| 摘要 |
PROBLEM TO BE SOLVED: To provide a device which hardly generates hot electrons as an MIS transistor structure, does not easily accumulate charges by repeating the judging operation of conduction status, permits a large discriminating current difference to be set and performs charge accumulation at a low voltage in a short time. SOLUTION: A nonvolatile semiconductor storage device is provided with a control gate 16a, which is composed of a second conductive-type diffusion layer formed in a first conductive-type semiconductor substrate, source and drain regions 15a and 15b, which are composed of the second conductive-type diffusion layer isolated from the control gate 16a, a charge injecting layer, which is composed of a second conductive-type diffusion layer 16b, isolated from the control gate 16a and a first conductive-type diffusion layer 17, and a floating gate 14, which is formed on the semiconductor substrate on the upper region of at least the control gate 16a and the charge injection layer through an insulating film and constitutes an MIS transistor with the source and drain regions 15a and 15b. |
