Electrical Characteristics of Au/n-GaN Schottky Junction with a High-k SrTiO3 Insulating Layer

Authors Varra Niteesh Reddy, D.V. Vivekananda, G. Sai Krishna, B. Sri Vivek, P. Vimala

Department of Electronics & Communication Engineering, Dayananda Sagar Collegeof Engineering, Shavige Malleshwara Hills, Kumaraswamy Layout, Banashankari, Bengaluru-560078,Karnataka, India.

Е-mail drvimala-ece@dayanandasagar.edu
Issue Volume 11, Year 2019, Number 4
Dates Received 07 May 2019; revised manuscript received 01 August 2019; published online 22 August 2019
Citation Varra Niteesh Reddy, D.V. Vivekananda, G. Sai Krishna, et al., J. Nano- Electron. Phys. 11 No 4, 04005 (2019)
DOI https://doi.org/10.21272/jnep.11(4).04005
PACS Number(s) 73.40.Qv, 85.30.Hi
Keywords n-type GaN, Strontium titanate, Electrical properties (19) , MIS junction, Barrier height (11) , Ideality factor (10) , Current conduction mechanism.

The electrical characteristics of Au/n-GaN Schottky junction (SJ) were improved by a place of high-k strontium titanate (SrTiO3) insulating layer in the middle of Au and n-GaN. The electrical properties of Au/n-GaN SJ and Au/SrTiO3/n-GaN metal/insulator/semiconductor (MIS) junction were explored by current-voltage and capacitance-voltage techniques. The MIS junction displayed an exquisite rectifying nature as compared to the SJ. The series resistance (RS) and shunt resistance (RSh) were found to be 30 Ω, 4.69  106 Ω and 250 Ω, 2.12  109 Ω for the SJ and MIS junction, respectively. The estimated barrier height (BH) and ideality factors of SJ and MIS junction were 0.67 eV, 1.44 and 0.83 eV, 1.78, respectively. Higher BH was achieved for the MIS junction than the SJ junction, suggesting the BH was effectually changed by the SrTiO3 layer. Also, the ideality factor, BH and series resistance of the SJ and MIS junction were estimated by employing the Cheung’s function and compared each other. Observations reveal the ohmic behavior at lower voltage regions and space-charge-limited conduction at higher voltage regions in the forward bias I-V characteristic of the SJ and MIS junctions. Also, the reverse leakage current conduction mechanism of SJ and MIS junctions was explored.

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