Sticking coefficients of selenium and tellurium

The sticking coefficients of selenium and tellurium were measured as a function of temperature. Molecular beams of the chalcogen elements supplied from thermal effusion cells were directed onto a heated quartz crystal microbalance, and the mass gain rate was detected as a function of temperature. Both sticking coefficients were found to sharply drop within a narrow temperature range of 20 and 30 degrees C from above 0.8 down to about 0.2 at film surface temperatures around 35 and 115 degrees C for selenium and tellurium, respectively. While the sticking coefficient of tellurium reached zero at temperatures above 150 degrees C, the sticking coefficient of selenium remained about 0.2 up to a film surface temperature of 60 degrees C, suggesting that selenium was supplied in different chemical forms. The direct and quantitative determination of the sticking coefficients provides important insights into the kinetics of chalcogenide-based film growth and points toward the need of a precise sample temperature control.

Automated summary

The sticking coefficients of selenium and tellurium were measured as a function of temperature, with both sharply dropping within a narrow temperature range. While the sticking coefficient of tellurium reached zero at high temperatures, selenium's coefficient remained around 0.2 even at elevated temperatures.