a-C:H(N)薄膜的慢正电子分析

The Study of a-C: H(N) Films by Low Energy Positron Beam

采用C2H2和N2的混合气体在单晶Si衬底上用射频一直流等离子化学气相沉积法制备a－C：H（N）薄膜，用Fourier红外谱研究了a-C：H（N）薄膜的结构。用慢正电子湮没技术研究了类金刚石薄膜中缺陷的深度分布以及N的百分含量对薄膜中缺陷浓度和缺陷类型的影响。Fourier红外测试结果表明，a－C：H（N）薄膜中氮含量随混合气体中N2百分含量的升高而增大，薄膜中碳氮原子形成C≡N键。慢正电子分析表明．单晶Si衬底具有很高的缺陷浓度，类金刚石薄膜中的缺陷浓度较低，且缺陷均匀分布，薄膜表面存在一缺陷浓度较高的薄层，而膜一基之间存在一很宽的界面层。a-C：H（N）薄膜的缺陷浓度随N含量的增加而增大，但含饲量不改变薄膜中的缺陷类型。

a -- C: H(N ) films were deposited on Si substrate from the mixture Of C2H2 and N2 by r. f. -d. c. plasma enhanced chemicalvapor deposition. The structure of a -- C: H (N ) films were studied by Fourier IR spectrum. The distribution of void, the influence of Ncontent on the density and the type of void in a -- C: H (N) films were systemstic alloy studied by low energy positron beam. The IRspectra shows that the N content of a -- C: H(N) films increase with the increasing of N2 percentage in the foed gas, and C≡N bonds canbe formed betWeen C and N atoms. The density of void in Si substrate is the highest. A constant distribution of void was obserVed throughthe tilms,the density of void is lower, but the densily Of void in the surface lay is higher. The density of void in the films increasesmonotonously with the increasing of N2 percentage in the feed gas, but the N content has no effect on the type of void.