Thin-Film-MeasurementSpectroscopic Reflectometer

Thin-Film-MeasurementSpectroscopic Reflectometer

NanoCalc-2000-UV/VIS/NIR

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Thin filmsVery thin layers of different materials that are deposited on the surface of another material (thin films) areextremely important to many technology-based industries. Thin films are widely used, for example, to providepassivation, insulating layers between conductors, diffusion barriers, and hardness coatings for scratch and wearresistance. The fabrication of integrated circuits consists primarily of the deposition and selective removal of aseries of thin films.

Films typically used in thin-film applications range from a few atoms to half a millimeter. (<1nm = 0.001µmup to 400µm). They can be formed by many different processes including spin coating, vacuum evaporation,sputtering, vapor deposition and dip coating.

To perform the functions for which they were designed, thin films must have the proper thickness, composition,roughness and other characteristics important to the particular application. These characteristics need to oftenbe measured, both during and after thin-film fabrication. The two ways to measure thickness are optical and stylusbased techniques.

The latter method uses a stylus in contact with the sample to measure the step height between the coated and thenon-coated surface. Optical techniques accurately measure the thickness of thin transparent and semi-transparentlayers by analyzing white light interference. This method is non-destructive and does not need any special samplepreparation.

Principle of white light interference

IntroductionIntroduction

TheoryTheory

InterferenceOptical techniques determine thin-film characteristicsby measuring how the film interacts with light. Opti-cal techniques can measure the thickness of a film.Optical constants describe how light propagatesthrough and reflects from a material. Optical techni-ques are usually the preferred method for measuringthin films because they are accurate, non-destructive,and require little or no sample preparation. The twomost common optical measurement methodes arespectral reflectance/transmittance and ellipsometry.Spectral reflectance measures the amount of lightreflected from a thin film over a range of wavelengt-hs, with the incident light normal (perpendicular) tothe sample surface. Ellipsometry is similar, exceptthat it measures reflectance at non-normal incidenceand at two different polarizations. In general, spec-tral reflectance is much simpler and less expensivethan ellipsometry, but it is restricted to measuring lesscomplex structures.

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Determining Film Propertiesfrom Spectral ReflectanceThe amplitude and periodicity of the reflectance ofthin films are determined by the films thickness, opti-cal constants and other properties such as interfaceroughness. In reflectometry it is not possible to solvefor film properties in closed form, nor is it possible tosolve for n and k at each wavelength individually.In practice, mathematical models are used thatdescribe n and k over a range of wavelengths usingonly a few adjustable parameters. Film propertiesare determined by calculating reflectance spectrabased on varying trial values of thickness and then and k model parameters, until the calculated re-flectance matches the measured reflectance best(Best-Fit-Algorithm).

Models for n and kThere are many models for describing n and k as afunction of wavelength. When choosing a model fora particular film, it is important that the model is ableto accurately describe n and k over the wavelengthrange of interest using as few parameters as possi-ble. In general, the optical constants of different clas-ses of materials (e.g., dielectrics, semiconductors,metals and amorphous materials) vary quite different-ly with wavelength and require different models todescribe them.

Display of varying n- and k-values of a single material

Measurement of a very thin layer (10 nm)

Measurement of a medium thick layer (500 nm)

Measurement of a thick layer (100µm)

TheoryTheory

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Thickness of optical layers can be measured quicklyand easily with NanoCalc advanced spectrometrysystems. The hardware setup is done within a fewminutes. The entire system sets up in minutes and

measurements can be made by anyone with basiccomputer skills. The simple hardware and intuitivesoftware provides thin-film capability to a whole newgroup of users.

Thin-Cilm Measurement on your bench topThin-Film Measurements on your bench top

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NanoCalc is an easy-to-use production oriented soft-ware tool for the acquisition and analysis of spectro-scopic data. NanoCalc allows the user to find solu-tions to a wide range of applications.

NanoCalc enables thickness measurements from10 nm up to about 250 µm (400 µm). Metallic layerscould be determined from 1nm till they are not anymore transparent. The system only needs the know-ledge of number and kind of the compound thinfilms. The refraction index behavior versus wave-length n(�) and the absorption index behavior k(�)are given by tabular data or Cauchy coefficients.

As a result single thickness with a resolution of 0.1nmcan be calculated. To avoid ambiguities in multilayersystems and to reduce the evaluation time it is helpfulto work with estimated thickness values. Single layerand multi-layer systems with estimated thickness canbe calculated in less than one second. Therefore it isalso possible to apply a two-dimensional scanningscheme.

The user mode is specifically designed such for littleor no experience in personal computers. In thismode, the user interacts with a single window toopen predefined recipes that automatically load alllayer settings and instruments parameters. The useronly needs to measure the experimental data.

