| 摘要 |
PURPOSE:To obtain a chip in high withstand voltage by a method wherein the semiconductor pellet is etched to be made mesa-type by using the first mask by photoresist and the second mask by screen printing which comes inside the 1st mask by the length approximately equal to a quantity of the pellet applied a side-etching in lateral direction after the mesa etching being applied. CONSTITUTION:P type layers 2, 3 are formed on both the face and the reverse of an N type Si substrate 1, respectively, an N type region 4 being diffusion-formed in the layer 2 on the top surface to be made the semiconductor chip in PNPN-structure, SiO2 films 5 to be made masks being cover-attached on the face and the reverse respectively and perforated openings 6 using the photoresist. At this time, the films 5 are opened holes due to pinholes being already made in the resist and the Si layer also is grown with holes through those holes 7, so that the Si layer is printed after positioning by the screen printing using abietic wax and applied the mesa etching after the mask 9 having been formed inside the films 5. Thus, a withstand decrease caused by holes is avoided to enable the yield to be improved. |
