in situ stokes ellipsometer
The Stokes In Situ Ellipsometer
permits real-time in-process monitoring of growing or etched films. Early
film growth on a bare substrate can be precisely measured in milliseconds to within 1
angstrom with the model L104ST. The measured DEL and PSI values also clearly determine the
end point during an etch so tight control can be achieved over your process.
The model L104ST is a super fast, highly reliable, no moving parts laser ellipsometer which is ideal for
measuring rapidly growing films in-process and in situ. Mounts onto CVD, electron-beam
evaporation, MBE, sputtering as well as other chambers that have an entry and exit window
port for the measuring beam.
The L104ST replaces complex optics
and mechanisms with new StokesMeter™ technology. The
completes a measurement in milliseconds by sampling the laser beam intensity at 4
detectors followed by a computer calculation. Since the compact 4" x 4"
measurement head has no moving parts, it is rugged, trouble-free and clean.
- Fastest possible instrument for thin film measurement.
- Trouble-free, no moving parts advanced StokesMeter™
- Measures complete state of polarization useful for rough,scattering
- Accurate, stable measurements using spectrally precise laser
- Simple, compact component instrument - competitively priced.
The adjustable polarizer and
analyzer modules mount onto window flanges outside your reactor or chamber. The polarizer
module emits a continuous low power laser beam, which passes thru the chamber window onto
a sample which must be precisely located. The beam then reflects from the sample passing
out of the chamber into the analyzer module which reads the polarization. An alignment
prism is supplied so that the user can position the sample together with the polarizer and
analyzer modules which have provision for fine angular adjustment. The angle of incidence,
measured with respect to the sample, is determined by the two chamber ports and can be
between 30 and 85 degrees although 70 degrees is most commonly used.
A unique feature is the Stokes
Ellipsometer's ability to compensate for small deviations in the measuring beam caused by
sample misalignment, sample out-of-flatness and small changes in sample thickness. This
important characteristic enables the Stokes Ellipsometer to be quickly installed onto your
chamber, ready for fast , accurate measurement.
A photopolarimeter for the
simultaneous measurement of all four Stokes parameters of light. The light beam, the state
of polarization of which is to be determined, strikes, at oblique angles of incidence,
three photodetector surfaces in succession, each of which is partially spectrally
reflecting and each of which generates an electrical signal proportional to the fraction
of the radiation it absorbs. A fourth photodetector is substantially totally light
absorptive and detects the remainder of the light. The four outputs thus developed form a
4x1 signal vector I which is linearly related, I=AS, to the input Stokes vector S.
Consequently, S is obtained by S=A(-1)I. The 4x4 instrument matrix A must be nonsingular,
which requires that the planes of incidence for the first three detector surfaces are all
different. For a given arrangement of four detectors, A can either be computed or
determined by calibration.
- One, two, three and four layer
- Contaminants on bare substrates
- PSI and DELTA for user
characterization of films and substrates.
Single Angle Ex situ Support Base for In situ Ellipsometer L104SB
Support frame for alternately
mounting the L104ST polarizer and analyzer modules at a fixed 70 degree angle of incidence
for ex situ measuring.
Variable Angle Ex situ Support L104SA
Support frame for alternately mounting the L104ST polarizer and analyzer modules for ex
situ measuring. Includes a combination Viewing Scope/Tilt Monitor and Tiltable
Stage. Incidence angles can be easily set to 30, 45, 50, 60 70,75,80,and 90 degrees.
This support converts the model L104ST into the table-top L116S Stokes Ellipsometer.
Calibration Kit L118-KIT
Stokes Calibration Kit permits
re-calibration of any Stokes Ellipsometer quickly and easily. Kit consists of calibration
software and 4 calibration samples.
L104ST can be equipped with the following laser options:
LS405 Substitutes 405 nm Blue
laser diode in place of 633 nm HeNe Gas Laser $13K
LS544 Substitutes 544 nm Green HeNe Gas laser in
place of 633 nm HeNe Laser $4K
LS830 Substitutes 830 nm laser diode in place of
633 nm HeNe Gas Laser $9K
ADD ADDITIONAL LASER FOR A 2
L2W405 Adds 405 nm Blue Laser Diode
to 633 nm ellipsometer $21K
L2W544 Adds 544 nm Green HeNe Gas Laser to 633 nm
L2W830 Adds 830 nm laser diode to 633 nm
ADD TWO ADDITIONAL LASERS FOR A 3 WAVELENGTH
L3W405.544 Adds 405 Laser Diode and 544
Green Gas Laser to 633 nm ellipsometer $26K
L3W405.830 Adds 405 Laser Diode and 830nm laser diode to
633 nm ellipsometer $29K
L3W544.830 Adds 544 Green Gas Laser and 830nm laser diode
to 633 nm ellipsometer $23K
L-SCAT SOLAR CELL / SCATTERING
SAMPLE MEASUREMENT OPTION $2K
Rough scattering samples common in the solar cell industry are difficult
to measure accurately with most ellipsometers because of the loss of signal
strength and depolarization of the measurement beam. Although there are ways
to boost the signal strength and capture more scattered light, dealing with
depolarization is much more difficult and requires the determination of the
complete state of polarization namely the measurement of the 4 stokes
parameters S0, s1, s2, s3. Gaertner Stokes
Ellipsometers do this naturally as our StokesMeterä
polarimeter is used as the ellipsometer analyzer. This gives Stokes
Ellipsometers the unique ability to instantly separate the polarized from
the unpolarized components of the measuring beam thereby delivering a highly
accurate measurement of film thickness and index based only on the totally
polarized component of light. The L-SCAT scatter option includes a hardware
modification to capture more of the scattered light from rough, textured
surfaces and a program display of the degree of polarization P.
in situ stokes ellipsometer L104ST specifications
user at a single incidence angle from 85° to 30° using an alignment prism
inch lateral shift both polarizer/analyzer
± 6° angular adjustment which is diminished by the amount of ± 1/4 inch lateral
632.8 gas laser
with USB port required
Index: ± .001 over most of the measurement range
115V, 220V, 230V, 240V
Dimensions: 14 x 33 x 43 cm
Weight: 17 lbs.
Interface cable to computer: 6.5 ft.
12 lbs. for L104ST
Interface cable to electronic unit: 6 ft.
Interface cable to electronic unit: 6 ft.
series Ellipsometers comply with European safety directives and carry the CE mark.