by Debra Vogler, Senior Technical Editor, Solid State Technology
Completing its suite of Optima single wafer product implanters, Axcelis introduced the last offering in the family: the Optima XE high-energy ion implanter, which supports a broad energy range (10keV to 4MeV) and targets the requirements of DRAM, NAND and NOR flash memory makers, as well as embedded memory and logic device manufacturers.
Generally speaking, the highest-energy implants are required for deep well formation in CCD applications, followed by NOR, NAND, DRAM, and then logic. The next highest energy is required for retrograde well formation in the same devices and in the same descending order. The company says its tool covers all these applications.
Based on the company’s RF Linac (RF linear accelerator) technology, the Optima XE operates in the single charge mode (vs. double or triple-charged ion modes). The advantage of running on single charge ions, according to Mike Chase, director of marketing for implant at Axcelis, is that the mode provides a higher beam current (i.e., more ions) than a double- or triple-charge mode. “Higher beam current means higher productivity,” he told WaferNEWS, adding that “running implanters in the single charge state extends source life.”
Axcelis has productized two different versions of the RF Linac technology. The higher-energy version is used in the Optima XE, while the mid-energy range version is used in the Optima HE tool, which was also introduced at the same time.
According to Chase, the Optima XE’s ability to handle a broad range of applications appeals to fab managers seeking flexibility — particularly important in an industry increasingly working with high product mixes. To balance the load in a fab, end users will back up medium-current tools with high-energy ones, and divert some of that load if they can be productive in the medium-current application space, he explained. “A fab doesn’t run in steady-state — there are peaks and valleys in WIP moving through the fab,” he said. “If they can qualify the same recipes used on medium current implanters on high-energy implanters, it gives them the flexibility to divert WIP to high-energy tools when it makes sense.” — D.V.