Patterning the World: The Rise of Chemically Amplified Photoresists

X-ray of tBOC photoresist. Courtesy Hiroshi Ito.

X-ray of tBOC photoresist. Courtesy Hiroshi Ito.

More systematically, CA photoresists escaped IBM as the computer giant participated in the growing trend among semiconductor manufacturers to obtain manufacturing equipment and materials from specialized external suppliers. As IBM came to rely more heavily on lithography tools produced by outsiders, the close coupling of tool with resist meant not only that the tool makers would need access to the best CA resists but that the tool makers’ other customers would also require access. Moreover, specialized photoresist houses had greater resources and incentives for pushing CA photoresists forward. In the mid-1990s IBM actively transferred the second- and third-generation CA photoresists developed by Ito and others to the outside world. In doing so, IBM accelerated future developments in CA resists, empowering the continued evolution of the digital age.

David C. Brock is a senior research fellow with CHF’s Center for Contemporary History and Policy and the editor of Understanding Moore’s Law: Four Decades of Innovation (CHF, 2006). The author wishes to thank CHF’s Gore Innovation Project for the support of the research leading to this article; Hiroshi Ito, C. Grant Willson, John Maltabes, and William Brunsvold for their time and candor in a series of research interviews; and Christophe Lécuyer for his revealing oral history with Jean Fréchet.