| 摘要 |
1,246,139. Manufacture of integrated circuits. NORTH AMERICAN ROCKWELL CORP. 17 Oct., 1968 [18 Oct., 1967], No. 49384/68. Heading H1K. A structure for use in the manufacture of integrated circuits has a monocrystalline insulative substrate bearing a plurality of semiconductor regions separated by isolating sidewalls borne by or forming part of the substrate. Circuits including diodes, transistors and passive components may be formed by normal diffusion techniques and interconnected by metal deposition across the flat surface of the structure. Substrate materials used are sapphire, magnesia, beryllia, spinel and chrysoberyl. Sidewalls may be formed of three materials or of silicon oxide. Silicon is the semi-conductor of the embodiments; germanium and gallium arsenide are suitable. In one embodiment a silicon oxide layer is deposited on a sapphire substrate, annealed to densify and vitrify it, and masked and etched to form sidewalls. Silicon is deposited overall (and between the sidewalls is epitaxial with the substrate) and the surface mechanically or chemically polished to remove material from the top of the sidewalls. In other embodiments the substrate and sidewalls are formed from an original insulative wafer by removal of material in the areas to be occupied by semi-conductor regions; semi-conductor is then applied by masked deposition. To remove the insulative material a phosphorus-doped oxide or phosphosilicate glass is heated in contact with the insulative wafer and the reaction product dissolved away. One method of applying a layer of the phosphorus-containing material is to decompose TEOS in an oxygencontaining atmosphere in the presence of trimethyl phosphate, trimethylphosphite or triethylphosphate. An alternative method of applying the layer is to deposit a thin silicon layer and to thermally oxidize this in the presence of a gaseous phosphorus-containing material. In each case the layer is then photoresist masked and etched away from the desired location of the sidewalls. The wafer is strongly heated in oxygen and then etched with hydrofluoric acid to remove the reaction product and excess phosphosilicate glass and leave the desired substrate and sidewalls. |
