Read only memory device

Abstract

Abstract PURPOSE:To enable to obtain the titled device having a high density and a short time until the product delivery by a method wherein code writing is enabled through a contact hole bored by self-alignment with a gate electrode, after the electrode is formed. CONSTITUTION:A polycrystalline Si film 3 and insulation films 4 and 5 are formed on an insulation thin film 2 formed on the surface of an Si substrate 1. Next, an insulation film 51 is formed on the side surface of the gate electrode 31, and further an interlayer insulation film 6 is formed after the formation of the source-drain 7. Then, the contact hole for writing ROM codes is etched by a method wherein insulation films 41 and 21 are etched but the film 51 is not. A conductive layer such as an Al film 8 connecting both contact holes is formed. Insulation gate type FET's Q1-Q3 are formed in such a manner, and among of them the FET Q2 is short-circuited between the source and drain. Thereby, code writing is enabled after the formation of the gate electrodes, and accordingly the time from code order reception to product delivery becomes shorter.

Inventors

• 👤 Eiji Sugimoto
• 👤 杉本　榮治

Bibliographic Details