Generation and reduction in SiO(2)/Si interface state density during plasma etching processes

作者：Ishikawa Yasushi; Ichihashi Yoshinari; Yamasaki Satoshi; Samukawa Seiji^*

来源：Journal of Applied Physics, 2008, 104(6): 063308.

DOI：10.1063/1.29824081

During plasma processes, the SiO(2)/Si interface state is generated by UV photon irradiation. We measured P(b) centers (Si dangling bond at SiO(2)/Si interface) in SiO(2)/Si film by electron spin resonance spectroscopy. The density of P(b) centers increased with increasing UV photon energy. This result indicates that high-energy photons effectively generate P(b) centers because of the absorption at the SiO(2)/Si interface. At the same time, we found that UV photon flux is also an important factor in increasing the density of P(b) centers. On the other hand, ion irradiations were not a significant factor in the generation of P(b) centers. Ions can penetrate only the surface (less than 5 nm) but they cannot induce a P(b) center at the SiO(2)/Si interface. Furthermore, pulse-time-modulated plasmas were used to reduce the UV photon irradiation during the plasma processes. The reduction in UV photon irradiation could completely eliminate the P(b) centers compared with the use of a conventional continuous wave plasma.

• 出版日期2008-9-15