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US 2014/0370643 A1Published application
Formulation for acidic wet chemical etching of silicon wafers
Assignee1366 Technologies, Inc.
InventorsEric Stern, Bradley M. West, Jason Criscione
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Abstract
Acid etch compositions for etching multicrystalline silicon substrates are disclosed which may include hydrofluoric acid, an oxidizer, an acid diluent, and soluble silicon. The soluble silicon may be hexafluorosilicic acid or ammonium fluorosilicate. Silicon substrates patterned with organic resist may be used with the acid etch compositions for selective silicon patterning for solar cell applications.
Claims29
A method of patterning silicon, comprising:
- exposing a silicon substrate patterned with organic resist on at least one surface to an as-prepared etching composition, the etching composition comprising hydrofluoric acid, at least one oxidizer capable of oxidizing silicon, and soluble silicon,
- wherein the etching composition etches exposed silicon surface of the silicon substrate without removing the organic resist.
An as-prepared aqueous acid etching composition, comprising:
- 1.4 to 7.1 M of hydrofluoric acid;
- 0.01 to 7.75 M of at least one oxidizer capable of oxidizing silicon;
- and
- 0.15 to 2.2 M of soluble silicon.
1 more element
A method of etching a silicon surface, comprising:
- providing an as-prepared aqueous acid etching composition comprising 1.4 to 7.1 M aqueous hydrofluoric acid, 0.01 to 7.75 M of at least one aqueous oxidizer capable of oxidizing silicon, and 0.15 to 2.2 M aqueous hexafluorosilicic acid;
- and
- exposing a silicon substrate to the as-prepared etching composition.
Dependencies are inferred from the claim text.