US 9,824,893 B1Granted

Tin oxide thin film spacers in semiconductor device manufacturing

AssigneeLam Research Corporation

InventorsDavid Charles Smith, Richard Wise, Arpan Mahorowala, Patrick A. Van Cleemput, Bart J. van Schravendijk

Life of this patent

Estimating the term…

Loading patent…

Abstract

Thin tin oxide films are used as spacers in semiconductor device manufacturing. In one implementation, thin tin oxide film is conformally deposited onto a semiconductor substrate having an exposed layer of a first material (e.g., silicon oxide or silicon nitride) and a plurality of protruding features comprising a second material (e.g., silicon or carbon). For example, 10-100 nm thick tin oxide layer can be deposited using atomic layer deposition. Next, tin oxide film is removed from horizontal surfaces, without being completely removed from the sidewalls of the protruding features. Next, the material of protruding features is etched away, leaving tin oxide spacers on the substrate. This is followed by etching the unprotected portions of the first material, without removal of the spacers. Next, underlying layer is etched, and spacers are removed. Tin-containing particles can be removed from processing chambers by converting them to volatile tin hydride.

Claims19

Dependent claims

A method of processing a semiconductor substrate, the method comprising:

(a) providing a semiconductor substrate having an exposed layer comprising a first material and at least one protruding feature comprising a second material that is different from the first material;
and
(b) depositing a SnO2 layer over both the first material and the second material, including sidewalls of the at least one protruding feature, wherein the first material and the second material are selected such that a ratio of an etch rate of the first material to an etch rate of SnO2 is greater than 1 for a first etch chemistry, and a ratio of an etch rate of the second material to an etch rate of SnO2 is greater than 1 for a second etch chemistry;
(c) after depositing the SnO2 layer, completely removing the SnO2 layer from horizontal surfaces of the semiconductor substrate without completely removing the SnO2 layer covering the sidewalls of the at least one protrusion;
and
(d) after removing the SnO2 layer from horizontal surfaces of the semiconductor substrate, completely removing the at least one protrusion using the second etch chemistry, without completely removing the SnO2 layer that was covering the sidewalls of the at least one protrusion, thereby forming SnO2 spacers.

3 more elements

Dependencies are inferred from the claim text.