Glass-Passivated GaAs Chip Tunnel Diode

A novel approach to the fabrication of tunnel diodes described. The experimental tunnel diode is a gallium arsenide planar device, using a conventional alloyed junction in an epitaxially grown GaAs substrate, and hermetically sealed by a high-temperature glass coating. The tunnel diode is fused to a circuit module using a solder reflow method. This package provides a high degree of mechanical reliability, great reduction in size, and an easy means of interconnection. Another unique feature is that the peak current is tailored electrically to within 1% by altering the impurity distribution near the junction, rather than by the conventional electrochemical etching technique. The resulting gallium arsenide tunnel diodes, having peak currents of 8 mA and capacitances of 5 pF, are suitable for use in a one-nanosecond switching circuit.