Toshiba Corp claims to have come close to finding the philosopher’s stone by perfecting a chip architecture that enables it to fabricate transistors that will switch from a power supply of only 500mV, cutting power consumption to a hundredth of that required for 5V devices and a fortieth of that for 3.3V devices. The company will describe the technique at the International Solid State Circuits Conference in San Francisco. The secret is a circuit structure and control methodology that enables the threshold voltage to be individually controlled for each transistor in the device; the approach makes use of the fact that the threshold voltage of a transistor falls when the electrostatic level on which it is fabricated is high, and vice versa. It uses a Silicon-On-Insulator substrate to isolate transistors from one another, and an original structure for individual control of the electrostatic level of each transistor’s substrate and its threshold voltage. This assures threshold voltage is kept below 0.2V when the transistor is on, and at 0.5V when off.
