Removal of oxygen atoms from a SiO/sub 2/ surface by incoherent vacuum ultraviolet excimer irradiation

Abstract

Summary form only given. Non-thermal photochemical removal of oxygen atoms from a SiO/sub 2/ layer on a silicon wafer using short wavelength emission has recently attracted much attention in the semiconductor industry and other related areas. It provides not only physics on the interaction between surface and high-energy photons, but also novel engineering aspects such as non-thermal nano-scale materials processing. In addition, the direct removal of oxygen atoms from a SiO/sub 2/ layer could open up the possibility of using a SiO/sub 2/ bulk as an insulator in the recent silicon-on-insulator (SOI) technology. The vacuum ultraviolet emission source was developed by use of a silent discharge, producing 9.8 eV photons with an intensity of 0.3 mWcm/sup -2/. Such high photon energy is larger than the energy gap of the SiO/sub 2/. The high-energy photon, therefore, directly excites the electronic transition in SiO/sub 2/. The emission intensity is so low that a temperature rise of the SiO/sub 2/ surface was estimated of the order of 10/sup -6/ K even during the irradiation. Surface morphology monitored by an atomic force microscope verified the non-thermal no damage processing.