Carbon nanotubes (CNTs) have been investigated as an emitter for field emission display (FED). In our FED fabrication process, the printed CNTs are raised by a laser irradiation for the purpose to improve the emission characteristics. Because the emitters have to be controlled in each pixel individually on FED, the uniformity of the emission characteristics is necessary. We could improve the emission characteristics uniformity successfully by two methods. In the first method, the distribution of CNT raisings was homogenized by the modification of the irradiation pattern that consisted of an array of small areas. The emission deviation was improved to approximately half by the method. In the second method, the impurities of CNT raisings were cleaned by post-laser-irradiation of which fluence was lower than that of first irradiation. The emission characteristics improved and the turn-on electric field reduced from 2.1 to 1.4V∕μm. The emission deviation also improved to approximately half.

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We have developed a new optical system that transforms the circle profile beam generated with near-Gaussian intensity distribution by a pulse green laser (YAG2omega laser; second harmonics of a Q-switched Nd:YAG laser) into a line-profile beam. For homogenization in the longitudinal direction, we employed a waveguide plate-type homogenizer. We successfully reduced interference fringes. In the width direction, the laser beam was focused up to the limited M2 value. This transformed beam has a uniform distribution to within 5% in the longitudinal direction, and it is approximately 100 mm long and 40 microm wide.

Abstract— A pulsed YAG2ω green laser with a line‐shaped beam was applied in the crystallization process to fabricate polycrystalline‐Si TFTs, and this procedure was compared with excimer‐laser annealing (ELA). YAG2ω lasers are superior to excimer lasers in that they have fewer items to maintain and a longer working time ratio. The crystallization mechanism for YAG2ω laser annealing (YLA) based on the lateral growth of grain is different from that of ELA. Its fluence margin was obtained from the n‐channel mobility measured from fabricated TFTs and was found to be twice as large as that for ELA. We also found that overlapping irradiation does not change the mobility of TFTs. This is because the distribution of grain size is almost the same as in non‐overlapping regions. This suggests the possibility of overlapping irradiation in YLA.

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