稀土元素Ce热引入Si单晶中及Ce在Si中的扩散系数

INTRODUCTION OF Ce INTO Si AND THE DIFFUSION COEFFICIENT OF Ce IN Si

利用真空淀积和真空热处理(1050℃,20h)向Si单晶中引入了稀土元素Ce,热处理过程中Ce首先与Si形成合金,然后向Si中扩散,于是在Si中形成Ce的扩散层。用二次离子质谱(SIMS)技术测定了Ce的纵向相对浓度分布,并据此分析了Ce在Si中的扩散系数。并在77—450K范围内测量了扩散层的平均电导率。

Ce has been introduced into single crystal Si by means of vacuum deposition of Ce onto Si wafer, and then annealing at 1050℃ for 20 hours in vacuum. In the annealing process, Ce-Si alloy was formed on the surface at first, and then the Ce atorms diffused into Si and produced a diffusion region of Ce with thickness about 4.5 μm. The concentration profile of Ce was determined by SIMS. The diffusion coefficient of Ce in Si at 1050℃ was obtained as 3.9×10^(-13) cm^2/s. The average resistivity ρ of the Ce diffusion layer was measured from 77K to 450K.