Hydrogenation Effects on Chemical Activity of Defects in Excimer-Laser-Annealed Polycrystalline Silicon Thin Films

Abstract

We irradiated H 2 and O 2 plasmas onto fluorinated Al 2 O 3 , which was prepared by exposing a virgin Al 2 O 3 sample to an SF 6 /O 2 plasma. The effects of the H 2 plasma irradiation were the reduction of the AlO x F y (x þ y ¼ 1:5) and AlF x (x < 3) bonding components and the realization of smooth sample surface. It was observed that the irradiation of the H 2 plasma induced Al-OH bonding. The Al-OH bonding was removed by the sequential irradiation of the O 2 plasma after the H 2 plasma irradiation. The O 2 plasma irradiation also resulted in peroxidation and an increase in surface roughness. #

Characterization of Defects in Polycrystalline Silicon Thin Films Using Chemical Etching, Hydrogenation, and Raman Spectroscopy

“…2(a Consistent results have been obtained in previous reports. 8) Therefore, the reproducibility of the above described results was confirmed. Thus, it was deduced that the electrochemical activity of GB is apparently reduced by hydrogenation.…”

“…We have previously reported that the hydrogenation of ELA poly-Si suppresses chemical etching at GB, where Raman spectroscopy was used to detect stress reflecting the progress of etching at the film/underlayer interface. 8) It is expected that a more detailed analysis of chemical etching will be useful for characterizing the electronic activity of defects. Moreover, hydrogenation might assist in the observation of defects hidden by a high density of GBs.…”

Oriented Lateral Growth and Defects in Polycrystalline-Silicon Thin Films on Glass Substrates

“…We studied defects in excimer-laser crystallized poly-Si (Kitahara et al, 2007(Kitahara et al, , 2009a. We irradiated a-Si films (50 nm thick) on SiO 2 -coated fused quartz substrates with a XeCl excimer laser with 95% overlap.…”

Electrochemical and Raman-Scattering Characterizations of Defects in Polycrystalline Silicon Thin Films Formed by Excimer-Laser Annealing, Solid-Phase Crystallization, and Continuous-Wave Laser Lateral Crystallization

“…7) The enhancement of the etching rate at defects was related to electron-hole recombination centers in the band gap of Si. [8][9][10] We previously reported that the hydrogenation of ELA poly-Si suppresses the etching at GBs, 11,12) which is attributed to the passivation of dangling bonds (DBs) by hydrogen. It was also found that a high density of active defects exists in grains.…”