| 摘要 |
PURPOSE:To obtain a small-size high dielectric strength device by a method wherein P-type guard rings and an N<+> type layer surrounding the guard rings are provided on an N-type Si substrate and a high resistance layer is provided on an insulator between them. CONSTITUTION:P<+> type protection rings 16 are formed in an N<-> type epitaxial layer 11 on an N<+> type substrate 10 surrounding an element region. A P-type base layer 12 is formed by using a gate oxide film 20 and a polycrystalline Si gate electrode 21 as a mask and suitable apertures are drilled in an SiO2 film 13 to form an N<+> type source layer 22 and an N<+> contact layer 17. An electrode 14 which is contacted with the N<+> type source layer 22 and electrodes 23 and 18 which are contacted with the protection rings 16 and the N<+> layer 17 are provided and a high resistance amorphous Si layer 19, contacted with the electrodes 18, is formed on the SiO2 film 13 between the final step protection ring and the N<+> type layer 17. A drain electrode 15 made of V-Ni-Au is applied to the back plane of the substrate. With this constitution, the expansion of the depletion layer in the Si substrate is enlarged and the electric field concentration is avoided by giving a potential gradient to the high resistance layer 19 so that a small size high dielectric strength planar type semiconductor device can be obtained. |
