The resistivity and structure of chromium thin films

The resistive properties of vacuum-deposited chromium films have been studied and related to their structure. Films deposited at a pressure of 10 -9 torr on substrates at temperatures of 300°C and 20°C have resistivities of approximately 1.5 times and 4 times bulk value respectively. The corresponding values for films deposited at a pressure of 10 -5 torr are 2 times and greater than 6 times bulk value. Investigation of film structure by electron microscopy, and measurement of film density, film impurities and vacuum-chamber residual gases during film deposition, show that the films consist of grains of relatively pure chromium with impurities at their boundaries and it is concluded that the grain size and impurity content - both of which depend upon deposition conditions - are the important factors that determine the resistive properties of the films.