Nova Patents
EP0200951A3

Anisotropic silicon etching in fluorinated plasma

Abstract

A method of high rate anisotropic etching of silicon in a high pressure plasma is described. The etching ambient is a mixture of either NF3 or SF6, N2, and a polymerizing gas such as CHF3 that creates conditions necessary for anisotropy not normally possible with nonpolymerizing fluorinated gases in a high pressure regime. The etch process is characterized by high etch rates and good uniformity utilizing photoresist or similar materials as a mask. In one embodiment the present process is used to etch deep trenches in silicon using a photoresist mask.

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Projected expiry passed 11 April 2006, 20.5 years ago.

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Citations
DocumentRelationOfficeCategoryCited during
EP0127188A1CitesEuropean Patent Office (EPO)ASearch report
US4473435ACitesUnited States of AmericaYSearch report
US4490209ACitesUnited States of AmericaASearch report
INTERNATIONAL ELECTRON DEVICES MEETING TECHNICAL DIGEST, Washington, 7th - 9th December 1981, pages 578-581, IEEE, New York, US; R.H. BRUCE et al.: "High rate anisotropic etching"Non-patent––Search report
EXTENDED ABSTRACTS, vol. 84, no. 1, 6th - 11th May 1984, page 135, abstract no. 92, Pennington, New York, US; R. PINTO et al.: "The effect of dilution of SF6 with O2, H2, N2 and Ar in RIE"Non-patent––Search report
PLASMA CHEMISTRY AND PLASMA PROCESSING, vol. 4, no. 1, March 1984, pages 1-14, Plenum Publishing Corp., New York, US; R. D'AGOSTINO et al.: "Radiofrequency plasma decomposition of CnF2n+2-H2 and CF4-C2F4 mixtures during Si etching or fluoropolymer deposition"Non-patent––Search report