Characterization of hafnium diboride thin film resistors by r.f. magnetron sputtering

摘要

The material properties of sputtered HfB_2 thin films (≈0.1 μm) are studied to better understand their behavior when used in ink-jet printing devices. The deposition conditions (i.e., working pressure, r.f. power, and heater temperature) were found to have large effects on the resistivity and stress of the film. The resistivity results obtained for HfB_2 could mainly be attributed to the grain size effects. The stress built in during deposition was confirmed to be the primary stress component for the as-deposited heater film. In addition, the stress variation in the HfB_2 sample during the thermal cycling was investigated. Under proper sputtering conditions, the HfB_2 stress can be repeatedly controlled from tension (+ 3 X 10~9 dyne cm~(-2), 100℃) to compression (-3.5 X 10~9 dyne cm~(-2), 400℃). This trend is quite useful and can be utilized to minimize the heater stress during ink-jet device operation.