Effects of interface formation process on electronic properties of n-type Ti_0.3Zn_0.7O_1.3/p-type Si stack structure

Abstract The interfacial properties between the oxide-based channel materials and Si were investigated with a view to their application in tunnel field effect transistors. We focused on Ti x Zn 1− x O 1+ x , a solid solution of TiO 2 and ZnO, as the channel material, expecting that the high oxygen bond dissociation energy ( E bd ) of Ti would suppress oxygen vacancies and interfacial states with Si. From the exploration of solid solution compositions by the combinatorial method, we confirmed that a composition of x = 0.3 satisfies all the conditions of an amorphous structure, low resistance, and low surface roughness. In addition, to understand the interfacial reactions between elements with different E bd and Si, the intermediate SiO 2 layers were investigated by electrical properties and photoelectron spectroscopy. It was found that the Ti 0.3 Zn 0.7 O 1.3 film with an initial TiO 2 layer in a TiO 2 /ZnO multiple stacked structure rather than a single Ti 0.3 Zn 0.7 O 1.3 target synthesis has less degradation of electrical properties and interfacial defects.