IMPROVEMENTS IN OR RELATING TO MEMORY DEVICES

摘要

1,201,659. Cathode ray storage tubes; semiconductor devices. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. 5 Dec., 1968 [25 Sept., 1967; 7 Dec., 1967], Nos. 39331/67 and 55787/67. Headings H1D and H1K. The target of a cathode-ray storage tube for storing binary data comprises an unsaturated oxide or fluoride layer of material which exhibits bombardment-induced conductivity which persists after the bombardment ceases, the material being supported on a conducting or semi-conducting substrate. In the drawing the target comprises a layer of silicon monoxide 11, which may be about 1 micron thick, deposited on an N-type silicon layer 13 which forms a junction with a P-type silicon layer 14. The strength of the scanning electron beam is controlled according to whether the operation desired is reading, writing or erasing, for which the beam intensities may be 5 Î 10-10, 10-8 and more than 10-7 A/square micron respectively. The sensitivity may be increased by applying a very thin layer of gold or platinum to the surface of the oxide layer, and the erase time may be reduced by operating the target at 200‹ C. The output may be derived from a returning beam reflected from the target to an electron multiplier (not shown) instead of from the junction between layers 13 and 14, and the semi-conductor substrate may be replaced by a metal one.