Fabrication of a Grating Pattern with Submicrometer Dimension in Silicon Crystal by Ion-Bombardment-Enhanced Etching

Abstract

Ion-bombardment-enhanced etching (IBEE) as a means for fabrication of submicron pattern is described. Electron beam lithography and lift-off technique are used to form a Cr mask pattern for ion-bombardment. The etched depth can be controlled from 83 to 128 nm by varying the ion dose with an accuracy of 10 nm. A grating pattern with a period of 0.6 µm is fabricated in a Si substrate by IBEE technique by using Ar+ ion. At an Ar+ ion energy of 60 keV, the amount of side etching is observed to be 40 nm for a 0.21-µm deep etched sample. This result shows the high resolution of IBEE.