| 摘要 |
<p>1,253,527. Semi-conductor devices. NATIONAL RESEARCH DEVELOPMENT CORP. 20 Nov., 1969 [30 Nov., 1968], No. 56979/68. Heading H1K. [Also in Division B6] A silicon wafer containing a plane PN- junction near one surface is bonded at that surface to a heat sink. Material is next uniformly removed from the other surface to thin the slice which is then oxide-masked and etched to delineate individual diodes. The resultant structure may be any of those shown in the figure, that of figure 3a being suitable for the production (by division of the heat-sink) of individual diodes. The preferred use is to parallel the individual diodes and use them in a single cavity as an avalanche microwave oscillator. Typically the heat sink is a copper plate and it and the silicon wafer, which is titanium-coated on its bonding face, are both coated with silver or gold so that they may be thermo-compression bonded together. Thickness reduction of the silicon may be by mechanical polishing and/or planar etching. The oxide mask may be silica produced by anodization or may be vapour deposited silicon monoxide. The structure shown in Fig. 3b may be formed using an etchant selective for N-type material. In making the structure of Fig. 3c etching is stopped at a point close enough to the junction that the diodes formed may be isolated in use by a depletion region associated with the reverse biased junction.</p> |
