Formulations to selectively etch silicon-germanium relative to silicon
AssigneeEntegris, Inc.
InventorSteven M. Bilodeau
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Abstract
Compositions useful for the selective removal by etching of silicon-germanium-containing materials relative to silicon-containing materials, from a microelectronic device having features containing these materials at a surface, the compositions containing hydrofluoric acid, acetic acid, hydrogen peroxide, and at least one additional acid that will improve performance as measured by one or more of an etching rate or selectivity and are tunable to achieve the required Si:Ge removal selectivity and etch rates.
Claims20
A method of selectively removing silicon-germanium from a surface of a microelectronic device relative to a silicon-containing material, method comprising:
- providing a microelectronic device surface that includes silicon and silicon-germanium,
- providing an aqueous etching composition comprising:
- hydrogen fluoride,
- dissolved hydrogen peroxide,
- dissolved acetic acid,
- dissolved formic acid, and
- dissolved sulfuric acid, and
- contacting the surface with the silicon-germanium-selective etching composition for time and at a temperature effective to selectively remove silicon-germanium relative to the silicon.
An etching composition for selectively removing silicon-germanium from a surface of a microelectronic device relative to silicon, comprising:
- hydrogen fluoride,
- dissolved acetic acid,
- dissolved formic acid, and
- dissolved sulfuric acid,
- in water.
An etching composition for selectively removing silicon-germanium from a surface of a microelectronic device relative to silicon, consisting essentially of:
- hydrogen fluoride,
- dissolved acetic acid,
- dissolved formic acid,
- dissolved sulfuric acid,
- optional lactic acid, and
- optional hydrogen peroxide,
- in water.
Dependencies are inferred from the claim text.