A 3D electrothermal model was developed to study the InP-based thin film In0.53Ga0.47As/In0.52Al0.48As superlattice microrefrigerators for various device sizes, ranging from 40x40mum(2) to 120x120mum(2). We discussed maximum cooling and cooling power densities for current devices, analyzed the non-idealities of current devices and proposed an optimized structure. The simulation results demonstrated a maximum cooling of 3degreesC with cooling power density over 300 W/cm(2) with an optimized structure based on the current device geometry. Furthermore, we also demonstrated that a maximum 2 cooling, over 10degreesC with power density over 900 W/cm(2), could be possible when the current figure of merit of InGaAs/InAlAs superlattice is enhanced five times with the non-conserved lateral momentum. Besides monolithic integration, we also propose a flip-chip bonded solution to integrate these microrefrigerator with the optoelectronic chips. Preliminary 3D electrothermal simulation will be present to analyze its cooling effects for this 2-chip integration model.