【摘要】 用化学气相淀积方法在Si(100)衬底上外延生长了Ge组分最高约0．40的组分渐变的Si1-x-yGexCy合金薄膜, 研究了生长温度等工艺参数的影响．结果表明,生长温度和C2H4分压的提高均导致薄膜中碳组分的增加和合金薄膜晶格常数的减小,这表明外延薄膜中的C主要以替位式存在．C掺入量的变化可有效地调节薄膜的禁带宽度,而提高生长温度有助于改善 Si1-x-yGexCy薄膜的的晶体质量．组分渐变的Si1-x-yGexCy合金薄膜包括由因衬底中Si原子扩散至表面与GeH4、 C2H4反应而生成的Si1-x-yGexCy外延层和由Si1-x-yGexCy外延层中Ge原子向衬底方向扩散而形成的Si1-xGex层．更多还原

【Abstract】 Ge graded Si1-x-yGexCy films, with the highest Ge mole fraction of 0.40, were epitaxially grown on Si(100) substrates by CVD. Carbon content in the film increases and the lattice constant of the epilayer decreases with increase of the substrate temperature and C2H4 partial pressure. It demonstrates that the incorporated C atoms mainly occupy the substitutional sites. The bandgap of the film can be effectively adjusted by varying the C content, while the quality of the film can be improved by increasing the substrate temperature. The Ge graded Si1-x-yGexCy film consists of the Si1-x-yGexCy layer and Si1-xGex layer. The former is due to the reaction between GeH4, C2H4 and Si atoms diffusing from the substrate to surface, and the latter is the result of Ge diffusing from the Si1-x-yGexCy epilayer to the substrate.更多还原