We prepared 1-μm-thick CdTe films by thermal evaporation or radio frequency magnetron sputtering. The film deposition was conducted at various substrate temperatures (Ts), and sputtered films were post-annealed in air or vacuum. The CdTe films deposited by evaporation had larger grain sizes than the films deposited by sputtering, likely because the bombardment of high-energy particles during sputtering disturbed the crystallization of the film. The sputtered film was amorphous when grown at room temperature (RT), but crystalline when the Ts was increased during deposition. In case of the evaporated films, the preferred orientation was C-(111) when the Ts was at RT. However, when the Ts was increased, the intensity of the X-ray diffraction peak of C-(111) decreased and that of the C-(220) and C-(311) peaks increased. Finally, sputtered films grown at RT were treated with a post-annealing step at various temperatures. After this treatment, there was no significant difference in the grain size and XRD patterns of the films, likely because the maximum annealing temperature, 400 oC, was insufficient to change the microstructure of the film.

Keywords: CdTe, Sputtering, Thermal evaporation, Heat treatment.