tcad-devsim/devsim/testing/mesh2.py

# Copyright 2013 DEVSIM LLC
#
# SPDX-License-Identifier: Apache-2.0

import devsim

devsim.load_devices(file="mesh2.msh")

for x in devsim.get_device_list():
    for y in devsim.get_region_list(device=x):
        print("%s %s" % (x, y))

device = "MyDevice"
interface = "MySiOx"
regions = ("MyOxRegion", "MySiRegion")

devsim.set_parameter(
    device=device, region="MySiRegion", name="Permittivity", value=11.1 * 8.85e-14
)
devsim.set_parameter(
    device=device, region="MySiRegion", name="ElectricCharge", value=1.6e-19
)

devsim.set_parameter(
    device=device, region="MyOxRegion", name="Permittivity", value=3.9 * 8.85e-14
)
devsim.set_parameter(
    device=device, region="MyOxRegion", name="ElectricCharge", value=1.6e-19
)

for region in regions:
    devsim.node_solution(device=device, region=region, name="Potential")
    devsim.edge_from_node_model(device=device, region=region, node_model="Potential")

    devsim.edge_model(
        device=device,
        region=region,
        name="ElectricField",
        equation="(Potential@n0 - Potential@n1)*EdgeInverseLength",
    )
    devsim.edge_model(
        device=device,
        region=region,
        name="ElectricField:Potential@n0",
        equation="EdgeInverseLength",
    )
    devsim.edge_model(
        device=device,
        region=region,
        name="ElectricField:Potential@n1",
        equation="-EdgeInverseLength",
    )

    devsim.edge_model(
        device=device,
        region=region,
        name="PotentialEdgeFlux",
        equation="Permittivity*ElectricField",
    )
    devsim.edge_model(
        device=device,
        region=region,
        name="PotentialEdgeFlux:Potential@n0",
        equation="diff(Permittivity*ElectricField, Potential@n0)",
    )
    devsim.edge_model(
        device=device,
        region=region,
        name="PotentialEdgeFlux:Potential@n1",
        equation="-PotentialEdgeFlux:Potential@n0",
    )

    devsim.equation(
        device=device,
        region=region,
        name="PotentialEquation",
        variable_name="Potential",
        edge_model="PotentialEdgeFlux",
        variable_update="default",
    )

devsim.set_parameter(device=device, name="topbias", value=1.0)
devsim.set_parameter(device=device, name="botbias", value=0.0)


devsim.node_model(
    device=device,
    region="MySiRegion",
    name="topnode_model",
    equation="Potential - topbias",
)
devsim.node_model(
    device=device, region="MySiRegion", name="topnode_model:Potential", equation="1"
)

devsim.node_model(
    device=device,
    region="MyOxRegion",
    name="botnode_model",
    equation="Potential - botbias",
)
devsim.node_model(
    device=device, region="MyOxRegion", name="botnode_model:Potential", equation="1"
)

devsim.contact_equation(
    device=device,
    contact="top",
    name="PotentialEquation",
    node_model="topnode_model",
    edge_charge_model="PotentialEdgeFlux",
)

devsim.contact_equation(
    device=device,
    contact="top",
    name="PotentialEquation",
    node_model="topnode_model",
    edge_charge_model="PotentialEdgeFlux",
)

devsim.contact_equation(
    device=device,
    contact="bot",
    name="PotentialEquation",
    node_model="botnode_model",
    edge_charge_model="PotentialEdgeFlux",
)

# type continuous means that regular equations in both regions are swapped into the primary region
devsim.interface_model(
    device=device,
    interface=interface,
    name="continuousPotential",
    equation="Potential@r0-Potential@r1",
)
devsim.interface_model(
    device=device,
    interface=interface,
    name="continuousPotential:Potential@r0",
    equation="1",
)
devsim.interface_model(
    device=device,
    interface=interface,
    name="continuousPotential:Potential@r1",
    equation="-1",
)
devsim.interface_equation(
    device=device,
    interface=interface,
    name="PotentialEquation",
    interface_model="continuousPotential",
    type="continuous",
)


def print_charge():
    print(
        devsim.get_contact_charge(
            device=device, contact="top", equation="PotentialEquation"
        )
    )
    print(
        devsim.get_contact_charge(
            device=device, contact="bot", equation="PotentialEquation"
        )
    )


def print_flux():
    devsim.print_edge_values(
        device=device, region="MySiRegion", name="PotentialEdgeFlux"
    )
    devsim.print_edge_values(
        device=device, region="MyOxRegion", name="PotentialEdgeFlux"
    )


def set_permittivities(ox, si):
    devsim.set_parameter(
        device=device, region="MySiRegion", name="Permittivity", value=si * 8.85e-14
    )
    devsim.set_parameter(
        device=device, region="MyOxRegion", name="Permittivity", value=ox * 8.85e-14
    )


devsim.solve(type="dc", absolute_error=1.0, relative_error=1e-10, maximum_iterations=30)
print_charge()
print_flux()

set_permittivities(si=1.0, ox=1.0)
devsim.solve(type="dc", absolute_error=1.0, relative_error=1e-10, maximum_iterations=30)
print_charge()
print_flux()

# makes sure this global scope does not interfere
devsim.set_parameter(device=device, name="Permittivity", value=11.1 * 8.85e-14)

set_permittivities(si=11.1, ox=3.9)
devsim.solve(type="dc", absolute_error=1.0, relative_error=1e-10, maximum_iterations=30)
print_charge()
print_flux()

devsim.print_edge_values(device=device, region="MySiRegion", name="ElectricField")
devsim.print_edge_values(device=device, region="MyOxRegion", name="ElectricField")

devsim.print_node_values(device=device, region="MySiRegion", name="Potential")
devsim.print_node_values(device=device, region="MyOxRegion", name="Potential")