Method of making a semiconductor device
AssigneeRCA Corporation
InventorAndrew Gordon Francis Dingwall
Life of this patent
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Abstract
A silicon-gate insulated gate field effect transistor device has a thick field oxide in contiguous surrounding relation to its gate electrode and with a surface coplanar with or slightly higher than the surface of the gate electrode, thus facilitating crossovers and contacts to the gate electrode. The method of making this device includes forming a self-aligned silicon gate structure on a silicon wafer, masking the gate structure against the diffusion of oxygen, and thereafter oxidizing the silicon wafer to grow a thick silicon dioxide layer in surrounding relation to the silicon gate structure.
Claims3
A method of making a semiconductor device, comprising the steps of:
- forming on a surface of a body of silicon a layered structure comprising a layer of insulating material on said surface, a refractory conductive layer adjacent to said layer of insulating material, and a layer of oxygen-impermeable insulating material on said conductive layer,
- selectively removing portions of said layer of oxygen-impermeable insulating material and correspondingly adjacent portions of said conductive layer and said layer of insulating material to expose correspondingly adjacent portions of said surface of said body of silicon,
- diffusing conductivity modifiers into said body of silicon through the portions of said surface exposed in the preceding step,
- selectively removing other portions of said layer of oxygen-impermeable insulating material, so that the remaining portions thereof overlie those portions of said conductive layer which are to remain in said device, and removing the portions of said conductive layer and said layer of insulating material which are adjacent to said other portions of said oxygen-impermeable insulating layer to expose correspondingly adjacent second portions of said surface of said body of silicon, and thereafter
- thermally oxidizing the material of said body of silicon adjacent to said second portions of the surface thereof to grow a silicon dioxide body which extends into said body from said surface and which contiguously surrounds the remaining portions of said conductive layer.
Dependencies are inferred from the claim text.