by M. David Levenson, editor-in-chief, Microlithography World
Gigaphoton, the Japanese producer of excimer lasers for lithography, reported 49% growth in revenue in 2007 and 28 laser shipments in 2Q08, with 14 of them intended designed for immersion steppers. Tatsuo Enami, GM of marketing, claimed a 58% share of the excimer laser market in 1Q08, with an installed base of 614 lasers. Gigaphoton sees the US and Europe as opportunities for expansion, with Hitoshi Tomaru heading up a USA division in Beaverton, OR, which will become a support and training facility.
The Gigaphoton product mix comprises four ArF lasers and five KrF, all built on two platforms (one for each wavelength). A third platform for EUV is being developed and its progress is on the ASML roadmap, according to Enami. Recent developments in excimer lasers include demonstration of 3B pulse gas fill lifetime using TGM (“total gas management”) as well as beta-testing of the GRYCOS and MPL innovations to extend hardware life. All can be retrofitted to any ArF laser, but come preinstalled on the latest GT62A.
In EUV, Gigaphoton has demonstrated 16W at the intermediate focus with a 100kHz laser drive on a tin-foil target and 1 steradian collection. They have also operated a tin droplet source producing 100μm diameter droplets produced at a 267kHz rate and a laser synchronized to heat every third droplet for 2min. The goal is 10hr operation by the end of 2008. Akira Sumitani of Komatsu commented that efficiency will be improved with smaller droplets and better laser beam overlap. — M.D.L.