Medium Energy Carbon and Nitrogen Ion Beam Induced Modifications in Charge Transport, Structural and Optical Properties of Ni/Pd/n-GaN Schottky Barrier Diodes.

Santosh Kumar,Seeram Ramakrishnna,Vinay Kumar Mariswamy,Arun Nimmala,Krishnaveni Sannathammegowda,Xiang Zhang,Varra Rajagopal Reddy,Asokan Kandasami,S V S Nageswara Rao,Jue Tang

doi:10.3390/ma13061299

Abstract

The irradiation effects of carbon and nitrogen medium energy ions (MEI) on charge transport, structural and optical properties of Ni/Pd/n-GaN Schottky barrier diodes are reported. The devices are exposed to 600 keV C2+ and 650 keV N2+ ions in the fluence range of 1 × 1013 to 1 × 1015 ions cm−2. The SRIM/TRIM simulations provide quantitative estimations of damage created along the trajectories of ion beams in the device profile. The electrical parameters like Schottky barrier height, series resistance of the Ni/Pd/n-GaN Schottky barrier diodes decreases for a fluence of 1 × 1013 ions cm−2 and thereafter increases with an increase in fluence of 600 keV C2+ and 650 keV N2+ ions. The charge transport mechanism is influenced by various current transport mechanisms along with thermionic emission. Photoluminescence studies have demonstrated the presence of yellow luminescence in the pristine samples. It disappears at higher fluences due to the possible occupancy of Ga vacancies. The presence of the green luminescence band may be attributed to the dislocation caused by the combination of gallium vacancy clusters and impurities due to MEI irradiation. Furthermore, X-ray diffraction studies reveal that there is a decrease in the intensity and shift in the diffraction peaks towards the lower side of two thetas. The reductions in the intensity of C2+ ion irradiation is more when compared to N2+ ion irradiation, which may be attributed to change in the mean atomic scattering factor on a given site for light C2+ ion as compared to N2+ ion.

Highlights

The rectifying (Schottky) metal–semiconductor (M-S) interface is an essential aspect of all electronic and photonic devices
The deviation in electrical parameters are correlated with the defects and the damage profiles estimated through Stopping and Range of Ions in Matter (SRIM)/Transport of Ions in Matter (TRIM) simulation, which are exceptionally reliant upon the fluences of medium energy ions (MEI)
We affirmed that the charge transport mechanism is affected by additional defects at higher fluences due to the contributions of various other current transport mechanisms along with the thermionic emission mechanism

Summary

Introduction

The rectifying (Schottky) metal–semiconductor (M-S) interface is an essential aspect of all electronic and photonic devices. Apart from its applications in electronic devices, the Schottky contacts are used as a tool for the study of semiconductors [1,2]. It is of significant importance to study the current transport properties of the M-S interface and its modification for a better understanding of the operations of electronic devices [3,4]. 3rd-generation semiconducting materials like gallium nitride (GaN), silicon carbide (SiC), and indium gallium nitride (InGaN), etc., have broad applications in power electronics, solid-state lighting, and microwave communication [5,6,7]. GaN devices offer great potential for operation in wide temperature and pressure ranges and in strong radiation environments, which cannot be accomplished with customary semiconductor devices technologies currently available [11,12] 3rd-generation semiconducting material like light-emitting diodes, photodetectors, diodes, solar cells, laser diodes, etc. have superior performance over 1st generation semiconducting material-silicon (Si) and 2nd-generation semiconducting material-gallium arsenide (GaAs) in terms of efficiency, frequency operation, temperature resistance, voltage resistance and radiation resistance etc. [5,6,8,9,10].

Methods

Results

Discussion

Conclusion