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The influence of atomic hydrogen was investigated using a polycrystalline germanium (poly-Ge) thin-film transistor. High-density-atomic hydrogens were generated by catalytic reaction on a heated W mesh. The defect density in the poly-Ge film and at the poly-Ge/SiO2 interface can be reduced by three orders of magnitude with the passivation ratio of 2.3 × 10−5. From the dependence of treatment time and air exposure time for long time, the defects in poly-Ge films were preferentially terminated in comparison with that at the poly-Ge/SiO2 interface.

Ge thin film is expected as an active layer in a thin-film transistor (TFT) because the electron mobility of Ge is larger than that of Si. In this study, the crystallization of Ge thin film by soft X-ray irradiation and the improvement of interface property of poly-Ge/SiO 2 in poly-Ge TFT by atomic hydrogen annealing (AHA) are investigated for realization of high-performance poly-Ge TFT. The drain current (I d ) did not depend on the gate voltage (V g ) before AHA treatment. However, as the AHA treatment time increased, the I d decreased and the I d came to depend on V g . The on/off ratio of 10 was obtained by AHA for 360 min. It is found that the defect density in poly-Ge film and at poly-Ge/SiO 2 interface can be reduced by AHA slightly.