With the device performance of 0.6eV InGaAs monolithic interconnected modules (MIMs) reaching open circuit voltages of 400 mV/junction and achieving excellent quantum efficiency, the next step to improve performance focuses on controlling the parasitic optical absorption in these MIMs. With an integrated spectral control approach, the design of grid finger and interconnect metallization affects both the output power and the optical absorption of the MIM. The effect of metal coverage on the optical and electrical performance of MIMs processed in a multi‐wafer environment is presented. © 2003 American Institute of Physics