MaskSpec

MaskSpec(
    operand1=None,
    operand2=None,
    operation='+',
    dilation=0,
    translation=(0, 0),
)

Mask specification.

This class is mainly used when creating an ExtrusionSpec for a Technology.

Args

• operand1 (str | tuple[int, int] | MaskSpec | Iterable[str | tuple[int, int] | MaskSpec]): Layers or sub-masks that compose this maks specification that are joined to create this specification.
• operand2 (str | tuple[int, int] | MaskSpec | Iterable[str | tuple[int, int] | MaskSpec]): Layers or sub-masks that can be combined with operand1 through a boolean operation.
• operation (Literal[”+”, "", ”-”, ”^”]): One of ”+” (union), "" (intersection), ”-” (difference), or ”^” (symmetric difference).
• dilation (float): Dilation (erosion, if negative) applied to the mask.
• translation (Sequence[float] | complex): Translation applied to the mask.

Examples

Masks specifications can be combined using arithmetic operations:

>>> layer_1_0 = pf.MaskSpec((1, 0))
>>> layer_2_0 = pf.MaskSpec((2, 0), dilation=0.1)
>>> difference = layer_1_0 - layer_2_0
>>> eroded_diff = difference ** -0.1
>>> eroded_diff
MaskSpec(...)

Note

An empty list of operands indicates the full component bounds. The inversion of a layer is indicated by subtracting it from the component bounds.

Methods

Method	Description
copy	Create a copy of this mask specification.
format	Create a string expression for this mask using names instead of layers.
get_layers	Get the set of all layers referenced by this mask specification.
parse	Parse a string expression into a mask specification.
uses_translation	uses_translation(self)

copy

copy(self)

Create a copy of this mask specification.

Returns

MaskSpec: New copy.

format

format(self, layer_names=None, technology=None)

Create a string expression for this mask using names instead of layers.

Args

• layer_names (dict[tuple[int, int], str] | None): Dictionary mapping layer tuples to names, that will replace the layer tuples in the resulting expression. If not set, the technology layer names are used instead.
• technology (Technology | None): Technology whose layers will be used to extract the layer names. Not used if layer_names is defined. If not specified, the current default technology is used.

Returns

str: Mask specification string.

Example

>>> mask = pf.MaskSpec.parse("(0, 0) * (1, 0)")
>>> mask.format({(0, 0): "A", (1, 0): "B"})
"'A' * 'B'"

get_layers

get_layers(self)

Get the set of all layers referenced by this mask specification.

Returns

set[tuple[int, int]]: Layer set.

parse

parse(expression, technology=None)

Parse a string expression into a mask specification.

Args

• expression (str): String expression to parse.
• technology (Technology | None): Technology to be used for layer names in the expression.

Returns

MaskSpec: Resulting mask specification.

Example

Invert layer (0, 0) and intersect the result with layer (10, 0):

>>> pf.MaskSpec.parse("-(0, 0) * (10, 0)")

Difference between layers ‘SLAB’ and ‘WG_CORE’ intersected with (9, 10):

>>> pf.MaskSpec.parse("('SLAB' - 'WG_CORE') * (9, 10)")

Union of ‘WG_CORE’ and ‘WG_CLAD’ eroded by 100 nm:

>>> pf.MaskSpec.parse("('WG_CORE' + 'WG_CLAD') ** -0.1")

uses_translation

uses_translation(self, /)

uses_translation(self)

Check whether this mask or sub-masks use any translation.

Returns

bool: Mask translation indication.

Attributes

Attribute	Description
dilation	float: Mask dilation.
layer	tuple[int, int] | None: Mask layer (read only).
operand1	list[MaskSpec]: First operand for this mask.
operand2	list[MaskSpec]: Second operand for this mask.
operation	Literal[”+”, ”*”, ”-”, ”^”]: Mask generation operation.
properties	Properties: Object properties.
translation	ndarray: Mask translation.

dilation

float: Mask dilation.

layer

tuple[int, int] | None: Mask layer (read only).

operand1

list[MaskSpec]: First operand for this mask.

operand2

list[MaskSpec]: Second operand for this mask.

operation

Literal[”+”, ”*”, ”-”, ”^”]: Mask generation operation.

properties

Properties: Object properties.

translation

ndarray: Mask translation.