Kawasaki Microelectronics, Inc.

Ryuji Ariyoshi

Isamu Kuno

Takahito Fukushima

Junji Aoike

Hiroyasu Kunitomo

Tomoaki Nimura

A semiconductor integrated circuit that includes a circuit element with a reduced parasitic capacitance and has a short start-up time. A well of the different type of conduction from that of the substrate is formed in the area of the surface of the semiconductor substrate under the circuit element. A constant voltage, which biases the junction between the well and the semiconductor substrate in a reverse direction, is applied to the well through a resistor having a higher impedance compared with the impedance of the capacitance of the reverse-biased junction between the well and the substrate at the frequency of the signal applied to the circuit element.

Semiconductor integrated circuit having a reduced parasitic capacitance and short start-up time

A semiconductor integrated circuit that has an output circuit in which an output-stage operating voltage lower than a power supply voltage is applied to an output stage is provided. Even when the power supply voltage is lowered, a sufficient output signal amplitude can be obtained. An increase in circuit scale can be prevented and the power consumption can be reduced. An output-stage operating voltage supply source, including an N-channel MOS transistor having a first threshold voltage, applies an operating voltage lower than a power supply voltage to the output stage of the output circuit. A drive-circuit operating voltage supply source, including an N-channel MOS transistor having a second threshold voltage lower than the first threshold voltage, applies a drive-circuit operating voltage higher than the output-stage operating voltage to a drive circuit.

Semiconductor integrated circuit having output circuit

A semiconductor integrated contains a first MOS transistor of a first conductivity type formed on a surface of a semiconductor substrate, and a second MOS transistor of the first conductivity type having a drain-source breakdown voltage lower than that of the first MOS transistor. The second MOS transistor is used as an anti-fuse, which can be changed to a conductive state with a low writing voltage that does not damage the first MOS transistor. The second MOS transistor is fabricated such that a concentration of a second conductivity type impurity in at least a portion of the channel region adjacent to the drain region is higher than that in a corresponding portion of the first MOS transistor.

Growing community of inventors

Chiba, Japan

Ryuji Ariyoshi