Date: 14/07/2011

Imec exposes semiconductor wafers using EUV ASML's scanner fitted with XTREME's LDP

Imec has printed first Extreme-Ultraviolet (EUV)-light semiconductor wafers with the ASML NXE:3100 preproduction scanner using XTREME technologies Laser assisted Discharge Plasma (LDP) source. Imec claims this tool shown significant improvement in throughput and overlay compared to ASML's Alpha Demo Tool (ADT). The NXE:3100 is reported to offer higher wafer throughput compared to the ADT. The exposure rate of the NXE:3100 today is said to be 20 times faster than that of the EUV ADT. A first test of dedicated chuck overlay showed the potential to achieve the <4nm target, which is significantly better than the ADT, according to imec.

The ASML NXE:3100 is interfaced with a TEL Lithius Pro EUV process track. Imec says It is the currently the only preproduction tool in the world equipped with a laser assisted discharge plasma (LDP) source from XTREME technologies. The source power is expected to scale to 100 Watts by early 2012, increasing the scanner throughput from the current level to 60 silicon wafers (300mm) per hour, adds imec.

The NXE:3100 integrates 4 image and 4 dose control sensors which were developed within imec's CMORE development and prototyping service. Installation of these new sensors combined with new wafer tables made both chucks equivalent for overlay, enabling full twinstage-type operation. At the same time, off-axis illumination options have been installed, which at factory acceptance have proven to resolve sub-20nm features using dipole illumination.

"The availability of the NXE:3100 at imec is an important milestone in our Advanced Lithography program as it will enable the next phase of the EUV program to focus on manufacturability, aside from further infrastructure related studies on masks, resists and design correction;" said Luc Van den hove, President and CEO of imec. "We are excited with the current results and throughput we achieve. Our decision to implement the LDP source from XTREME technologies is an important added value for our partners since it allows them to test both our LDP (laser assisted discharge plasma) and the LPP (laser produced plasma) sources currently installed at other sites. We are convinced that our program will bring significant contributions to bringing EUV to mass manufacturing for the 16nm node by 2013."

"We are pleased that imec has joined the ranks of customers which have started exposing wafers with ASML's second-generation EUV tool," said Ron Kool, ASML Senior Vice President EUV. "The work at imec exemplifies the strong industry momentum behind EUV and will help prepare the ground for the introduction of EUV into high-volume manufacturing."

"Jointly with ASML and imec, our teams have worked hard to install the first LDP EUV source," said Marc Corthout, president of XTREME technologies. "We are pleased to be partnering with imec. Today is a major milestone in the advancement of EUV lithography. XTREME technologies' LDP light source will enable high-resolution and high-throughput EUV lithography used in the mass manufacturing of advanced ICs with critical dimensions below 22nm. XTREME technologies' LDP light source will thus enable the continuation of Moore's Law for multiple chip generations to come. Through its partnership with imec, XTREME technologies is committed to support the whole semiconductor industry in its transition to EUV", stressed Shiro Sugata, President & CEO of USHIO Inc.

This work was executed in collaboration with imec's key partners in its core CMOS programs Globalfoundries, INTEL, Micron, Panasonic, Samsung, TSMC, Elpida, Hynix, Fujitsu, Sony and Powerchip.

Imec has also announced that it has broadened its research program with SUSS MicroTec to develop an in-fab approach to EUV (Extreme Ultra-Violet) mask integrity.

Unlike photomasks used in optical lithography today, EUV masks will not have the protection of a pellicle, making it sensitive to particle and organic contamination. A higher cleaning frequency will be required to mitigate the risk of wafer loss and yield loss from contamination of the patterned side of the mask. However, of increasing concern is contamination on the backside of the mask which, if introduced into the scanner, could transfer to the reticle clamp causing serious overlay issues. To clean the reticle clamp the scanner would require extensive downtime at a considerable cost to the semiconductor manufacturer.

Kurt Ronse, program director advanced lithography at imec said, "Our goal to provide an EUV infrastructure that delivers a defect-free mask at point-of-exposure, has not changed. Building on our important progress on mask cleaning, we are excited to expand the scope of our research to deliver a holistic mask management system. The installation of the MaskTrack Pro InSync and our on-going collaborative research efforts with SUSS Microtech provides a world-class team and resources focused on mask integrity for the advancement of EUV technology."

"We are very pleased to continue our collaboration with imec on an EUV mask integrity infrastructure for next generation lithography," said Frank P. Averdung, President and CEO of SUSS MicroTec AG. "The MaskTrack Pro InSync, is the only mask management system available that can automatically interface with the unique EUV dual pod in a fully-controlled environment. Designed to cluster EUV mask cleaning, transfer and storage in a pristine environment, InSync provides a holistic approach to mask management throughout the life of the mask."