Cutting Microchips Like Cookies
WHEN HE SUGGESTED THAT THE ULTRATHIN lines on tomorrow's microchips could be stamped out "almost like they were cookies, they thought I was crazy," admits Stephen Y. Chou, professor of electrical engineering at the University of Minnesota. The usual view is that future chips will require very exotic technology, such as X-ray lithography--not old-fashioned stamping.
Now, two years later, nobody's laughing. Chou's research team recently imprinted silicon wafers with circuit patterns just 0.025 micron wide--a tenth the size of the finest lines now in commercial production. And he's "quite confident" the technique can produce 0.01-micron lines--"maybe even smaller."
Etching the original circuit pattern into the stamping mold does require sophisticated electron-beam lithographic tools. The big nut that still needs cracking: A chip has many circuit layers, and each successive layer must be precisely aligned with the others. This is mainly an engineering challenge, Chou says, but it will take more money than he has left on his David & Lucile Packard Foundation fellowship. Once it's solved, Chou believes his cookie-cutter approach could dramatically reduce chipmaking costs.