Write Field

The Write Field is a logical window, that is placed on top of your design. Depending on your exposure setup, it can have the meaning of the physical write field size (the area that can be reached by the beam and can therefore be exposed without moving the sample), or not.

_images/writefield.png

The write filed is depicted as “two windows”, in the default configuration.

Depending on your task, design, and setup, you can choose to set the write field size to the physical size, the boundaries of your design, or to ignore it at all (you can disable the drawing of the write filed in the Document settings).

smile2 can show (in its default configuration, it does so) the write field as two sizes:

  • The smaller size (called safe area) is the actual write field that can be set with the Write Field Setting.
  • The large size shows the hardware limit. This is actually the size that can be accessed by the hardware. In the default configuration, the

safe area is always by a factor of 0.68 smaller than the hardware limit. There are mainly two reasons this:

  • Alignment. Even in worst case, where the structure is rotated by 45° and even shifted after alignment, it still can be fully exposed.
  • The actual “by the hardware reachable area” is influenced by many factors (eg. the write field calibration, or the beam parameter compensation matrices) an is not a well-defined rectangle but a

parallelogram that depends on many factors.

Hint

The Write Field can be actually smaller than the bounding box of your structure. If so, the elements outside or partially outside the write field are clipped and ignored.

Note

  • The write field is a square, meaning it has a size and position. The position can be used to focus on a certain region of your structure. The write field position has no effect on stage positions.
  • The write filed can be set in the “Document Settings” property sheet in the Attribute Editor
  • Using the “correct” write filed is important during alignment. The “correct” write filed in this context is the write field that will used to expose the design after alignment.

Warning

Changing the position of the write field, does change only the position of the write field within the design, and has no influence on the position of the stage.

More on how to set up write fields in a “multi-structure” exposure task, consult the Structure Entry reference chapter and the Stage View chapter.