Process for forming deep trench DRAMs with sub-groundrule gates
First Claim
1. A process for fabricating sub-GR gates in a semiconducting substrate of a dynamic random access memory array, said substrate having a deep trench, a shallow trench isolation, and nitride seal regions formed thereon;
- comprising the steps of;
depositing a sacrificial spacer on said semiconductor substrate;
etching a recess in a selective portion of said sacrificial spacer;
filling said recess with insulating material to form a column-shaped structure having opposing sides;
removing the remaining portion of said sacrificial spacer;
etching a trench along each side of said column-shaped structure of insulating material; and
filling trenches with conductive material to form a pair of trench gates.
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Accused Products
Abstract
A method of fabricating sub-GR gates in a deep trench DRAM cell. The method comprises depositing, removing, and selectively etching a plurality of layers which include sacrificial spacers, liners, masking, and resist layers of both semiconducting and non-semiconducting materials on a semiconductor substrate according to specific process flows designed to circumvent the problems associated with prior art sub-GR processes. The method represents an improvement on standard gate conductor processes and provides a device which achieves an up to now unachieved decoupling of channel doping and junction doping.
33 Citations
24 Claims
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1. A process for fabricating sub-GR gates in a semiconducting substrate of a dynamic random access memory array, said substrate having a deep trench, a shallow trench isolation, and nitride seal regions formed thereon;
- comprising the steps of;
depositing a sacrificial spacer on said semiconductor substrate; etching a recess in a selective portion of said sacrificial spacer; filling said recess with insulating material to form a column-shaped structure having opposing sides; removing the remaining portion of said sacrificial spacer; etching a trench along each side of said column-shaped structure of insulating material; and filling trenches with conductive material to form a pair of trench gates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
- comprising the steps of;
Specification