Previous investigation has shown that a combination of rf cosputtering, film temperature control, and substrate bias control can produce ternary films with a range of different compositions from a single basic target configuration. Some of the detailed relationships between film composition in the Te–As–Ge ternary system and film deposition parameters, especially film temperature and film bias, are described in this present research. The main sputtering target was Te75As25. Ge was the cosputtered element, and it contributed theoretically predicted amounts of material to the films up to the 16 1/2 at. % Ge level. Substrate temperature and substrate bias had a strong influence on the As/Te ratio of the films, but had little effect on the Ge content. The Te content of the film decreased for substrate temperatures between −150° and +20° , and then increased for temperature between +20° and +90° C. This temperature effect appeared to be linear. Application of an rf bias caused a linear decline in the Te content of the films. These effects are interpreted in terms of sticking coefficient and preferential resputtering. The addition of Ge enhanced the Te content in the film and this effect is examined in terms of bond energies.