Electron beam induced selective etching and deposition technology

Abstract

W deposition, using a WF 6 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 1.5 Å/min at 3.5×10 −7Torr and β-W clusters are formed by electron beam irradiation of the WF 6 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 WF 6 gas pressure. Furthermore, a nanostructure involving a W rod with 15 nm diameter has been demonstrated by using electron beam induced surface reaction. Direct writing into Si and GaAs has been demonstrated by electron beam induced surface reaction using XeF 2 and Cl 2 sources. A scanning tunneling microscope(STM) has been used to directly write deposition patterns of metal and carbon, and etching patterns of Si. These features have been obtained down to 50nm. A 0.6 μm resist pattern has been precisely transfered into a Si substrate by showered-electron beam assist-etching at 1×10 −4Torr Cl 2 gas pressure. A side-wall roughness of replica grating patterns has been successfully measured by using a new STM tip made by electron beam deposition.