The etfect of structural disorder on mechanical stress in a-Si : H films

The effect of ion implantation on mechanical stress in a-Si:H films was stu died with the aim of separating the contributions that the hydrogen content and structural defects make to the intrinsic compressive stress. The a-Si: H films were prepared by plasma-enhanced chemical vapour deposition. Silico n ions with an energy of 160 keV were implanted and the implantation-induce d structural damage was studied by means of Raman backscattering spectrosco py. The stress in the films was compressive and its value correlated with t he short and intermediate range orders. The results have shown that the val ue of compressive stress in the material could be lowered by changing the s tructural order of the silicon network without changing the hydrogen conten t.