| 摘要 |
1518988 Semiconductor device manufacture PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 5 Sept 1975 [10 Sept 1974] 36624/75 Heading H1K In the manufacture of a planar IC an insulating layer on a semiconductor wafer surface is first covered with an apertured auxiliary layer, a corresponding aperture formed in the insulating layer via the aperture in the auxiliary layer, a second insulating layer roughly as thick as the first provided over the auxiliary layer and apertures, and the auxiliary layer removed together with overlying portions of the second insulating layer to give a level unbroken insulating surface. In the described processes in which the semiconductor is silicon, both insulating layers silicon oxide, and the auxiliary layer aluminium, the first insulating layer is apertured by etching in buffered hydrofluoric acid and the aluminium layer removed by treatment with ferric chloride or a mixture of acetic and phosphoric acids. In one embodiment the second insulating layer contains dopant which is subsequently diffused into the water. In another a P-type layer is initially diffused into an N-type wafer via the aperture in the first insulating layer, two apertures formed in the second (undoped) insulating layer at opposite ends of the diffused layer, and aluminium finally deposited overall and anodized patternwise throughout its thickness to define together with the diffused layer two intersecting conductors 27b and 27c-21 (Fig. 7) isolated by the second insulating layer 24 where they cross. In a variant of this embodiment, after removal of the auxiliary layer an aperture is formed in the first insulating layer, aluminium deposited overall to contact the semiconductor via the aperture and covered with an oxide through apertures in which it may contact a further layer of metallization. Alternative materials suggested are germanium and gallium arsenide as semiconductor, alumina and silicon nitride for insulating layers, and tungsten and molybdenum, for which suitable etchants are specified, for the auxiliary layer. |
