3.3.3.93. NXellipsometry

Status:

application definition, extends NXopt

Description:

Ellipsometry, complex systems, up to variable angle spectroscopy. ...

Ellipsometry, complex systems, up to variable angle spectroscopy.

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_sensors: Number of sensors used to measure parameters that influence the sample, such as temperature or pressure.

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.

N_observables: Number of observables that are saved in a measurement. e.g. one for intensity, reflectivity or transmittance, two for Psi and Delta etc. This is equal to the second dimension of the data array ‘measured_data’ and the number of column names.

N_time: Number of time points measured, the length of NXsample/time_points

Groups cited:

NXbeam_path, NXdetector, NXentry, NXinstrument, NXlens_opt, NXmonochromator, NXprocess, NXsample, NXsource, NXwaveplate

Structure:

ENTRY: (required) NXentry ⤆

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 defines:

  • elements of the experimental instrument

  • calibration information if available

  • parameters used to tune the state of the sample

  • sample description

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.

experiment_description: (required) NX_CHAR ⤆

An optional free-text description of the experiment. ...

An optional free-text description of the experiment.

However, details of the experiment should be defined in the specific fields of this application definition rather than in this experiment description.

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

  • imaging ellipsometry

INSTRUMENT: (required) NXinstrument ⤆

Properties of the ellipsometry equipment.

company: (optional) NX_CHAR ⤆

Name of the company which build the instrument.

construction_year: (optional) NX_DATE_TIME ⤆

ISO8601 date when the instrument was constructed. ...

ISO8601 date when the instrument was constructed. UTC offset should be specified.

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

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)

software: (required) NXprocess ⤆

program: (required) 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 metadata. This program converts the measured signals to ellipsometry data. If home written, one can provide the actual steps in the NOTE subfield here.

BEAM_PATH: (required) NXbeam_path ⤆

light_source: (required) NXsource ⤆

Specify the used light source. Multiple selection possible.

source_type: (required) NX_CHAR

Any of these values: arc lamp | halogen lamp | LED | other

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.

data_correction: (required) 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.

DETECTOR: (required) NXdetector

Properties of the detector used. Integration time is the count time ...

Properties of the detector used. Integration time is the count time field, or the real time field. See their definition.

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.

spectrometer: (optional) NXmonochromator ⤆

The spectroscope element of the ellipsometer before the detector, ...

The spectroscope element of the ellipsometer before the detector, but often integrated to form one closed unit. Information on the dispersive element can be specified in the subfield GRATING. Note that different gratings might be used for different wavelength ranges. The dispersion of the grating for each wavelength range can be stored in grating_dispersion.

SAMPLE: (required) NXsample ⤆

backside_roughness: (required) 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: (required) NXprocess ⤆

data_type: (required) NX_CHAR ⤆

Select which type of data was recorded, for example Psi and Delta ...

Select which type of data was recorded, for example Psi and Delta (see: https://en.wikipedia.org/wiki/Ellipsometry#Data_acquisition). It is possible to have multiple selections. Data types may also be converted to each other, e.g. a Mueller matrix contains N,C,S data as well. This selection defines how many columns (N_observables) are stored in the data array.

Any of these values:

  • Psi/Delta

  • tan(Psi)/cos(Delta)

  • Mueller matrix

  • Jones matrix

  • N/C/S

  • raw data

Hypertext Anchors

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

NXDL Source:

https://github.com/nexusformat/definitions/blob/main/contributed_definitions/NXellipsometry.nxdl.xml