Production of spacers at flanks of a transistor gate

摘要

The production of spacers at flanks of a transistor gate, including a step of forming a dielectric layer covering the gate and a peripheral region of a layer of semiconductor material surrounding the gate, including forming a superficial layer covering the gate and the peripheral region; partially removing the superficial layer configured so as to completely remove the superficial layer at the peripheral region while preserving a residual part of the superficial layer at the flanks; and selective etching of the dielectric layer vis-à-vis the material of the residual part of the superficial layer and vis-à-vis the semiconductor material.

主权项

1. A method for producing spacers at flanks of a transistor gate, the gate being situated above a layer of a semiconductor material, the method comprising successively the following steps:
forming a dielectric layer that covers the gate and at least a peripheral region of the layer of semiconductor material surrounding the gate; anisotropic etching of the dielectric layer, thereby reducing a thickness of the dielectric layer at a region covering an upper surface of the gate and at the peripheral region, while substantially preserving a thickness of the dielectric layer at the flanks; forming a superficial layer covering the dielectric layer; partial etching of the superficial layer configured so as to completely remove the superficial layer at the peripheral region while preserving a residual part of the superficial layer at the flanks, and while at least partly preserving the dielectric layer at the peripheral region; and then, after the partial etching, selectively etching the dielectric layer with respect to the residual part of the superficial layer and with respect to the layer of semiconductor material.