Planar Schottky diodes with low barrier height for microwave detector application

The results of designing and investigation of a sensitivity of microwave detectors, based on planar GaAs diodes with low effective Schottky barrier height are reported. Low pressure metalorganic chemical vapor deposition (MOCVD) technology was used for the modification of the effective Schottky barrier height by means of precise δ-doping of near-surface layer and for successive deposition of an aluminium film in non-interrupted growth run. A complete quantum-mechanical numerical simulation of the effect produced by δ-doping on the current-voltage characteristic of the modified diodes is carried out. Comparison of computational results with the experimental characteristics of diodes shows a rather good agreement. Analysis of the carried-out research has allowed one to choose optimum parameters of δ-layers for producing low barrier diodes (∼0.2 eV) with a reasonable ideality factor (n<1.5). The best performance of the low barrier diode corresponding to γ=5000 V/W and NEP=(3÷6)·10-12 W·Hz-12/ at 150 GHz was at zero bias voltage.