Beam Induced Modification of Polysilane For Fine Pattern Generation

抄録

Polysilane thin films have been grown by the glow discharge of SiH₄ gas at a substrate temperature of -110°C. The infrared absorption spectra have shown that polysilane (SiH₂)_n chains are predominantly incorporated in the matrix together with SiH₃ which terminates the chain. The bonded hydrogen in the film is effused by electron beam (EB) or ArF eximer laser irradiation, resulting in three-dimensional Si network formation. An as-deposited polysilane is easily oxidized in air at room temperature, while the beam irradiated region is hardly oxidized. The fine silicon line and pillar of about 0.12μm embedded in SiO₂ are formed by irradiating electron beam at an acceleration voltage of 25kV with a dose of 20mC/cm². The silicon pattern is basically in amorphous phase and crystallized by annealing at 800 °C. Also, the silicon line of about 1μm is generated by irradiating ArF excimer laser through a conventional mask at a pulse energy of 10 mJ•cm^-2/shot with 1000 shots. The generated silicon line is found to be polycrystalline.