Effect of metal contacts on (100) β-Ga2O3 Schottky barriers

Abstract

The Schottky barriers of Ti, Mo, Co, Ni, Pd, and Au on (100) β-Ga2O3 substrates were analyzed using a combination of current-voltage (J-V), capacitance-voltage (C-V), and current-voltage-temperature (J-V-T) measurements. Near-ideal, average ideality factors for Ti, Mo, Co, and Ni were 1.05–1.15, whereas higher ideality factors (∼1.3) were observed for Pd and Au contacts. Barrier heights ranging from 0.60 to 1.20 eV were calculated from J-V measurements for the metals with low ideality factors. C-V measurements of all Schottky metals were conducted and yielded average barrier heights ranging from 0.78 to 1.98 eV. J-V-T measurements of Ti and Co diodes yielded barrier heights of 0.81 and 1.35 eV, respectively. The results reveal a strong positive correlation between the calculated Schottky barrier heights and the metal work functions: the index of interface behavior, S = 0.70, 0.97, and 0.81 for J-V, C-V, and J-V-T data, respectively.

β-Ga2O3 material properties, growth technologies, and devices: a review

“…A variety of Schottky metals including tungsten (W), copper (Cu), nickel (Ni), iridium (Ir), platinum (Pt), and gold (Au) have been reported for n-Ga 2 O 3 [55][56][57]. Pt and Ni are the most common ones used for device fabrication among them.…”

Control and understanding of metal contacts to β-Ga2O3 single crystals: a review

“…Tables 4 and 5 show the research results in the literature obtained from Schottky contacts to ( 100) and ( 010 Figure 4a shows the plots of barrier height versus metal work function using the data taken from Lyle et al [78], revealing a strong correlation between the calculated barrier heights and the metal work functions. Similarly, Fig.…”

“…Thus, an additional process for minimizing the plasma-induced surface damage is crucial to realize suitable device performance. Yang Because the thermal stability is critical in the performance of β-Ga 2 O 3 based devices, the temperaturedependent I − V measurements were mainly performed at elevated temperatures [42,50,72,78,79,87]. But this does not provide full information about the conduction mechanism and the properties of the barrier formation.…”

“…Fig 4. Plots of barrier height versus metal work function for a (100) β-Ga 2 O 3 Schottky contacts using the barrier heights taken from Lyle et al[78] and b (010) β-Ga 2 O 3 Schottky contacts using the barrier heights taken from Yao et al[25] and Farzana et al[88]. The metal work functions were taken from ref.…”

Nanoscale Characterization of Chemical and Structural Properties of the Au/(100) β-Ga2O3 Interface

“…Studies of electrical contacts to semiconductors provide an understanding of the interplay between fundamental material properties and metal–semiconductor interfaces, which are the building blocks for larger-scale, commercially employed devices such as Schottky barrier diodes , and power MOSFETs. Such studies of Schottky and ohmic contacts have been conducted on various orientations of β-Ga 2 O 3 , including the (100), − (2̅01), − (010), − and (001) , surfaces. Further, due to applications for β-Ga 2 O 3 under high temperatures, high electric fields, and high current densities, there is a significant desire to develop thermally stable contacts to withstand these conditions .…”