摘要:
An object of the present invention is to provide a technique of reducing the power consumption of an entire low power consumption SRAM LSI circuit employing scaled-down transistors and of increasing the stability of read and write operations on the memory cells by reducing the subthreshold leakage current and the leakage current flowing from the drain electrode to the substrate electrode.Another object of the present invention is to provide a technique of preventing an increase in the number of transistors in a memory cell and thereby preventing an increase in the cell area.Still another object of the present invention is to provide a technique of ensuring stable operation of an SRAM memory cell made up of SOI or FD-SOI transistors having a BOX layer by controlling the potentials of the wells under the BOX layers of the drive transistors.
摘要:
The present invention provides a high speed and low power consumption LSI operable in a wide temperature range in which a MOS transistor having back gates is used specifically according to operating characteristics of a circuit.In the LSI, an FD-SOI structure having an embedded oxide film layer is used and a lower semiconductor region of the embedded oxide film layer is used as a back gate. A voltage for back gates in the logic circuits. having a small load in the logic circuit block is controlled in response to activation of the block from outside of the block. Transistors, in which the gate and the back gate are connected to each other, are used for the circuit generating the back gate driving signal, and logic circuits having a heavy load such as circuit block output section, and the back gates are directly controlled according to the gate input signal.
摘要:
An object of the present invention is to provide a technique of reducing the power consumption of an entire low power consumption SRAM LSI circuit employing scaled-down transistors and of increasing the stability of read and write operations on the memory cells by reducing the subthreshold leakage current and the leakage current flowing from the drain electrode to the substrate electrode.Another object of the present invention is to provide a technique of preventing an increase in the number of transistors in a memory cell and thereby preventing an increase in the cell area.Still another object of the present invention is to provide a technique of ensuring stable operation of an SRAM memory cell made up of SOI or FD-SOI transistors having a BOX layer by controlling the potentials of the wells under the BOX layers of the drive transistors.
摘要:
Thresholds of MISFETS of a Full Depletion-type SOI substrate cannot be controlled by changing impurity density as with bulk silicon MISFETs. Therefore, it is difficult to set a suitable threshold for each circuit. According to the semiconductor device of the present invention, gate electrodes of P-channel type MISFETs composing a memory cell are made of N-type polysilicon, gate electrodes of N-channel type MISFETs are made of P-type polysilicon and gate electrodes of P-channel type and N-channel type MISFETs of peripheral circuits and a logic circuit are made of P-type silicon germanium. A suitable threshold can be achieved for each circuit using a SOI substrate, thereby making it possible to fully leverage the characteristics of the SOI substrate.
摘要:
The present invention provides a high speed and low power consumption LSI operable in a wide temperature range in which a MOS transistor having back gates is used specifically according to operating characteristics of a circuit.In the LSI, an FD-SOI structure having an embedded oxide film layer is used and a lower semiconductor region of the embedded oxide film layer is used as a back gate. A voltage for back gates in the logic circuits having a small load in the logic circuit block is controlled in response to activation of the block from outside of the block. Transistors, in which the gate and the back gate are connected to each other, are used for the circuit generating the back gate driving signal, and logic circuits having a heavy load such as circuit block output section, and the back gates are directly controlled according to the gate input signal.
摘要:
An object of the present invention is to provide a technique of reducing the leakage current of a drive circuit for driving a circuit that must retain a potential (or information) when in its standby state.A semiconductor integrated circuit device of the present invention includes a drive circuit for driving a circuit block. This drive circuit is made up of a double gate transistor with gates having different gate oxide film thicknesses. When the circuit block is in its standby state, the gate of the double gate transistor having a thinner gate oxide film is turned off and that having a thicker gate oxide film is turned on. This arrangement allows a reduction in the leakage currents of both the circuit block and the drive circuit while allowing the drive circuit to deliver or cut off power to the circuit block.
摘要:
In this invention, high manufacturing yield is realized and variations in threshold voltage of each MOS transistor in a CMOS•SRAM is compensated. Body bias voltages are applied to wells for MOS transistors of each SRAM memory cell in any active mode of an information holding operation, a write operation and a read operation of an SRAM. The threshold voltages of PMOS and NMOS transistors of the SRAM are first measured. Control information is respectively programmed into control memories according to the results of determination. The levels of the body bias voltages are adjusted based on the programs so that variations in the threshold voltages of the MOS transistors of the CMOS•SRAM are controlled to a predetermined error span. A body bias voltage corresponding to a reverse body bias or an extremely shallow forward body bias is applied to a substrate for the MOS transistors with an operating voltage applied to the source of each MOS transistor.
摘要:
When threshold voltages of constituent transistors are reduced in order to operate an SRAM circuit at a low voltage, there is a problem in that a leakage current of the transistors is increased and, as a result, electric power consumption when the SRAM circuit is not operated while storing data is increased. Therefore, there is provided a technique for reducing the leakage current of MOS transistors in SRAM memory cells MC by controlling a potential of a source line ssl of the driver MOS transistors in the memory cells.
摘要:
The semiconductor device makes a comparison between a word-line timing signal for determining a word-line activation time and a reference signal, applies a back-gate bias for enlarging a read margin when the result of the comparison represents a low condition of the read margin, and applies a back-gate bias for enlarging a write margin when the comparison result represents a low condition of the write margin. The reference signal is selected depending on whether to compensate an operating margin fluctuating according to the word-line activation time (or word-line pulse width), or to compensate an operating margin fluctuating according to the process fluctuation (or variation in threshold voltage). By controlling the back-gate biases according to the word-line pulse width, an operating margin fluctuating according to the word-line pulse width, and an operating margin fluctuating owing to the variation in threshold voltage during its fabrication are improved.
摘要:
A speed performance measurement circuit that may perform speed performance measurement is provided between a first logic circuit and a second logic circuit. The speed performance measurement circuit includes a first flip flop that stores first data, a first delay circuit that delays the first data and generates second data, and a second flip flop that stores the second data. Furthermore, the speed performance measurement circuit includes a first comparator circuit that compares output of the first flip flop to output of the second flip flop, and a third flip flop that stores output data from the first comparator circuit in accordance with timing of the first clock signal. Data in a normal path is compared to data in a path delayed by a certain time to measure speed, and power voltage of a circuit is determined based on such comparison. Thus, change in speed with respect to power voltage in a critical path can be measured.