| 摘要 |
1,246,294. Semi-conductor devices. SONY CORP. 3 Dec., 1968 [12 Dec., 1967], No. 57279/68. Heading H1K. A monocrystalline semi-conductor substrate is prepared for the side-by-side deposition of mono- and poly-crystalline regions as follows. The surface is masked with a first layer and a seeding site layer deposited at least on the surfaces exposed through the mask, then a second masking layer is formed covering at least the areas exposed by the first mask and the parts of the seeding layer left exposed are etched away. Finally both masking layers are removed to expose the required seeding site layer. Vapour deposition of semi-conductor material then results in a layer which is polycrystalline over areas covered by the seeding site layer and monocrystalline elsewhere. Typically the substrate and seeding site layers are of silicon and the masking layers of silicon oxide or nitride. The masks are shaped using photo-resist and etching steps and the exposed parts of the seeding site layer etched away in a hydrofluoric-nitric acid mix. The seeding site layer is at least 50 Š thick so that areas covered by it can be visually distinguished from the adjacent oxide to facilitate registration of the masks. Where substrate and seeding site layers are of germanium, sodium hypochlorite is used as an etchant. |
