Reactive magnetron sputtering of germanium carbide films at different substrate temperature

HU Chao-quan, WANG Yan-hui, GUO Long-fei, ZHENG Wei-tao

Dept. of Materials Science,Key Laboratory of Mobile Materials,MOE,State Key Laboratory of Superhard Materials,State Key Laboratory on Integrated Optoelectronics,and College of Electronic Science and Engineering,Jilin University,Changchun 130012,China



Abstract:

To explore the relationship between the chemical bonding and mechanical properties for germanium carbide (Ge1-xCx) films,the Ge1-xCx films are prepared via reactive magnetron sputtering in a mixture of CH4/Ar discharge,and their composition,chemical bonding and hardness were investigated as a function of substrate temperature (Ts). The results show that Ts remarkably influences the chemical bonding of Ge1-xCx film,which results in a pronounced change in the film hardness. As Ts increases from ambient (60 ℃) to 500 ℃,the Ge content in the film gradually increases,which promotes forming sp3 C-Ge bonds in the film at the expense of sp2C-C bonds. Furthermore,it is found that with increasing Ts the fraction of C-H bonds in Ge1-xCx film gradually decreases,which is attributed to an enhancement in the desorption rate of C-Hn(n=1,2,3) species decomposed from methane. The transition from graphite-like sp2 C-C to diamond-like sp3C-Ge bonds as well as the reduction in C-H bonds in the film with increasing Ts promotes forming the compact three-dimensional network structure,which significantly enhances the hardness of the film from 5.8 to 10.1 GPa.

Key words:  germanium carbide films  reactive magnetron sputtering  substrate temperature

DOI：10.11916/j.issn.1005-9113.2010.03.026

Clc Number:O484.5

Fund: