Electrical characteristics and structural properties of ohmic contacts to p-type 4H-SiC epitaxial layers

Vasilevskii, K. V.; Rendakova, S.; Nikitina, I. P.; Babanin, A.I.; Andreev, A. N.; Zekentes, K.

doi:10.1134/1.1187850

Cited by 13 publications

(5 citation statements)

References 15 publications

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“…Where Is is the saturation current density, ΦB0 is the BH, A is the area of the diode, n is the ideality factor, and A* is effective Richardson's constant (146 Acm -2 K -2 ). k the Boltzmann's constant, q the electron charge, T the absolute temperature [29][30][31].…”

Section: Resultsmentioning

confidence: 99%

Analysis of Barrier Inhomogeneities of P-Type Al/4H-SiC Schottky Barrier Diodes

Ziko

Koel

Rang

et al. 2020

MSF

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The diffusion welding (DW), known as direct bonding technique could be more used as an alternative approach to develop silicon carbide (SiC) Schottky rectifiers to existing mainstream metallization contact technologies. Measured results for p-type 4H-SiC Schottky barrier diodes (SBD) arepresented. And comprehensive numerical study to characterize the device has been performed. The simulations are carried out with ATLAS software (Silvaco). The measured and numerically simulated forward current-voltage (I–V) and capacitance-voltage (C–V) characteristics in a large temperaturerange are analyzed. Some of the measured p-type 4H-SiC Schottky diodes show deviation in specific ranges of their electrical characteristics. This deviation, especially due to excess current, dominates at low voltages (less than 1 V) and temperatures (less than room temperature). To verify the existence of electrically active defects under the Schottky contact, which influences the Schottky barrier height (SBH) and its inhomogeneity, the deep level transient spectroscopy (DLTS) technology was applied. DLTS measurements show the presence of a deep-level defect with activation energy corresponding typically for multilevel trap clusters.

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Section: Resultsmentioning

confidence: 99%

Analysis of Barrier Inhomogeneities of P-Type Al/4H-SiC Schottky Barrier Diodes

Ziko

Koel

Rang

et al. 2020

MSF

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“…where, I is the total forward current, I s is the saturation current, Φ B0 is the BH, A is the area of the diode, n is the ideality factor, and A* is effective Richardson's constant (146 Acm −2 K −2 ), k is the Boltzmann's constant, q is the electron charge and T is the absolute temperature [29][30][31]. The temperature-dependent Φ B0 , n and I s can be extracted from the experimentally obtained forward (I-V) characteristics, which will clarify the conduction mechanism in the Al-Foil/4H-SiC SBDs.…”

Section: Temperature Dependence Of I-v Characteristicsmentioning

confidence: 99%

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

et al. 2020

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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.

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“…It was found that the RTA at 1000 • C led to formation of a Ni 2 Si layer at the surface while the TiC layer was located close to the interface between the contact film and SiC. This contact demonstrates ohmic behaviour when deposited on p-type 4H-SiC although the nickel silicide was separated from SiC by the titanium carbide layer [19,20]. Thus, the structure of titanium and nickel containing films deposited on SiC and annealed at temperatures ranging from 800 to 1000 • C still remains poorly covered.…”

Section: Introductionmentioning

confidence: 99%

“…Ohmic contacts to n-type SiC are usually formed by deposition of nickel [11][12][13][14][15] or titanium [16][17][18] films followed by hightemperature annealing. Recent development of metallization schemes based on duplex Ti-Ni coating with following anneal led to fabrication of low-resistivity ohmic contact to p-type 4H-SiC [19,20] as well as of high-quality Schottky barriers on n-type 6H-SiC [21].…”

Section: Introductionmentioning

confidence: 99%

“…Increasing the bottom Ti layer thickness up to 30 nm led to the creation of a Ni 2 Si/TiC two-phase layer at the interface between the reaction zone and SiC, resulting in rectifying behaviour [29]. In contrast a clearly different structure of the resulting film was discovered after rapid thermal anneal (RTA) of a 50 nm thick Ti film deposited on 4H-SiC and covered by a 100 nm thick Ni [19,20,30]. It was found that the RTA at 1000 • C led to formation of a Ni 2 Si layer at the surface while the TiC layer was located close to the interface between the contact film and SiC.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structural pattern formation in titanium–nickel contacts on silicon carbide following high-temperature annealing

Nikitina

Vassilevski

Horsfall

et al. 2006

Semicond. Sci. Technol.

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The composition and microstructure of compound contacts to 4H-SiC containing both titanium and nickel were investigated. Samples were prepared by metal evaporation on commercial 4H-SiC wafers followed by rapid thermal annealing (RTA). Contact structures with three different metal deposition sequences were investigated: (A) SiC/Ti(4 nm)/Ni(150 nm); (B) SiC/Ti(100 nm)/Ni(50 nm) and (C) SiC/Ti(4 nm)/Ni(50 nm)/ Ti(100 nm). RTA was performed in a vacuum at 800, 925 and 1040 • C for a period of 800 s. X-ray diffraction, Auger electron spectroscopy and transmission electron microscopy were used for the characterization. A distinct spatial separation of nickel silicide and titanium carbide layers was observed in all samples. It was discovered that the final distribution of solid-state reaction products in B-and C-samples was independent of the order of the deposition of the initial metal films. In both samples, a two-phase TiC+C layer was found to be adjacent to the SiC substrate. Factors controlling phase formation and segregation are discussed. A two-stage reaction model is proposed to explain the reaction zone structure formed in the Ni-Ti-SiC system after high-temperature treatment.

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Electrical characteristics and structural properties of ohmic contacts to p-type 4H-SiC epitaxial layers

Cited by 13 publications

References 15 publications

Analysis of Barrier Inhomogeneities of P-Type Al/4H-SiC Schottky Barrier Diodes

Analysis of Barrier Inhomogeneities of P-Type Al/4H-SiC Schottky Barrier Diodes

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

Structural pattern formation in titanium–nickel contacts on silicon carbide following high-temperature annealing

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