The optical constants of silicon

• Main Author: Kuppenheimer, John Daniel
• Language: en_US
• Published: Boston University 2019
• Subjects: Silicon
• Online Access: https://hdl.handle.net/2144/33498

Thesis (M.A.)--Boston University === PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at [e-mail]. Thank you. === In this thesis, the optical constants of an atomically clean wafer of silicon have been determined by the analysis of elliptically polarized light produced by reflection of plane polarized light from the sample surface. First the theory of the reflection and transmission of plane polarized light at an interface between a dielectric and a conducting material is reviewed, and expressions relating the index of refraction n and the extinction coefficient K of the conductor to other physical parameters are derived. Then the production of elliptically polarized light by reflection at the interface is analyzed. Expressions are derived relating the optical constants of the conductor to the angle of incidence Φ, the azimuth of restored polarization Ψ, and a variable Δ which is related to the phase difference between the components of the elliptically polarized light. The operation of a Babinet compensator is discussed, and methods for determining Ψ and Δ are analyzed. The preparation of the silicon sample by grinding, chemical polishing, and heating to 1000°K in an ultra high vacuum is described. This method of preparation was chosen in order to produce an atomically clean surface for the reflection experiment. The method of obtaining data on Ψ and Δ with the aid of a Babinet compensator attached to a student spectroscope is described, and experimental problems encountered in the course of the measurements are discussed. Results of measurements on the silicon sample are recorded for four wavelengths, 6430 Å, 5890 Å, 5461 Å, and 4358 Å. At each wavelength, n and K are given for various angles of incidence, varying from 30° to 85°. Values of Ψ and of Δ are interpolated by graphical analysis to obtain Φ and ψ at each wave length, and these values are compared with those of other workers in the field. The values which were thus compared are the following: λ Φ ψ K n 6340 Å 75.25° 4.25° 0.14 3.76 5890 Å 76.50° 5.00° 0.17 4.10 5461 Å 77.00° 4.75° 0.16 4.27 4358 Å 78.50° 11.50° 0.41 4.53 === 2031-01-01