The new roadmap indicates that traditional optical scanners could remain viable for several years and push out the need for so-called next-generation lithography (NGL) tools for mainstream chip production until the 45-nm node (0.045-micron). The 45-nm node is expected to appear in the 2010 time frame.

At that time, NGL tools will supposedly appear for mainstream chip production, according to the roadmap. NGL includes extreme ultraviolet (EUV), electron-beam projection lithography (NPL), X-ray, among other technologies.

But for the 45-nm and beyond, the 2001 ITRS roadmap also indicates that EUV will become the "primary" NGL tool for chip production, implying that NPL and other advanced lithography technologies will play a secondary role in the future.

The architects of the 2001 ITRS roadmap are also quick to point out that the lithography technology nodes are somewhat conservative--that is at least for cutting-edge chip makers like IBM Corp., Intel Corp., Taiwan Semiconductor Manufacturing Co. Ltd. and others.

"The ITRS roadmap is a consensus that is on the conservative side," said Peter Silverman, director of lithography capital equipment development at Intel's Technology Manufacturing Engineering division. "There is a disconnect between the ITRS roadmap and leading-edge companies like Intel," Silverman said.

For example, Intel hopes to use EUV tools in chip-making applications well before the 2010 time frame, Silverman said. The company--which is expected to obtain its first EUV tools in 2005--will move these systems into production around 2007, he told SBN.

The Santa Clara, Calif.-based chip giant and other companies are part of a U.S.-based consortium that is developing EUV tools. The consortium--called the EUV Limited Liability Co. (LLC)--is targeting these tools for use in making chips at 0.07-micron and below.

Japan's Canon Inc. is also developing its own EUV tool, while Japanese chip-equipment giant Nikon Corp. and IBM Corp. are co-developing the rival EPL technology, it was noted.

Analysts pointed out that there are several challenges to develop these exotic NGL tools, as well as next-generation optical scanners. The ITRS roadmap also warns that transistor-gate lengths in microprocessors could be hitting some fundamental process limits in just six years because manufacturers have greatly accelerated physical shrinks of those structures using post-lithographic process techniques (see Nov. 28 story ).

One of the biggest reasons that processors and other chips may hit what some call the "red brick wall" is clear: delays and problems with current and future lithography tools.

In fact, there have been some major problems and delays with the 193- and 157-nm optical scanners. For example, the 193-nm tools were expected to become the workhorse tools for the production of 0.13-micron devices.

But the lack the lithography-lens materials, coupled with immature photoresists and other issues, pushed out the mass adoption of 193-nm tools for 0.13-micron chip production--at least for now. ASM Lithography, Canon, and Nikon have recently rolled out second-generation, 193-nm tools that promise to develop chips at the 130-nm node (0.13-micron) and beyond.

According to the 2001 ITRS roadmap, the 193-nm tools--coupled with a technology called phase-shift masks--are expected to become the tools for mainstream chip production at the 90-nm node (0.09-micron), which is expected to appear in 2004.

Then, in 2007, the newfangled, 157-nm tools are expected to appear at the 65-nm node (0.065-micron) node, according to the ITRS roadmap.

But the jury is out on whether the problem of intrinsic birefringence will delay the arrival of 157-nm tools. The problem--in which unpolarized light passes through the calcium fluoride crystalline material at different speeds, creating fuzzy images at the wafer level--was identified in May by John Burnett, a physicist at the National Institute of Standards and Technology (NIST) (see July 20 story ).

The potential problems worry chip makers. "This is a big concern," said Chenming Hu, chief technology officer for Taiwan Semiconductor Manufacturing Co. Ltd., the world's largest pure-play silicon foundry provider. "We have installed 193-nm scanners in our fabs, but there are no 157-nm tools available in the market right now," Hu said in an interview with SBN at a press event at Intel's headquarters.

Following the 157-nm tools, NGL is expected to appear in 2010--or sooner. On the ITRS roadmap, the NGL tools are expected to be used for mainstream chip-making applications at the 45-nm node (0.045-micron) in 2010, the 32-nm node (0.032-micron) in 2013, and the 22-nm node (0.022-micron) in 2016.

At present, there are several NGL technologies vying for dominance in the market: EUV, EPL, X-ray, and others. "EUV will be the main NGL technology," said Wolfgang Arden, senior staff member of Germany's Infineon Technologies AG, based in Munich.

Some believe that the technologies will co-exist. "EUV and EPL are complimentary," TSMC's Hu said, adding that EUV will be required for the critical layers in chip making applications. "EPL will be required for the contacts and vias," he added.