Trenched Schottky rectifiers

US6441454B2 · kind B2 · utility

Assignee

• KONINKLIJKE PHILIPS ELECTRONICS NV · NL

Inventors

• Erwin Hijzen · Eindhoven, NL
• Raymond J. E. Hueting · Helmond, NL

Key dates

• Filing date: Feb 1, 2001
• Grant date: Aug 27, 2002
• Expiry date: Feb 1, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D8/605

Abstract

Inner trenches (11) of a trenched Schottky rectifier (1a; 1b; 1c; 1d) bound a plurality of rectifier areas (43a) where the Schottky electrode (3) forms a Schottky barrier 43 with a drift region (4). A perimeter trench (18) extends around the outer perimeter of the plurality of rectifier areas (43a). These trenches (11, 18) accommodate respective inner field-electrodes (31) and a perimeter field-electrode (38) that are connected to the Schottky electrode (3). The inner field-electrodes (11) are capacitively coupled to the drift region (4) via dielectric material (21) that lines the inner trenches (11). The perimeter field-electrode (38) is capacitively coupled across dielectric material (28) on the inside wall (18a) of the perimeter trench 18, without acting on any outside wall (18b). Furthermore, the inner and perimeter trenches (11, 18) are closely spaced and the intermediate areas (4a, 4b) of the drift region (4) are lowly doped. The spacing is so close and the doping is so low that the depletion layer (40) formed in the drift region (4), from the Schottky barrier (43) and from the field-relief regions (31,21; 38,28) in the blocking state of the rectifier, may deplete the whole o…