摘要
已知,在使用PECVD法沉积的硅薄膜中,掺硼所能获得的最高室温电导率要比在同样沉积条件下掺磷硅膜低一个数量级。我们用SIMS及声表面波技术测得,氢化硅膜中起受主作用的活性硼原子在其总掺硼量中仅占0.7％,而绝大部份掺入的硼原子是非活性的。这是由于氢化硅薄膜网络结构中的氢填补了未饱和的B—Si键,使之形成中性的B—H—Si复合体所致。使用低能电子束流辐照掺硼样品,引起退氢化作用,从而使大量的B—H—Si中性复合体转变成活性的B—Si键,能使其电导率提高一个数量级,达到与掺磷硅膜同一水准。
It is well known that the conductivity σ_(rt) of B-doped silicon films is one order lower thanthe magnitude of the value of P-doped silicon films deposited at the same deposition conditionsin a PECVD system. We adoped the SIMS and SAW methods to measure the active boronatoms. It is shown that the amount of the active boron atoms only takes a small fraction,about～0.7%, in the total amount of incorporated boron, therefore the most fraction of theincorporated boron atoms in network exists in a non-active state. As a result of that the hydrogenatoms in network can compensate the un-saturated B-Si bonds, it may form a neutralB-H-Si complexes. Using the energetic electron beam irradiation to the B-doped samples,it can cause the dehydrogenated effect, which would be enabled the most of the neutral complexesB-H-Si transfered into active B-Si bonds and increased the conductivity of B-dopedsamples by one order of magnitude reaching the same level of P-doped samples.
基金
国家自然科学基金~~
关键词
微晶硅
硅薄膜
杂志
受主态
Boron
Doping (additives)
Infrared spectroscopy
Microanalysis
Semiconducting silicon
Spectrum analysis
