System and method for controlling directionality of fast-wet etching of crystalline silicon, c-Si
AssigneesNational University of Singapore, Agency for Science, Technology and Research
InventorsUtkur Mirsaidov, Michel Bosman, Tanmay Ghosh, Zainul Aabdin, Frank Holsteyns, Antoine Pacco
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Abstract
This document describes a system and method for selectively switching the fast-wet-etching direction of crystalline silicon, c-Si, nanostructures between the (100) and the (110) crystallographic planes of c-Si by a simple method of sample agitation. This method effectively allows the invention to achieve anisotropic and isotropic wet-etching of c-Si.
Claims8
A method for controlling directionality of fast-wet-etching of crystalline silicon, c-Si, the method comprising:
- anisotropically wet-etching the c-Si along a first crystallographic plane of the c-Si using an etching solution that wet-etches the c-Si along the crystallographic plane at a faster rate than the c-Si along a second crystallographic plane of the c-Si, wherein the etching solution comprises potassium hydroxide (KOH) and the etching byproducts from the wet-etched c-Si comprises orthosilicic acid, Si(OH)4, and wherein the KOH solution comprises concentration levels <10% (w/v), and is maintained at a temperature range between 20° C.-30° C.;
- and
- increasing the rate of removal of etching byproducts from the second crystallographic plane of the wet-etched c-Si to cause the wet-etching of the c-Si along the second crystallographic plane to be at a faster rate than the wet-etching of the c-Si along the first crystallographic plane of the c-Si.
A system for controlling directionality of fast-wet-etching of crystalline silicon, c-Si, the system comprising:
- a wet-etching setup configured to:
- anisotropically wet-etch the c-Si along a first crystallographic plane of the c-Si using an etching solution that wet-etches the c-Si along the first crystallographic plane at a faster rate than the c-Si along a second crystallographic plane of the c-Si, wherein the etching solution comprises potassium hydroxide (KOH) and the etching byproducts from the wet-etched c-Si comprises orthosilicic acid, Si(OH)4, and wherein the KOH solution comprises concentration levels <10% (w/v), and is maintained at a temperature range between 20° C.-30° C.;
- and
- increase the rate of removal of etching byproducts from the second crystallographic plane of the wet-etched c-Si to cause the wet-etching of the c-Si along the second crystallographic plane to be at a faster rate than the wet-etching of the c-Si along the first crystallographic plane of the c-Si.
Dependencies are inferred from the claim text.