Yield prediction of acoustic charge transport transversal filters

Abstract

A yield model for gallium arsenide acoustic charge transport transversal filters is presented. It differs from previous IC yield models in that it is not assumed that individual failures of the nondestructive sensing taps necessarily cause a device failure. In this way, a redundancy in the number of taps included in the design is accounted for. Poisson statistics are used to describe the tap failures. A representative design example is presented, and the critical area for device failure is calculated. Yield is predicted for a range of defect densities, distribution functions, and redundancies. To verify the model, a Monte Carlo simulation is performed on an equivalent circuit model of the device. The results of the yield model are then compared to the Monte Carlo simulation. Better than 95% agreement is obtained for the Poisson model weighted by a triangular distribution function with one redundant circuit.<>