Diodes including multiple Schottky contacts

A diode comprising:

• a substrate of a first conductivity type;
• a semiconductor layer of the first conductivity type disposed on the substrate;
• a plurality of shield regions of a second conductivity type disposed in the semiconductor layer, the plurality of shield regions including a first shield region and a second shield region separated by a drift region;
• a first Schottky material layer having:
• a first portion disposed on a first portion of the first shield region and on a first portion of the drift region, and defining a first Schottky contact with the drift region;
• and
• a second portion disposed on at least a portion of the second shield region and on a second portion of the drift region, and defining a second Schottky contact with the drift region;
• a second Schottky material layer disposed on a third portion of the drift region, the second Schottky material layer being disposed, at least in part, between the first portion of the first Schottky material layer and the second portion of the first Schottky material layer, and defining a third Schottky contact with the drift region,
• the first Schottky contact and the second Schottky contact having a first barrier height, the third Schottky contact having a second barrier height, the first barrier height being less than the second barrier height;
• and
• a metal deposited on a second portion of the first shield region and defining an ohmic contact to the first shield region, wherein the metal is adjacent to and different from a Schottky material of the first Schottky material layer.

A diode comprising:

• a substrate of a first conductivity type;
• a semiconductor layer of the first conductivity type disposed on the substrate;
• a plurality of shield regions of a second conductivity type disposed in the semiconductor layer and arranged in a cellular layout, the plurality of shield regions including a first shield region, a second shield region, and a third shield region;
• a drift region disposed in the semiconductor layer, the drift region including:
• a first portion separating the first shield region from the second shield region;
• a second portion separating the second shield region from the third shield region;
• a third portion separating the third shield region from the first shield region;
• and
• a fourth portion central to the first shield region, the second shield region, and the third shield region;
• a first Schottky material layer disposed on the first portion, the second portion, and the third portion of the drift region and forming one or more first Schottky contacts having a first barrier height;
• and
• a second Schottky material layer disposed on the fourth portion of the drift region and forming a second Schottky contact having a second barrier height greater than the first barrier height.