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Metrology of Critical Dimensions on Reticle

Objective

At the 100nm Technology Node, the industry roadmap calls for photomasks with a minimum linewidth of 260nm (at 4X reduction ratio) and a linewidth uniformity of better than 10nm. The McD'OR project will install and test a beta type metrology system for Critical Dimensions on photomasks at a user site. Using DUV optics, the equipment will be capable to measure lines down to a width of 100nm with high precision and repeatability. A large degree of automation will support the measurement system, internal control loops and product handling. In the course of the project the McD'OR system will be optimised to a level that a measurement repeatability of 1.5nm (3 Sigma) will be achieved under production conditions (3 masks/h, 100 measurements/mask). Towards the end of the project this performance will be verified in a stable operating phase under close to production conditions.

Objectives:
Manufacturing of photomasks with a linewidth uniformity of better than 10nm requires a metrology system with a repeatability of better than 2nm (3 Sigma).

The main objectives of the project are:
- to establish an agreed equipment specification derived from the requirements of different users (merchant and captive mask manufacturers from Europe, Asia-Pacific and USA),
- to develop a test design on a mask or a set of masks and test procedures to verify the equipment performance,
- to demonstrate precision linewidth measurement on Chrome-on-Glass lines down to a width of 100nm,
- to improve the machine stability (mechanics, optics) to a level necessary for a long-term measurement repeatability of 1.5nm (3 Sigma),
- to demonstrate precision linewidth measurement on Chrome-on-Glass lines through pellicle down to a width of 200nm,
- to optimise the system for a through-put of 4 masks/h (100 measurements per mask),
- to verify the machine performance under close to production conditions.

Work description:
The project is organized in 4 Work Packages (WP):
- Work Package 1: Initial Test and Project Management,
- Work Package 2: Equipment Development,
- Work Package 3: User Trials,
- Work Package 4: Measurement and Evaluation.

The project will start with a task under WP1 to further detail, and if necessary, to update, the User Requirements for CD measurement on photomasks at the 100nm Node. From there, the initial set-up and tuning of the beta system will be carried out. After a Factory Acceptance Test the tool will be moved to the user site. Parallel to the installation, the first set of improvements will be implemented on the system. This will include a new illumination system and a new optical tool set-up. The improvement of the system performance will be verified by means of a Site Acceptance Test. In order to allow for fast user feedback, the planned development under WP2 will be carried out and implemented in two steps. In a first step work will focus on new methods for the illumination unit alignment and on testing of DUV objectives, while the second step will comprise the optimisation of the whole system for maximum stability (signal-to-noise ratio) and the implementation of new software for image processing and defect printability analysis at DUV. Both steps will be followed by user trials under WP3.The final set-up of the beta system is scheduled to be available after 10 months. This will provide a 3-month period of stable operation under close to production conditions. During this period the McD'OR system will be assessed by the users in the consortium and additional Site Visitors.

Milestones:
- Factory Acceptance Test (Month 3),
- Site Acceptance Test (Month 4),
- Resolution better than 100nm,
- Illumination Unit Alignment Control,
- Repeatability of 1.5nm and 1.0nm (long-term/short-term),
- Release for Phase III (testing under production conditions, Month 9),
- Product Cycle Time 20 min. (Standard Measurement Job),
- CD Measurement Capability on Lines/Spaces > 100nm,
- CD Measurement Capability on Contacts > 500nm (4x reticle scale),
- CD Measurement Capability on Serifs > 160nm.

Call for proposal

Data not available

Coordinator

COMPUGRAPHICS INTERNATIONAL LIMITED
Address
Eastfield Industrial Estate, Newark Road North
KY7 4NT Glenrothes
United Kingdom
 

Participants (5)

INFINEON TECHNOLOGIES AG
Germany
Address
St. Martin Strasse 53
81609 Muenchen
 
INTERUNIVERSITAIR MICRO-ELECTRONICA CENTRUM VZW
Belgium
Address
Kapeldreef 75
3001 Leuven
 
MUETEC AUTOMATISIERTE MIKROSKOPIE UND MESSTECHNIK GMBH
Germany
Address
Wildermuthstrasse 88
80993 Muenchen
 
PDF SOLUTIONS GMBH
Germany
Address
Bayerstrasse 115/9
80335 Muenchen
 
TAIWAN MASK CORPORATION
Taiwan
Address
No. 11, Innovation Rd. I,
300 Science-based Industrial Park, Hsinchu,