Grooved planar DRAM transfer device using buried pocket
AssigneeInternational Business Machines Corporation
InventorsGary Bronner, Toshiharu Furukawa, Mark C. Hakey, Steven J. Holmes, David Horak, Jack A. Mandelman
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Abstract
A grooved planar DRAM transfer device having a grooved gate formed in a groove in a substrate located between source and drain regions. The grooved gate has sidewall portions and a bottom portion which defines a channel therealong. The bottom portion includes a doped pocket such that the threshold voltage Vt on the bottom portion is substantially less than Vt on the sidewall portions, such that the sidewall portions predominantly control electric current through the device.
Claims12
A method of fabricating a semiconductor device comprising the steps of:
- forming first and second regions of a first conductivity type in a substrate of a second conductivity type;
- forming a grooved gate having at least a length formed in a groove located in said substrate between said first and second regions;
- said grooved gate having sidewall portions and a bottom portion, wherein said bottom portion is connected to said sidewall portions by bottom corners, and a channel located in said substrate along said entire groove length including along said groove gated sidewall and said bottom portions;
- and
- forming a doped region of said first conductivity type in said channel at said bottom portion and said bottom corners of said grooved gate where Vt within said channel at said bottom portion and bottom corners is substantially less than Vt within said channel at said sidewall portions, such that said sidewall portions predominantly control electric current through the device, wherein said first and second regions of the first conductivity type comprise a source and drain region that abut a portion of said channel, and said channel has a center region between the source and drain, and the doped region of said first conductivity type extends across a portion of the center region but does not extend to the source and drain.
Dependencies are inferred from the claim text.