Next-generation semiconductor processing
Research into materials for next-generation semiconductor processing using quantum beamsThe micro processing technology (lithography) which has contributed to the semiconductor industry in Japan (and the world) realized microfabrication by utilizing short-wavelength light sources (improvement of energy efficiencies) and by improving the exposure methods and processes for the resist materials that are used in microfabrication. Extreme ultraviolet (EUV) wavelengths have been expected to be used in the next-generation lithography toward semiconductor processing at 16 nm or less. In the EUV lithography, the energy of a light source exceeds the ionization energy of the materials. This makes it critical to understand the response of the resist material to the quantum beams such as electron beams.
When ionized radiation is irradiated to substances, the substance is ionized and excited after absorbing energy. The chemical phenomenon observed here is the so-called ‘radiation chemical reaction.’ It is known that in a radiation chemical reaction, various reaction intermediates including ions and radicals will be generated during the irradiation process. Many studies have attempted to elucidate the reaction mechanisms involved here. However, the lifetime of the reaction intermediates is very short and it is difficult to identify the mechanisms through direct observation. Therefore, the ‘pulse radiolysis method’ which traces the generation process of short lived chemical species over time by irradiating pulsed radiation to a specimen is used. This method enables observation of these ultra-fast physical, chemical phenomena generated by the radiation in the form of photoemission and -absorption. Our laboratory has conducted research into the process for next-generation lithography through irradiation experiments using small electron beam system and EUV exposure devices and simulations as well as the pulse radiolysis method.