ZEISS ForTune Systems
Exceeding the Boundaries of Lithography
Wafer Fabs highly depend on predictability and credibility. Achieving high yields is essential to convince their customers of the capability of the fab. Any process excursion that reduces the yield significantly undermines the trust of the customer into the fab’s capability and reliability. ZEISS offers an innovative solution preventing excursion by improving intra-field CDU and improving the Wafer On-Product-Overlay (OPO).
Intra-field high lateral resolution solutions for CDU & OVL
With its latest optical design ZEISS ForTune takes the two main tuning applications to the next level in terms of efficiency, accuracy and throughput.
Improving wafer overlay for EUV technology
ZEISS ForTune EUV is a high-performance mask tuning system improving wafer overlay for EUV technology, based on mask registration or wafer intra-field overlay input.
For ForTune and ForTune EUV
A high volumen computational platform enables productivity and reliability enhancement for fast computation.
Reducing process defects
By Excursion Prevention applying ForTune
Patterning excursion is referring to (multiple) parameters deviation from normal that leads to process out of the allowed tolerances. The patterning excursion can be caused by process parameters and lithography parameters like focus, mask CDU and dose. Patterning defects can be caused by interaction of multiple lithography parameters, even if the individual parameters are in spec.
To reduce wafer intra-field process defects Excursion Prevention by ZEISS ForTune system is a proven strategy. This can be achieved by using the CDC Application of ForTune: It enables excursion prevention at low effort and low cost in wafer fabs. As a result, yield loss will be reduced significantly.
Improved Wafer On-Product Overlay
Registration control functionality helps to achieve better OPO for DUV and EUV
The Wafer On-Product Overlay (OPO) is another limiting key parameter for chip performance which needs to be well controlled. The main contributed parameters can be categorized as inter-field and intra-field parameters. Both can be controlled by the scanner. However, the scanner is limited in the intra-field overlay resolution and can control only up to the 3rd order polynomial across the slit. This scanner limitation leads to Non-Correctable Errors (NCE) in high orders that cause OPO is out of specification. ForTune converts NCE to CE (Correctable Errors) resulting in an improved intra-field contribution. This helps to reduce the Wafer On-Product Overlay for DUV as well as for EUV masks.
Improved Mix and Match
ForTune EUV reduces Overlay between DUV and EUV mask layers and EUV to EUV layers
A high-end mask set consists of multiple DUV masks and some EUV masks. The various layers must be printed accurately on top of each other to achieve a functional and high performing microchip.
With its RegC® functionality, ForTune EUV reduces the Intra-field contribution which leads to an optimized Wafer Mix & Match Overlay (MMO).