In the administrator mode, the administrator specifiesthe recipe settings. Each recipe contains the layerand material settings and instrument parametersettings. These recipes can be saved for later use.The administrator mode is protected by a defineablepassword.

Measurement of a medium thick layer

Measurement of a thick layer

Measurement of a triple layer

NanoCalc-SoftwareNanoCalc-Software

Up to three layers can be specified in the film stack.The various films and substrate materials may bemetallic, dielectric, amorphous or crystalline semicon-ductors. NanoCalc incorporates a large library ofn- and k-values for the more widely used materials,which the user can edit and expand. Material typescan also be defined by equation/dispersion formu-las. The user simply specifies the appropriate coeffi-cients and the program calculates the correct indices.

NanoCalc materials data baseIn the data base of NanoCalc a large number ofmaterials are already included. This makes the imme-diate measurement of standard materials fast andsimple. Additionally it is very easy to create newcustomized materials or catalogs of materials.

Edit layer structure

Extraction from material data base

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Edit Layer StructureEdit Layer Structure

semi-conductorsSia_Sia_Si_1a_Si_2a_Si_3AlGaAs19AlGaAs31AlGaAs41AlGaAs49AlGaAs59AlGaAs70AlGaAs80GaAsGaAs_(100)GaAs_(111)GeGe_(100)Si_(100)Si_(110)Si_(111)Si_poly_1Si_poly_2Si_poly_10Si_poly_20Si_poly_30Si_poly_40Si_poly_50Si_poly_60Si_poly_70Si_poly_80Si_poly_90Si_porous

PoSi1PoSi2

oxidesSiO2_(therm)Al2O3CeO2CuOFe2O3HfO2ITOITO1ITO2ITO3MgONb2O5POSiOSiO2_(CVD)SnO2(F)Ta2O3Ta2O5TiO2TiO2_aWO3Y2O3Y2O3aZrO2

polymerspmmapmma_495pmma_950copolymer_resists

polyimidesHitachi_PIQ

glassesBK77059Borofloat40LASF9SF11SodaLime

nitridesSi3N4AlNGaNSiN1SiN2SiN3SiON_00SiON_20SiON_40SiON_60SiON_80TiN

metalsAgAl

AuCoCo_2CrCuFeIrLiMoNiNi50Cr50OsPdPtRhsteelTaTiVW

carbidesSiCSiC_1

fluoridesBaF2CaF2LiFMgF2SrF2ThF2

selenidesZnSe

silicidesCoSi2_4TaSi2_ATaSi2_BTaSi_AVSi2_AVSi2_BWSi2_AWSi2_B

sulfidesCdSPbSZnS

resists_ClariantAZ6212AQUATARAZ_EL_2015AZ_NOVA_2071AZ_OFPR_800AZ111_expAZ111_non_expAZ1350H_expAZ1350J_expAZ1350J_non_exp

AZ1518AZ1518_SFDAZ1518HS_WIAZ4500AZ6210BAZ7209AZ7510AZ7700AZ8100aAZ8112BARLIDX46

resists_ShipleySPR500SPR955UV5UV6

resists_MRTSU8ARU400ma-N400ma-P100

resists_Arch(Olin)APIIARCH2ARCH5000seriesBPRS-100

ex-KTI_NegResHiPR 6512HiPR 6512GH_025HiPR 6514HC_17HCHiPR 6517HiPR 6517GH_050HiPR 6517GH_070HPR 200_500OCG 825OCG 895OCG 896-10iOCG NegResOFR 6800OiR 32OiR 32HDOiR 32MDOiR 5503OiR 620OiR 622OiR 64OiR 643OiR 644OiR 670OiR 672OiR 897OiR 897_12MKOiR 906OiR 907OiR 908

telluridesHgCdTe0HgCdTe2HgCdTe3PbTePZTZnCdTe0ZnCdTe1ZnCdTe3ZnCdTe5ZnCdTe7ZnCdTe9ZnCdTe10ZnSeTe0ZnSeTe1ZnSeTe3ZnSeTe5ZnSeTe7ZnSeTe9ZnSeTe10

othersa_CAirBCBDiamondDiaplate132DLC_aDLC_bH20IRX

The NanoCalc Mapping module extends NanoCalc to a fully functionalmapping software. With this software it is very easy to define the scanregion and to measure this region of interest afterwards. The results can bedisplayed as 2D- or 3D-plot. Additionally they can be stored and printed.All adjustments can be stored in a mapping-recipe, so that the same scancan be repeated later.

