GB1084598A - A method of making passivated semiconductor devices - Google Patents

Abstract

1,084,598. Semi-conductor devices. RADIO CORPORATION OF AMERICA. July 30, 1965 [Aug. 7, 1964], No. 32673/65. Heading H1K. Passivated semiconductor devices are made by forming a planar PN junction parallel to the major surfaces of a wafer of semi-conductor, forming grooves in one major surface to cut through the PN junction and thus give a plurality of mesas, filling the grooves with passivating material and attaching electrodes the exposed portions of the mesas. The major surface which is not grooved is fixed to a conductive substrate. A p<SP>+</SP> type substrate 22 of Si, has semi-conductor wafer of Si, Ge or GaAs containing a PN junction joined thereto by a layer 24 of Cr, Ni, Ta, W, Nb, Mg, Ag, Co, Cu or Ti. The wafer and substrate are joined by hot pressing in an induction furnace between carbon blocks. Grooves are then cut in the wafer to give mesa portions 40, the sides of which are coated with SiO 2 44 and then the grooves filled with glass 46. The exposed surfaces of the mesas and the substrate are coated with electroless nickel and then solder applied. Electrodes are applied and soldered in place using a carbon jig (Fig. 8, not shown). The structure may then be cut vertically into a number of separate devices. In a modification a horizontal cut may be made prior to applying the lower electrode, to cut away the connecting substrate portions. Instead of joining individual electrodes in the array of devices, a plurality of devices may be joined by one conductive strip for use in integrated circuits.