Infrared semiconductor laser irradiation used for crystallization of silicon thin films

• Published in: Journal of non-crystalline solids Vol. 358; no. 17; pp. 2162 - 2165
• Main Authors: Sameshima, T., Hasumi, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier B.V 01-09-2012; Elsevier
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Effective mobility; Electronics; Exact sciences and technology; Infrared semiconductor laser; Laser crystallization; Materials; Other nonelectronic physical properties; Physical properties of thin films, nonelectronic; Physics; Polycrystalline silicon films; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film transistor; Transistors; Infrared semiconductor laser; Polycrystalline silicon films; Thin film transistor; Laser crystallization; Effective mobility; Voltage threshold; Radiation effects; Line shape; Crystallization; Laser assisted processing; Polycrystals; Laser irradiation; Thin film transistors; Laser beams; Infrared irradiation; Carbon; Thin films; Semiconductor lasers; Laser radiation; Electron mobility; Silicon; Threshold voltage; Carrier mobility
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2011.12.030

We report the rapid thermal crystallization of silicon films using infrared semiconductor laser. Carbon films were used on silicon films to absorb the laser light. Uniform crystalline regions were achieved by a line shape laser beam with a length of 20μm. Polycrystalline silicon thin film transistors were fabricated in crystallized regions. The effective electron carrier mobility and threshold voltage were achieved to be 130cm2/Vs and 0.4V, respectively, when the crystalline volume ratio of the silicon films was 0.95.
► Rapid 976-nm semiconductor laser heating was developed for about 20μs. ► 40-nm-thick amorphous silicon films were successfully crystallized. ► A crystalline volume ratio of 0.95 was achieved by the heating for 25μs. ► Polycrystalline thin film transistors were fabricated in the crystallized films. ► The carrier mobility and threshold voltage were achieved to be 130cm2/Vs and 0.4V.