Real-Time Control of Nonflatness of Components of Infrared-Range Flip-Chip Photodetectors

Abstract

A possibility of using the autocollimation and interference methods for real-time nondestructive check of the wafer nonflatness of photodetector arrays that are sensitive in the infrared range and are fabricated by the flip-chip technology is considered. These methods allow monitoring the wafer nonflatness and the maximum deflections. These methods are applied in the present study to measure the wafer nonflatness of fragments of silicon slices and arrays of photosensitive elements on GaAs substrates, as well as the wafer nonflatness of photodetectors at different stages of fracture and in the course of thermal cycling.