Translator Disclaimer
9 December 2004 Laser direct write patterned indium tin oxide films for photomasks and anisotropic resist applications
Author Affiliations +
A laser direct write process has been developed for turning patterned bimetallic Sn/In film into a indium tin oxide layer. Sn over In films (15-120nm thick) with a 1:10 thickness ratio were deposited by DC sputtering. An argon laser beam (0.1 - 0.9 W, spot size: 2 micron, scan speed: 1 cm/s) exposes the film into patterns. These Sn/In films' optical absorption changed from 3 OD at deposition to 0.24 OD after exposure (at 356 nm). XRD, SEM, EDX, and Auger have been used to investigate the film's microstructure and composition suggesting ITO like characteristics. XRD indicated a preferred In2O3 (222) orientation which is similar to ITO films deposited by other methods. Four-point probe tests showed a converted film resistivity of 0.26x10-3 to 9.7x10-3 ohm-cm depending on the laser power and Sn concentration. Hall tests indicated that the bulk carrier concentration was in the range of 1018 to 1020 cm-3. Developed in a wet HCl: H2O2: H2O =1:1:48 solution removes unexposed Sn/In leaving patterned ITO films created at much lower laser power levels than needed for ablative patterning of ITO. Developed films are also resistant to KOH anisotropic etching at a 1:700 ratio producing <111> trenches in Si (100). The large change in optical density means Sn/In films can be used as a material of the direct write photomasks.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jun Peng, Glenn H. Chapman, and Yuqiang Tu "Laser direct write patterned indium tin oxide films for photomasks and anisotropic resist applications", Proc. SPIE 5578, Photonics North 2004: Photonic Applications in Astronomy, Biomedicine, Imaging, Materials Processing, and Education, (9 December 2004);

Back to Top