At Semitool, manufacturers of wet chemical processing equipment for semiconductors, the idea is not to think outside the box, but into the next box to reach the outer limits of innovative technology, as Lorie Greenspan discovers.
Semitool® is a company born in the highly intense environment that was Silicon Valley more than 23 years ago but since has made Montana its home base. As this implies, Semitool, a world leader in the design, manufacture and support of high performance, wet chemical processing equipment for the semiconductor industry, has become a self-reliant pioneer, making the rugged landscape the backdrop for its entrepreneurial spirit.
Founded by Ray Thompson, president and CEO, Semitool has become a highly innovative producer of batch and single wafer process tools that provide surface preparation for cleaning, stripping and etching, as well as electrochemical deposition processes for copper, solder, gold and other metals. “We have become extremely vertically integrated; we manufacture a lot of our own products,” says Paul Siblerud, vice president of marketing, in discussing the company’s move to Montana.
With 2001 sales of over $150 million and more than 1,000 employees, Semitool has become a revered leader in an industry that went from infancy to maturity virtually overnight. As it looks forward to its silver anniversary, Semitool also can look back on some significant milestones that have helped propel it to global leadership status.
Inventors and leaders
“Semitool is known in the industry as being innovators and we put a tremendous effort into R&D,” maintains Siblerud. How innovative? Reinvesting nearly 16 percent of revenue into R&D has enabled it to capitalize on new fronts. For starters, the company founded the now-widely-used spray process technology.
“The traditional method was immergent technology,” he explains, in which wafers were placed in a tank filled with acid or another solution, a process that could be repeated up to three times, before drying. “You’re effectively moving the wafers to the chemistry,” says Siblerud. “The spray process brings the chemistry to the wafers, so the wafers are not transported. It allows for multiple steps and more flexibility.” More importantly: No wafer movement. But Semitool did not ignore immersion technologies; in 1992, it developed single wafer immersion for wafers requiring different environmental conditions.
In 1994, the company led the way in gold electroplating technology, for wafers made for items such as cell phones. In such high-frequency applications, electrons are transferred on a microscopic level; this transfer requires gold and electroplated gold is the primary material used. In 1995, Semitool pioneered copper technology as a wafer conductor. Since then, the entire industry has followed suit and made the switch from aluminum to copper conductors, which greatly improve performance.
As a company that has set its barometer well past what the competition is doing, Semitool has led the way into the next frontier: advanced packaging technology. In 1998, Semitool developed processes for advanced packaging technology to spark advances in miniaturization, enabling more features in a device such as photos, digital images and displays. Through intensive R&D efforts, it found that copper interconnects allowed miniaturization while not compromising on quality. “There are various methods of being able to place copper on a device,” explains Sibelrud. “We saw electroplating was best and saw it was the best to produce.”
“Copper technology and advanced packaging technology play big roles in next generation products,” adds Siblerud. Its most effective contribution to this trend, he adds, is the company’s Paragon tool, now the industry standard for copper technology.
Paragon is a modular, automated electrochemical deposition system for high-volume manufacturing and can be configured for 150, 200 or 300mm wafers. It combines several key processes into one small footprint with high throughput results. Semitool’s patented ECD seed technology repairs problematic seed layers for ultra-thin and void-free films. The CFD2 reactor delivers high deposition rates, excellent fill characteristics and software-controlled, user-defined thickness profiles with unmatched uniformity.
More advanced products
In the area of single wafer processing, Semitool offers the Millennium, the most precise, flexible and cost-effective wafer cleaning system incorporating Semitool’s spray, vapor, immersion, megasonic and Thermium™ anneal technologies partnered with the Capsule™ process system. It accommodates multiple processes at a single time or the same process in all modules, available for 100 to 200mm wafers. The Millennium 300 is a single wafer tool and can incorporate 200mm bridge capability.
The LT-210c is a high-volume electromechanical deposition platform that delivers high throughput in a small footprint, providing a complete solution for copper fill with superior uniformity and film characteristics.
The Apx advanced packaging platform is a low-cost innovation from Semitool. An automated platform for solder deposition, this is designed for flexible, foundry-style applications such as multiple metal deposition and etching/stripping on both six- and eight-inch substrates. Batch systems include the Spectrum Solvent, a space efficient, automated wafer surface preparation platform for high volume manufacturing with flexible process formats and precise process control. The Solvent provides solutions for FEOL to BEOL manufacturing as well as wafer scale packaging, and can be equipped with a chemical process chamber and rinser dryer chamber or dual CPCs. Spectrum Acid contains an automated four-axis, linear-track robot and simplified configuration for optimum productivity for 150, 200 and 300mm processing. The Spectrum 300 is designed to all 300mm guidelines.
Also in the batch system category is the Scepter Solvent, designed for throughput and production efficiency of wafers as large as 200mm. The Rinser Dryer system builds on Semitool’s production-proven 25-wafer Spin Rinser Dryer first introduced in 1979, designed for high throughput and production efficiency. The Scepter Acid is based on Semitool’s successful Spray Acid Tool with more than 1,000 chambers installed worldwide, features a Teflon® 50-wafer process chamber for two 250 wafer cassettes loaded sequentially. The spray solvent tool (SST) was introduced in 1982 and now there are almost 1,300 SST chambers installed worldwide; it continues to demonstrate repeatability, cost efficiency and high yield, professing wafers as large as 200mm.
The SAT300 is the perfect tool for bridge applications capable of processing both 200mm and 300mm products, and the SST 300 is a semi-automated solvent tool that can be configured for polymer removal, chemical stripping, developing and cleaning. It is the perfect tool for bridge applications capable of processing both 200mm and 300mm products.
In the area of auxiliary tools, the company provides the ACMS – Automated Chemical Management System – that controls and maintains the components of an electrolyte plating bath and is able to serve up to four Semitool ECD™ tools. In container cleaning, Storm II is a high-capacity system designed to clean carriers, boxes and SMIF pods as large as 200mm. Storm III is the economy version, designed for lower volume and smaller footprint requirements and Storm 300 offers centrifugal spray cleaning for 300mm FOUPs and FOSBs and carriers.
Spreading the word on innovative thinking
Taking its leadership role quite seriously, Semitool has shown that to be a creative inventor you must spread the knowledge and join with others in the pursuit of advancing technology. This philosophy led the company, in 2000, to be a founding member of SECAP (Semiconductor Equipment Consortium for Advanced Packaging) which has played an integral role in establishing new processes and methodologies in the quickly accelerating miniaturization arena.
For Semitool, such is the logic by which you function on a daily basis. “You have to be an innovative leader and focus on end results and not on the method to get there,” says Siblerud. “As innovators you need to look at where the industry is going. You need to focus on results the customers can make money on and not on the status quo.”