Electron beam induced selective etching and deposition technology

Abstract

W deposition, using a WF6 source by electron beam induced surface reaction, has been studied by Auger electron spectroscopy (AES) and transmission electron microscopy (TEM). The initial growth process has been observed in situ by AES and TEM. As a result, it became clear that a growth rate for W is ∼1 Å/min at 2×10−7 Torr and β-W clusters are formed by electron beam irradiation of the WF6 adlayer. Moreover, it has been observed that W layers are formed by coalescing the W clusters by electron beam irradiation at 5×10−7 Torr WF6 gas pressure. Furthermore, a nanostructure involving a W rod with a 15-nm diameter has been demonstrated by using electron beam induced surface reaction. Direct writing onto Si, GaAs, and poly(methylmethacrylate) (PMMA) resist have been demonstrated by electron beam induced surface reaction using XeF2, Cl2, and ClF3 sources. The electron beam stimulated etched depth is proportional to the electron dose. A 0.5-μm linewidth Si and PMMA resist patterns have been fabricated at 4×10−3 and 2×10−3 C/cm2 doses, respectively. The PMMA resist etched depth profile control has been demonstrated by changing doses. GaAs etching has been achieved by heating the substrate.