| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device equipped with a correction function of global dispersion of a threshold. SOLUTION: A measuring circuit 9, after performing writing to any one SRAM out of SRAMs 2, 3, and 4 with a voltage lower than the normal voltage, detects the number of writing defective bits by performing reading of each memory cell with a normal voltage, performs writing with the normal voltage to detect the number of disturb defective bits by performing reading with the voltage lower than the normal voltage, and reading with the normal voltage to each memory cell, determines a state of the global threshold dispersion from a large and small relation of the number of detected writing defective bits and the number of the disturb defective bits, decides a back gate bias to be applied from the larger number of the defective bits, and records it in a fuse box 7. The back gate bias is applied to all the carried SRAMs by a well bias which a well bias generation circuit 8 generates based on the back gate bias recorded in the fuse box 7. COPYRIGHT: (C)2010,JPO&INPIT
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