Effect of bias on the As-deposited grain structure of Cr thin film

Abstract

The film growth of Cr thin film by DC-magnetron sputter deposition was investigated by experimentally measuring the evolution of grain size distribution and by computing the film growth using Monte Carlo simulation. The as-deposited Cr thin film by sputter deposition typically grows in a columnar grain structure at the substrate temperature 260°C, which is far lower than 0.3 Tm. The stagnation of columnar grain structure does not occur in the case of no-bias condition up to the investigated film thickness of about 800 nm. However, the application of a negative bias of 200 V results in a stagnation of columnar grain structure at film thickness of about 50 nm and at the deposition temperature of 260°C. This is believed to arise from the fact that the mobility of ad-atoms is greatly enhanced and the Ar+ ions pin the grain boundary as a result of bias application.