High current density, low contact resistance wide bandgap contacts

US10505031B1 · kind B1 · utility

Assignee

• National Technology & Engineering Solutions of Sandia, LLC · US

Inventors

• Erica Ann Douglas · Albuquerque, US
• Albert G. Baca · Albuquerque, US
• Shahed Reza · Albuquerque, US
• Michael David Henry · Tucson, US

Key dates

• Filing date: Oct 30, 2018
• Grant date: Dec 10, 2019
• Expiry date: Oct 30, 2038

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/602

Abstract

A high current density, low contact resistance contact for wide bandgap (WBG) or ultra-wide bandgap materials (UWBG) is disclosed. The contact is lithographically formed so that a total perimeter length of the contact structure is at least twice the length of the side of a contact pad closest to the gate in a high electron mobility transistor (HEMT). The contact structure may take the form of a plurality of columns having various cross-sectional shapes, or may take the form of a convoluted geometrical shape, such as a comb-like, serpentine, or spiral shape. The depth of the contact structure permits direct contact with the two-dimensional electron gas (2DEG) in the HEMT by the perimeter of the contact structure. The contact structure is formed of at least one metal layer, at least one doped material regrown layer, or at least one implanted region. The contact structure may be applied to other WBG and UWBG devices.