chapter 2, EUV LLC: An Historical Perspective

Excerpt

2.1 Introduction

The Extreme Ultraviolet Limited Liability Company (EUV LLC) was formed in 1997 to advance the R&D for EUV lithography. The company contracted with the Department of Energy (DOE) Virtual National Laboratories (VNL) consisting of Lawrence Berkeley, Lawrence Livermore and Sandia National Laboratories to accelerate the EUV technology development and to reduce the risks associated with developing manufacturing tools and transferring the technology to industry for commercialization. The program started as a three-year program and later was extended to six years.

It can be stated with a significant level of confidence that the EUV technology as applied to lithography would not be a future contender for IC manufacturing if it had not been for the formation and pursuit of the technology by the LLC. EUVL research would have stopped within the U.S. in the 1997 time frame and the technology would not have provided a future manufacturing option.

The EUV LLC program demonstrated the viability of EUV lithography, reduced the commercialization risks for EUVL to an acceptable level, and enabled the following key accomplishments:

• Design and fabrication of a complete, integrated, full-field (24 × 32.5 mm), scanning, alpha-class lithography tool denoted as the Engineering Test Stand (ETS).

• Development and integration of computer-aided design methods to support thermal, dynamic, and vibration design and analysis of individual components, subsystems, and complete system operation.

• Development of a reflective EUV mask technology including multilayer (ML) coated, low thermal expansion material (LTEM) mask blanks complete with metrology, ML defect repair methods, patterning inspection, and repair processes.

• Implementation of EUV optics fabrication projects with industry to demonstrate continuous optics fabrication technology improvement and development of engineered MLs with capping layers to provide good reflectivity and stability.

• Demonstration of extensive EUV lithographic printing using extended deep ultraviolet (DUV) resists.

• Collection of over 150 domestic and foreign patents and numerous technical∕trade secrets.

This chapter summarizes the initial EUV LLC program vision, history, successes, delays, and issues. Included are comments regarding changes that could have been made during the early phases of the program to improve technological success and commercial implementation.