| 摘要 |
<p>PURPOSE: To prevent deterioration due to a hot carrier effect by depositing high-density polycrystalline silicon in an etching hole part formed by using a nitride and a low-density polycrystalline silicon side wall as a mask, and forming a low-density polycrystalline side wall and a high-density polycrystalline silicon by thermally diffusing impurities. CONSTITUTION: The side wall 12 formed of a nitride layer 10 and n- polycrystalline silicon is used as the mask to etch an oxide layer below the polysilicon side wall 12. Then the polycrystalline silicon layer is diposited through an emitter window 13 formed by etching the oxide layer. After high- density n+ polycrystalline silicon is obtained by ion implantation, an n+ polycrystalline silicon layer 14 is formed by photolithography. Then the n+ polycrystalline silicon layer 14 and n-polycrystalline silicon side wall 12 are used as a diffusion source to perform diffusion, thereby forming an n-type emitter region.</p> |
