We have developed a highly integrated method of mask and silicon metrology. The method adopts a
metrology management system based on DBM (Design Based Metrology). This is the high accurate
contouring created by an edge detection algorithm used in mask CD-SEM and silicon CD-SEM. We have
inspected the high accuracy, stability and reproducibility in the experiments of integration. The accuracy
is comparable with that of the mask and silicon CD-SEM metrology. In this report, we introduce the
experimental results and the application. As shrinkage of design rule for semiconductor device advances,
OPC (Optical Proximity Correction) goes aggressively dense in RET (Resolution Enhancement
Technology). However, from the view point of DFM (Design for Manufacturability), the cost of data
process for advanced MDP (Mask Data Preparation) and mask producing is a problem. Such trade-off
between RET and mask producing is a big issue in semiconductor market especially in mask business.
Seeing silicon device production process, information sharing is not completely organized between
design section and production section. Design data created with OPC and MDP should be linked to
process control on production. But design data and process control data are optimized independently.
Thus, we provided a solution of DFM: advanced integration of mask metrology and silicon metrology.
The system we propose here is composed of followings.
1) Design based recipe creation:
Specify patterns on the design data for metrology. This step is fully automated since they are interfaced
with hot spot coordinate information detected by various verification methods.
2) Design based image acquisition:
Acquire the images of mask and silicon automatically by a recipe based on the pattern design of
CD-SEM.It is a robust automated step because a wide range of design data is used for the image
3) Contour profiling and GDS data generation:
An image profiling process is applied to the acquired image based on the profiling method of the field
proven CD metrology algorithm. The detected edges are then converted to GDSII format, which is a
standard format for a design data, and utilized for various DFM systems such as simulation.
Namely, by integrating pattern shapes of mask and silicon formed during a manufacturing process
into GDSII format, it makes it possible to bridge highly accurate pattern profile information over to the
design field of various EDA systems.
These are fully integrated into design data and automated. Bi-directional cross probing between mask
data and process control data is allowed by linking them. This method is a solution for total optimization
that covers Design, MDP, mask production and silicon device producing.
This method therefore is regarded as a strategic DFM approach in the semiconductor metrology.