United States of America As Represented by the Secretary of the Air Force

Darin J Leahy

Michael N Alexander

Jonathan M Mooney

Maxwell M Chi

The invention provides method and apparatus for fast, accurate, and nondestructive imaging of defects and determining defect densities in solid materials including a semiconductor wafer. A wafer is illuminated on one side by an infrared (IR) source and a camera is placed on the other side of the wafer, to detect IR radiation that is transmitted through such wafer. The inventive method employs an imaging camera, e.g. a focal plane array camera, to image the so illuminated wafer. The wafer material must be substantially transparent in the camera bandwidth but can contain defects that absorb or scatter radiation in such bandwidth. Camera filters are used, for example, to select specific wavelengths or bands of wavelengths, to detect and image precipitates, subsurface defects, residual damage from polishing and other defects.

Growing community of inventors

Stoneham, MA, United States of America

Darin J Leahy