Government of the United States of America, As Represented by the Secretary of Commerce

National Institute of Standards and Technology

Robert D Larrabee

Richard M Silver

Ravikiran Attota

Jay F Marchiando

Wall mounted distribution center

A method of imaging critical dimensions by measuring the zeroeth order of diffracted light. The method involves providing a target, directing light onto the target so as to cause the target to diffract the light. The zeroeth order of the diffracted light is collected and analyzed to determine structural features of the target. The target can be an article of manufacture, such as a semiconductor device, or a separate target that is provided or fabricated on an article of manufacture. One of at least the wavelength and the angle at which the light is directed onto the target can be scanned. The target can fill all or only a portion of the field of view.

Zeroeth order imaging

A method of measuring the linewidth of an electrical conductor on a semiconductor substrate includes preparing mutually separated test and interconnection areas on a surface of a semiconductor substrate; forming an electrical interconnection conductor on the surface of the substrate in the interconnection area with a substantially uniform linewidth electrically interconnecting elements on the surface; simultaneously with forming the interconnection conductor, forming in the test area a test structure having a plurality of closed loops of the electrical conductor having the same linewidth as the interconnection conductor; measuring the impedance or complex reflection coefficient of the test structure using a head disposed opposite the test area, spaced from the surface, and coupled to the test structure without directly contacting the test structure; and correlating the measured impedance or complex reflection coefficient of the test structure with measurements of geometrically identical structures of conductors having known linewidths to determine the linewidth of the test structure and, thereby, the linewidth of the interconnection conductor.

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Derwood, MD, United States of America

Robert D Larrabee