2.3.3.3.108. NXellipsometry

Status:

application definition, extends NXoptical_spectroscopy

Description:

This is the application definition describing ellipsometry experiments. ...

This is the application definition describing ellipsometry experiments.

Such experiments may be as simple as identifying how a reflected beam of light with a single wavelength changes its polarization state, to a variable angle spectroscopic ellipsometry experiment.

The application definition specifies optical spectroscopy (NXopt), by extending the terms and setting specific requirements.

Information on ellipsometry is provided, e.g. in:

  • H. Fujiwara, Spectroscopic ellipsometry: principles and applications, John Wiley & Sons, 2007.

  • R. M. A. Azzam and N. M. Bashara, Ellipsometry and Polarized Light, North-Holland Publishing Company, 1977.

  • H. G. Tompkins and E. A. Irene, Handbook of Ellipsometry, William Andrew, 2005.

Open access sources:

Review articles:

Symbols:

Variables used throughout the document, e.g. dimensions or parameters.

N_spectrum: Length of the spectrum array (e.g. wavelength or energy) of the measured data.

N_measurements: Number of measurements (1st dimension of measured_data array). This is equal to the number of parameters scanned. For example, if the experiment was performed at three different temperatures and two different pressures N_measurements = 2*3 = 6.

N_detection_angles: Number of detection angles of the beam reflected or scattered off the sample.

N_incident_angles: Number of angles of incidence of the incident beam.

Groups cited:

NXdata, NXentry, NXfabrication, NXinstrument, NXlens_opt, NXprogram, NXsample, NXwaveplate

Structure:

ENTRY: (required) NXentry ⤆

definition: (required) NX_CHAR ⤆

An application definition for ellipsometry. ...

An application definition for ellipsometry.

Obligatory value: NXellipsometry

@version: (required) NX_CHAR ⤆

Version number to identify which definition of this application ...

Version number to identify which definition of this application definition was used for this entry/data.

@URL: (required) NX_CHAR ⤆

URL where to find further material (documentation, examples) relevant ...

URL where to find further material (documentation, examples) relevant to the application definition.

title: (recommended) NX_CHAR ⤆

experiment_type: (required) NX_CHAR ⤆

Specify the type of the optical experiment. ...

Specify the type of the optical experiment.

You may specify fundamental characteristics or properties in the experimental sub-type.

Obligatory value: ellipsometry

ellipsometry_experiment_type: (required) NX_CHAR

Specify the type of ellipsometry. ...

Specify the type of ellipsometry.

Any of these values:

  • in situ spectroscopic ellipsometry

  • THz spectroscopic ellipsometry

  • infrared spectroscopic ellipsometry

  • ultraviolet spectroscopic ellipsometry

  • uv-vis spectroscopic ellipsometry

  • NIR-Vis-UV spectroscopic ellipsometry

  • other

ellipsometry_experiment_type_other: (optional) NX_CHAR

If the ellipsometry_experiment_type is other, a name should be specified here.

INSTRUMENT: (required) NXinstrument ⤆

Properties of the ellipsometry equipment.

ellipsometer_type: (required) NX_CHAR

What type of ellipsometry was used? See Fujiwara Table 4.2. ...

What type of ellipsometry was used? See Fujiwara Table 4.2.

Any of these values:

  • rotating analyzer

  • rotating analyzer with analyzer compensator

  • rotating analyzer with polarizer compensator

  • rotating polarizer

  • rotating compensator on polarizer side

  • rotating compensator on analyzer side

  • modulator on polarizer side

  • modulator on analyzer side

  • dual compensator

  • phase modulation

  • imaging ellipsometry

  • null ellipsometry

  • other

ellipsometer_type_other: (optional) NX_CHAR

If the ellipsometer_type is `other`, a specific ellipsometry_type" should ...

If the ellipsometer_type is other, a specific ellipsometry_type” should be added here.

rotating_element_type: (required) NX_CHAR

Define which element rotates, e.g. polarizer or analyzer. ...

Define which element rotates, e.g. polarizer or analyzer.

Any of these values:

  • polarizer (source side)

  • analyzer (detector side)

  • compensator (source side)

  • compensator (detector side)

focussing_probes: (optional) NXlens_opt ⤆

If focussing probes (lenses) were used, please state if the data ...

If focussing probes (lenses) were used, please state if the data were corrected for the window effects.

type: (required) NX_CHAR ⤆

Any of these values:

  • objective

  • lens

  • glass fiber

  • none

  • other

data_correction: (recommended) NX_BOOLEAN

Were the recorded data corrected by the window effects of the ...

Were the recorded data corrected by the window effects of the focussing probes (lenses)?

angular_spread: (recommended) NX_NUMBER {units=NX_ANGLE}

Specify the angular spread caused by the focussing probes.

device_information: (optional) NXfabrication ⤆

rotating_element: (optional) NXwaveplate ⤆

Properties of the rotating element defined in ...

Properties of the rotating element defined in ‘instrument/rotating_element_type’.

revolutions: (optional) NX_NUMBER {units=NX_COUNT}

Define how many revolutions of the rotating element were averaged ...

Define how many revolutions of the rotating element were averaged for each measurement. If the number of revolutions was fixed to a certain value use the field ‘fixed_revolutions’ instead.

fixed_revolutions: (optional) NX_NUMBER {units=NX_COUNT}

Define how many revolutions of the rotating element were taken ...

