Methods of forming implant regions relative to transistor gates
AssigneeMicron Technology, Inc.
InventorPhong N. Nguyen
Life of this patent
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Abstract
The invention includes methods of forming implant regions between and/or under transistor gates. In one aspect, a pair of transistor gates is partially formed, and a layer of conductive material is left extending between the transistor gates. A dopent is implanted through the conductive material to form at least one implant region between and/or beneath the partially formed transistor gates, and subsequently the conductive material is removed from between the gates. The gates can be incorporated into various semiconductor assemblies, including, for example, DRAM assemblies.
Claims61
A method of forming conductively-doped regions relative to a pair of adjacent transistor gates, comprising:
- partially forming a pair of adjacent transistor gates over a semiconductor substrate, the partially-formed transistor gates having a layer of conductive material from the gate extending between them and joining the gates;
- forming at least one conductively-doped region between the partially-formed adjacent transistor gates;
- and
- after forming the at least one conductively-doped region, removing the layer of conductive material from between the adjacent transistor gates.
A method of forming angled implants relative to a pair of adjacent transistor gates, comprising:
- forming a gate stack over a substrate, the gate stack comprising a layer of electrically conductive material;
- etching only partially through the layer of electrically conductive material to leave an unetched remaining portion of the electrically conductive material and to partially form a pair of adjacent transistor gates from the gate stack;
- implanting at least one dopant at an angle other than 0° relative to vertical to form pocket implant regions under the partially formed adjacent transistor gates;
- and
- after the implanting, etching through the remaining portion of the electrically conductive material and completing formation of the pair of adjacent transistor gates.
A method of forming angled implants relative to a pair of adjacent transistor gates, comprising:
- forming a gate stack over a substrate, the gate stack comprising a first layer;
- etching only partially through the first layer to leave an unetched remaining portion of the first layer and to partially form a pair of adjacent transistor gates from the gate stack, the partially formed transistor gates have sidewall edges;
- forming a second layer along the sidewall edges of the partially formed pair of adjacent transistor gates;
- after forming the second layer, implanting at least one dopant at an angle other than 0° relative to vertical to form pocket implant regions under the partially formed adjacent transistor gates;
- and
- after the implanting, etching through the remaining portion of the first layer and completing formation of the pair of adjacent transistor gates.
A method of forming a DRAM assembly, comprising:
- forming a gate stack over a substrate, the gate stack comprising a layer of electrically conductive material;
- etching only partially through the layer of electrically conductive material to leave an unetched remaining portion of the electrically conductive material and to partially form a pair of adjacent transistor gates from the gate stack;
- one of the adjacent transistor gates ultimately being incorporated into a first DRAM cell and the other of the adjacent transistor gates ultimately being incorporated into a second DRAM cell;
- forming pocket implant regions under the partially formed transistor gates;
- after the forming the pocket implant regions, etching through the remaining portion of the electrically conductive material, and completing formation of the pair of adjacent transistor gates;
- forming a heavily doped source/drain region shared by the adjacent transistor gates;
- forming first and second data storage devices for the first and second DRAM cells, respectively;
- and
- forming a bitline contact in electrical with the source/drain region.
A method of forming a pair of adjacent memory cells sharing a common bitline, comprising:
- forming a gate stack over a substrate, the gate stack comprising a layer of electrically conductive material;
- etching only partially through the layer of electrically conductive material to leave an unetched remaining portion of the electrically conductive material and to partially form a pair of adjacent transistor gates from the gate stack;
- one of the adjacent transistor gates ultimately being incorporated into a first transistor and the other of the adjacent transistor gates ultimately being incorporated into a second transistor;
- defining three source/drain region locations relative to the partially formed transistor gates, a first of the source/drain region locations being associated with only the first transistor;
- a second of the source/drain region locations being shared by the first and second transistors, and a third of the source/drain region locations being associated with only the second transistor;
- forming a mask over the first and third source/drain region locations;
- while the mask is over the first and third source/drain region locations, implanting at least one dopant at an angle other than 0° relative to vertical to form pocket implant regions under the partially formed transistor gates;
- after the implanting, removing the mask, etching through the remaining portion of the electrically conductive material, and completing formation of the pair of adjacent transistor gates;
- forming first, second and third heavily doped source/drain regions at the first, second and third source/drain region locations, respectively;
- forming first and second data storage devices in electrical connection with the first and third source/drain regions, respectively;
- and
- forming a bitline contact in electrical with the second source/drain region.
A method of forming an electronic system, comprising:
- forming a gate stack over a substrate, the gate stack comprising a layer of electrically conductive material;
- etching only partially through the layer of electrically conductive material to leave an unetched remaining portion of the electrically conductive material and partially forming transistor gates from the gate stack;
- at least some of the partially formed transistor gates being paired adjacent transistor gates;
- forming pocket implant regions under at least some of the partially formed paired adjacent transistor gates;
- after the forming the pocket implants, etching through the remaining portion of the electrically conductive material, and completing formation of the transistor gates;
- forming source/drain regions proximate the transistor gates, some of the source/drain regions being shared by paired adjacent transistor gates;
- forming data storage devices in electrical connection with at least some of the source/drain regions;
- forming bitline contacts in electrical with at least some of the shared source/drain regions;
- the data storage devices, paired adjacent transistors and bitline contacts being incorporated into an array of memory cells;
- forming addressing circuitry coupled to the array of memory cells for accessing individual memory cells in the array of memory cells;
- and
- forming a read circuit coupled to the array of memory cells for reading data from memory cells in the array of memory cells.
Dependencies are inferred from the claim text.