UC Santa Barbara

The low-frequency power spectrum has been measured for ErAs:InAlGaAs diodes and shows at least a ten-times reduction of 1/f noise compared to traditional Al Schottky diodes on the same semiconductor material. These junctions are grown by molecular beam epitaxy, preventing oxidation and other contamination at the junction. The major noise source for these devices is attributed to the sidewalls and not the junction itself. Low-frequency oscillations have also been observed and associated with a deep trap level estimated to be similar to 200 meV below the conduction band edge by the comparison of diodes with different InAlGaAs compositions and confirmed by deep level transient spectroscopy. This deep level could be associated to erbium incorporation in the depletion region.