| 摘要 |
A preparation method for a power diode, comprising: providing a substrate (10), the substrate (10) having a front surface and a back surface opposite to the front surface, an N-type layer (20) growing on the front surface of the substrate (10), and the N-type layer (20) having a first surface deviating from the substrate (10); forming a terminal protection ring (31, 32, 33); forming an oxide layer (50), and performing knot pushing on the terminal protection ring (31, 32, 33); conducting photoetching using a photoetching plate of an active region and etching the oxidation layer (50) of the active region, and forming a gate oxide layer (60) on the first surface of the N-type layer (20) of the active region; depositing on the gate oxide layer (60) to form a polysilicon layer (70); conducting photoetching using a polysilicon photoetching plate, taking a photoresist (40) as a mask layer to inject P-type ions into the N-type layer (20), and forming a P-type body region (82) beneath the polysilicon layer (70) through ion scattering; forming an N-type heavily doped region; forming a P+ region; conducting thermal annealing, activating injected impurities and removing the photoresist (40); and conducting metallization processing on the first surface and the back surface of the substrate (10). |