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Software OptionsSoftware Options

NanoCalc OnlineNanoCalc Online

The Online-Module can print or show XY-plots andhistograms of the layer thickness and removal rate.Terminator point detection and on-line measurementof layer thickness can be readily obtained. The reci-pes and results can be directly input to MS-Excelto produce process statistics making this softwaremodule a genuine production tool. Data readingcan be initiated by time, keyboard input or an exter-nal TTL-Trigger. These capabilities make this Thin FilmEquipment a true professional on-line and in-situmeasuring system.

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Semiconductor Process FilmsNanoCalc measurement systems are routinely used to measurethe thickness of oxides, SiNx, photoresists and other semicon-ductor process films. In addition to these single-layer applications,many two- and three-layer film measurements are also possible.

In-Situ MeasurementsA flexible optical probe assemblymakes on-line and in-situ thicknessmeasurements easily possible. All thatis required is optical access for nor-mal-incidence reflectance measure-ments. An example is online-measuringof removal rate in nm per second whileremoving resist-layers from wafers.Call us for more details about interfa-cing with your production equipment.

Software OptionSoftware Option

ApplicationsApplications

NanoCalc-RemoteThis option allows control of theNanoCalc Software by a diffe-rent software application usingActiveX remote commands.

The TestActiveX sample applica-tion shows the functionality of allavailable commands.

NanoCalc application runningas ActiveX component

Sending command– load recipe – measure – analyse – …

Receiving results– Thickness – Fitness

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Optical CoatingsOptical Coatings are used for scratch resistanceand/or antireflection coatings in many industries.Automotive plastics, eyeglass lenses, and many pla-stics packaging applications use thin films.For hardcoats, a primer layer is often applied first forimproved film adhesion. Mikropack systems are cap-able of measuring the thickness of these layers indivi-dually or simultaneously.

Coatings onRough SurfacesUsually Thin-Film-Mathematics andoptical reflectometry are based on perfect smoothsurfaces. If for example photoresist layers growthicker than 20µm, the surface will not be smoothany longer. There is a roughness. In the world ofcoatings are many Thin-Film-Applications with roughsubstrates like steel, aluminum, brass, copper, cera-mic and plastic. These surfaces can be coated byDLC (Diamond Like Carbon Layers) or other coatings.All these rough surfaces are causing a lack of signalbecause of stray light loss. NanoCalc is able tomeasure rough surfaces with three different and verymuch improved methods, without having prior know-ledge about the roughness of the samples. The systemmeasures and compensates simultaneously.

ApplicationsApplications

NanoCalc- NanoCalc- NanoCalc- NanoCalc- NanoCalc- NanoCalc- NanoCalc-Specifications 2000-VIS 2000-NIR 2000-NIR-HR 512-NIR 2000-VIS/NIR 2000-UV/VIS 2000-UV/VIS/NIRWavelength: 400-850nm 650-1100nm 700-978nm 900-1700nm 400-1100nm 250-850nm 250-1100nmThickness Range: 50nm...20µm 70nm...70µm 1...250µm 50nm...200µm 50nm...100µm 10nm...20µm 10nm...70µmResolution: 0,1nm 0,1nm 0,1µm 20nm 0,1nm 0,1nm 0,1nmRepeatablity: 0,3nm 0,3nm 10nm 10nm 0,3nm 0,3nm 0,3nmAbs.Accuracy: <1% (100nm...100µm)Measurement Time: 100ms.....<1sNumbers of Layers: 1...3 (NanoCalc-MS maybe needed)Distance with fiber: 1-5mmDistance with optic: 5mm...100mmAngle of incidence: 90°Spotsize: Standard 400µm (optional 100/200µm)Microspot: 1...20µm with Microscope 10x/20x/50x Magnification and MFA-AdapterFiber cable length: 2m (other lengthes on request)Interface: USB 1.1 (RS-232)Power consumption: 12 VDC@1,2A 24VDC@1,2A 12 VDC@1,2APower requirements: 90...240 VAC 50/60 HzSize: 180mm x 152 mm x 263mmWeight: ~ 3,5 kg

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MPM-2000-2 x 8

The Mikropack 16-Channel Multiplexer MPM-2000allows the measurement from up to 8 individualfixed fiber positions in less than 8 seconds. Usingthe ActiveX Remote NanoCalc Software in combina-tion with the MPM 2000 it can be easily customizedto integrate into most sample transfer systems.

Stage – Single point reflection measurement

Probeholder for simple reflection measurements onoptical layers. Base plate for parts with maximaldiameter of 150 mm. Height adjustment for standard6,35mm fiberprobe.

Stage RTL – (T) Transparent samplemeasurement

This Stage-System is useful for different kinds of Thin-Film- and Spectroscopy-Measurement-Setups. To mea-sure the reflection from below gives the advantage ofconstant distance between measuring-fiber and sam-ple surfaces. Therefore the thickness of the sample isnot relevant. The setup with a light trap is importantto measure transparent materials to avoid backgroundreflections and ambient light. The Stage RTL-T enablesthe transmission setup. Two extra fiber cables areneeded.

