MANUFACTURE OF SEMICONDUCTOR ELEMENT

PURPOSE:To reduce the area of a contact layer, by opening an ion implanting window in one sheet of a mask, forming the contact layer and a second operating layer, and connecting the contact layer to electrode metal by a lead out conductive layer. CONSTITUTION:An Si3N4 film 22 with a specified pattern is provided on a semiconductor substrate 21, selective oxidation is performed with the film 22 as a mask, and a thick SiO2 film 23 is formed at the peripheral part of the substrate 21. Then, the film 22 is removed, a polycrystalline film 24 is deposited on the entire surface, and the Si3N4 film having the specified pattern is again provided on the film 24. With a film 22 as a mask, the exposed part of the film 24 is selectively oxidized, and the window for forming the contact layer and the second operating layer is opened. Thereafter only 22-1 of the film 22 is left, and a polycrystal Si layer 25 which is to become the lead out layer is deposited again, and the contact layer 26 is formed by the ion implantation and the like. Then the film 22-1 are removed, and only the lead out conductive layer 25-2 is left. A first operation layer 27 is formed by the implantation and the second operating layer 29 is formed in the layer 27.