stokes laser ellipsometer LSE-USB description
The Stokes Ellipsometer LSE-USB with convenient USB interface
uses advanced StokesMeter™ technology
(previous winner of Photonics Spectra and R&D 100 best new products awards). The
unit's simple robust design offers unprecedented ease of use and instantaneous
measurement. It is a popular alternative to overly
complicated ellipsometers for routine measurement .
The LSE-USB ellipsometer uses advanced StokesMeter™
technology with no moving parts and no modulators to quickly and
accurately determine the complete polarization state of the 6328Å laser measuring beam at a 70° incidence angle.
The laser light source has ample light intensity for increased measurement accuracy of absorbing and rough
scattering films. Laser sources
have the added advantage of being spectrally precise, stable and long lasting. Their use permits optimum instrument
design in optics, detectors and other components so that
measurements can be made highly accurate. The space-saving design
features a small footprint yet it can accommodate large samples up to
300mm wide. The sample stage can be easily moved by hand to measure any point on
the sample surface. The sample table includes a manual tilt and table
height adjustment which is
set using an alignment screen on the computer.
high speed film thickness system measures routinely in
less than a second!
- Tilt-free, focus free, hands-off operation for similar wafers.
- 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 tabletop instrument - competitively priced.
gaertner ellipsometer measurement
program LGEMP description
The LGEMP Windows software is versatile and can measure single layer films such as
oxides, nitrides and photoresists as well the top layer on a known 1, 2, or
3 layer stack such as poly on oxide and oxide on poly on oxide.
Monolayer organic films are an excellent application for the precision and
stability of the model LSE-USB.
Handler" enables saving and quick retrieval of frequently used measurement
setup parameters. Four user-defined setup files can be
assigned to one step "press-and-go" shortcut buttons for
fast access of
different measurement setups.
The Enlarged PSI-Delta Map within the
LGEMP program permits theoretical
"what if" type simulation of your Thin Film Model
deeper understanding of the film modeling. The top
layer film Thickness T1(pink line), Refractive indexNf1(red line),
Absorption Kf1(brown line), Y(yellow
line), D(green line), with moveable
sliders on the left side quickly show the effects of varying the model parameters
on the film refractive index resolution and measurability. The aqua color lines are lines of
constant film refractive index Nf1. The white lines are
regions of Autofix of Nf1 where the index is not easily resolved in
description of stokesmeter™ technology
This advanced device uses no
moving parts and no modulators to quickly and accurately determine the
complete polarization state of the measuring beam.
The diagram above shows the StokesMeter™ 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
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.
The simple, compact StokesMeter™
replaces a typical rotating analyzer assembly consisting of a drum, prism, encoders,
switches, motor and detector and their associated electronics. In addition, the waveplate
mechanism on the polarizer arm, is eliminated resulting in a fast, precise,
moving parts ellipsometer.
An outstanding feature is the
Stokes Ellipsometer's compensation for small changes in angular beam deviation caused by
sample out-of-flatness; thus permitting fast, uninterrupted measurement over the entire wafer
surface without the need to pause to correct for focus and tilt. .
Extremely precise and stable the model LSE-USB Stokes Ellipsometer is an
excellent value in a basic uncomplicated ellipsometer. The LSE-USB model ellipsometer ships complete with
LGEMP Windows™ software, USB cable, 6 inch sample stage and reference wafer. It interfaces to your Windows™
PC or Laptop with a USB 2.0 port.
LSE-USB can be equipped with the following options:
Optional Small Spot optic LSS $ 1 K
Reduces standard 1 mm laser beam to 0.25 x 0.75
mm on sample
See our model LSE-MS for 15 x
45 micron on sample
Optional 8 inch Sample Stage L8 $
Substitutes 8 inch sample stage in place of standard 6 inch
Optional L-SCAT SOLAR CELL / SCATTERING
SAMPLE MEASUREMENT $ 2 K
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's 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.
However some samples are simply too rough and
scatter too much light to be measured ellipsometrically.
Optional WIN 10 Laptop PC
With preloaded drivers and software and
Optional Stokes Calibration Kit L118-KIT
Recalibrate any Stokes Ellipsometer using
4 Gaertner traceable wafers plus glass $ 2 K (L118G-KIT) or
4 NIST traceable wafers plus glass $ 3.5 K (L118N-KIT). Most
not require ellipsometer recalibration.
Intended for the
most exacting semiconductor manufacturers with extremely tight tolerances and
regulatory compliant users.
stokes ellipsometer LSE-USB
||Manually adjusted tilt
and table height using computer alignment screen.
||Advanced StokesMeter™ determines the complete measuring beam polarization using no moving parts and no
modulators, only 4 stationary silicon detectors so measurements are
stable and exact.
HeNe Gas Laser with 1mm measuring beam diameter
mm wide X unlimited length
||6 inch hand
positioning table with tilt and table height adjustment.
||Windows™ LGEMP 4 layer program included.
Windows™ desktop or laptop with USB 2.0 port (not included)
60,000 Angstroms on substrate or on 1, 2, 3, or 4 known sublayers.
||Sub-Angstrom over most of the measurement range.
over most of the measurement range.
||100V-240V, 50-60Hz., 1 A
16.5 Width: 27.5 Depth: 16 inches
Net Weight: 45 lbs. Shipping Weight: 65 lbs.
laser ellipsometers supplied by Gaertner comply with CDRH requirements 21CFR 1040 for a
Class II laser product emitting less than 1 mW or Class IIIb less than 5
mW of low power radiation. As with any
bright source such as the sun or arc lamp, the operator should not stare directly into the
laser beam or into its reflection from highly reflecting surfaces.
comply with European safety directives and carry the CE mark.
||1 year warranty covers all parts and labor exclusive of