KLA Corporation
LOW-REFLECTIVITY BACK-ILLUMINATED IMAGE SENSOR

Abstract:

An image sensor for short-wavelength light includes a semiconductor membrane, circuit elements formed on a first surface of the semiconductor membrane, and a boron-coated, textured surface on a second surface of the semiconductor membrane. The textured surface comprises pseudo-random, periodic, and/or random distribution of upright pyramids, inverted pyramids, and/or nanocones. The textured surface reduces the reflection of incident light across wide bands in the DUV and VUV regimes, thus increasing the amount of light absorbed and improving the efficiency of the image sensor. Reflectance may be further reduced by applying an antireflective coating on the textured surface. The image sensor may be a two-dimensional area sensor, or a one-dimensional array sensor. and incorporated in an inspection system.