Effect of substrate temperature on the electrical characteristics of MoSex thin films and back-gated MoSex transistors

We have studied the structure, composition and electrical properties of the MoSex films deposited at different substrate temperature ranging from 298 to 573 K and the electrical characteristics of the back-gated MoSex field effect transistors (FETs). Results show that these characteristics depend deeply on the substrate temperature. With the increment of the substrate temperature, the MoSex films transfer from amorphous state to crystalline state, the concentration of the bond Mo and Se decreases first and then increases, and the bonding atomic ratio of Se/Mo increases. When the substrate temperature is at 423 K, the MoSex film has the highest Hall mobility (6.71 cm2 V−1 s−1) and the lowest room temperature resistivity (3.28 Ω cm). Moreover, MoSex FET fabricated by amorphous MoSex film channel has higher Ion/Ioff ratio and field-effect mobility. Using the MoSex channel deposited at 423 K, the highest Ion/Ioff ratio and field-effect mobility of the FET are about 105 and 15.7 cm2 V−1 s−1, respectively.