April 6, 2001 – Tokyo, Japan – Hitachi Ltd. has unveiled a device that reportedly could extend the useful lives of today’s steppers into tomorrow’s future generations of microprocessors.
Hitachi’s “slimming” device can, according to the company, narrow circuit lines formed with steppers to as little as one-third their original width.
The slimming device will allow today’s steppers to be utilized for the making of future generations of microprocessors with line rules as narrow as .05-microns.
In the semiconductor-manufacturing process, a photoresist is coated on the silicon substrate and then exposed to light through a mask using a stepper in order to transfer the pattern to the silicon.
An etching gas removes the material not protected by the pattern and the substrate is then ashed to remove the remaining resist, leaving behind the circuit pattern.
Hitachi’s slimming device is used at the step after the pattern transfer and before the etching. Resist is an organic compound, and the slimming device used ozone to oxidize the material into carbon dioxide and water. The chemical reaction proceeds from the surface, narrowing the resist pattern and the circuit pattern it defines, according to Hitachi.
A 0.13-micron pattern today can be slimmed to 0.07-microns, and after etching the final linewidth is just 0.05-microns, Hitachi said.
The company is marketing the device as the SP-1200, with a 90 million yen price tag.