ArF laser light source to enable production of sub-45 nm semiconductors

Posted by Wolfgang Gruener

San Diego (CA) - Cymer, a supplier of deep ultraviolet (DUV) laser light sources currently used in semiconductor manufacturing, today unveiled what the firm claims to be the world's first argon fluoride (ArF) laser light source for 45 nm production immersion photolithography.

Compared to the preceding product generation, the ArF device offers a 50% improvement in energy stability and more than 20% reduction in cost of ownership, Cymer claims. ArF lasers are generally known as producing high-energy laser pulses that last from five to 20 ns and achieve repetition rates of up to 2000 Hz.

Immersion photolithography is considered the next phase of 193 nm wavelength DUV lithography, preceding extreme ultraviolet (EUV), a major and expensive transition in chip production that uses a 13.5 nm technology to "print" smaller circuit structures. Compared to traditional photolithography, immersion lithography employs a liquid medium between the optics and the wafer surface.

As immersion lithography is deployed into 45 nm production, it is critical for chipmakers to employ laser light sources that enable improved critical dimension (CD) control, Cymer said. The firm's new XLR 500i light source replaces the conventional power amplifier stage with a re-circulating ring, which results in an improvement of pulse energy stability, the manufacturer claims. An improved performance can also reduce the number of laser pulses consumed during the wafer exposure process, which can reduce incurring cost per wafer.

DUV 193 nm processes have in place and were expected to need a replacement with the arrival of 100 nm structures. Today 65 nm processors are in mass production and chip manufacturers currently believe that they will have to switch to EUV with the introduction of 32 nm processors in or around 2009. However, IBM recently showed 29.9 nm structures that were created with the help of "high-index immersion".