| 摘要 |
PURPOSE:To obtain the mesa type semiconductor device which has high withstand voltage and high reliability by mesa etching a P-N junction to its lower portion by employing a PSG and Si3N4 layer masks, then removing the Si3N4 layer mask and seizing glass powder to the mesa groove. CONSTITUTION:An SiO2 layer 13, a PSG layer 14 and an Si3N4 layer 14 are laminated on an Si substrate 11 having a P-N junction, and masks are thus formed thereon. The substrate thus laminated is etched to the lower portion of the P-N junction with a mixture solution of hydrofluonitric acetic acid and the mesa grooves 16 are formed thereon. Subsequently, the Si3N4 layer 15 is etched with a H3PO4, is then dipped in an isopropyl alcohol to thereby enhance the wettability of the grooves 16, the substrate is disposed then in a dispersant medium in which glass powder is suspended together with adding agent in isopropyl alcohol, the glass powder is thus coated selectively on the grooves 16 by an electrophoresis, is then seized, and a glass film 17 is formed thereon. Subsequently, the layers 14, 13 are removed with a mixture solution of HF+NH4F, electrode openings 18 and scribing lines 19 are formed thereon, electrodes 20 are attached thereto, and the substrate is divided to be thus completed. The glass film may be uniformly formed in narrow groove width according to this method. |
