Fujitsu Corporation

Tatsuhiro Watanabe

Shinya Fujioka

Yoshiaki Okuyama

Nobumi Kodama

Yasuhiro Takada

A burn-in test, including first to sixth steps where voltages are applied for the same lengths of time in each step, is applied to a semiconductor memory having alternately arranged bit line pairs with twist structure where the bit lines cross each other and bit line pairs with non-twist structure where the bit lines are parallel to each other. Since lengths of time in which a stress is applied for all bit lines can be equally set, no deviation occurs in lengths of time where stress is applied between the bit lines. Characteristics of memory cells can be prevented from excessively deteriorating from the burn-in test. Further, the number of bit lines not having stress applied can be minimized in the first to sixth steps. Accordingly, the ratio of the bit lines having stress applied can be increased, which reduces the burn-in test time. Thus, test cost can be reduced.

Semiconductor memory and burn-in test method of semiconductor memory

A semiconductor memory device includes respective regions of a column decoder and a sense amplifier drive circuit arranged to lie opposite to each other on a semiconductor chip, respective regions of a memory cell array, a column gate and a sense amplifier arranged between the regions of the column decoder and the sense amplifier drive circuit, a plurality of column selection lines led out from the region of the column decoder, connected to respective column gate portions of the region of the column gate, and collected and arranged with units of groups of a predetermined number above the region of the column gate so as to have a smaller arrangement pitch than that of the column gate portion, and at least one sense amplifier drive signal line led out from the region of the sense amplifier drive circuit, connected to respective sense amplifier portions of the region of the sense amplifier, and arranged above the region of the sense amplifier so as to lie next to each group of the column selection lines. By the constitution, it is possible to constitute the memory device without any problem or difficulty from a viewpoint of the layout thereof even if it is a large capacity memory such as a 16 M-bit DRAM.

Growing community of inventors

Kawasaki, Japan

Tatsuhiro Watanabe