Radiation chemistry of polymeric materials: novel chemistry and applications for microlithography

In the last two decades, major advances in fabricating very large scale integration (VLSI) electronic devices have placed increasing demands on microlithography, the technology used to generate today's integrated circuits. In 1970, state-of-the-art devices contained several thousand transistors with minimum features of 10-12 mu m. Today, they have several million transistors and minimum features of less than 0.3 mu m. Within the next 10-15 years, a new form of lithography will be required that routinely produces features of less than 0.2 mu m. Short-wavelength (deep-UV) photolithography and scanning and projection electron-beam and X-ray lithography are the possible alternatives to conventional photolithography. The consensus candidate for the next generation of lithography tools is photolithography using 193 nm light. At this wavelength, the opacity of traditional materials precludes their use, and major research efforts to develop alternative materials are currently underway. Notably, the materials being developed for these short UV wavelengths are demonstrating compatibility with the more advanced electron-beam technologies. Materials properties must be carefully tailored to maximize lithographic performance with minimal sacrifice of other performance attributes, eg adhesion, solubility and RF plasma etching stability. (C) 1999 Society of Chemical Industry.