In this study, we successfully achieved a relatively high field-effect mobility of 37.7 cm 2 /Vs in an InZnO thin-film transistor (TFT) fabricated by excimer layer annealing (ELA). The ELA process allowed us to fabricate such a high-performance InZnO TFT at the substrate temperature less than 50 C according to thermal calculation. Our analysis revealed that high-energy irradiation in ELA produced a mixed phase of InZnO and SiO 2 , leading to the deterioration of TFT characteristics. Oxide semiconductor films deposited by sputtering have recently attracted considerable attention in the fields of transparent and flexible electronics for next-generation displays, in comparison with conventional amorphous silicon-based materials. In particular, an In 2 O 3 -doped ZnO (IZO) thin film is widely recognized as a suitable oxide semiconductor since thin-films transistors (TFTs) with that material in the channel layer yield a higher field-effect mobility than amorphous InGaZnO (a-IGZO) TFTs. [1][2][3] In the case of the IZO film, the amorphous phase generally provides a high conductivity of about 400 X À1 cm À1 , which is much higher than the conductivity suitable for the TFT's channel layer. 4,5 The conductivity of this material can possibly be reduced by a thermal annealing process. 6,7 In previous reports, thermal annealing with a relatively high temperature of about 300 C has been proposed to produce operative IZO TFTs. 8,9 However, such a high-temperature process in postannealing limits the choice for plastic flexible substrates. The excimer laser annealing (ELA) process with short pulses has been widely utilized to achieve a low processing temperature to produce a polycrystalline silicon thin film on a glass substrate. 10 This technique has also been utilized for oxide-semiconductor materials. Nakata et al. reported the fabrication of a-IGZO TFTs by ELA process, which acted as a postannealing process, and the improvement of the TFTs characteristics by ELA, 11 suggesting that the ELA process is also a promising technique for improving the characteristics of oxide-semiconductor devices. In this study, we focused on an IZO TFT with a higher field-effect mobility than an a-IGZO TFT. We assumed that an ELA process crystallizes IZO with nanograins easily since this material has a lower crystallization temperature than a-IGZO 12,13 and that an IZO film composed of nanograins has better characteristics than a noncrystallized IZO TFT since carrier scattering is suppressed in the disordered film. We considered it is necessary to use a laser with a wavelength shorter than 400 nm, for the laser to be absorbed by the IZO film since IZO has a wide band gap (higher than 3 eV). 14 We used an XeCl excimer laser with a sufficiently short wavelength of 308 nm (photon energy: 4.02 eV) 15,16 and investigated the effects of the ELA process on the IZO TFT characteristics and film properties.A thermally oxidized SiO 2 film of 100 nm thickness was formed on a highly doped p-type silicon wafer (<0.002 X cm) as a gate insulator. IZO films with...

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We report high performance single-grain Ge TFTs by μ-Czochralski process. Electron mobilites are 3337cm 2 /Vs with on/off ratio of 10 8 @V DS =0.1V. Hole mobilities are 1719cm 2 /Vs with on/off ratio of 10 8 @V DS =0.05V. The high mobility is due to improved interface property and tensile stress.Introduction:

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