Electron Injection of N-type Pentacene-Based OFET with Nitrogen-Doped LaB₆ Bottom-Contact Electrodes

Abstract

In this study, the effect of nitrogen-doped (N-doped) LaB₆ bottom-contact electrodes and interfacial layer (IL) on n-type pentacene-based organic field-effect transistor (OFET) was investigated. The scaled OFET was fabricated by using photolithography for bottom-contact electrodes. A 20-nm-thick N-doped LaB₆ bottom-contact electrodes were formed on SiO₂/n⁺-Si(100) substrate by RF sputtering followed by the surface treatment with sulfuric acid and hydrogen peroxide mixture (SPM) followed by diluted hydrofluoric acid (DHF; 1% HF) at room temperature (RT). Then, a 1.2-nm-thick N-doped LaB₆ IL was deposited at RT. Finally, a 10-nm-thick pentacene film was deposited at 100^°C followed by the Al back-gate electrode formation by using thermal evaporation. The current of electron injection was observed in the air due to the effect of surface treatment and N-doped LaB₆ IL.