This application relates to integrated semiconductor circuits and devices, and more specifically, to fabrication of integrated semiconductor circuits and devices having integrated photonic components, devices, and systems.
Integration of integrated circuits and optoelectronic circuits is desirable in many applications, including various optical sensing devices, imaging devices, and optical fiber communication devices and systems near 1.31 and 1.55 microns. One of widely-used components in optoelectronic circuits is optical detectors for converting optical signals into electronic signals. A photodiode may be used as an optical detector in optoelectronic circuits. Typically, such a photodiode includes a three-layer p-i-n (PiN) structure that is electrically biased to be sensitive to received light. The “p” layer in the PIN structure is a p-doped layer; the “i” layer is an undoped intrinsic layer or a lightly-doped layer; and the “n” layer is a n-doped layer. For sensing light near 1.31 and 1.55 microns, indium phosphide (InP) and germanium (Ge) may be used as the light sensing materials to form p-i-n structures in photodiode detectors.