Variable-wavelength frequency-domain terahertz ellipsometry

被引：73

作者：

Hofmann, T. ^{[1
,2
]}

Herzinger, C. M. ^{[3
]}

Boosalis, A. ^{[1
,2
]}

Tiwald, T. E. ^{[3
]}

Woollam, J. A. ^{[3
]}

Schubert, M. ^{[1
,2
]}

机构：

[1] Univ Nebraska, Dept Elect Engn, Lincoln, NE 68588 USA

[2] Univ Nebraska, Nebraska Ctr Mat & Nanosci, Lincoln, NE 68588 USA

[3] JA Woollam Co Inc, Lincoln, NE 68508 USA

来源：

REVIEW OF SCIENTIFIC INSTRUMENTS | 2010年 / 81卷 / 02期

基金：

美国国家科学基金会;

关键词：

backward wave oscillators; ellipsometry; optical polarisers; phosphorus; silicon; OPTICAL-CONSTANTS; TIME; SPECTROSCOPY; MULTISAMPLE; CALIBRATION; SILICON;

D O I：

10.1063/1.3297902

中图分类号：

TH7 [仪器、仪表];

学科分类号：

0804 ; 080401 ; 081102 ;

摘要：

We report an experimental setup for wavelength-tunable frequency-domain ellipsometric measurements in the terahertz spectral range from 0.2 to 1.5 THz employing a desktop-based backward wave oscillator source. The instrument allows for variable angles of incidence between 30 degrees and 90 degrees and operates in a polarizer-sample-rotating analyzer scheme. The backward wave oscillator source has a tunable base frequency of 107-177 GHz and is augmented with a set of Schottky diode frequency multipliers in order to extend the spectral range to 1.5 THz. We use an odd-bounce image rotation system in combination with a wire grid polarizer to prepare the input polarization state. A highly phosphorous-doped Si substrate serves as a first sample model system. We show that the ellipsometric data obtained with our novel terahertz ellipsometer can be well described within the classical Drude model, which at the same time is in perfect agreement with midinfrared ellipsometry data obtained from the same sample for comparison. The analysis of the terahertz ellipsometric data of a low phosphorous-doped n-type Si substrate demonstrates that ellipsometry in the terahertz spectral range allows the determination of free charge-carrier properties for electron concentrations as low as 8x10(14) cm(-3).

引用

页数：7

共 47 条

[11] Materials for terahertz science and technology [J].

Ferguson, B ;

Zhang, XC .

NATURE MATERIALS, 2002, 1 (01) :26-33

[12] Concept of a miniaturised free-electron laser with field emission source [J].

Floreani, F ;

Koops, HW ;

Elsässer, W .

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 2002, 483 (1-2) :488-492

[13]

Fujiwara H., 2009, SPECTROSCOPIC ELLIPS

[14]

Hecht E., 1987, OPTICS

[15]

Herzinger C. M., 2004, U. S. Patent, Patent No. [6 795 184, 6795184]

[16] DETERMINATION OF ALAS OPTICAL-CONSTANTS BY VARIABLE-ANGLE SPECTROSCOPIC ELLIPSOMETRY AND A MULTISAMPLE ANALYSIS [J].

HERZINGER, CM ;

YAO, H ;

SNYDER, PG ;

CELII, FG ;

KAO, YC ;

JOHS, B ;

WOOLLAM, JA .

JOURNAL OF APPLIED PHYSICS, 1995, 77 (09) :4677-4687

[17] Ellipsometric determination of optical constants for silicon and thermally grown silicon dioxide via a multi-sample, multi-wavelength, multi-angle investigation [J].

Herzinger, CM ;

Johs, B ;

McGahan, WA ;

Woollam, JA ;

Paulson, W .

JOURNAL OF APPLIED PHYSICS, 1998, 83 (06) :3323-3336

[18] Terahertz magneto-optic generalized ellipsometry using synchrotron and blackbody radiation [J].

Hofmann, T. ;

Schade, U. ;

Herzinger, C. M. ;

Esquinazi, P. ;

Schubert, M. .

REVIEW OF SCIENTIFIC INSTRUMENTS, 2006, 77 (06)

[19] Conduction-band electron effective mass in Zn0.87Mn0.13Se measured by terahertz and far-infrared magnetooptic ellipsometry -: art. no. 042105 [J].

Hofmann, T ;

Schade, U ;

Agarwal, KC ;

Daniel, B ;

Klingshirn, C ;

Hetterich, M ;

Herzinger, CM ;

Schubert, M .

APPLIED PHYSICS LETTERS, 2006, 88 (04) :1-3

[20] Hole diffusion profile in a p-p+ silicon homojunction determined by terahertz and midinfrared spectroscopic ellipsometry [J].

Hofmann, T. ;

Herzinger, C. M. ;

Tiwald, T. E. ;

Woollam, J. A. ;

Schubert, M. .

APPLIED PHYSICS LETTERS, 2009, 95 (03)

← 1 2 3 4 5 →