离子束增强沉积制备氮化硅薄膜的计算机模拟

Computer Simulation of the Ion Beam Enhanced Deposition of Silicon Nitride Films

Monte-Carlo计算机模拟程序,SIBL,用来描述离子束增强沉积(IBED)制备氧化硅薄膜的生长过程,提供薄膜组分的深度分布及界面混合等有关信息.它是TRIMSP的发展,并利用了ZBL(Ziegler,Biersack,Littmark)最新的二体势和电子阻止本领.模拟计算中,用一个间断交替的薄膜生长过程(先沉积一层硅原子,然后注入一定量的氮离子)来代替实验上一个沉积原子和离子轰击同时进行的连续过程,且在注入一定量的离子后,对每层原子的组份,密度进行修正,使模拟达到动态化.计算结果表明,薄膜组份比随离子原子到达比的变化关系以及组份的深度分布和实验符合很好.

A Monte-Carlo computer simulation code,SIBL,has been developed to describe the growthof silicon nitride films by ion beam enhanced deposition (IBED).The universal potential andthe electronic stopping by ZBL (1985) are used in the code.A successive and alternate process.of deposition of silicon and implantation of nitrogen ions has been applied to simulate the ac-tual continuous and synchronous process of IBED.The changes of the composition and thedensity profile are taken into account during film growth both due to the spatial distribution oftarget atoms deposited in collision cascades,and due to the presence of the implanted ions. The relationship between the calculated composition of the film and the atomic arrival ra-tio N/Si has been established.The composite profile obtained by compputer simulation is in,good agreement with the experimental results.