Media Coverage and Awards
IC-equipment startup ReVera tackles compositional metrology
Mark LaPedus -- Silicon Strategies, 2/12/2004
SUNNYVALE, Calif.--Startup ReVera Inc. here has announced the formation of a new semiconductor-equipment company, which is gearing up to compete in the emerging compositional metrology arena.
ReVera, which opened up its doors for business last month, has received its first round of funding and officially launched its first tool for use in gate film thickness and compositional metrology applications at the 130-nm node and beyond.
Crosslink Capital and members of ReVera's executive management team have invested an undisclosed amount of funds in the company. The funding will be used to expand the company's product development efforts and support infrastructure, said Thomas Larson, vice president of marketing for the Sunnyvale-based startup.
At the same time, the company has officially rolled out its first product--the RVX 1000, which is being billed as a high-precision gate metrology tool. Using X-ray photoelectron spectroscopy, the RVX 1000 can simultaneously perform multiple, automated measurements, including film thickness and elemental concentration in gate dielectric applications, Larson said.
"Our first application is the gate dielectric," Larson said. "This includes the nitrided gate oxides being used almost universally at 130-nm and below. It also includes the high-k gate dielectrics now under development."
Roots of a new machine
ReVera's roots can be traced back to metrology and analytical-instrument provider Physical Electronics Inc. of Eden Prairie, Minn. Last year, Physical Electronics reached an agreement to transfer its analytical instrument product lines to its joint venture partner, Ulvac-Phi. Ulvac-Phi is a joint venture between Physical Electronics and Japan's Ulvac Corp. Physical Electronics is part of High Voltage Engineering Corp. (HVE) of Wakefield, Mass.
Physical Electronics also had an internal division, which was--and still is--developing a gate metrology tool for semiconductor applications. After two or so years under its parent company, the metrology unit implemented a leveraged buyout and formed ReVera last month. "We've parted from HVE," Larson said. "We've raised money and now we're an independent company."
Dave Ring, president and CEO of Physical Electronics, now holds similar titles at ReVera. Ring also held executive positions at ATE provider LTX Corp. Meanwhile, prior to ReVera, Larson worked at Applied Materials Inc., where he was director of marketing for the Advanced Process Control (APC) and integrated metrology programs.
ReVera itself is entering into what the company calls the new "compositional metrology market." According to estimates, the overall market for film metrology tools is expected to grow at a compound annual growth rate of 25 percent to $1.1 billion by 2007.
In the film metrology segment, the company potentially competes against the likes of KLA-Tencor, Nanometrics, Rudolph, ThermaWave, among others, according to analysts.
But unlike competitive metrology tools, ReVera's RVX 1000 performs compositional metrology, especially for current and future gate stacks. "We can tell what the composition is on a film," Larson said.
For these applications, chip makers tend to have their own captive labs, which perform these functions via analytical instruments. "The trouble with this method is that the turnaround is too slow," he said.
Open up the gates
ReVera's RVX 1000 is designed to solve these issues for 130-nm applications and below in 200- and 300-mm fabs. The tool is a turnkey, small footprint system, based on X-ray photoelectron spectroscopy.
It is geared for advanced gate metrology applications. Today, leading chip makers are moving towards a modified compound of silicon dioxide for gate stacks. In doing so, they are adding nitrogen to the mix, creating silicon oxynitride (SiON) as the gate dielectric material.
"This approach leads to reductions in the equivalent oxide thickness (EOT) while maintaining acceptable leakage current for low voltage operation," according to ReVera. "The technique employed by the ReVera RVX 1000 utilizes a highly stable, high flux X-ray source in conjunction with enhanced photoelectron detection optics and advanced algorithms to determine nitrogen concentration and layer thickness with high precision."
To perform these tasks, the company's tool deploys a monochromatic X-ray beam, which induces the emission of electrons from the surface of the sample. "The electrons that are detected lack the energy to escape from a depth of more than ~10-nm, making the technique inherently surface sensitive. The binding energy of the emitted electrons is measured over a broad spectral range and used to identify and quantify the elements present," according to the company.
"Unlike traditional optical methods, which use some form of contamination-sensitive ellipsometry to determine thickness, the RVX 1000 counts only the atoms of interest (Si, O, N, Hf, Al, etc.), making it immediately applicable to current generation gate dielectrics and readily extendible to next generation systems, such as high k dielectrics and strained silicon," it added.
Overall throughput is less than 10 wafers an hour. ReVera's tool is shipping to undisclosed chip makers.