SEZ announces next entry for FEOL
The SEZ Group has introduced its Esanti platform targeting front-end-of-line (FEOL) cleaning and resist-stripping processes. SEZ has become the market leader in the back-end-of-line (BEOL) single wafer wet processing by being the first in the arena and maintaining a technology lead. The FEOL has a number of players wanting to control this lucrative market and the industry has being waiting to see what SEZ will offer. Being the first in the BEOL market meant that others had to respond to their lead. For the FEOL the company has taken an approach of specific entry and has been happy to let others rush while they have been more content to work with their customers.
The Esanti platform is primarily intended to address chipmakers' FEOL cleaning roadmaps for 45 nm and below. It builds on the company's core spin-processor technology, adding new capabilities that enhance defect removal and surface drying to effectively address a wide range of high-volume manufacturing applications. The new platform is the latest addition to SEZ's FEOL-focused offerings, following the July announcement of its proprietary Enhanced Sulfuric Acid (ESA ) strip process, which is optimized for deployment with the Esanti platform.
Single-wafer technology—in particular, wet processing—is growing increasingly popular as demand for greater process control with reduced cycle times and costs continues to escalate. Once dominated exclusively by batch processes (wet benches and spray tools), the cleaning market has transitioned in recent years to single-wafer approaches in the back-end-of-line (BEOL). Today, companies are ready to convert FEOL cleaning and stripping steps to single-wafer processes, due to their ability to overcome a host of limitations associated with batch techniques. They deliver significantly improved defect density via minimal cross-contamination (both intra- and inter-wafer) with superior process control, uniformity, cycle times and matching to other single-wafer tools.
"As the world leader in single-wafer wet processing, with a comprehensive portfolio of BEOL and FEOL spin processing solutions, SEZ is ready to meet customer needs through continued innovation born from close collaboration with key industry players and consortia," said Kurt Lackenbucher, executive vice president and chief operating officer for the SEZ Group. "Having pioneered and subsequently dominated the shift to BEOL single wafer processing, SEZ is once again leading this conversion for FEOL cleaning and stripping, adding to our portfolio as market and customer requirements dictate."
The Esanti platform features a multiple open-chamber design that delivers the flexibility to address either a broad range of FEOL cleaning applications that include pre-diffusion, pre-gate, contact and pre-metal cleans; or high temperature (140-degree C) post-strip/ash, post-etch and post-implant wet resist stripping and cleaning, and photoresist rework. The platform integrates proven capabilities previously integrated into SEZ's Da Vinci family of products, such as polymer cleaning and backside treatment, with a range of new features. Chief among these are double-side treatment capability, Active-Jet spray technology for enhanced defect removal, and SEZ's proprietary atmospheric surface drying (ASD) technology, which prevents watermark formation and pattern collapse on a variety of structures during the drying process.
As with the Da Vinci series, Esanti platform tools will be available in a variety of configurations. Customers can select a four- or eight-chamber version, compatible with either 200-mm or 300-mm wafers. The platform boasts batch-comparable throughputs and a flexible, external chemical-delivery system that enables use of up to four chemicals and process-chamber levels, so that more than one process can be run in the same tool with minimal impact. Separate drains and exhaust for different chemistries facilitate changes in chemical sequence without necessitating a chamber change. SEZ reports that it has multiple Esanti systems in beta test with customers, who are achieving promising results. The company is currently accepting orders for production Esanti products. With manufacturers stating they are actively looking to single wafer wet processing at the FEOL, SEZ have made no secret of their intention to capture this lucrative market. Rather than seeing single wafer processing as a replacement to current methods, the company understands that future manufacturing below 45nm will be a mixture of processing as manufacturers need to protect the amount of loss through each process. The most likely way forward will be a mix of processes.
A key factor for the manufacturers is the potential loss of any downtime. The loss of a batch rather than single wafer is economically fairly obvious. As wafer sizes increase and complexity of devices increase, the risk of a wafer loss is economically increasing.
"As a company we have a careful entry plan into FEOL single wafer processing," said Leo Archer, Vice President of Emerging Technologies at SEZ. "The knowledge we have gained in our successful history enables us to work closely with our customers and to time our entry into the market. Because of this we can leverage our 20 years experience with single-wafer wet cleans while watching and learning from the potential mistakes of our competitors who have rushed to market, rather than the other way around."
