Seiko Epson Corporation

Saiko Epson Corporation

Takeshi Kumagai

Junichi Karasawa

Satoru Kodaira

Kunio Watanabe

Hitoshi Kobayashi

Masaya Uehara

A semiconductor memory device has a peripheral circuit area and a memory cell area on a main surface thereof. The semiconductor memory device includes a first well formed in the peripheral circuit area, a second well of a first conductivity type formed in the memory cell area, a third well of a second conductivity type formed in the memory cell area, and a device isolation structure formed in the memory cell area for isolating an element formed in the second well from an element formed in the third well. The second well of the first conductivity type has a depth shallower than a depth of the first well. The third well of the second conductivity type is equal in depth to the second well. The second and third wells are formed down to a level lower than the device isolation structure.

Semiconductor memory device and method for manufacturing the same

A semiconductor memory having a plurality of memory cells includes a first terminal that becomes a power supply terminal for the semiconductor memory, a second terminal that becomes a ground terminal for the semiconductor memory, a third terminal for inputting a burn-in mode signal to place the semiconductor memory in a burn-in mode and a fourth terminal for inputting an external clock signal. The semiconductor memory further includes an address signal generation section that generates an address signal for selecting each of the plurality of memory cells based on counting of the clock signal while the burn-in mode signal is input. A data signal generation section generates a data signal based on the clock signal while the burn-in mode signal is input. A data writing section writes data of the data signal in the memory cells selected by the address signal.

Semiconductor memory and burn-in method for the same

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Chino, Japan

Takeshi Kumagai