Electrical Properties of Pseudo-Single-crystalline Ge Films Grown by Au-induced Layer Exchange Crystallization at 250 °C

We study the electrical properties of pseudo-single-crystalline Ge (PSC-Ge) films grown by a Auinduced layer exchange crystallization method at 250 degrees C. By inserting the SiNx layer between PSC-Ge and SiO2, we initiatively suppress the influence of the Ge/SiO2 interfacial defective layers, which have been reported in our previous works, on the electrical properties of the PSC-Ge layers. As a result, we can detect the influence of the ionized Authorn donors on the temperature-dependent hole concentration and Hall mobility. To further examine their electrical properties in detail, we also fabricate p-thin-film transistors (TFTs) with the PSC-Ge layer. Although the off-state leakage currents are suppressed by inserting the SiNx layer, the value of on/off ratio remains poor (<10(2)). Even after the post-annealing at 400 degrees C for the TFTs, the on/off ratio is still poor (similar to 10(2)) because of the gate-induced drain leakage current although a nominal field effect mobility is enhanced up to similar to 25 cm(2)/V s. Considering these features, we conclude that the Au contaminations into the PSC-Ge layer can affect the electrical properties and device performances despite a low-growth temperature of 250 degrees C. To achieve further high-performance p-TFTs, we have to suppress the Au contaminations into PSC-Ge during the Au-induced crystallization growth. Published by AIP Publishing.