Anisotropic single crystal silicon etching solution and method
AssigneeMotorola, Inc.
InventorsPing-Chang Lue, Henry G. Hughes
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Abstract
A method of anisotropically etching single crystal silicon includes providing single crystal silicon to be etched and placing it in an etching solution consisting essentially of R.sub.4 NOH and solvent wherein R is an alkyl group having between 0 and 4 carbon atoms. The solution will preferentially etch <100> or <110> oriented single crystal silicon. Additionally, electrochemical etching may be employed to preferentially etch P type single crystal silicon.
Claims8
An electrochemical method of anisotropically etching single crystal silicon comprising the steps of:
- providing single crystal silicon to be etched;
- and
- anisotropically etching said silicon in an electrochemical bath having an etching solution consisting essentially of more than 20% by weight R.sub.4 NOH and solvent wherein R is an alkyl group having between 0 and 4 carbon atoms.
An electrochemical method of preferentially etching single crystal silicon having a <100>
- or <110>
- crystallographic orientation comprising the steps of:
- providing single crystal silicon having a <100>
- or <110>
- crystallographic orientation to be etched;
- and
- preferentially etching said silicon in an electrochemical bath having an etching solution consisting essentially of R.sub.4 NOH and H.sub.2 O wherein R is an alkyl group having between 0 and 4 carbon atoms and said solution comprises more than 20% R.sub.4 NOH by weight.
Dependencies are inferred from the claim text.