US Patent 7728402 Semiconductor devices including schottky diodes with controlled breakdown

A semiconductor device includes a semiconductor layer having a first conductivity type, a metal contact on the semiconductor layer and forming a Schottky junction with the semiconductor layer, and a semiconductor region in the semiconductor layer. The semiconductor region and the semiconductor layer form a first p-n junction in parallel with the Schottky junction. The first p-n junction is configured to generate a depletion region in the semiconductor layer adjacent the Schottky junction when the Schottky junction is reversed biased to thereby limit reverse leakage current through the Schottky junction. The first p-n junction is further configured such that punch-through of the first p-n junction occurs at a lower voltage than a breakdown voltage of the Schottky junction when the Schottky junction is reverse biased.