Spacer formation with straight sidewall

摘要

Disclosed herein is a semiconductor device comprising a first dielectric disposed over a channel region of a transistor formed in a substrate and a gate disposed over the first dielectric. The semiconductor device further includes a second dielectric disposed vertically, substantially perpendicular to the substrate, at an edge of the gate, and a spacer disposed proximate to the second dielectric. The spacer includes a cross-section with a perimeter that includes a top curved portion and a vertical portion substantially perpendicular to the substrate. The perimeter further includes a discontinuity at an interface of the top curved portion with the vertical portion. Further, disclosed herein are methods associated with the fabrication of the aforementioned semiconductor device.

主权项

1. A method of fabricating a semiconductor device, comprising:
disposing a gate structure on a substrate, the gate structure comprising:
a gate, a first dielectric disposed beneath the gate, and a second dielectric at least on sidewalls of the gate and over the gate; disposing a first layer of material over the second dielectric; disposing a second layer of material over the first layer of material; etching the second layer of material such that portions of the second layer of material remain on sidewalls of the first layer of material; etching the first layer of material with an etchant having substantially higher selectivity to the first layer of material than to the second layer of material; and etching the portions of the second layer of material remaining on the sidewalls of the first layer of material.