Investigation of Barrier Inhomogeneities and Electronic Transport on Al-Foil/p-Type-4H-SiC Schottky Barrier Diodes Using Diffusion Welding

Abstract

The diffusion welding (DW) is a comprehensive mechanism that can be extensively used to develop silicon carbide (SiC) Schottky rectifiers as a cheaper alternative to existing mainstream contact forming technologies. In this work, the Schottky barrier diode (SBD) fabricated by depositing Al-Foil on the p-type 4H-SiC substrate with a novel technology; DW. The electrical properties of physically fabricated Al-Foil/4H-SiC SBD have been investigated. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics based on the thermionic emission model in the temperature range (300 K–450 K) are investigated. It has been found that the ideality factor and barrier heights of identically manufactured Al-Foil/p-type-4H-SiC SBDs showing distinct deviation in their electrical characteristics. An improvement in the ideality factor of Al-Foil/p-type-4H-SiC SBD has been noticed with an increase in temperature. An increase in barrier height in fabricated SBD is also observed with an increase in temperature. We also found that these increases in barrier height, improve ideality factors and abnormalities in their electrical characteristics are due to structural defects initiation, discrete energy level formation, interfacial native oxide layer formation, inhomogenous doping profile distribution and tunneling current formation at the SiC sufaces.

Barrier properties and current conduction mechanism for metal contacts to lightly and highly doped p-type 4H-SiC

“…It is noted that non-ideal behaviors (large n TE values compared to ideal unity and big discrepancies between f q Bp TE and f q Bp CV ) are observed for the lightly doped samples. [10][11][12][13] For the highly doped samples, large n TFE values (>1) can also be observed, likely to be ascribed to the tunneling effects by a high doping level. In addition, we found that f q Bp TFE and f q Bp CV are comparable.…”

“…The abnormal behaviors from the TE model for the lightly doped samples are usually ascribed to the barrier inhomogeneities, which may be due to the surface contaminants, subsurface traps, dopant clustering, non-uniform interfacial oxide layer, active defects etc. [10][11][12][13][18][19][20][21][22] It can be speculated that some patches with their low and high local barriers may be embedded in the surrounding of uniform barrier height, 11,23) as schematically shown in Fig. 3.…”

“…2,[5][6][7] Unfortunately, studies on the barrier properties at metal/p-type SiC junctions are still limited. [8][9][10][11][12][13] Therefore, understanding of the barrier properties and specific current conduction mechanisms at metal/p-type SiC interface is indispensable to help clarify the physical mechanism of Ohmic contacts formation on p-type SiC. 14) In this work, a systematic study was performed to investigate the barrier properties of different metals (Ti, Ni and Pt) contact to lightly (9 × 10 16 cm −3 ) and highly (9 × 10 18 cm −3 ) doped p-type 4H-SiC by using currentvoltage-temperature (I-V-T) and capacitance-voltage (C-V ) measurements.…”

Energy harvesting from radio waves using few-layer 2D galena (galenene)

“…The decrease of barrier height with temperature can be explained by the inhomogeneity at the metal–semiconductor interface. 33,34 The carriers do not have enough energy to surpass the higher energy barrier at low temperatures. As a result, current transport is dominated by current flowing along the channel with the lowest barrier height, increasing the ideality factor.…”

Development and Investigation of SiC and SiC-Based Devices

“…The last article in the collection also focuses on optimizing Schottky diode technology [8]. It was shown that the diffusion welding (DW) is a comprehensive mechanism that can be extensively used to develop silicon carbide (SiC) Schottky rectifiers as a cheaper alternative to existing mainstream contact forming technologies.…”