| 摘要 |
PURPOSE:To prevent the diffusion of phosphorus from PSG to Si and the oxidation of the surface of the diffusion region of the Si substrate and to finish the etching of the contact hole with single process by using poly Si instead of Si3N4. CONSTITUTION:After forming the electrode 4 of low resistivity poly Si, the interlayer insullation film is deposited on the surface in the order of SiO2 3, poly Si 5b, and PSG6. By the heat treatment in oxygen atmosphere, PSG6 is smoothed and poly Si 5b between the interlayer insullation films SiO2 3 and PSG6 is oxidized. The contact with the poly Si electrode 4 is finished by the etching of the contact hole. In the process of annealing to smooth PSG in oxygen atmosphere, the diffusion of phosphorus from PSG to Si and the oxidation of the surface of the diffusion layer in the Si substrate are prevented, and the etching of the contact hole is finished by single process. |
