Kla Tencor Corporation

Daniel Kapp

Charles Amsden

David W Shortt

Steven R Lange

Shiyu Zhang

Junwei Wei

Timothy Russin

A method of focusing includes irradiating an object by directing radiation output by a radiating source through an objective lens, measuring a first intensity of reflected radiation that is reflected from the object, adjusting a distance between the objective lens and the object, measuring a second intensity of reflected radiation, and analyzing the first intensity of reflected radiation and the second intensity of reflected radiation to determine a focal distance between the objective lens and the object. The distance between the objective lens and the object is adjusted to the focal distance and the irradiating intensity is increased to mark the object. In another example, measuring the first intensity of reflected radiation is performed by directing reflected radiation from the object through the objective lens, a beam splitter, a focusing lens, and a pinhole and onto a sensor that outputs a signal indicative of sensed radiation intensity.

Laser marking focus feedback system having an intensity indication of reflected radiation passed through an objective lens, a beam splitter and a pinhole

Methods and systems for accurately locating buried defects previously detected by an inspection system are described herein. A physical mark is made on the surface of a wafer near a buried defect detected by an inspection system. In addition, the inspection system accurately measures the distance between the detected defect and the physical mark in at least two dimensions. The wafer, an indication of the nominal location of the mark, and an indication of the distance between the detected defect and the mark are transferred to a material removal tool. The material removal tool (e.g., a focused ion beam (FIB) machining tool) removes material from the surface of the wafer above the buried defect until the buried defect is made visible to an electron-beam based measurement system. The electron-beam based measurement system is subsequently employed to further analyze the defect.

Defect marking for semiconductor wafer inspection

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Pleasanton, CA, United States of America

Daniel Kapp