This paper describes the use of advanced circuitry nondestructive eddy current techniques to map compound semiconductors. Surface profiles, contour maps and diameter scans are obtained from the process wafers tested providing the necessary information to control the processes for maximum yield.
We will report on how the statistics and data analysis using sophisticated computer routines to study the radial uniformity of the compound semiconductors can be used for optimum output. Additionally, a review is presented of the basic principles of measurement and the applicable test methods and standards.
Important aspects that enable feedback to deposition and implant equipment enabling uniformity improvements are discussed. Specification improvements resulting from recent circuit and software additions and the measurement results are discussed.