Localmesh

The area of the added local mesh will override the default automatic mesh, regardless of the mesh step.

The setting of the minimum mesh step in the solver is the globally smallest mesh size allowed in the simulation. This setting takes priority over other mesh constraints, including local mesh regions.

3.1 Add local mesh

The syntax and properties of adding local mesh are shown below. This function does not return any data.

add(
        name: str,
        property: dict,
    )

General properties

dx/dy/dz: Specify the mesh size in the x/y/z direction.

Geometry properties

Parameter	Type	Default	Description
x, y, z	number	-	The center position of the local mesh region.
x_span, y_span, z_span	number	-	X span, Y span, Z span of the local mesh region.
x_min, x_max	number	-	X min, X max position of the local mesh region.
y_min, y_max	number	-	Y min, Y max position of the local mesh region.
z_min, z_max	number	-	Z min, Z max position of the local mesh region.

Example:

The following command sets the local mesh region to 6 um 3 um 3 um and the local mesh step to 0.2 um in the x, y and z directions. This script assumes that the project has been added to the simulation environment, and the pj is an instance of the Project.

lm = pj.LocalMesh()
lm.add(name="sub_mesh",
        property={"general": {"dx": 0.2, "dy": 0.2, "dz": 0.2},
                    "geometry": {"x": 0, "x_span": 6, "y": 0, "y_span":3, "z": 0, "z_span": 3 } } )

3.2 Add Electrical Local Mesh

In the context of electrical simulation, we present guidelines on how to incorporate meshing to ensure the precision and dependability of the simulation outcomes. The code explanations and a practical example provided below.

add_emesh(
            self,
            *,
            name: str,
            property: Dict[str, Any],
         )

Parameters	Description
name	Electric local mesh name.
property	Electric local mesh property.

Example:

st.add_emesh(name="local_mesh", type="EMesh", property={
        "general": {"mesh_size": 0.01},
        "geometry": {"geometry_type": "directly_defined", "x": st_x_mean, "x_span": 0,
                     "y": 0, "y_span": 0.8, "z_min": -0.1, "z_max": 0.3}})

Property list of electrical local mesh in a rectangle region:

	default	type	notes
general.mesh_size	0.01	float	The minimum value of the local mesh region.
general.geometry_type	directly defined	string	Selections are ['directly defined', 'solid','solid_solid']
solid_solid	-	string	Names of the two structures at the interface.
solid_1	-	string	Available when geometry_type is 'solid_solid'
solid_2	-	string	Available when geometry_type is 'solid_solid'

Local mesh of electrical simulation in rectangle region property list, when geometry_type is directly defined:

Parameters	Default	Type	Notes
geometry.x	-	float	The x-coordinate of the center point position of the electrical mesh.
geometry.x_span	-	float	The length in x direction of the electrical mesh. Restrained by condition: >0.
geometry.x_min	-	float	The minimum x-coordinate endpoint data of the electrical mesh.
geometry.x_max	-	float	The maximum x-coordinate endpoint data of the electrical mesh.
geometry.y	-	float	The y-coordinate of the center point position of the electrical mesh.
geometry.y_span	-	float	The width in y direction of the electrical mesh. Restrained by condition: >0.
geometry.y_min	-	float	The minimum y-coordinate endpoint data of the electrical mesh.
geometry.y_max	-	float	The maximum y-coordinate endpoint data of the electrical mesh.
geometry.z	-	float	The z-coordinate of the center point position of the electrical mesh.
geometry.z_span	-	float	The thinckness in z direction of the electrical mesh. Restrained by condition: >0.
geometry.z_min	-	float	The z-coordinate of the bottom position of the thickness of the electrical mesh.
geometry.z_max	-	float	The z-coordinate of the top position of the thickness of the electrical mesh.
mesh_size	-	float	The max size of electrical simulation mesh.

Note: When the simulation region is in the xy plane, only the parameters in the x, y direction are effective, and parameters in the z direction will be ignored. Similarly for the rest.

By implementing an electric mesh in solid or its boundary, enhancing the comprehensiveness of your simulation results.

Example:

# Example of electrical local mesh in a solid

   lm = pj.LocalMesh()
    
    lm.add(name="EMesh_Si", type="EMesh", property={
        "general": {"mesh_size": 0.02},
        "geometry": {"geometry_type": "solid", "solid": st["Si_base"]}
    })

# Example of electrical local mesh in the solid boundary

   lm = pj.LocalMesh()

    lm.add(name="Ge_Boundary", type="EMesh", property={
        "general": {"mesh_size": 0.002},
        "geometry": {"geometry_type": "solid_solid", 
                     "solid_1": st["Ge"],
                     "solid_2": st["Ge"],
                     "growth_ratio": 2}
    })