A Low Cost Optical Inspection System for Rapid Measurement of Surface Roughness of Polycrystalline Silicone Fabricated by Frontside and Backside Excimer Laser Crystallization

作者：Kuo C C^*; Chen Y R

来源：Lasers in Engineering, 2013, 24(5-6): 315-330.

• Surface roughness
• optical measurement
• polycrystalline silicon
• excimer laser crystallization (ELC)

Excimer laser crystallization (ELC) is the most commonly employed technology for fabricating low temperature polycrystalline silicon (LTPS). Investigations on the surface roughness of polycrystalline silicon (poly-Si) thin films become an important issue because the surface roughness of poly-Si thin films is widely believed to be related to its electrical characteristics. A low-cost optical measurement system for rapid surface roughness measurement of poly-Si thin films fabricated by frontside ELC and backside ELC is developed in this study. It is found that the incident angle of 20 degrees is a good candidate for measuring the surface roughness of poly-Si thin films. The surface roughness, y, of poly-Si thin films can be determined rapidly from the average value of the reflected total power, x, measured by the optical system developed using the trend equation of y = -0.9369x+1.0267. The maximum measurement error rate of the optical measurement system developed is less than 6.21%. The savings in measurement time of the surface roughness of poly-Si thin films is up to 83%. Backside ELC is recommended for batch production of low-temperature polycrystalline silicon thin-film transistors due to lower surface roughness of poly-Si films and higher laser beam utilization efficiency.

• 出版日期2013