Abstract: 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.

Abstract: A MOS P-N junction diode device includes a substrate having a first conductivity type, a field oxide structure defining a trench structure, a gate structure formed in the trench structure and a doped region having a second conductivity type adjacent to the gate structure in the substrate. The method for manufacturing such diode device includes several ion-implanting steps. After the gate structure is formed by isotropic etching using a patterned photo-resist layer as a mask, an ion-implanting step is performed using the patterned photo-resist layer as a mask to form a deeper doped sub-region. Then, another ion-implanting step is performed using the gate structure as a mask to form a shallower doped sub-region between the gate structure and the deeper doped sub-region. The formed MOS P-N junction diode device has low forward voltage drop, low reverse leakage current, fast reverse recovery time and high reverse voltage tolerance.

Abstract: A trench Schottky diode and its manufacturing method are provided. The trench Schottky diode includes a semiconductor substrate having therein a plurality of trenches, a gate oxide layer, a polysilicon structure, a guard ring and an electrode. At first, the trenches are formed in the semiconductor substrate by an etching step. Then, the gate oxide layer and the polysilicon structure are formed in the trenches and protrude above a surface of the semiconductor substrate. The guard ring is formed to cover a portion of the resultant structure. At last, the electrode is formed above the guard ring and the other portion not covered by the guard ring. The protruding gate oxide layer and the protruding polysilicon structure can avoid cracks occurring in the trench structure.