Ohmic Contact of Pt/Au on Hydrogen-Terminated Single Crystal Diamond

Minghui Zhang,Renan Bu,Fang Lin,Fengnan Li,Genqiang Chen,Hongxing Wang,Jingwen Zhang,Haris Abbasi,Feng Wen,Yan-Feng Wang,Wei Wang,Dan Zhao

doi:10.3390/coatings9090539

Minghui Zhang, Renan Bu + Show 10 more

Open Access

https://doi.org/10.3390/coatings9090539

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Journal: Coatings	Publication Date: Aug 23, 2019
Citations: 6	License type: CC BY 4.0

Affiliation: Xi'an Jiaotong University

Abstract

In this study, contact properties of platinum/gold (Pt/Au) on the surface of hydrogen-terminated single crystal diamond (H-SCD) were studied with several treatment conditions. The electrodes of Pt (20 nm)/Au (100 nm) were deposited on H-SCD surface by electron beam evaporation technique. Then, the specific contact resistance (ρc) of the as-fabricated sample was measured by the circular transmission line model, which showed good ohmic properties with the value of 5.65 × 10−4 Ω·cm2. To identify the thermal stability of Pt/Au/H-SCD, the sample was annealed in hydrogen ambient from 200 to 700 °C for 20 min at each temperature. As the temperature increased, ρc demonstrated better thermal stability. In addition, the barrier height was evaluated to be −0.67 ± 0.12 eV by X-ray photoelectron spectroscopy (XPS) technique.

Highlights

The immaturity of doping processes greatly limits the development of diamond-based electronic devices
The properties like high melting point and good chemical stability indicate platinum (Pt) as a good material for ohmic contacts. It can be considered as a promising candidate to form ohmic contact with diamond film
The single crystal diamond surface morphology was evaluated by an atomic force microscope The single crystal diamond surface morphology was evaluated by an atomic force microscope (AFM, Innova, Bruker, Billerica, MA, USA) with the scan range 5 μm, which showed a smooth (AFM, Innova, Bruker, Billerica, MA, USA) with the scan range 5 μm, which showed a smooth surface with the root mean square (RMS) roughness around 0.6 nm [22,23]

Summary

Introduction

Diamond exhibits excellent properties [1,2,3,4], such as wide bandgap (5.47 eV), high breakdown field (>10 MV·cm−1 ), high thermal conductivity (22 W·cm−1 ·K−1 ), high carrier saturation velocity (107 cm·s−1 ), low dielectric constant (5.7), high carrier mobility of electron (4500 cm2 ·V−1 ·s−1 ) and hole (3800 cm2 ·V−1 ·s−1 ), etc., demonstrating a potential application in the field of electron devices such as Schottky diodes [5,6,7,8], field-effect transistors (FETs) [9,10,11,12], and other electronic devices [13,14]. Along with the improvement in the performance of diamond-based devices, an excellent ohmic contact between the electrode metal layer and the diamond film is vital. Many investigations of ohmic contact between metal and diamond have been reported. The properties like high melting point and good chemical stability indicate platinum (Pt) as a good material for ohmic contacts. It can be considered as a promising candidate to form ohmic contact with diamond film. -transmission line the ohmic contact, and specific resistance was evaluated by circular model (C-TLM). Barrier height at the interface of Pt/Au/H-SCD

Experiment

The diamond substrate was cleaned in an acid mixture solution

Result and Discussion

70 Diamond nm-Pt

Conclusion

Conclusions