HIGH-CURRENT DENSITY CARBON-DOPED STRAINED-LAYER GAAS (P+)-INGAAS(N+)-GAAS(N+) P-N TUNNEL-DIODES

Data are presented showing that a GaAs p-n tunnel diode can be modified, and improved, with the introduction of an InxGa1-xAs layer (L(z) approximately 100 angstrom) in the barrier region to reduce the energy gap (and carrier mass) and increase the tunneling probability without sacrificing the high injection barrier and voltage of GaAs. Peak tunnel current densities in the range (1-1.5) X 10(3) A/cm2 are obtained, with peak-to-valley current ratios of approximately 20:1 and voltage ''swings'' from peak tunnel current to equal injection current of greater than or similar to 1 V (less-than-or-equal-to 1 V for GaAs). The C-doped GaAs(p+)-InGaAs(n+)-GaAs(n+) diodes are grown by metalorganic chemical vapor deposition and are compared to GaAs tunnel diodes fabricated by the usual alloy process (i.e., local liquid phase epitaxy).