Patent ID: 8734659
Filing Date: 2014-05-27
Classification: B81C,H01L,Y10T

Abstract:
1. A process for etching a silicon-containing substrate to form structures comprising the steps of: (a) depositing and patterning metal onto a silicon-containing substrate in such a way that the metal is present and touches silicon where etching is desired and is blocked from touching silicon or not present elsewhere, (b) submerging the metallized substrate into an etchant aqueous solution comprising about 4 to about 49 weight percent HF and an oxidizing agent, thus producing a metallized substrate with one or more trenches, wherein the trenches have an aspect ratio larger than about 80:1 and have smooth sidewalls, (c) optionally employing a second different silicon etch to remove nanowires inside the one or more trenches, wherein the patterning of metal takes place by using photolithography, surface stamping, screen-printing, or dip-pen techniques.