UK litho pioneer reaches 20
Most recently, International SEMATECH in the USA and Exitech announced an agreement to develop the world's first ultra high numerical aperture (NA=1.3) 193nm wavelength immersion lithography tool. The MS 193I development tool will be used to develop the critical infrastructure for immersion lithography at SEMATECH's Immersion Technology Center in Austin, Texas.
It was during the mid-1990s that Exitech began developing micro lithography tools for the major silicon microchip manufacturers qualifying new techniques for future production of ever-smaller transistors. The pioneering tools started with a high resolution mask imaging microstepper at an exposure wavelength of 193nm, followed by a 157nm microstepper.
With the industry now looking at the increases in numerical aperture (NA) and hence optical resolution promised by using liquid media rather than air/gas between the mask and the wafer (immersion), it was natural that researchers would turn to Exitech for a 193nm immersion microstepper development tool.
Excimer has also developed the world's first extreme ultraviolet (EUV) microstepper lithography tool with a 13.4nm pinch plasma source. EUV will hopefully enable resolution down to the 32nm node and beyond.
The next semiconductor technology development for Exitech has been a reticle imaging microscope (RIM). This tool has been developed to inspect the very fine features on the EUV reticles that will be used in the lithography industry after 2009.
Dr Malcolm Gower and Dr Phil Rumsby co-founded Exitech in 1984 while still working as laser researchers at the Rutherford Appleton Laboratories (RAL), near Oxford. Purchasing a second hand UV excimer laser, Phil and Malcolm would spend their evenings and weekends qualifying applications for customers and using new techniques of excimer laser beam delivery to develop now well known optical techniques such as line-narrowing, homogenisation and mask projection.
It was six months before Exitech had its first official employee. After 18 months, with the advent of the modern PC and CCD cameras and with help from their second employee - Dr Paul Apte - the world's first real time PC based laser beam profiler was developed.
By the end of the 1980s and the early 1990s Exitech was becoming a serious systems integrator developing and exploiting new applications for laser micromachining. At that time laser micromachining was only beginning to be developed and Exitech was the first company targeting its commercial exploitation.
The company employed six people and both Phil and Malcolm realised that they had to commit to the business full time. Phil left RAL in 1989 and Malcolm joined him in 1990. The move to become a systems integrator was driven solely by the requirement of Exitech's existing customers, who were demanding laser systems with more control and more sophisticated beam delivery techniques. The majority of systems built in these early days were sold to Japanese customers.
Exitech still relied heavily on performing in-house applications work as a means of maintaining a stable income, developing a growing expertise in several modern fields including microdrilling, displays, lithography and solar power applications.
Although Exitech originally evolved predominantly from UV excimer laser micromachining systems, the company now views laser sources as a black box commodity which they select according to a diverse range of factors. These can be categorised by application, economics, running costs and process speed. Today excimer, CO2 and diode pumped solid state lasers are all used in Exitech's integrated systems. It was the first company to pioneer the technique of micro via drilling of PCBs using two laser sources - a third harmonic Nd:YAG laser for drilling the copper layer and an RF CO2 laser for the dielectric layer. Excellon in the USA is now licensed to produce tools based on this technology.
The development and growth of the company has been solely funded by gross profits generated rather than through external capital investment. Annual turnover in 2003 was some $20mn. This independence from external funding ensures that Exitech stays in control of its business objectives and remains flexible in a wide variety of ever changing high-tech industries.
Exitech's head office is now in the Oxford Industrial Park in Yarnton including a 5200m2 manufacturing facility and more than 1850m2 of clean room space dedicated to tool and process R&D. The company employs 100 people and has subsidiary sales and service offices in Japan and the USA.
