| 摘要 |
1,261,651. Etching. INTERNATIONAL BUSINESS MACHINES CORP. 3 March, 1969 [1 March, 1968], No. 11127/69. Heading B6J. In a method of making semi-conductor devices, a first material is deposited on the surface of a. semi-conductor body to leave selected areas of the surface uncovered, a layer of a second material is deposited over the body which is then subjected to an etchant which penetrates the layer to dissolve underlying first material and subsequently any of the second material previously supported by the first material is removed. In a first embodiment, Figs. 1A-5A, a silicon substrate 1 bearing N- conductivity silicon layer 2 and a. silicon oxide layer 3 is etched at 5 in an atmosphere of hydrogen or argon. Concurrently with etching, N+ silicon is deposited. Ohmic contacts 7 are formed. by vapour deposition of gold/antimony and the protruding oxide edges removed by etching, ultrasonically or by wiping. The areas not covered: by silicon oxide are electrolytically coated with a nickel mask 10. The central silicon oxide bridge is then removed by etching through a. photo-resist with buffered hydrofluoric acid. A. layer of gold/chromium, G, is then deposited and the photoresist removed. The nickel mask 10 is then etched away with nitric acid. This acid also removes areas of nickel underlying areas of gold/chromium deposited therein in the step of forming area G. Finally all gold/chromium except at G is removed by wiping. In a second embodiment, Figs. 6-10, there is formed, on the surface of an N- silicon insert 24 in silicon dioxide layer 21, a layer 25 of gold/ antimony.. Part of, layer 21 is removed by etching, Fig. 7, and a. nickel layer 26 is deposited. A further portion of the silicon dioxide layer 21' is then removed by etching and the entire surface subsequently coated with gold/ chromium layer 22. Nickel layer 26 is then etched through the gold/chromium layer using nitric acid. The gold/chromium layer at 27. is then wiped off. The remaining gold/chromium layer 22 may then be electrolytically reinforced and a layer 23 of silicon dioxide deposited by cathode sputtering. Drain electrode 25<1> is then formed over the layer 23. |
