Sidewall protection by nitrogen in anisotropic etching of P-doped poly-Si1.xGex has been investigated using electron-cyclotron-resonance (ECR) chlorine plasma. It is found that the sidewall protection with only N2 addition in chlorine plasma is weaker than that of P-doped poly-Si. Highly anisotropic etching of P-doped poly-Si0.4Ge0.6 is achieved by both N2 and SiCl4 additions. In the investigation of X-ray photoelectron spectroscopy (XPS) for P-doped poly-Si0.4Ge0.6 after the radical dominant etching, it is found that an ultrathin Si nitride film is formed by the addition of both SiCl4 and N2. From these results, it is suggested that highly anisotropic etching of P-doped poly-Si 1-xGex is achieved by the protective Si nitride formation on the sidewall against chlorine radical etching.
|Number of pages||8|
|Publication status||Published - 2004 Dec 1|
|Event||SiGe: Materials, Processing, and Devices - Proceedings of the First Symposium - Honolulu, HI, United States|
Duration: 2004 Oct 3 → 2004 Oct 8
|Other||SiGe: Materials, Processing, and Devices - Proceedings of the First Symposium|
|Period||04/10/3 → 04/10/8|
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