| In this work, the fabrication and integration process for both on-wafer metal-semiconductor-metal (MSM) PDs and thin film inverted MSM (I-MSM) PDs is discussed in detail. Both on-wafer MSM PDs and I-MSM PDs were investigated for the dark current, responsivity, impulse response, bandwidth, and capacitance variation as a function of varying forger width, spacing, active area size, and absorbing layer thickness. The responsivity, bandwidth, and capacitance of on-wafer MSM PDs were statistically modeled using a DOE matrix. The DOE modeling revealed that the finger width, active area size, and material thickness are not critical factors defining the bandwidth. However, the capacitance is sensitive to the active area of the MSM PDs. The I-MSM PDs were studied for the correlation to on-wafer MSM PDs for responsivity and impulse response. It shows that the MSM PDs fabricated in this work with typical structures are transit time limited, so the devices with 1 mum finger spacing have the best AC performance.;The thin film I-MSM PDs were integrated into photoreceiver and waveguide optical links. The photoreceiver integrated with I-MSM PDs demonstrated a bandwidth of 400 MHz with large size detectors, 200 mum x 200 mum square. An I-MSM PD with a 40 mum diameter was integrated onto a 10 Gbps CMOS chip and is under test. An optical link with an embedded thin film I-MSM PD in a channel waveguide showed a good eye diagram at 1 Gpbs on both Si/SiO 2 and ceramic substrates. Rectangular I-MSM PDs were also optimized and integrated onto ceramic substrates for an optical link at 10 Gbps. |
