Patent ID: 6570239
Filing Date: 2003-05-27
Classification: H01L

Abstract:
A semiconductor device comprising:a semiconductor substrate of a first conductivity type, wherein the substrate has a main surface and a back surface; a resistive element of a second conductivity type that is located in a trench formed in the main surface, wherein the resistive element extends inwardly and perpendicularly from the main surface and has a generally U-shaped cross section, the ends of which terminate at the main surface, wherein a resistance length of the resistive element is determined by a U-shaped path that corresponds to the U-shaped cross section, the resistive element having an impurity concentration that is approximately uniform in a direction perpendicular to the main surface; a second semiconductor layer of the first conductivity type, wherein the second semiconductor layer is located in the resistive element and extends perpendicularly from the main surface; and a pair of electrodes located on a surface of the resistive element and are separated by the second semiconductor layer, wherein the resistance between the electrodes is determined at least by a depth of the resistive element.