Gas Source Depletion Study of High-Order Silanes of Silicon-Based Epitaxial Layers Grown with RPCVD and Low Temperatures

Abstract

In this paper, silicon gas-source depletion of silane, disilane, and a high-order silane, TF, is studied on oxide wafers. Two different growth mechanisms were discovered for TF. The faster mechanism depletes readily at temperatures as low as 525 oC. The "slower" mechanism does not deplete even at temperatures as high as 600 oC. This second growth mechanism has a growth rate as high as 13 nm/min at 550 oC and 43 nm/min at 600 oC under a chamber pressure 100 Torr. Two techniques, of reducing growth temperature and reducing growth pressure, are shown to suppress gas-source depletion. After the suppression of gas-source depletion, the faster mechanism exhibited a growth rate of 35 nm/min at 550 oC and a chamber pressure of 10 torr. Due to the two different growth mechanisms of TF, uniform growth deposition can be achieved for both low and high pressures for temperatures up to 600oC.