CSH – Probe holder for curved samples

Probeholder for simple reflection measurements onoptical parts with curved surfaces. A hard rubberpart prevents samples against scratches.

AccessoriesAccessories

Stage RTL -T Stage RTL

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MAPPING 6“ and 12“Are scanning stages with high precision- linear androtary axes. Travel range is 150 x150mm for the 6”and 300 mm for the R-Theta 12” stage. The Mapping6” and 12” Stages are interfaced by RS 232 andcould be powered wide range 110 -240 VAC50-100 Hz. The fiber probe (6,35mm) is placedin a swivel arm, for easy sample change.Special-Vacuum-Chucks and holders for other mate-rials are available on request.

Microscope Adapter / Micro-SpotThe MFA-C-Mount adapter allows easy mountingof the fiber probe to the C-mount exit of almost anymicroscope. Depending on the microscope magni-fication a measurement spot size between 1µm and40µm can be realized. The measurement spot itselfcan be observed through the eyepieces or an addi-tional CCD-camera for accurate positioning of thesample.

ReferenceThis special Reference Step Wafer consists of a4inch Si-wafer with 6 silicon dioxide (SiO2) stepsbetween 0nm (native Oxide) and 500nm. Eachthickness step has a laser marked area for whichaccurate ellipsometric thickness data are suppliedon the corresponding calibration sheet.

AccessoriesAccessories

Thinfilm Thickness Reflectometer System NanoCalc-2000

NanoCalc-2000-VIS Wavelength 400 -850 nm, Thickness 50 nm....20 µm, (SiO2 on Si)Spectrometer, A/D-Converter, USB- and RS232-Interface,Halogen-Lightsource, Reflection Probe, NanoCalc Software

NanoCalc-2000-NIR Wavelength 650 -1100 nm, Thickness 70 nm....70 µm,Spectrometer, A/D-Converter, USB- and RS232-Interface,Halogen-Lightsource, Reflection Probe, NanoCalc Software

NanoCalc-2000-VIS/NIR Wavelength 400 -1100 nm, Thickness 50 nm....100 µm (optional1µm....250 µm). Spectrometer, A/D-Converter, USB- and RS232-Interface,Halogen-Lightsource, Reflection Probe, NanoCalc Software

NanoCalc-2000-UV/VIS Wavelength 250 -850 nm, Thickness 10 nm....20 µm, Spectrometer,A/D-Converter, USB- and RS232-Interface, Deuterium-Halogen-Lightsource, Reflection Probe, NanoCalc Software

NanoCalc-2000-UV/VIS/NIR Wavelength 250 -1100 nm, Thickness 10 nm....70 µm, Spectrometer,A/D-Converter, USB- and RS 232-Interface, Deuterium-Halogen-Lightsource, Reflection Probe, NanoCalc Software

NanoCalc-2000-NIR-HR Wavelength 700 -978 nm, Thickness 1µm....250 µm (400 µm)High Resolution Spectrometer, A/D-Converter, USB- and RS 232-Interface,Halogen-Lightsource, Reflection Probe, NanoCalc Software

NanoCalc-512-NIR Wavelength 900 -1700 nm, Thickness 50 nm....200 µm, InGaAs-512Element-Array-Spectrometer, A/D-Converter, USB- and RS 232-Interface, High-Power-Halogen-Lightsource, Reflection Probe, NanoCalc- and Scout-Software

Software

NanoCalc Thin Film Measurement Software for Windows™Measurement, simulation and analysis of a single-layer systems

NanoCalc MS Thin Film Measurement Software for WindowsMeasurement, simulation and analysis of a multi-layer systems

NanoCalc Mapping Mapping module software (needs NanoCalc or NanoCalc MS)Complete 3D-Mapping-Modul with control-software for Mapping StageMapping-6’’ and Mapping-12’’

NanoCalc Online Online module software (needs NanoCalc or NanoCalc MS). Online display ofXY-graphs and histograms of layer thickness and removal rate. End point detection,on-line check of layer thickness. Recipe, result list, statistics with data transfer to Excel®

NanoCalc Remote Remote module (needs NanoCalc or NanoCalc MS)Active-X functionality allows to control most of the NanoCalc functions from anyother software. Comes with a example program (MS Visual Basic).

Mikropack GmbHMaybachstraße 11D-73760 Ostfildern (Germany)Phone +49(0)711/3416 96-0Fax +49(0)711/3416 96-85e-Mail: ThinFilm@Mikropack.deInternet: www.mikropack.de

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