SEMICONDUCTOR DEVICE

PURPOSE:To obtain the picture element of an infrared detection device with improved sensitivities by a method wherein the surface opposite to a Schottky electode forming surface formed in the photosensitive region is provided with a refraction region that refracts an incident infrared ray. CONSTITUTION:When an Si substrate 1 of the crystal orientation 100 is etched with an alkaline etchant, a V-groove 3 of isosceles triangle where an angle of 70 deg.C is the vertex is formed. Since an infrared ray comes vertically to the si substrate, an angle of incidennce I in the part of the groove 3 becomes 55 deg., and an angle of incidence alpha to the substrate 1 becomes 14 deg., resulting in the refraction of an infrared ray hnu at 41 deg. shown by beta. In such a manner, the infrared ray incident to the V-groove 3 comes to the photosensitive region S. The V- groove 3 is thus formed as the infrared ray refraction region at the back of the non-photosensitive region N of the substrate 1 into a structure of no incidence to the region N because of the lens function due to the difference in refractive index, thus enabling the incidence infrared rays to be convergent effectively to a Schottky electrode the photosensitive region. Therefore, it becomes possible to improve sensitivity and reduce the non-photosensitive region.