therein which is electrically coupled to the first and second EEPROM memory cells, using the first protection layer as an implant mask that protects the word line from implant damage. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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Specification