SEMICONDUCTOR DEVICE

• Main Author: NARA HAJIME
• Format: Patent
• Language: English
• Published: 12.05.1989
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INFORMATION STORAGE; PHYSICS; SEMICONDUCTOR DEVICES; STATIC STORES

PURPOSE:To recognize the contents of a ROM data by observing an outward appearance by a method wherein an impurity to form the ROM data is doped through an insulating layer such as an oxide film or the like and, after that, the insulating layer in a doped part is etched in such a way that it is left up to an extent capable of being used as a gate insulating film. CONSTITUTION:In a semiconductor device having a ROM data region formed by an MIS type semiconductor element, an impurity to form a data is injected through an insulating layer 6 such as an oxide film or the like; after that, the insulating layer 6 in this doped part 3 is etched in such a way that it is left up to an extent capable of being used as a gate insulating film. For example, an insulating layer 6 is formed on a semiconductor substrate 7; when a ROM data is to be produced, a patterned resist is formed on the insulating layer 6; only a part where the resist does not exist is doped with an impurity through the insulating layer 6. Then, the resist is left as it is; the insulating layer 6 is etched; a difference 5 in level is formed to clarify a place 3 which has been doped with the impurity. Then, the resist is stripped off; after that, a gate electrode 1 is formed; a ROM can be finally formed.