MANUFACTURE OF SEMICONDUCTOR DEVICE

• Main Author: SUDO KATSUHIKO
• Format: Patent
• Language: English
• Published: 10.02.1989
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To unnecessitate a high energy ion implantation device and to contrive to conduct a treatment process at high speed by a method wherein, after a gate oxide film has been formed, the first impurities for the ROM coding of the second transistor are ion-implanted before formation of a poly Si film. CONSTITUTION:After an oxide film 12 and a heat-resisting oxidizing insulating film 13 have been formed on a one-conductivity type semiconductor substrate 11, they are selectively oxidized, and an oxide film 15 is formed. Subsequently, the first impurities 14 are implanted on the whole surface by conducting an ion implanting method, and an opposite conductivity type impurity diffusion layer 16 is formed. Then, a polycrystalline semiconductor film 17 is selectively formed on the region where the first and the second transistors will be formed. A resist film 18 is formed on the whole surface of the substrate 11, an aperture is provided on the source S and the drain D forming region where the first transistor will be formed, and a oneconductivity type impurity diffusion layer 20 is formed by implanting the second impurities 19. The resist film 18 is removed, the third impurities 21 are implanted on the whole surface, and a source S and a drain D are formed.