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一、引言多晶硅薄膜在集成电路制造工艺中应用日趋增多,诸如利用多晶硅薄膜制造硅栅、多晶硅薄膜电阻、多晶硅引线、双极性晶体管的发射区等。多晶硅薄膜的激光退火能使其晶粒长大,使杂质电激活,可以提高多晶硅薄膜的电学性能,引起了人们的广泛重视,特别是绝缘衬底上的多晶硅薄膜经激光退火后有可能转变为单晶,给立体大规模集成电路的实现带来希望,吸引了不少活跃在这一研究领域的科学工作者。在半导体激光退火中,激光束的脉冲宽度对激光退火的结果有决定性的影响。微微秒脉冲宽度的激光束能使单晶半导体材料变成非晶材料,毫微秒脉冲宽度的激光束以熔化外延方式再结晶,使离子注入半导体单晶材料的非晶层转变为单晶,毫秒脉冲宽度的激光束(连
I. INTRODUCTION Polycrystalline silicon (polycrystalline silicon) films are increasingly used in integrated circuit manufacturing processes, such as the fabrication of silicon gates, polycrystalline silicon thin film resistors, polysilicon leads, and bipolar transistor emitters using polysilicon films. Polysilicon thin film laser annealing can make its grain growth, the electrical activation of impurities, can improve the electrical properties of polycrystalline silicon thin films, aroused widespread concern, especially on the insulating substrate polycrystalline silicon film after laser annealing may be transformed into Single crystal, to the realization of three-dimensional large-scale integrated circuit hope, has attracted many active in this area of scientific workers. In semiconductor laser annealing, the pulse width of the laser beam has a decisive influence on the result of the laser annealing. A laser beam with a picosecond pulse width can make a single crystal semiconductor material into an amorphous material, a laser beam with a nanosecond pulse width is recrystallized in a melt epitaxial manner, an amorphous layer of the ion implanted semiconductor single crystal material is converted into a single crystal, Laser beam of millisecond pulse width (with