Passivation of wide band-gap based semiconductor devices with hydrogen-free sputtered nitrides

US7858460B2 · kind B2 · utility

Assignee

• Cree, Inc. · US

Inventors

• Zoltan Ring · Chapel Hill, US
• Helmut Hagleitner · Knightdale, US
• Jason Henning · Carrboro, US
• Andrew Mackenzie · Cary, US
• Scott Allen · Apex, US
• Scott Sheppard · Chapel Hill, US
• Richard Peter Smith · Carrboro, US
• Saptharishi Sriram · Cary, US
• Allan Ward · Durham, US

Key dates

• Filing date: Mar 16, 2009
• Grant date: Dec 28, 2010
• Expiry date: Mar 16, 2029

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/8503
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A passivated semiconductor structure and associated method are disclosed. The structure includes a silicon carbide substrate or layer; an oxidation layer on the silicon carbide substrate for lowering the interface density between the silicon carbide substrate and the thermal oxidation layer; a first sputtered non-stoichiometric silicon nitride layer on the thermal oxidation layer for reducing parasitic capacitance and minimizing device trapping; a second sputtered non-stoichiometric silicon nitride layer on the first layer for positioning subsequent passivation layers further from the substrate without encapsulating the structure; a sputtered stoichiometric silicon nitride layer on the second sputtered layer for encapsulating the structure and for enhancing the hydrogen barrier properties of the passivation layers; and a chemical vapor deposited environmental barrier layer of stoichiometric silicon nitride for step coverage and crack prevention on the encapsulant layer.