api ¶

Bases: BaseModel

Where an electrode meets a doped Region: an ohmic contact.

The curve the two Regions share becomes a named line group on the mesh, and DEVSIM drives the contact's bias there.

Attributes:

• name (str) –

  Contact name, also its mesh group name (e.g. "anode").

• semiconductor (str) –

  The doped Region the contact injects into.

• electrode (str) –

  The Region on the other side: the metal, or any Region that is neither doped nor declared insulating.

Methods:

• validate_sides –

  Require two different Regions.

validate_sides() -> Self

Bases: _Named[Contact]

The declared contacts, by name.

Methods:

• add –

  Declare a contact between a doped Region and its electrode.

add(*, name: str, semiconductor: str, electrode: str) -> Contact

Bases: MutableModel

The cross-section plane and the extent of the meshed 2D domain.

Attributes:

• plane (str | None) –

  Cross-section plane, "x=<um>" or "y=<um>".

• window (AscendingInterval | None) –

  In-plane (min, max) clip of the domain in um (y for an x-plane, x for a y-plane); None keeps the full extent.

• window_z (AscendingInterval | None) –

  Vertical (min, max) clip of the domain in um.

• margin_x (float | None) –

  Airbox margin along x in um.

• margin_y (float | None) –

  Airbox margin along y in um.

• z_above (float | None) –

  Airbox extension above the stack top in um.

• z_below (float | None) –

  Airbox extension below the stack bottom in um.

The four airbox fields default to None: the mesh preset decides. Setting any of them configures the airbox, the unset ones at 0 um.

Methods:

• validate_plane –

  Require an x= or y= plane spec.

validate_plane(value: str | None) -> str | None

The doping profiles, each naming the mesh Region it applies to.

Methods:

• add –

  Add a profile (see :mod:gsim.tcad.doping) and return it.

• clear –

  Remove every profile.

• regions –

  The doped Regions, in the order the profiles first name them.

• remove –

  Remove one profile.

add(profile: DopingProfile | Mapping[str, Any]) -> DopingProfile

clear() -> None

regions() -> list[str]

remove(profile: DopingProfile) -> None

Bases: MutableModel

The component and the layer stack it is extruded with.

Attributes:

• component (Any | None) –

  The gdsfactory component the cross-section is cut from.

• stack (Any | None) –

  A gsim LayerStack, the path of a stack YAML file, or None to extract the stack of the active PDK.

Methods:

• validate_stack –

  Accept a LayerStack, a YAML path, or None.

validate_stack(value: Any) -> Any

Bases: BaseModel

An insulating Region taking part in the electrostatic solve only.

Attributes:

• region (str) –

  Mesh region (volume group) name, e.g. "sio2".

• relative_permittivity (float) –

  Static relative permittivity of the Region.

Bases: BaseModel

Where two doped Regions meet: potential and carriers are continuous.

An Interface carries no terminal voltage; that is what separates it from a :class:Contact.

Attributes:

• name (str) –

  Interface name, also its mesh group name (e.g. "junction").

• region_a (str) –

  One doped Region.

• region_b (str) –

  The other doped Region.

Methods:

• validate_sides –

  Require two different Regions.

validate_sides() -> Self

Bases: _Named[Interface]

The declared interfaces between doped Regions, by name.

Methods:

• add –

  Declare an interface between two doped Regions.

add(*, name: str, region_a: str, region_b: str) -> Interface

Bases: MutableModel

Semiconductor parameters and the insulators joining the solve.

Attributes:

• temperature_k (float) –

  Lattice temperature (K) of the silicon parameter set.

• semiconductor (str) –

  DEVSIM material name given to the doped Regions.

• mobility (MobilityModel) –

  Low-field mobility against the total doping, evaluated node by node. DEVSIM's own silicon defaults are two constants whatever the doping, which misstates the series resistance of a slab doped from 1e17 to 1e20 cm^-3.

• insulators (dict[str, PositiveFloat]) –

  Insulating Regions solved for the potential alone, Region name to static relative permittivity. Empty by default, which keeps the electrostatics inside the doped semiconductor; a declared insulator lets the field fringe around the Junction through it. An :class:Insulator or a list of them is also accepted.

Methods:

• coerce_insulators –

  Allow {"sio2": 3.9}, Insulator models, or a list of them.

coerce_insulators(value: Any) -> Any

Bases: MutableModel

Mesh resolution, Newton convergence and small-signal settings.

Attributes:

• mesh_preset (Literal['coarse', 'default', 'fine'] | None) –

  Mesh quality preset of the shared native-2D pipeline; None uses the pipeline's default.

• refined_mesh_size_um (PositiveFloat | None) –

  Mesh size near conductors and regions marked fine (um), overriding the preset.

• max_mesh_size_um (PositiveFloat | None) –

  Largest element size (um), overriding the preset.

• refinement_boxes (list[RefinementBox] | None) –

  Boxes (h_min, h_max, z_min, z_max, size) in um held to size over their whole area, e.g. where a depletion edge moves.

• absolute_error (PositiveFloat) –

  Newton absolute error target of devsim.solve.

• relative_error (PositiveFloat) –

  Newton relative error target of devsim.solve. With extended precision the 2D drift-diffusion Newton reaches 1e-12 on the test diode.

• max_iterations (int) –

  Newton iteration cap.

• bias_step_v (PositiveFloat) –

  Step (V) the swept contact is ramped in between biases.

• extended_precision (bool) –

  Use DEVSIM's 128-bit extended-precision assembly. Keep it on: in double precision the Newton on the test diode does not converge even to the default 1e-6.

• small_signal_freq_hz (PositiveFloat) –

  Frequency (Hz) of the quasi-static AC solve that extracts C(V).

• junction_freq_hz (PositiveFloat) –

  Frequency (Hz) of the AC solve whose admittance the series-RC junction fit reads: high enough that the capacitive current dominates the DC leakage, far below the branch's own RC rolloff.

• claim_devsim_namespace (bool) –

  Claim DEVSIM's process-global namespace at device setup: drop the circuit and the devices gsim created earlier. Foreign DEVSIM devices are never touched. Turn it off only when an earlier charge-transport device must stay alive.

Bases: BaseModel

The mesh a :class:gsim.tcad.Simulation solves on.

Attributes:

• mesh_path (Path) –

  The shared native-2D mesh (um), the one Palace BoundaryMode sees.

• devsim_mesh_path (Path) –

  Its copy with coordinates in cm, loaded by DEVSIM.

• groups (dict[str, Any]) –

  Physical groups of the mesh (volumes, contact lines, interface lines, shared curves).