Integration of Si-CMOS embedded photo detector array and mixed signal processing system with embedded optical waveguide input

Arrays of embedded bipolar junction transistor (BJT) photo detectors (PD) and a parallel mixed-signal processing system were fabricated as a silicon complementary metal oxide semiconductor (Si-CMOS) circuit for the integration optical sensors on the surface of the chip. The circuit was fabricated with AMI 1.5μm n-well Si-CMOS process and the embedded PNP BJT PD has a pixel size of 8μm by Sμm. BJT PD was chosen to take advantage of its higher gain amplification of photo current than that of PiN type detectors since the target application is a low-speed and high-sensitivity sensor. The photo current generated by BJT PD is manipulated by mixed-signal processing system, which consists of parallel first order low-pass delta-sigma (ΔΣ) oversampling analog-to-digital converters (ADC). There are 8 parallel ADCs on the chip and a group of 8 BJT PDs are selected with CMOS switches. An array of PD is composed of three or six groups of PDs depending on the number of rows.

Duke Scholars

Author Martin A. Brooke Electrical and Computer Engineering

Author Nan Marie Jokerst Electrical and Computer Engineering