CVD生长Si基Si1-x-yGexCy合金层应变的研究

用Raman谱和AES能谱分析了用RTP/VLP-CVD方法生长在Si衬底上的SiGeC合金外延薄膜的应变。结果表明:用RTP/VLP-CVD方法生长的SiGeC合金中掺入的C呈间隙原子或替位原子的形式分布,其中大部分为间隙原子,少量为替位C原子,但是替位C原子的存在有效地调节了SiGeC合金层的应变;另外由于采用乙烯做C源,生长温度较高也使SiGeC合金层的应变部分被弛豫。由于C的掺入,Si基上生长SiGeC合金的应变和相同Ge含量的SiGe合金相比较大大减小,临界厚度大大增加,有利于在Si衬底上生长出达到一定厚度的更高质量的族元素合金半导体材料。

Study on the Strain in SiGeC Alloy Films Grown on Si Substrate by CVD

In this paper,we studied the strain in SiGeC films grown on Si substrate by RTP/VLP-CVD.Raman spectra and AES were used to analyze the strain in SiGeC films.It is shown that there are two carbon incorporation modes in the SiGeC films:substitutional mode and interstitial mode.The majorities of C atoms are in interstitial mode,while the minorities of substitutional C atoms modulate the strain in SiGeC films sufficiently.Because of high temperature of growth,the strain in SiGeC films is partially relaxed.Compared to the SiGe films with the same Ge composition on Si substrate,due to the substitutional C atoms,the SiGeC films have much lower strain and higher critical thickness,which means that SiGeC films with larger thickness and better quality than SiGe films can be grown on Si substrate.