Etch of silicon nitride selective to silicon and silicon dioxide useful during the formation of a semiconductor device

Abstract

A method for etching silicon nitride selective to silicon dioxide and silicon (polycrystalline silicon or monocrystalline silicon) comprises the use of oxygen along with an additional etchant of either CHF3 or CH2F2. Flow rates, power, and pressure settings are specified.

Description

[0001] This is a continuation of U.S. Ser. No. 10 / 819,517 filed May 6, 2004 and issued Jun. 13, 2006 as U.S. Pat. No. 7,060,629, which is a continuation of U.S. Ser. No. 09 / 854,206 filed May 11, 2001 and issued Apr. 6, 2004 as U.S. Pat. No. 6,716,759.FIELD OF THE INVENTION [0002] This invention relates to the field of semiconductor manufacture and, more particularly, to an etch useful for removing silicon nitride selective to silicon and silicon dioxide. BACKGROUND OF THE INVENTION [0003] During the manufacture of semiconductor devices such as a memory devices, logic devices, and microprocessors, various processes are commonly performed. Etching silicon nitride selective to silicon (such as polysilicon) and to silicon dioxide with various etch ratios is often required. For example, hot phosphoric acid isotropically etches silicon nitride selective to silicon dioxide and silicon. Other processes for etching Si3N4 selective to SiO2 and Si are discussed in “Highly Selective Etching of ...

AI Technical Summary

Benefits of technology

The method provides a rapid and controllable etch rate for silicon nitride with improved selectivity to silicon and silicon dioxide, reducing processing time and ensuring minimal damage to silicon wafers, resulting in more precise and efficient semiconductor device manufacturing.

Problems solved by technology

As semiconductor manufacture typically requires high volume processing to lower costs, any decrease in temporal processing requirements can result in a large increase in product throughput.

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