Abstract: In the semiconductor memory device according to the present invention, a n type drain diffused region (9a) to be connected to a bit line (12) is formed on a p type semiconductor substrate (1) and a n type source diffused region (9b) is formed with a prescribed spacing from the n type drain region (9a). On the p type silicon substrate (1), a p type diffused region (16a) of high impurity density and p type diffused region (16b) of high impurity density are formed in such a manner that they are in contact with the n type drain diffused region (9a) and the n type source diffused region (9b), respectively, but not in the channel region of the n channel MOS transistor (18). Consequently, the .alpha. particle-generated charges can be decreased without changing the threshold voltage of the transfer gate transistor.

Abstract: An electrically programmable read only memory cell formed in a face of a semiconductor substrate which includes a floating gate transistor having a floating gate and a control gate formed at least partially in a trench in the substrate. The trench has bottom corners sufficiently sharp so as to enhance the likelihood of tunnelling between corner regions of the trench and the floating gate over that between planar surface regions of the trench and floating gate.

Abstract: A circuit is described that provides a quick charge and discharge of a row of memory cells. A first transistor has its collector-emitter path coupled between a first voltage and a row of memory cells, and a base coupled to an input terminal. A second transistor has its collector-emitter path coupled to the first voltage by a resistor and to a voltage level setting device, and a base coupled to the input terminal. A third transistor has its collector-emitter path coupled between the row of memory cells and a second voltage, and a base coupled to a voltage level shifting device. As the row of memory cells are selected, the third transistor becomes less conductive, thereby sinking less current from the row of memory cells and allowing the inherent capacitance of the row of memory cells to charge more quickly. As the row of memory cells are deselected, the third transistor becomes more conductive, thereby sinking more current from the row of memory cells and discharging the inherent capacitance more quickly.

Abstract: A disk drive is provided with a vent tube which is long (i.e., 20 inches) compared to its bore (i.e., 0.013 inch) to minimize diffusion of water vapor into the drive without seriously affecting pressure gradients along the length. Minimum bore diameters are given for specified lengths of vent tube. Conveniently, a desiccant is employed with a heater to absorb water vapor admitted to the drive and to expel water vapor when the drive is operated. A thermally-operated valve is also employed to expel water vapor when the drive operates. The desiccant may be employed in a chamber separated from the disk chamber, whereupon pressure valves are provided to adjust the pressures in the drive.