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Substrates

Substrates are the base materials on which you deposit thin films or grow materials. Proper substrate tracking ensures you can trace your samples back to their starting materials and identify batch-specific effects.

Overview

This schema package defines:

  • DTUSubstrate - An individual substrate wafer or piece with specific properties (size, thickness, surface orientation, supplier information)

  • DTUSubstrateBatch - A collection of substrates from the same supplier batch, sharing common properties. This enables efficient documentation when you purchase and use multiple identical substrates.

Both extend NOMAD's CompositeSystem entity, providing lab ID tracking and referenceable objects that can be linked from synthesis processes.

Typical Usage

  1. Document substrate batch: When substrates arrive, create a DTUSubstrateBatch entry with supplier info, batch number, and common properties
  2. Reference in synthesis: When performing sputtering or thermal evaporation, reference the substrate or substrate batch used
  3. Track consumption: Monitor which substrates have been used for which experiments
  4. Batch analysis: Identify if results correlate with specific substrate batches

Schema Documentation

DTUSubstrate

description: Schema for substrates in the DTU Nanolab.

inherits from: nomad_material_processing.general.CrystallineSubstrate, nomad.datamodel.data.EntryData

properties:

name type
substrate_polishing ['1 sided', '2 sided', 'none'] default=1 sided

normalization:

If the elemental composition list is empty, the normalizer will iterate over the components and extract all the elements for populating the elemental composition list. If masses are provided for all components and the elemental composition of all components contain atomic fractions the normalizer will also calculate the atomic fractions for the composite system. The populated elemental composition list is added to the results by the normalizer in the System super class.

DTUSubstrateReference

inherits from: nomad.datamodel.metainfo.basesections.v1.CompositeSystemReference

properties:

name type
reference DTUSubstrate The reference to the substrate entity.

normalization:

Will attempt to fill the reference from the lab_id or vice versa.

DTUSubstrateBatch

description: Schema for substrate batches in the DTU Nanolab.

inherits from: nomad.datamodel.metainfo.basesections.v1.Collection, nomad.datamodel.data.EntryData

properties:

name type
material str The material of the substrate.
default=Si
supplier str default=Siegert Wafer
substrate_polishing ['1 sided', '2 sided', 'none'] default=1 sided
doping_type_of_substrate ['N-type', 'P-type'] default=N-type
doping_of_substrate float64 The doping of the substrate measured as the electrical resistivity.
unit=meter * ohm, default=0.2
doping_elements str shape=['*'], default=['P']
shape ['Circular', 'Rectangular'] The shape of the substrate. Circular (wafer) or rectangular. If the shape is circular, the diameter is used to define the size of the substrate. If the shape is rectangular, the length and width are used to define the size of the substrate.
default=Rectangular
diameter float64 Only used if the shape is circular. The diameter of the substrate.
unit=meter, default=0.1524
length float64 Only used if the shape is rectangular. The length of the substrate.
unit=meter, default=0.04
width float64 Only used if the shape is rectangular. The width of the substrate.
unit=meter, default=0.04
thickness float64 unit=meter, default=0.000675
create_substrates bool (Re)create the substrate entities.
number_of_substrates int The number of substrates in the batch.
entities DTUSubstrateReference References to the entities that make up the collection.
sub-section, repeats
substrate_identifiers nomad.datamodel.metainfo.basesections.v1.ReadableIdentifiers sub-section

normalization:

The normalizer for the DTUSubstrateBatch class.

Args: archive (EntryArchive): The archive containing the section that is being normalized. logger (BoundLogger): A structlog logger.

CleaningStep

inherits from: nomad.datamodel.metainfo.basesections.v1.ProcessStep

properties:

name type
cleaning_agent ['Acetone', 'Ethanol', 'H2O', 'IPA', 'N2-gun'] default=N2-gun
sonication bool default=False

DTUSubstrateCleaning

description: Schema for substrate cleaning at the DTU Nanolab.

inherits from: nomad.datamodel.metainfo.basesections.v1.Process, nomad.datamodel.data.EntryData

properties:

name type
substrate_batch DTUSubstrateBatch The substrate batch that was cleaned.
steps CleaningStep An ordered list of all the dependant steps that make up this activity.
sub-section, repeats

normalization:

The normalizer for the DTUSubstrateCleaning class.

Args: archive (EntryArchive): The archive containing the section that is being normalized. logger (BoundLogger): A structlog logger.

DTUSubstrateCutting

description: Schema for substrate cutting at the DTU Nanolab.

inherits from: nomad.datamodel.metainfo.basesections.v1.Process, nomad.datamodel.data.EntryData

properties:

name type
substrate_batch DTUSubstrateBatch The substrate batch that was cut.
instrument_name str default=microSTRUCT vario from the company 3D-Micromac AG
laser_power float64 unit=watt, default=50
laser_wavelength float64 unit=meter, default=5.32e-07
repetition_rate float64 unit=hertz, default=200
pattern_repetitions int default=6
writing_speed float64 unit=meter / second, default=0.05

normalization:

The normalizer for the DTUSubstrateCutting class.

Args: archive (EntryArchive): The archive containing the section that is being normalized. logger (BoundLogger): A structlog logger.