FABRICATION AND PERFORMANCE-CHARACTERISTICS OF HIGH-SPEED ION-IMPLANTED SI METAL-SEMICONDUCTOR-METAL PHOTODETECTORS

We have fabricated high-speed Si metal-semiconductor-metal photodetect ors using F-19(+) ion implantation in low-doped Si. Bandwidths in exce ss of 6 GHz have been obtained that represent more than an order-of-ma gnitude improvement over unimplanted counterparts. Measurements with s hort optical pulses show that the increase in bandwidth is due primari ly to a shorter carrier lifetime in implanted In the absence of implan tation, the response under short optical pulse excitation has a long d ecay with a time constant of similar to 0.35 ns. We carried out an opt ical fiber transmission experiment using a GaAs (lambda similar to 0.8 5 mu m) laser source and the implanted Si photodetector. Error-free tr ansmission (bit error rate < 10(-11)) with good receiver sensitivity w as obtained at 2 Gbits/s. These results demonstrate that implanted Si can be used asa detector for short-wavelength fiber-optic communicatio n systems for speeds to a few gigabits per second. Monolithic integrat ion of this detector technology with conventional Si processing offers the potential for low-cost receiver designs. (C) 1997 Optical Society of America.