High Rate Deposition of CdSe Thin Films by Pulsed DC Magnetron Sputtering

The efficiency of cadmium telluride solar cells has recently been increased by adding selenium as a CdSeTe alloy at the front of the device. In this paper, we report on the use of pulsed dc magnetron sputtering to deposit thin films of Cadmium Selenide from a compound target. The deposition rates are surprisingly high and exceed 10nm/sec at a power of only 1.5kW on a 6 inch diameter target. The deposited thin films are dense and columnar. The thin films have been characterized using X-Ray diffraction, UV-vis Spectrophotometry, SEM, and Hall effect to analyse the structural, optical and electrical properties. Magnetron sputtering is widely used in thin film manufacturing and the high rates reported here make the use of pulsed dc sputtering an attractive industrial production technique for CdSe deposition in the CdSeTe device stack.