| 摘要 |
1,139,746. Diodes. PHILCO-FORD CORP. 22 June, 1966 [22 June, 1965], No. 27886/66. Heading H1K. The PN junction of a tunnel diode lies between a mesa of one conductivity type and a smaller mesa of the opposite type. A typical device is made in multiple by coating one face of an N-type germanium wafer with aluminium, reducing this to a series of dots by etching, cutting into individual units and then flash alloying the aluminium to the germanium. After thermocompression bonding a gold wire to the aluminium residue the device is electrolytically etched in potassium hydroxide to undercut the bond and form a mesa. Subsequently the device is re-etched in oxalic acid, preferably mixed with hydrogen peroxide and a wetting agent, to preferentially remove the aluminium-alloyed region to form the second mesa of smaller cross section. The completed device is then mounted in a ceramic tube between metal end plugs. |
