Chemical amplification resists: History and development within IBM

IBM Journal of Research and Development, Volume 41, Issue 1/2, pp. 69-80 (1997).

This paper describes an important advance in resist technology that occurred when the minimum feature sizes of semiconductor devices were reduced and wavelengths of less than 300 nm were required for resist patterning. Although ultraviolet laser sources were available, resists at ultraviolet wavelengths were insufficiently sensitive to radiation to form high-resolution resist patterns. In 1982, H. Ito discovered that the sensitivity of certain resists in the ultraviolet and deep-ultraviolet regimes was significantly enhanced by irradiation. In these chemically amplified resist systems, a catalytic species generated by irradiation induces a cascade of subsequent chemical transformations, providing a gain mechanism. This enhancement process was successfully used first by IBM and currently is widely accepted by the lithography community. The development of chemically amplified resists was among the accomplishments cited when IBM received the 2004 U.S. National Medal of Technology.

See the 2004 National Medal of Technology awarded to the IBM Microelectronics Division in 2005 and the IBM Press Release of the announcement.