International Business Machines Corporation

George Hrebin, Jr

Ronald A Knapp

John L Forneris

Robert K Lewis

Carl H Orner

Gregory B Forney

Joanne M Davidson

Richard A Cavanagh

A method for the characterization of large scale wafer topography is applied to improving yields in the manufacture large scale integrated (LSI) devices. First, the heights at the center, the edge and an intermediate point are measured on eight equally spaced radii. This provides eight values each for Y.sub.s and Y.sub.e which are averaged. Then the shape angle .alpha. is computed using the following equation: ##EQU1## The shape magnitude M is also computed using the following equation: ##EQU2## The thus computed values of .alpha. and M are correlated with individual wafer characteristics as to device performance and yield. Based on these results, the wafer processing is controlled to provide optimal wafer yield and isolation characteristics.

Control of large scale topography on silicon wafers

The method is comprised of the following steps:

Method for forming a buried subcollector in a semiconductor substrate by

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Verbank, NY, United States of America

George Hrebin, Jr