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Non Destructive Technique for Thickness and Refractive Index Measurements of Transparent Films

IP.com Disclosure Number: IPCOM000096249D
Original Publication Date: 1963-Mar-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Pliskin, WA: AUTHOR [+2]

Abstract

This measurement technique is a method for measuring transparent films of several hundred angstroms to several microns in thickness on highly reflective substrates.

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Non Destructive Technique for Thickness and Refractive Index Measurements of Transparent Films

This measurement technique is a method for measuring transparent films of several hundred angstroms to several microns in thickness on highly reflective substrates.

Microscope 20 equipped with monochromatic filter 22 and illuminated with fluorescent light source 24 determines the thickness of sample film 30 on reflective substrate 31 adhered to rotating sample mount 28. Mount 28 is structurally related to microscope 20. The apparatus also has mirror 32 for reflecting the fluorescent light onto film 30. The reflected light is directed through filter 22 to the microscope field. Mount 28 is adapted to be rotated. Its angular position can be read from a calibrated dial, now shown, attached to the shaft, not shown, of mount 28.

Mirror 32 is rotated and positioned by hand to maintain the proper reflected light on sample 30. With vertically illuminated microscopes a mirror in a fixed mount perpendicular to the rotating stage can be used provided it is close to the point under examination on the substrate. Similarly, with the apparatus described here, fairly good results can be obtained with a fixed mirror mounting on the stage provided the mirror is mounted close to the point under examination and is inclined at about 100 degrees.

As the sample and sample mount rotate, observation through the microscope indicates maxima (bright) and minima (dark) fringes on the sample film. As...