Selective deposition of diamond in thermal vias

US9196703B2 · kind B2 · utility

Assignees

• NORTHROP GRUMMAN SYSTEMS CORPORATION · US
• United States of America as represented by the Secretary of the Air Force · US
• The Regents of the University of California · US

Inventors

• Karl D. Hobart · Alexandria, US
• Tatyana I. Feygelson · Springfield, US
• Eugene I. Imhoff · Washington, US
• Travis J. Anderson · Alexandria, US
• Joshua D. Caldwell · Nashville, US
• Andrew D. Koehler · Alexandria, US
• Bradford B. Pate · Arlington, US
• Marko J. Tadjer · Greenbelt, US
• Rajinder S. Sandhu · Castaic, US
• Vincent Gambin · Rancho Palos Verdes, US
• Gregory Lewis · Mountain View, US
• Ioulia Smorchkova · Lakewood, US
• Mark Goorsky · Valencia, US
• Jeff McKay · Walnut, US

Key dates

• Filing date: Aug 20, 2014
• Grant date: Nov 24, 2015
• Expiry date: Aug 20, 2034

Classification

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

Abstract

A method for fabricating a semiconductor device, such as a GaN high electron mobility transistor (HEMT) device, including etching a thermal via into a back-side of a semiconductor substrate and depositing a diamond nucleation seed layer across the back-side of the substrate. The method further includes coating the diamond nucleation with a mask layer and removing mask material outside of the thermal via on the planar portions of the back-side of the substrate. The method includes removing portions of the diamond nucleation layer on the planar portions and then removing the remaining portion of the mask material in the thermal via. The method then includes depositing a bulk diamond layer within the thermal via on the remaining portion of the diamond nucleation layer so that diamond only grows in the thermal via and not on the planar portions of the substrate.