OPTICAL LITHOGRAPHY--using light to "print" circuits on computer chips--is a charmed technology. Reports of its pending demise pop up so often that they have acquired a "cry wolf" status in chip circles. The dilemma: As light beams are focused to print smaller and smaller circuit lines, they begin to bump up against physical limitations. When light-based printing equipment can go no further, the chip industry will have to chuck decades of accumulated technology.
Until now, those limits were pegged at about 0.18 micron--small enough to create 1-gigabit memory chips expected to come out around 2002, but probably not good enough for 4-gigabit chips in 2005.
However, the silicon wizards may have again extended light's lease on life. In late February, Sandia National Laboratories in Livermore, Calif., unveiled an experimental system that uses so-called extreme ultraviolet light. Researchers believe it will let them print circuit lines a mere 0.1 micron wide. That's one-thousandth the width of a human hair and one-fifth the size of the lines on today's best chips. Developed by Sandia and AT&T Bell Laboratories, the technique could handle 16- and perhaps even 64-gigabit chips. The latter would have enough space to store 27 sets of the Encyclopaedia Britannica.