Topic of the Talk: Lithography to 1/20th of wavelength

Invited Speaker: Prof. Burn J. Lin (NCTU)

Time: Sept. 20. Thur. 2018

Venue: SC001 Lecture Hall

Abstract:

The minimum feature size of semiconductors has shrunk from 5 mm to 5 nm in 21 generations since the 80s. The numerical aperture of the imaging lens has improved from 0.15 to 1.35 while the imaging wavelength has reduced from 436 to 193 nm. With just these improvements, the minimum half pitch can only be shrunk to 114 nm. Many other innovations are needed to reach the 5 nm minimum feature size.

In this presentation, the techniques and tools to reach this phenomenal l/40 feature size are explained. These include wavelength reduction optically and chemically, increase of the numerical aperture, resolution restoration and enhancement using phase-shifting masks, off-axis illumination, reflection and vibration control, optimized numerical aperture, optical proximity correction, multiple patterning, E-D window, and lithography galaxy. The outlook in lithography using e-beam and EUV light are also covered.