Control of Point Defects in Si and its Application to Process Simulation

本文研究了在硅表面直接覆盖氮化硅（Si_3N_4）薄膜的结构中，退火过程中Si_3N_4薄膜和衬底的应力及其对硼（B）扩散和扩展缺陷的影响。在退火过程中，Si_3N_4薄膜内部产生拉应力，导致衬底表面产生压应力。从Si_3N_4薄膜厚度和退火温度对B扩散率和衬底应力的依赖性的结果发现，在薄膜下退火时，B扩散受到阻碍，衬底具有高的弹性压应变。这些结果表明，由于弹性压应变的作用，产生了过量的空位，从而阻碍了B的扩散。本文还研究了Si_3N_4薄膜对P和Sb在Si中扩散的影响。氮化物膜下的Si中P的扩散受到抑制，而Sb的扩散得到增强。确定了P和Sb在Si中扩散的非晶态组分分数分别约为0.96和0。

In the structure of silicon directly covered with silicon nitride (Si_3N_4) films, stresses of Si_3N_4 films and substrates during annealing, and its effect on boron (B) diffusion and extended defects are studied. During annealing, tensile stress is generated in the Si_3N_4 film, resulting in compressive stress at the surface of the substrates. From the results of Si_3N_4 film thickness and annealing temperature dependence on both B diffusivity and stress in the substrates, B diffusion is found to be retarded and the substrates are found to have high elastic compressive strain during annealing under the films. These results indicate that excess vacancies are generated by elastic compressive strain, causing the retardation of interstitial-mediated diffusion of B.The effect of Si_3N_4 films on diffusion of phosphorus (P) and antimony (Sb) in Si has also been studied. P diffusion is retarded, while Sb diffusion is enhanced in Si under nitride films. It is determined that fraction of interstitialcy component in P and Sb diffusion in Si is approximately 0.96 and 0, respectively.