Patent ID: 7433811
Filing Date: 2008-10-07
Classification: B81C,C25F,H01L

Abstract:
1. A method for directly generating a three-dimensional pattern, the method comprising steps of: selecting a substrate having a silicon surface; affixing a first electrical conductor for carrying a first charge to a backside of said substrate; selecting a second electrical conductor for carrying a second charge opposite of said first charge; immersing said substrate and said second electrical conductor into a hydrofluoric acid-containing solution; projecting an image onto said silicon surface; applying a current to said first conductor and said second conductor until an appropriate charge density is attained; removing said substrate from said hydrofluoric acid containing solution; and dissolving a porous layer from the substrate by contact to a chemical dissolution solution to leave a three-dimensional pattern having a correspondence to the image projected in said step of projecting.