Etching process of silicon material

• US 5,200,028 A
• Filed: 08/07/1991
• Issued: 04/06/1993
• Est. Priority Date: 08/08/1990
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tatsumi, Tetsuya
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): GOUDREAU, GEORGE A
• Application Number:
  US07/741,735
• Time in Patent Office: 608 Days
• Field of Search: 156/643, 156/646, 156/656, 156/657, 156/653, 437/193, 437/200
• US Class Current: 438/695
• CPC Class Codes: H01L 21/32137 of silicon-containing layers

Abstract

A process is disclosed for etching a silicon-based structure comprised of a silicon layer and a high-melting silicide layer. Good shaping results from etching of the two layers with use of two gaseous mixtures having their respective different ratios of a hydrogen bromide gas and a fluorine radical-donating gas. Separate etching is possible of the silicon layer with a hydrogen bromide gas and of the silicide layer with a gaseous mixture of the above type. A silicon-containing layer is also etched with a hydrogen gas alone with the end point of etching being precisely detected.

Claims

1. A process for subjecting a silicon-based structure to etching, said structure having a silicon layer and a high-melting silicide layer superposed one on the other over a substrate, which process comprises etching said silicon layer with a first gaseous medium, and etching said silicide layer with a second gaseous medium, each of said first and second gaseous media having a hydrogen bromide gas and a fluorine radical-donating gas contained in a selected ratio, said first and second gaseous media differing in each selected ratios from each other.

2. A process according to claim 1, wherein said silicide layer comprises a tungsten, titanium or molybdenum metal.

3. A process for subjecting a silicon-based structure to etching, said structure having a silicon layer and a high-melting silicide layer superposed one on the other over a substrate, which process comprises etching said silicon layer with a first gaseous medium, and etching said silicide layer with a second gaseous medium, each of said first and second gaseous media having a hydrogen bromide gas and a fluorine radical-donating gas contained in a selected ratio, said first and second gaseous media differing in each selected ratios from each other, and wherein said fluorine radical-donating gas is a sulfur hexafluoride, nitrogen trifluoride, chlorine trifluoride, fluorine or hydrogen fluoride gas.