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Title: Carrier-lifetime-controlled selective etching process for semiconductors using photochemical etching

Abstract

The minority carrier lifetime is significantly much shorter in semiconductor materials with very high impurity concentrations than it is in semiconductor materials with lower impurity concentration levels. This phenomenon of reduced minority carrier lifetime in semiconductor materials having high impurity concentration is utilized to advantage for permitting highly selective semiconductor material etching to be achieved using a carrier-driven photochemical etching reaction. Various means may be employed for increasing the local impurity concentration level in specific near-surface regions of a semiconductor prior to subjecting the semiconductor material to a carrier-driven photochemical etching reaction. The regions having the localized increased impurity concentration form a self-aligned mask inhibiting photochemical etching at such localized regions while the adjacent regions not having increased impurity concentrations are selectively photochemically etched. Liquid- or gas-phase etching may be performed.

Inventors:
 [1];  [2]
  1. Edgewood, NM
  2. Albuquerque, NM
Issue Date:
Research Org.:
AT & T CORP
OSTI Identifier:
868181
Patent Number(s):
5092957
Assignee:
United States of America as represented by United States (Washington, DC)
DOE Contract Number:  
AC04-76DP00789
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
carrier-lifetime-controlled; selective; etching; process; semiconductors; photochemical; minority; carrier; lifetime; significantly; shorter; semiconductor; materials; impurity; concentrations; concentration; levels; phenomenon; reduced; utilized; advantage; permitting; highly; material; achieved; carrier-driven; reaction; various; means; employed; increasing; local; level; specific; near-surface; regions; prior; subjecting; localized; increased; form; self-aligned; mask; inhibiting; adjacent; selectively; photochemically; etched; liquid-; gas-phase; performed; selective etching; impurity concentration; surface region; etching process; chemical etching; semiconductor materials; semiconductor material; minority carrier; highly selective; localized region; near-surface regions; concentration levels; carrier lifetime; photochemical etching; selectively photochemically; various means; near-surface region; selective etch; chemically etched; surface regions; concentration level; /438/

Citation Formats

Ashby, Carol I. H., and Myers, David R. Carrier-lifetime-controlled selective etching process for semiconductors using photochemical etching. United States: N. p., 1992. Web.
Ashby, Carol I. H., & Myers, David R. Carrier-lifetime-controlled selective etching process for semiconductors using photochemical etching. United States.
Ashby, Carol I. H., and Myers, David R. Wed . "Carrier-lifetime-controlled selective etching process for semiconductors using photochemical etching". United States. https://www.osti.gov/servlets/purl/868181.
@article{osti_868181,
title = {Carrier-lifetime-controlled selective etching process for semiconductors using photochemical etching},
author = {Ashby, Carol I. H. and Myers, David R},
abstractNote = {The minority carrier lifetime is significantly much shorter in semiconductor materials with very high impurity concentrations than it is in semiconductor materials with lower impurity concentration levels. This phenomenon of reduced minority carrier lifetime in semiconductor materials having high impurity concentration is utilized to advantage for permitting highly selective semiconductor material etching to be achieved using a carrier-driven photochemical etching reaction. Various means may be employed for increasing the local impurity concentration level in specific near-surface regions of a semiconductor prior to subjecting the semiconductor material to a carrier-driven photochemical etching reaction. The regions having the localized increased impurity concentration form a self-aligned mask inhibiting photochemical etching at such localized regions while the adjacent regions not having increased impurity concentrations are selectively photochemically etched. Liquid- or gas-phase etching may be performed.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1992},
month = {1}
}

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