Laser Crystallization of Silicon for Large Area Electronics

Abstract

AbstractLaser crystallization of silicon is discussed for forming polycrystalline silicon thin films used to fabricate polycrystalline silicon thin film transistors (poly-Si TFTs). Laser-induced rapid heating is important for crystalline film formation with a low thermal budget. Structural and electrical properties of poly-Si films are discussed. Reduction of electrical active defects located at grain boundaries is essential for achieving poly-Si TFTs with high performances. The internal film stress is attractive to increase the carrier mobility. Recent development in laser crystallization methods with pulsed and continuous wave (CW) lasers is then reviewed. Control of the heat flow results in crystalline grain growth in the lateral direction, which is essential for fabrication of large crystalline grains. We also report an annealing method using a high power infrared semiconductor laser. High power lasers will be attractive for rapid crystallization of silicon films over a large area and activation of doped regions.