| abstract |
1,263,980. Making semi-conductor devices. MATSUSHITA ELECTRONICS CORP. 28 May, 1969 [5 June, 1968; 12 Aug., 1968 (2)], No. 26948/69. Heading H1K. In most embodiments manufacture of semiconductor devices utilizes the fact that whereas a deposited film of palladium or high palladium alloy will adhere strongly to a metal or semiconductor surface it has only low adhesion to silicon oxide and will peel away from this when exposed to an atmosphere containing hydrogen. In one process palladium is deposited on to a silicon body covered with an apertured silicon oxide layer and is then exposed to a hydrogenous atmosphere. A gas blast will then blow away palladium except that in contact with the silicon. Aluminium may be deposited and patterned to complete the contact. (A Schottky barrier or ohmic contact may be formed in dependence on the resistivity of the silicon). In another process an aluminium contact is formed within an apertured silicon oxide layer and also overlies the surrounding oxide. Palladium is deposited over the entire surface and stripped with hydrogen except where it overlies the aluminium. A gold wire may be thermocompression bonded to the palladium. In a further process palladium is deposited through and on to a silicon oxide layer and the deposit is covered with aluminium. That part of the palladium overlying the oxide is then pulled away carrying with it the overlying aluminium. In a different embodiment a process is suggested in which a metal other than Pd but which similarly has poor adhesion to silicon oxide is coated over an apertured oxide layer and is itself coated overall with Pd. Exposure of the structure to hydrogen then lifts the Pd and other metal only in the region where the composite coating overlies oxide. In the above methods aluminium alloys, gold, or nickel may replace aluminium. |