Patent ID: 6494098
Filing Date: 2002-12-17
Classification: G01N,G01S

Abstract:
A method of non-destructively testing a sputtering target having a front wall and comprising sputtering material having grain boundaries and an approximately known grain size, said method comprising the steps of:(1) directing a pulsed beam of sonic energy from a transmission point toward said target, said sonic energy having a frequency such that its wavelength in said target is substantially equal to said known grain diameter and said beam being directed such that a portion thereof passes through said front wall, reflects off said grain boundaries, passes again through said front wall and travels to a reception point having a predetermined position relative to said transmission point; (2) sensing said beam portion at said reception point and generating a corresponding sensing signal; and (3) determining for said sensing signal a histogram of the number of occurrences of said sensing signal at a predetermined amplitude level.