离子注入形成SOI结构的界面及埋层的俄歇能谱研究

AUGER ELECTRON SPECTROSCOPIC STUDIES OF INTERFA CE AND BURIED LAYER OF SOI STRUCTURE FORMED BY ION IMPLANTATION

本文中研究了O^+(200keV,1.8×10^(18)/cm^2)和N^+(190keV,1.8×10^(18)/cm^2)注入Si形成SOI(Silicon on Insulator)结构的界面及埋层的化学组成。俄歇能谱的测量和研究结果表明:注O^+的SOI结构在经1300℃,5h退火后,其表层Si和氧化硅埋层的界面存在一个不饱和氧化硅状态,氧化硅埋层是由SiO_2相和这不饱和氧化硅态组成,而且氧化硅埋层和体硅界面不同于表层Si和氧化硅埋层界面;注N^+的SOI结构在经1200℃,2h退火后,其氮化硅埋层中存在一个富N的疏松夹层,表层Si和氮化硅埋层界面与氮化硅埋层和体硅界面性质亦不同。这些结果与红外吸收和透射电子显微镜及离子背散射谱的分析结果相一致。还对两种SOI结构界面与埋层的不同特征的原因进行了分析讨论。

The chemical composition and interface structure of silicon on insulator (SOI) formed by O+ (200 keV, 1.8×l0^(18)/cm^(-2)) or N+ (190 keV, 1.8×10^(18)/cm^(-2)) implanted into silicon have been investigated by using Auger electron spectroscopy (AES) with in situ sputtering. For SOI structure produced by O^+ implantation and annealing at 1300℃ for 5 hours, the characteristic Auger spectrum for the interface between the top silicon layer and the buried oxide layer was measured and a chemical state of silicon was identified, whose major transition was at 85 eV, different from that of the bulk silicon or silicon in SiO_2. This chemical state was also discovered in the buried oxide layer. For SOI structure produced by N+ implantation and annealing at 1200℃ for 2 hours, a nitrogenrich porous layer was observed in the buried nitride layer. For both SOI structures, the strong asymmetry of the two main interfaces was observed. These results are in agreement with the results of infrared absorption (IR) analysis and transimission electron microscopy (TEM) analysis. The detailed explanation of these results is also presented in this paper.