PATENT COVER GRAPHIC |
United States Patent 3,498,833 March 3, 1970 Double Masking Technique For Integrated Circuit William I. Lehrer Filed July 8, 1966 |
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Abstract of the DisclosureA deposited pattern is sharply defined on a surface by use of a two-step lifting process. To do this, a first layer of liftable material is deposited on the surface in the shape of the desired pattern. Then a second layer of lifting material is deposited over the exposed surface and the first layer of liftable material. The first layer of liftable material is removed, leaving the second layer of lifting material to sharply define the desired pattern on the exposed surface. Metal or other permanent material is then deposited on both the exposed surface and the second layer of lifting material. Removal of this second layer of lifting material leaves on the surface the sharply defined metal pattern. Precise control of the substrate temperature as a function of the thickness of the deposited material controls the depth of the alloy formed between the deposited material and the surface. |
Figure descriptions: cover graphic |
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Citations [54]:2,995,461 08/1961 Bolcey 2,923,624 02/1960 Hensler 2,748,031 05/1956 Kafig 3,379,568 04/1968 Holmes |
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