Home | Customer Support | Download Center | Literature | Search

FilmTek™ 4000

Multiple Angle Reflectometry

FilmTek™ 4000 is our most advanced model for thick-film applications.  It incorporates multiple detectors positioned at different angles of incidence — plus our patented multi-angle Differential Power Spectral Density analysis capability — to accurately measure the index of refraction with a resolution of 0.00002.  That's 100 times the performance of the best non-contact method, 10 times that of the best prism coupler contact systems.  Additionally, the FilmTek™ 4000 can measure birefringence of anisotropic materials.  With the hot plate option, the index of refraction and thermal expansion of a film can be characterized as a function of temperature.  A prime application for this system is measuring the index of refraction and thickness of planar waveguide films.  The addition of the spectroscopic ellipsometer (SE) option extends the FilmTek™ 4000 measurement capability down to very thin films as well.  The FilmTek™ 4500 adds transmission measurement capability for transparent samples.  The FilmTek™ 4000 is available in a variety of configurations ranging from table-top systems suitable for R&D to fully automated, standalone production tools.

FilmTek™ 4000 High Precision Measurement of Index

This unique FilmTek™ 4000 capability employ’s our patented DPSD (Differential Power Spectral Density) technique.  Spectroscopic reflection data are gathered at normal incidence and 70 degrees.  PSD processing results in two peaks in the Power Spectral Density domain.  The ratio of their positions is a function of the index of refraction of the film, and the angle of incidence of the oblique measurement.  This ratio is used to calculate the index.  Once the index is known, the thickness can be calculated from the optical thickness of the normal incident peak.

FilmTek™ 4000 Features

	Versatile: FilmTek™ 4000 incorporates SCI’s generalized material model with advanced global optimization algorithms for simultaneous determination of:   - Multiple layer thicknesses from 1Å to 350µm - Optical properties from 190nm-1700nm - TE and TM indices of refraction [ n(l ) ] - Extinction (absorption) coefficients [ k(l ) ] - Energy band gap [ Eg ]         - Constituent and void fraction - Surface roughness
	No Special Knowledge Required: FilmTek™ 4000 software is designed so that minimal experience in personal computers, thin film optical design, or measurement techniques is required.
	Complete "turn key" System: A fully integrated spectrophotometer measurement system with calibration, acquisition, and analysis software.
	Non-contact and non-destructive.
	Flexible: FilmTek™ 4000 hardware and software can be easily modified to satisfy unique customer requirements.
	Optional features: - Spectroscopic ellipsometry option for thin films (rotating compensator design) - Cassette to cassette wafer handling - Heating/cooling chuck - 300mm, FOUP, and SMIF compatible

 SiO₂ Film Properties vs Temperature

Measured by FilmTek™ 4000 with heating chuck during one heat-cool cycle.

Applications

Virtually all translucent films ranging in thickness from 1 angstrom to approximately 250 microns can be measured with high precision. Typical applications include:

	Semiconductor and dielectric materials			Computer disks
	Multilayer optical coatings			Coated glass
	Optical antireflection coatings			Laser mirrors
	Electro-optical materials			Thin Metals

Example Films
	SiOx			a-Si
	SiNx			a-C:H
	DLC			ITO
	SOG			Polysilicon
	Photoresist			Polyimide
	Thin Metals			Low K Dielectric Films

Example Substrates
	Silicon			GaAs
	SOI			Glass
	SOS			Aluminum

Technical Specifications

Methodology

FilmTek™ simultaneously solves for refractive index n(l), extinction coefficient k(l), and thicknesses of multi-layer film structures.  A self-consistent solution is obtained by using SCI’s generalized dispersion formula to model fitted values of the dielectric function e (l).  The SCI dispersion formula is quite general and applies to metallic, amorphous, crystalline, and dielectric materials (Figures 1-3).  This approach allows the user to model complex multi-layer structures with reflection/transmission data.  Global optimization methods are used to obtain the best solution while avoiding local minima and minimizing sensitivity to the user’s initial guess of fitted parameters (e.g., layer thickness).  FilmTek™ optimizes both the reflectance and power density spectrum (FFT) simultaneously.  This unique feature allows for accurate thickness determination over a wide range of thickness (1Å to 350µm).

Fig. 1 n and k spectra of Silicon

Fig. 2 n and k spectra of SiO2

Fig. 3 n and k spectra of Tantalum

Related Information

Copyright© Scientific Computing International 1993-2013. All rights reserved.

Top