Measurement of the Depth of Diffused Layers in Silicon by the Grooving Method

A technique for the determination of the depth of diffused layers presented first by Happ and Shockley in 1956 is evaluated and compared with conventional methods. The process involves cutting a groove of cylindrical shape into a diffused specimen, delineating the junction by standard techniques, and, under magnification, measuring two variables which can be substituted into a simple equation to calculate the thickness of the diffused layer. The regularity of the groove contour is evaluated from measurements with interference fringes. Diffused layers as thin as 0.2μ can be measured with a deviation of ± 0.04μ over an entire slice.