PATACON - PC-cluster for EPL
PATACON PC-Cluster For EPL is a software product running on multiple Linux PC`s for converting semiconductor mask design data to manufacturing data for EB steppers.This software has specialized functions for EPL, such as pattern placement for EPL mask structure, complementary division for stencil masks, stitching for connecting divided portions, proximity effect correction, generation of machine control data and mask inspection data, alignment mark insertion, and verification.
In EPL mask structure, each sub-field (a re a for pattern placement) is surrounded by strut, and the CAD data is required to be divided by sub-field boundary.
- Avoid unnecessary division by applying fuzzy boundaries.
- Prevent small-figures and thin figures from being generated.
Not to make a slit by SF division or Complementary division, a supplementary pattern-overlapping can be added to the joint. The following shapes are available in stitching.
- Rectangle (Simple extension)
- Trapezoid
- Triangle
- Multi-step triangle
- Comvex/Concave
- Multi-step Convex/Concave
Doughnut, long line, leaf, and large area patterns are not allowed in making stencil mask. Therefore, such patterns are divided into two or more parts which are not dangerous to stencil mask. Each divided pattern is distributed to complementary membranes.
Since EBstepper uses high accelerating voltage(IOOKeV) in exposure, proximity effect correction on wafer is required. And since the unit of exposure is sub-field, correction by mask bias is also needed. The following types of correction with model-based pattern reshaping are available.
- Bias type : for shorter processing time and smaller data size
- Serif type : for higher quality in correction The influence of stitching figures is taken into consideration.