Atomic layer deposition of chemical passivation layers and high performance anti-reflection coatings on back-illuminated detectors

US8680637B2 · kind B2 · utility

Assignee

• CALIFORNIA INSTITUTE OF TECHNOLOGY · US

Inventors

• Michael E. Hoenk · Pasadena, US
• Frank Greer · Pasadena, US
• Shouleh Nikzad · Valencia, US

Key dates

• Filing date: Jun 23, 2011
• Grant date: Mar 25, 2014
• Expiry date: Mar 6, 2032

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50

Abstract

A back-illuminated silicon photodetector has a layer of Al2O3 deposited on a silicon oxide surface that receives electromagnetic radiation to be detected. The Al2O3 layer has an antireflection coating deposited thereon. The Al2O3 layer provides a chemically resistant separation layer between the silicon oxide surface and the antireflection coating. The Al2O3 layer is thin enough that it is optically innocuous. Under deep ultraviolet radiation, the silicon oxide layer and the antireflection coating do not interact chemically. In one embodiment, the silicon photodetector has a delta-doped layer near (within a few nanometers of) the silicon oxide surface. The Al2O3 layer is expected to provide similar protection for doped layers fabricated using other methods, such as MBE, ion implantation and CVD deposition.