Hitachi, Ltd.

Wataru Arakawa

Masamichi Ishihara

Hidetoshi Iwai

Kazuya Ito

Yoshinobu Nakagome

Yutaka Ito

Toshitsugu Takekuma

Toshiyuki Sakuta

Shigetoshi Sakomura

Masanori Tazunoki

An arrangement is provided for preventing DC defects in a memory or logic device after switching to a redundant circuit, improving the product yield of the device by cutting a leakage current path through a defective element or circuit. The cutting points formed by the predetermined wirings as a whole or a part thereof are provided to the device. A probe test of the formed chip is executed under the wafer condition by predetermined test equipment, and wiring correction data regarding the cutting of the cutting points is generated based on the result of test. Moreover, this wiring correction data is transmitted in an on-line fashion to the wiring correction equipment so that the corresponding cutting points can be cut. The wiring correction equipment can be formed by an EB direct writing apparatus, an FIB apparatus or a laser repair apparatus. With this arrangement, the leakage current path formed by a defective element or circuit left unused in conventional circuits is cut, and the product yield of the device is raised significantly. This arrangement can be used for a variety of memory or logic devices, including DRAMs, SRAMs, multiport memories and gate arrays.

Semiconductor integrated device and wiring correction arrangement

A dynamic RAM provided with a data retention mode intended for low power consumption is provided. In the data retention mode, the current supply capabilities of voltage generation circuits which generate decreased voltage, increased voltage, reference voltage, etc., are limited in the range in which information retention operation in memory cells can be maintained, and the number of selected memory mats in the data retention mode is increased with respect to that of memory mats selected in the normal read/write mode and refresh mode. Special modes such as the data retention mode are set by combining an address strobe signal and other control signals and dummy CBR refresh is executed to release the special mode.

Special mode control method for dynamic random access memory

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Ohme, Japan

Wataru Arakawa