Stokes Waferskan™ Ellipsometer LSE-WS

300mm stokes waferskan™ ellipsometer
The model LSE-WS Stokes WAFERSKAN Ellipsometer is a high speed film thickness mapping system measuring one site per second including stage travel! It uses advanced StokesMeter™ technology (previous winner of Photonics Spectra and R&D 100 best new products awards) to give tilt-free, focus free, 2D/3D color thickness and index images on any size wafer up to 300mm . The units' elegant design offers unprecedented ease of use and instantaneous measurement at a cost much lower than conventional production control metrology systems. Affordably priced the LSE-WS is a popular choice in a high precision scanning ellipsometer. 

features

• Trouble-free, no moving parts advanced StokesMeter™ measurement head.

• Measures complete state of polarization providing increased accuracy.

• Accurate, stable measurements using spectrally precise laser ellipsometry.

• Fastest possible instrument for thin film measurement.

• Tilt-free, focus free, hands-off operation for similar wafers.

• Simple, compact tabletop instrument - competitively priced.

high accuracy and performance
The model LSE-WS builds on the production proven Gaertner WAFERSKAN™ line of ellipsometers in widespread use throughout the world. From thin gate oxides only tens of angstroms thick to thick polyimides and photoresists Gaertner has earned a reputation for providing precise, reliable results. The model LSE-WS sets a high performance standard to meet today's more demanding metrology applications.

Films such as oxides, nitrides and photoresists can be measured to sub-angstrom precision. Measure film thickness, film refractive index, PSI and Delta. Two, three and four layer films, with know bottom layers such as poly on oxide and oxide on poly on oxide can be measured for the thickness and refractive index of the top layer or for both thicknesses. Windows™ software enhances ease of use and understanding.

great graphics 
The measurement results are displayed on the computer monitor and can be sent to a printer. Results stored in a text data file are displayed in a 2D contour or 3D Map images. The images can be rotated, tilted, reduced or enlarged for immediate viewing and interpretation.

Easy to use

The LSE-WS Stokes WAFERSKAN™ is simple to operate. The user interacts with a single main program screen so the set up is easy to understand and the measurement can be quickly made. Stored recipes are readily accessed for scanning different films and patterns. Similar wafers are automatically scanned with a single mouse click. The operator can chose 1, 5, 9, or 49 point circular measurement,  X-Y grid, diameter, or Polar Scans with up to 1000 measurement points and set the wafer edge exclusion. 

High precision stages

High quality Newport stepping motor stages provide precise and repeatable positions. The wafer is held on the optically flat table by vacuum. The stages move automatically in rapid yet precise steps under programmed computer control. Measurement time is less that one second per point including stage travel. Step precision is better than 10 microns, with the area of coverage and points within that area easily set for automatic scanning.

Speed and stability

The LSE-WS Ellipsometer measures by reflecting a polarized laser beam from the sample surface at a 70° incident angle and determines the change in polarization caused by the sample virtually instantaneously. Since there are no moving parts in the StokesMeter™ measuring head the measurements are accurate and repeatable even after many months of continuous use. Precision of measurement is further enhanced by the use of a stable, spectrally precise, high signal to noise HeNe gas laser light source.

 Stokes Waferskan™ Ellipsometer LSE-WS Specifications

Alignment: Tilt and table height via computer alignment screen. Proprietary tilt and table height system corrects ordinary sample tilt and out of-
flatness with no need for sample readjustment or complicated, costly and slow autofocusing systems.
Incidence Angle: 70°
Method of Measurement: Advanced StokesMeter reads the complete beam polarization using no moving parts and no . .
modulators, only 4 stationary silicon detectors so measurements are exact and stable.
Measurement Time: One second per point including stage travel.
Measurement Laser: Spectrally precise, stable, long lasting HeNe 6328A Laser with 1 mm beam diameter (1x3 mm on
wafer at 70 Typical lifetime is over 3 years. Similar light source used by NIST to produce calibration standards.
Optional Microspot has a 15 x 45 micron spot with CCD camera viewing.
Alignment Laser: 670 nm Laser Diode
Software: 2D/3D color graphics runs under Windows™ included
Sample (Wafer) Size: Up to 300mm diameter standard. Vacuum held (requires 5 inch Hg.).
Stages: Precision Stepping Motors under user programmed computer control with manual pushbutton
override. 150mm linear and 360°
rotary motion covers any point on the sample. Tiltable table permits correction for sample out-of-
flatness up to 1° in both X and
Y planes. Map any size wafer up to 300mm at 1 second per point.
Stage Precision: Within 10 microns
Data Output: 2D/3D color images of film thickness, refractive index and location to monitor, file or printer. Text
data file is easily exported to
other programs.
Computer: Windows™ 10 Laptop PC included
Film Thickness Range: 0 - 60,000 Angstroms on substrate or on 1, 2 or 3 known sublayers
Precision & Repeatability: Sub-Angstrom over most of the measurement range.
Refractive Index: ± .0005 over most of the measurement range.
Power: 115V, 100V, 220V, 240V (50/60 Hz)
Dimensions(LSE-WS): Height: 18 inches Width: 28 inches Depth: 20 inches
Net Weight: 85 lbs. Shipping Weight: 200 lbs.
CE Compliance: S series Ellipsometers comply with European safety directives and carry the CE mark.
CDRH Compliance: All 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.
Warranty: 1 year warranty covers all parts and labor exclusive of shipping costs