Hybrid integration of waveguide photodiode and preamplifier IC using Au stud bump

The authors developed an InP photodiode (PD) module integrated with an InP HBT preamplifier IC by using an Au stud bump. Theoretical analysis shows that the deviation of the group delay linearly increases in the inductance between the PD and IC. The flip-chip bonding based on the Au stud bump effectively reduces the inductance without sacrificing the individual device performance and reliability. Experimental results show that this technique is suitable for the receiver modules designed for applications with a bandwidth greater than 40 Gb/s