Method for measuring refractive index and thickness of film and

Details Method for measuring refractive index and thickness of film and Method for measuring refractive index and thickness of film and

1993-08-09

1995-05-30

Pham, Hoa Q.

Optics: measuring and testing

Refraction testing

356369, 250225, G01N 2141, G01N 2121

Patent

active

054206804

ABSTRACT:
In method and apparatus for measuring a refractive index and a thickness of a thin film formed on a substrate, the thin film has m (m.gtoreq.1) layers and a transparent uppermost layer is set as a first layer. A total of (3m+1) parameters include a refractive index n(0) of an incident medium, a refractive index n(j) (j=1 to m) of a j-th layer, absorption coefficients k(j) (j=2 to m) of second to m-th layers, a refractive index n(m+1) and an absorption coefficient k(m+1) of the substrate, and thicknesses d(j) (j=2 to m) of the second to m-th layers. Arbitrary one of the (3m+1) parameters is unknown and the other 3m parameters are known. This method and apparatus measure the unknown parameter. Monochromatic light having a wavelength is incident to the film having the m-layers at a predetermined incident angle from a first layer side in the incident medium to measure reflectances about S and P polarized light. A function of the unknown parameter is specified using measured values of the reflectances, the wavelength and 3m known parameters. An equation about this function is numerically solved to determine the unknown parameter.

REFERENCES:
patent: 4672196 (1987-06-01), Canino
patent: 4695162 (1987-09-01), Itonaga
patent: 4792227 (1988-12-01), Yoshizawa
patent: 4806776 (1989-02-01), Kley
patent: 4906844 (1990-03-01), Hall
patent: 4983823 (1991-01-01), Isobe
patent: 5073026 (1991-12-01), Isobe
patent: 5096298 (1992-03-01), Isobe
patent: 5107105 (1992-04-01), Isobe
patent: 5108185 (1992-04-01), Mansuripur et al.
Applied Optics, vol. 19, No. 7, Apr. 1, 1980, pp. 1031-1033.
Philips Technische Rundschau, Ein schnelles Refraktometer Fur Dunne Aufdampfschichten 35; 1975/76; Nr. 3, pp. 70-71.
R. Mittra, "A Method For Measuring The Refractive Index Profile Of Thin-Film Waveguides", IEEE Transactions on Microwave Theory and Techniques, Jan. 1975, vol. MTT-23, pp. 176-177.
A. J. Warnecke, et al., "Refractive Index Dispersion In Semiconductor-related Thin Films", IBM J. Res. Develop., May 1973, pp. 256-262.
J. Raif, et al., "Rapid nondestructive method for measuring the refractive index and thickness of thin dielectric films", J. Phys., 1973, vol. 6, pp. 48-50.
N. J. Harrick, "Determination of Refractive Index and Film Thickness from Interference Fringes", Applied Optics, Oct. 1971, vol. 10, No. 10, pp. 2344-2349.

Affiliated with

Also associated with

Rating

Method for measuring refractive index and thickness of film and does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method for measuring refractive index and thickness of film and , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for measuring refractive index and thickness of film and will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-366479