Thesis Examination Committee

Prof Kevin Kim‐Pong TAM, SOSC/HKUST (Chairperson)
Prof Man Sun CHAN, ECE/HKUST (Thesis Supervisor)
Prof Tso‐Ping MA, School of Engineering & Applied Science, Yale University (External Examiner)
Prof Philip Kwok Tai MOK, ECE/HKUST
Prof Andrew Wing On POON, ECE/HKUST
Prof Jiannong WANG, PHYS/HKUST

Abstract

Contact engineering by 2D graphene film is investigated including two forms of function, which are the contact to semiconductor formed directly by 2D graphene film and the contact modification by an inserted graphene layer between metal and semiconductor. The source for the non-ideal Schottky junction formed by graphene and Si is uncovered. The semi-metal graphene is prone to be doped by the electric field of the depletion region in Si, which leads to the non-saturating reverse current. And the recombination current originated from the metal residue carried by graphene film and the voltage-dividing effect across the native oxide of Si and the interface trap charges contribute to an inferior voltage control over the junction and a high ideality factor in the graphene-Si junction. Methods to restore the ideality are introduced. We also proposed a graphene-inserted tunneling contact IGZO TFT deviated from the classic transistor. It manifests a strong and early saturation in the output curves which does not follow the pinch-off theory. This makes it prospecting for application in energy-efficient driving circuit for flat panel display.