BACKSIDE CONTACT WITH STRAIGHT PROFILE

Abstract: a method for fabrication of a semiconductor device includes forming a sacrificial dielectric layer in a trench over a dielectric liner, forming an inner spacing layer on the sacrificial dielectric layer and an additional dielectric layer over the inner spacing layer. contact openings are patterned in the additional dielectric layer down to the inner spacing layer. a breaking through etch is performed on the inner spacing layer in accordance with the contact openings to expose the sacrificial dielectric layer and to expose a thickness of the inner spacing layers within the contacts openings. the thickness of the inner spacing layer is treated to form inner spacers in sidewalls of the contact openings. etching to remove the sacrificial dielectric layer from the contact openings is performed wherein the inner spacers in sidewalls of the contact openings protect the sidewalls from tapering during the etching. contacts are formed in the contact openings.

Inventor(s): Tsung-Sheng Kang, Tao Li, Ruilong Xie, Chih-Chao Yang

CPC Classification: H10D86/0214 (No explanation available)

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