A Study of Thickness Distribution and Crystal Structure of Sputter-deposited Silicon Thin Films

Silicon thin films have a wide range of applications in different industries such as microelectronics and solar cells. Controlling the properties of the film such as thickness, uniformity and crystal structure during the deposition process is of crucial importance in the final performance of the device. In this work, the thickness distribution and crystal structure of silicon films deposited by the magnetron sputtering technique were studied. A computer model was developed to simulate the thickness distribution of sputter-deposited silicon films. The simulation results were compared to the measured film thickness profiles obtained by X-ray reflectometry measurements. The good agreement between the experimental and simulation results demonstrates that the model is consistent with the observed experimental results. The crystal structure of silicon films were examined by means of the X-ray diffraction measurements. Silicon has an as-deposited amorphous structure. To induce the crystallization at low temperatures, a copper layer was deposited on top of the silicon film. The crystallization of silicon was observed at 340°C which is considerably lower than the solid phase crystallization of amorphous silicon (~700°C). It is also shown that silicon crystallites tend to grow in the [111] direction. The full width at half maximum of the silicon (111) peak is less than 2 degrees which indicates a strong texture along this direction.