摘要
通过在热丝化学气相沉积(HWCVD)制备纳米晶硅薄膜过程中施加衬底偏压,研究衬底偏压对HWCVD制备纳米晶硅薄膜结晶性能的影响。利用拉曼(Raman)光谱,X射线衍射(XRD)和扫描电子显微镜(SEM)对所制备的纳米晶硅薄膜的结构性能进行分析。结果表明,与未施加衬底偏压的薄膜相比,当衬底偏压为-300V时,薄膜的晶化率由42.2%升高至46.2%;当衬底偏压升高至-600V时,晶化率又降至40.6%;未施加衬底偏压与施加-300V偏压的纳米晶硅薄膜表面由长约200nm、宽约100nm的晶粒构成,-600V衬底偏压的薄膜表面晶粒尺寸明显变小,并且出现大量非常细小的晶粒。分析产生上述现象的原因,主要与高温热丝发射电子、电子在电场作用下加速运动并与反应气体、基团碰撞发生能量传递有关。
In this paper,the effect of substrate bias on the structural properties of nanocrystalline silicon films deposited by hot-wire chemical vapor deposition （HWCVD） is studied by adding a direct current （DC） bias between the floated graphite substrate holder and the stainless steel chamber. The structural properties of the films are analyzed by Raman, X-ray diffraction （XRD） and scanning electron microsco- py （SEM）. The results show that the crystalline fraction is increased from 42.2% to 46.2% by adding -300 V substrate bias. By further raising the substrate bias to -600 V, the crystalline fraction is reduced to 40. 6 %. The surface of the nanocrystalline silicon films deposited without and with -300 V substrate bias is composed of crystallites with length of about 200 nm and width of about 100 nrn. While raising the substrate bias to -600 V, the grain size is obviously reduced, and a large number of fine grains appear in the deposited nanocrystalline silicon film. These phenomena are mostly related to the electrons emitted from the hot wires. When the tantalum wires are heated to a relatively high temperature, a lot of electrons would be emitted from them. These emitted electrons are accelerated in the elec- trical field, transferring the kinetic energy： to the reactants by inelastic collisions.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2015年第12期2325-2330,共6页
Journal of Optoelectronics·Laser
基金
国家高技术研究发展计划(863)计划(2006AA03Z219)
江苏省高校自然科学研究(14KJB480001)
江苏高校优势学科建设工程
苏州市科技计划(SGZ2013126)资助项目
