Tunnel diodes complement high-performance detectors

Manufacturing techniques for producing high reliability Ge tunnel diodes for microwave and EW systems are surveyed. Batch-processed wafers which can operate in 100 C environments are packaged in hermetic pill, microstrip and coaxial forms. Processing involves die-attach and wire-bonding methods similar to those involved in manufacturing Schottky diodes. Tests have shown that the devices can be driven to 20 dB over rating before burnout occurs. The diodes are planar, which eliminates the presence of delicate structures, and are subjected to oxide passivation as a protective measure. Heavily doped junctions are the source of the tunneling effect from which the device name is derived. Comparisons of the performances of back, tunnel and Schottky diodes are provided to emphasize the strong points of each.