MOS P-N JUNCTION DIODE WITH ENHANCED RESPONSE SPEED AND MANUFACTURING METHOD THEREOF

摘要

A MOS P-N junction diode includes a semiconductor substrate, a mask layer, a guard ring, a gate oxide layer, a polysilicon structure, a central conductive layer, a silicon nitride layer, a metal diffusion layer, a channel region, and a metal sputtering layer. For manufacturing the MOS P-N junction diode, a mask layer is formed on a semiconductor substrate. A gate oxide layer is formed on the semiconductor substrate, and a polysilicon structure is formed on the gate oxide layer. A guard ring, a central conductive layer and a channel region are formed in the semiconductor substrate. A silicon nitride layer is formed on the central conductive layer. A metal diffusion layer is formed within the guard ring and the central conductive layer. Afterwards, a metal sputtering layer is formed, and the mask layer is partially exposed.

主权项

1. A method for manufacturing a MOS P-N junction diode, comprising steps of:
providing a semiconductor substrate; performing a first ion implantation process and a thermal drive-in process to form a guard ring layer in the semiconductor substrate; forming a mask layer on the semiconductor substrate; forming a gate oxide layer on the semiconductor substrate and the guard ring layer, forming a polysilicon structure on the gate oxide layer and the mask layer, and forming a polysilicon oxide layer on the polysilicon structure; performing an etching process to partially remove the polysilicon oxide layer, the polysilicon structure and the gate oxide layer, and performing a second ion implantation process to form a central conductive layer in the semiconductor substrate; performing a third ion implantation process to form a channel region beside the central conductive layer; forming a silicon nitride layer on a part of the central conductive layer; forming a metallic evaporation film on exposed surfaces of the mask layer, the polysilicon oxide layer, the guard ring layer, the central conductive layer and the silicon nitride layer; performing a diffusion treatment to diffuse the material of the metallic evaporation film into the guard ring layer and the central conductive layer, thereby forming a metal diffusion layer within the guard ring layer and the central conductive layer; removing the polysilicon oxide layer; forming a metal sputtering layer on exposed surfaces of the mask layer, the polysilicon structure, the guard ring layer, the central conductive layer and the silicon nitride layer; and etching the metal sputtering layer to partially remove the metal sputtering layer, so that a part of the mask layer is exposed.