High speed, high efficiency resonant-cavity enhancedInGaAs MSM photodetectors

Abstract
Resonant-cavity-enhanced In/InGaAs metal-semiconductor-metal photodetectors designed for 1.31 µm wavelength and rear illumination are demonstrated. The bottom mirror of the microcavity consists of an InGaAlAs/InAlAs buried Bragg reflector, and the top mirror comprises the interdigitated contact metallisation and a Si/SiNx quarter wave stack deposited on the surface. An external quantum efficiency of 77%, and a 3 dB bandwidth of 10 GHz, are achieved with an InGaAs absorber thickness of 300 nm.