Simple fabrication of high density concave nanopyramid array NPA/on Si surface

A simple process to fabricate two-dimensional 2-D.concave nanopyramid array NPA.with nanometer period on Si surface has been developed by using electron beam EB. irradiation and wet etching. The enhanced etch rate ER. of EB-exposed SiO2 in HF-based solution has been utilized. Mask oxide layers with the thicknesses of 11–30 nm were shot with 30-keV focused EB at spot doses ranging from 20 to 140 pCrdot. EB-exposed SiO2 layers were selectively etched by dipping in 1% HF or buffered HF BHF.. The Si substrates were then dipped in anisotropic etchant hydrazine N2H4PH2O. to form concave NPAs, where patterned SiO2 layers were used as etch mask. By using this simple process, 50-nm period concave NPA with the size of 20 nm was fabricated successfully. q2000 Elsevier Science B.V. All rights reserved.