| 摘要 |
PURPOSE:To obtain a mask having good blocking capability to the diffusion of impurities and preventing composition elements from invading into host crystal by a method wherein multilayer structure is made by using three kinds or more of thin films such as an SiO2 film, a phosphorus glass film, an SiO2 film which are coated from the surface of Ge crystal. CONSTITUTION:An SiO2 film 2, a PSG film 3 and an SiO2 film 4 are provided as the first layer, the second layer and the third layer respectively. The first layer, SiO2 film 2 is for preventing phosphorus in the PSG film 3 from diffusing in Ge crystal. The second layer, PSG film 3 is also the film for preventing the diffusion of Zn. The third layer, SiO2 film 4 is provided with the purpose of a protective film to the moisture-proof PSG film 3. |
