By Kenton Williston, DSP DesignLine
November 12, 2008
Last month I got an eye-opening, insider perspective of the semiconductor industry. I finally understood how chips are manufactured, why ASICs, cost so much, and a whole host of other issues. But before I share these secrets, let me tell you how I stumbled onto them—I think it's a fascinating story.
Last month I attended a press event at the headquarters of ASML, the world's leading provider of lithography systems for the semiconductor industry. ASML brought us in for the unveiling of its latest machine, the TWINSCAN NXT immersion lithography platform. I consider myself a jaded skeptic—almost nothing impresses me—but I was absolutely blown away by this machine. In one machine, the TWINSCAN NXT combines:
- High-performance linear motors that can out-accelerate an attack missle,
- Maglev technology that would be at home in an advanced high-speed rail system,
- Carbon fiber and other materials straight out of an F1 race car, and
- A control system that is so precise it can achieve positioning within just a few atoms.
Lithography is the stage of the manufacturing process where the chip image is "burned" onto a silicon wafer. Think of exposing an image onto film, and you'll have the right idea. In fact, the silicon wafer is rather like a roll of film, in that you don't expose the whole thing at once. Instead, the chip image is burned onto a small part of the wafer, then the wafer is moved—much as you would advance a roll of film—and the chip image is exposed onto a new area of the wafer (Figure 1). A single wafer can easily hold 100 chips, so exposing the whole thing involves a tremendous amount of repositioning.
