Device characteristics of Schottky barrier diodes using In-Ga-Zn-O semiconductor thin films with different atomic ratios

• Published in: Journal of alloys and compounds 2019-01, Vol.771, p.658-663
• Main Authors: Kim, Jae-Won, Jung, Tae-Jun, Yoon, Sung-Min
• Format: Article
• Language: English
• Subjects: Atoms & subatomic particles; Barriers; CMOS; Composition effects; Diodes; In-Ga-Zn-O; Indium gallium zinc oxide; Oxide semiconductor; Partial pressure; PN junction devices; Schottky barrier diode; Schottky diodes; Schottky junction; Thin films
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.08.289

Oxide semiconductor Schottky barrier diodes (SBDs) were fabricated by using amorphous In-Ga-Zn-O (IGZO) semiconducting thin films with different atomic ratios. Higher rectification ratios and Schottky barrier heights (SBHs) were obtained when the oxygen partial pressure was high during the sputtering deposition of the IGZO films. The increase in Ga composition effectively enhanced the device characteristics, including the rectification ratio and the SBH of the SBDs. These properties were closely related to the control of oxygen vacancy concentration within the IGZO and the resulting conduction behaviors owing to Fermi-level pinning and tunneling current through the Schottky barrier. The fabricated SBD using IGZO with a higher Ga composition (In:Ga:Zn = 1.0:0.8:0.3) exhibited a rectification ratio of 8.3 × 106 and an SBH of 0.79 eV. •We fabricated Schottky barrier diodes using In-Ga-Zn-O oxide semiconductors.•Effects of oxygen partial pressures (PO2) and film compositions were investigated.•PO2 conditions during the sputtering has marked impacts on device characteristics.•Increase in Ga composition is effective for enhancing the diode performance.•Less amount of oxygen vacancies within the IGZO is preferred for the diodes.