High-speed blue-, red-, and infrared-sensitive photodiode integrated in a 0.35 μm SiGe:C-BiCMOS process

Abstract

A monolithically integrated photodiode with SiGe:C anode, which exhibits an excellent spectral responsivity of typically 0.21/0.42/0.53 A/W at 410/660/785nm and sub-ns rise/fall times, fabricated without process modification is presented. The bandwidth of the photodiode exceeds 1300/490/260MHz at 410/660/785nm favoring this device for universal optical storage applications. By applying a reverse bias voltage up to 10 V the photodiode features responsivities up to 0.6 A/W for 410nm due to avalanche multiplication.

A High Performance Photodetector Suitable for Visible Light and Near Infrared Applications

“…5) Table I tabulates the comparison among a couple of detectors in BiCMOS processes reported in recent years for optical storage application. 3,4) Nemecek et al reported the pure-Si p-i-n diode with 17 V operating voltage. 3) By comparing the p-i-n photodiode with PTPD, the former needs larger detecting region and higher bias voltage than the latter.…”

“…The responsivity of the latter is higher than that of the former. In Meinhardt's research, 4) the conventional PT degenerated into a photodiode. Blue light could be absorbed by a simple BC junction but could not be further amplified.…”

“…Responsivities of 0.25 and 0.42 A/W at wavelengths of 410 and 660 nm under 17 V bias were reached, respectively, but the high operating voltage is not convenient to portable device applications. Meinhardt et al 4) provided a special heterojunction phototransistor (HPT) without the emitter in a 0.35 mm SiGe:C BiCMOS process. The conventional BC junction and the buried-n þ / p-sub junction are utilized for visible light absorption.…”

Integration of Photonic Detectors in Standard SiGe HBT BiCMOS

“…Our SiGe:C BiCMOS process offers some opportunities to solve this problem and all modifications affect only mask layouts and leave the fabrication process itself unchanged (23). A very effective way to extend the applicability over the entire visible range is to make use of the double diode (DPD) concept proposed in (2).…”