Silicon-based resonant-cavity-enchanced photodiode with a buried SiO2 reflector

We report on a silicon-based resonant cavity photodiode with a buried silic on dioxide layer as the bottom reflector. The buried oxide is created by us ing a separation by implantation of oxygen technique. The device shows larg e Fabry-Perot oscillations. Resonant peaks and antiresonant troughs are obs erved as a function of the wavelength, with a peak responsivity of about 50 mA/W at 650 and 709 nm. The leakage current density is 85 pA/mm(2) at -5 V , and the average zero-bias capacitance is 12 pF/mm(2). We also demonstrate that the buried oxide prevents carriers generated deep within the substrat e from reaching the top contacts, thus removing any slow carrier diffusion tail from the impulse response. (C) 1999 American Institute of Physics. [S0 003-6951(99)02109-9].