| 摘要 |
PURPOSE:To improve remarkably the efficiency of burn-in and apply stably the stress of voltage like DC to a word line part by applying simultaneously voltage stress to all word lines or word lines more than the number of the lines selected in the time of usual operation through a word line driving circuit in the time of a voltage stress test, in view of circumstances peculiar to DRAM to wish to make positively the object of screening the cell transistor, to the gate of which a boosted voltage is applied. CONSTITUTION:A DRAM includes a control circuit to control so that a word line driving circuit selects lines more than the lines selected according to the input of an outer address signal in the time of usual operation, on the basis of the control signal of a stress test. A PMOS transistor is used to the transistor for driving the word line of a high potential side where a cell transistor is a NMOS transistor, the gate of this PMOS transistor is fixed into the earth potential in the time of the stress test, and its gate node is stably kept. |