Define how many revolutions of the rotating element were taken into account for each measurement (if number of revolutions was fixed to a certain value, i.e. not averaged).

max_revolutions: (optional) NX_NUMBER {units=NX_COUNT}

Specify the maximum value of revolutions of the rotating element ...

Specify the maximum value of revolutions of the rotating element for each measurement.

SAMPLE: (required) NXsample ⤆

backside_roughness: (optional) NX_BOOLEAN

Was the backside of the sample roughened? Relevant for infrared ...

Was the backside of the sample roughened? Relevant for infrared ellipsometry.

data_collection: (optional) NXdata ⤆

Measured data, data errors, and varied parameters. This may be used to descr ...

Measured data, data errors, and varied parameters. This may be used to describe indirectly derived data or data transformed between different descriptions, such as: Raw Data –> Psi Delta Psi, Delta –> N,C,S Mueller matrix –> N,C,S Mueller matrix –> Psi, Delta etc.

Other types of data, such as temperature or sample location, may be saved in a generic (NXdata) concept from NXopt, or better directly in the location of the sample positioner or temperature sensor.

data_identifier: (recommended) NX_NUMBER ⤆

An identifier to correlate data to the experimental conditions, ...

An identifier to correlate data to the experimental conditions, if several were used in this measurement; typically an index of 0-N.

data_type: (recommended) NX_CHAR

Select which type of data was recorded, for example intensity, ...

Select which type of data was recorded, for example intensity, reflectivity, transmittance, Psi and Delta etc. It is possible to have multiple selections. The enumeration list depends on the type of experiment and may differ for different application definitions.

Any of these values:

  • intensity

  • reflectivity

  • transmittance

  • Psi/Delta

  • tan(Psi)/cos(Delta)

  • Mueller matrix

  • Jones matrix

  • N/C/S

  • raw data

NAME_spectrum: (optional) NX_FLOAT (Rank: 1, Dimensions: [N_spectrum]) {units=NX_ANY}

Spectral values (e.g. wavelength or energy) used for the measurement. ...

Spectral values (e.g. wavelength or energy) used for the measurement. An array of 1 or more elements. Length defines N_spectrum. Replace ‘SPECTRUM’ by the physical quantity that is used, e.g. wavelength.

@units: (optional) NX_CHAR

If applicable, change 'unit: NX_ANY' to the appropriate NXDL unit. ...

If applicable, change ‘unit: NX_ANY’ to the appropriate NXDL unit. If the unit of the measured data is not covered by NXDL units state here which unit was used.

measured_data: (required) NX_FLOAT (Rank: 3, Dimensions: [N_measurements, N_observables, N_spectrum]) {units=NX_ANY}

Resulting data from the measurement, described by 'data_type'. ...

Resulting data from the measurement, described by ‘data_type’.

The first dimension is defined by the number of measurements taken, (N_measurements). The instructions on how to order the values contained in the parameter vectors given in the doc string of INSTRUMENT/sample_stage/environment_conditions/PARAMETER/values, define the N_measurements parameter sets. For example, if the experiment was performed at three different temperatures (T1, T2, T3), two different pressures (p1, p2) and two different angles of incidence (a1, a2), the first measurement was taken at the parameters {a1,p1,T1}, the second measurement at {a1,p1,T2} etc.

@units: (optional) NX_CHAR

If applicable, change 'unit: NX_ANY' to the appropriate NXDL unit. ...

If applicable, change ‘unit: NX_ANY’ to the appropriate NXDL unit. If the unit of the measured data is not covered by NXDL units state here which unit was used.

measured_data_errors: (optional) NX_FLOAT (Rank: 3, Dimensions: [N_measurements, N_observables, N_spectrum]) {units=NX_ANY}

Specified uncertainties (errors) of the data described by 'data_type' ...

Specified uncertainties (errors) of the data described by ‘data_type’ and provided in ‘measured_data’.

@units: (optional) NX_CHAR

If applicable, change 'unit: NX_ANY' to the appropriate NXDL unit. ...

If applicable, change ‘unit: NX_ANY’ to the appropriate NXDL unit. If the unit of the measured data is not covered by NXDL units state here which unit was used.

varied_parameter_link: (optional) NX_CHAR (Rank: 1, Dimensions: [N_sensors])

List of links to the values of the sensors. Add a link for each ...

List of links to the values of the sensors. Add a link for each varied parameter (i.e. for each sensor).

reference_data_link: (optional) NX_CHAR

Link to the NeXus file which describes the reference data if a ...

Link to the NeXus file which describes the reference data if a reference measurement was performed. Ideally, the reference measurement was performed using the same conditions as the actual measurement and should be as close in time to the actual measurement as possible.

data_software: (optional) NXprogram

@URL: (optional) NX_CHAR

Website of the software.

program: (recommended) NX_CHAR ⤆

Commercial or otherwise defined given name of the program that was ...

Commercial or otherwise defined given name of the program that was used to generate the result file(s) with measured data and/or metadata (in most cases, this is the same as INSTRUMENT/software). If home written, one can provide the actual steps in the NOTE subfield here.

version: (recommended) NX_CHAR

Either version with build number, commit hash, or description of a ...

Either version with build number, commit hash, or description of a (online) repository where the source code of the program and build instructions can be found so that the program can be configured in such a way that result files can be created ideally in a deterministic manner.

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/FAIRmat-NFDI/nexus_definitions/tree/fairmat/contributed_definitions/NXellipsometry.nxdl.xml