Method of making small transistor lengths
OwnerThorsten B. Lill, Jitske Kretzinventors
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Abstract
Transistor gate linewidths can be made to be effectively smaller by etching a notch at the bottom of the gate to reduce the effective linewidth. This can be done by etching at a layer interface, such as a silicon-germanium interface. in an over-etch step.
Claims10
In an etch process for etching a silicon layer over a germanium layer, the improvement comprising carrying out an over-etch using an etchant to etch a notch at the silicon-germanium interface.
A method of forming transistor gates having effective linewidths of 100 nm or less from a gate stack comprising a germanium layer, an amorphous silicon layer and a plasma enhanced chemical vapor deposited silicon oxide layer over a gate oxide layer comprising
- etching through the plasma enhanced chemical vapor deposited silicon oxide layer, the amorphous silicon layer and the germanium layer, and
- over-etching using an etchant for germanium to form a notch at the silicon-germanium interface.
Dependencies are inferred from the claim text.