高功率脉冲激光致硅表面氧的退吸研究

A STUDY OF OXYGEN DESORPTION ON SURFACE OF SILICON IRRADIATED BY PULSED LASER

引言近儿午来,离子注入硅的激光退火研究,引起了人们广泛的兴趣。许多文献报导,高功率脉冲激光退火,能够消除离子注入硅引起的辐射损伤,并使非品态转变为单品。但是,对于激光退火硅样品表面的氧沾污和扩散问题却研究不多。从仅有的研究中发现,不同作者所得结果颇不一致。文献[4,5]从深能级的瞬态谱研究结果证实。

A study of oxygen indiffusion or desorption on surface of silicon irradiated by pulsed laser has been performed by means of the ^(16)O(α, α_0)^(16)O resonance scattering. The results show that no evidence for oxygen indiffusion into the silicon bulk whose surface is cleanned by pulsed laser in UHV environment was found. In which oxygen concentration lower than oxygen solubility limit in silicon. This result differs from previous results given by other authors. It was suggested that most of oxygen, on surface is desorbed. This is consisent with the dissolution time of SiO_2 in silicon, which is order of magnitude longer than the calculated melt duration of silicon surface according to thermal melting model with moving boundary conditions. This finding provides an understanding of mechanism on atomically clean surfaces caused by pulsed laser.