扩展电阻分析对砷在硅中本征扩散系数的研究

Studies on Intrinsic Diffusivity of Arsenic in Silicon by Spread Resistance Analysis

本文扼要叙述了扩展电阻分析用以测量较低浓度砷的剖面的有效性,进而研究了较低浓度砷在硅中的扩散问题.由于通过快速热退火对样品进行预处理,排除了辐照损伤对扩散系数测定的影响,从而测得砷在硅中本来意义下,即替位扩散意义下的本征扩散系数.如所预期,这组数据比国外直至目前所测得的数据要低.浓度剖面的实验数据由非线性扩散方程的数值解进行拟合.结果表明:SUPREM III所采用的模型在较高浓度区扩散系数随浓度递增速率较小,Hu理论仍然和本实验(?)较符合.本文还求得了扣除辐照损伤增强扩散效应后,砷在硅中的激活能为4.

It was briefly described that the spread resistance analysis (SRA) can be effectively used tomeasure the profiles of As in Si with lower concentration, and therefore SRA was used to studyAs diffusion in Si.Rapid thermal annealing (RTA) was adopted as preannealing for the sam-ples to exclude the enhanced diffusion of irradiation damage.The intrinsic diffusivity of Asin Si can be therefore determined under original meaning that means the diffusion should besubstitutional.The data obtained in this paper are smaller than that obtained by other authors.Numerical resolution of a non-linear diffusion equation was used to fit the experimental data.The results demonstrated that Hu's theory is more precise to describe the experimental data ofdiffusion in this work than SUPREM III, because the rate, with which the diffusivity increaseswith As concentration in higher concentration area, is reduced by the diffusion model adoptedin SUPREM III.The diffusion active energy without irradiation damage enhanced effect was de-termined to 4.42 eV in this paper as well.