Stress Analyzer for Microelectronic Devices

Multilayer thin films deposited onto Si wafers often exhibit high residual stresses during processing, leading to structural failure and/or electrical breakdown. Traditional scanning x-ray diffraction provides an accurate measurement of complex stress behavior in multilayer structures, but is difficult to carry out on a routine basis. Laser deflection methods are easy to perform but provide a limited macroscopic indication of only planer stress in a single layer. ATM, in conjunction with Penn State University and Proto Manufacturing, proposes to develop a routine wafer stress mapping instrument that offers comprehensive analysis of x-ray diffraction combined with the simplicity/mapping capability of laser deflection. The proposed system utilizes a compact, non-moving fiber-optic detector, a small (only 200 watt) x-ray source, and single exposure measuring technique. Proposed system is based on a commercially proven XRD stress system for bulk metals stress analysis. Automated mapping and thermal cycling capabilities will be included in the system. Successful completion of Phase 1 program will result in a fully operational stress mapping system to be marketed and manufactured for commercial sale during Phase II.