A schottky diode may include a schottky junction including a well formed in a semiconductor substrate and a first electrode contacting the first well. The well may have a first conductivity type. A first ohmic junction may include a first junction region formed in the well and a second electrode contacting the first junction region. The first junction region may have a higher concentration of the first conductivity type than the well. A first device isolation region may be formed in the semiconductor substrate separating the schottky junction and the first ohmic junction. A well guard having a second conductivity type opposite to the first conductivity type may be formed in the well. At least a portion of the well guard may be formed under a portion of the schottky junction.