Patent ID: 7023247

Claim:
A semiconductor device comprising a driver circuit for supplying a voltage at an output node in accordance with an input signal received at an input node, said driver circuit including: a first transistor connected between a first voltage and the output node, and turned on and off in accordance with voltage level of a first internal node; a second transistor connected between the output node and a second voltage, and turned on and off in accordance with voltage level of a second internal node; a third transistor connected in parallel with said second transistor, between the output node and the second voltage, and turned on and off, complementarily to said first transistor, in accordance with the voltage level of the first internal node; a control circuit for controlling voltages of the first and second internal nodes to complementarily turn on said first transistor and said second and third transistors in accordance with the input signal; and a fourth transistor connected between the second voltage and the second internal node, wherein said control circuit sets one of the first and second voltages for turning on said second and third transistors, turns off said first transistor when said second and third transistors are turned on, and supplies the one of the first and second voltages to the second internal node for a predetermined period, said second transistor has a driving force for supplying the second voltage to the output node and higher than a driving force of said third transistor, said fourth transistor is turned on when said first transistor turns on, and said first, second, third, and fourth transistors are field-effect transistors having respective gate oxide films, and the gate oxide film of said fourth field-effect transistor has a dielectric constant different from dielectric constant of said gate oxide film of at least one of said first, second, and third transistors.