A Novel Tungsten–Nickel Alloy Ohmic Contact to SiC at 900 $^{\circ}\hbox{C}$

Okojie, Robert S.; Evans, Laura J.; Lukco, Dorothy; Morris, J. P.

doi:10.1109/led.2010.2050761

Cited by 28 publications

(13 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…% Al in Ni/Al with ρ c ≈10 −4 Ω cm 2 for both doping types (N D =1.3×10 19 cm −3 ; N A =7.2×10 18 cm −3 ) [17]. In 2010 Ohmic contacts using W:Ni alloys in a 1:1 atomic ratio exhibited specific contact resistances of ρ c ≈10 −5 Ω cm 2 on n-6H-SiC (N D >2×10 19 cm −3 ) and ρ c ≈10 −4 Ω cm 2 on both p-6H-SiC (N A >1×10 20 cm −3 ) and n-4H-SiC (N D >2×10 19 cm −3 ), with qualitative proof for p-4H-SiC (N A >2×10 19 cm −3 ) as well [18]. Ti/Ni bilayers on both doping types (N D , MAX and N A, MAX =1.0×10 20 cm −3 ) demonstrated smoother morphology than Ni contacts while also being less sensitive to interfacial oxidation when forming Ohmic contacts by annealing, albeit with ρ c ≈10 −3 Ω cm 2 on p-4H-SiC [19].…”

Section: Introductionmentioning

confidence: 90%

Characterization of tungsten–nickel simultaneous Ohmic contacts to p- and n-type 4H-SiC

Kragh-Buetow¹,

Okojie²,

Lukco³

et al. 2015

Semicond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Ohmic contacts to p-and n-type 4H-SiC using refractory alloyed W:Ni thin films were investigated. Transfer length measurement test structures to p-type 4H-SiC (N A =3×10 20 cm −3 ) revealed Ohmic contacts with specific contact resistances, ρ c , of ∼10 −5 Ω cm 2 after 0.5 h annealing in argon at temperatures of 1000 °C, 1100 °C, 1150 °C, and 1200 °C. Contacts fabricated on n-type 4H-SiC (N D =2×10 19 cm −3 ) by similar methods were shown to have similar specific contact resistance values after annealing, demonstrating simultaneous Ohmic contact formation for W:Ni alloys on 4H-SiC. The lowest ρ c values were (7.3±0.9)×10 −6 Ω cm 2 for p-SiC and (6.8±3.1)×10 −6 Ω cm 2 for n-SiC after annealing at 1150 °C. X-ray diffraction shows a cubic tungsten-nickel-carbide phase in the Ohmic contacts after annealing as well as WC after higher temperatures. Auger electron spectroscopy depth profiles support the presence of metal carbide regions above a nickel and silicon-rich region near the interface. X-ray energy dispersive spectroscopy mapping showed tungsten-rich and nickelrich regions after annealing at 1100 °C and above. W:Ni alloys show promise as simultaneous Ohmic contacts to p-and n-SiC, offering low and comparable ρ c values along with the formation of W x Ni y C.

show abstract

Section: Introductionmentioning

confidence: 90%

Characterization of tungsten–nickel simultaneous Ohmic contacts to p- and n-type 4H-SiC

Kragh-Buetow¹,

Okojie²,

Lukco³

et al. 2015

Semicond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Formation of titanium-tungsten ohmic contact with specific contact resistance of 3.3 × 10 −5 cm 2 to n-type 4H-SiC epilayer with doping concentration of 1.1 × 10 19 cm −3 were reported [21]. A high thermal stability was observed for W-Ni ohmic contacts to n-type 4H-SiC characterized by specific contact resistivity of 7.69 × 10 −4 and 5.81 × 10 −4 cm 2 for doping level equal 1.4 and 2 × 10 19 cm −3 , respectively [22]. Similar value of specific contact resistivity equal 5 × 10 −4 cm 2 was obtained for W-Ni ohmic contact to n-type epitaxial layer with doping concentration in the range 5-7 × 10 18 cm −3 deposited on p-type 4H-SiC substrate [23].…”

Section: Introductionmentioning

confidence: 99%

Effects of annealing temperature on the structure and electrical properties of tungsten contacts to n-type silicon carbide

Rogowski

Kubiak

2015

Materials Science and Engineering: B

View full text Add to dashboard Cite

“…A number of metals such as Ni, Ti, Co, Al, Nb and Pt have been studied to obtain high-quality ohmic contacts to SiC. [16][17][18][19][20][21] Among these candidates, Ni is the most widely used to form ohmic contacts to SiC because of its low specific contact resistance. The mechanism of formation of Ni/SiC ohmic contacts has been studied by many groups.…”

Section: Introductionmentioning

confidence: 99%

Influence of Ni and Nb thickness on low specific contact resistance and high-temperature reliability of ohmic contacts to 4H-SiC

Cuong

Ishikawa

Maeda

et al. 2019

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

The influence of Ni and Nb thickness on the electrical properties and high-temperature reliability of Ni(x)/Nb(100 – x)/n-type 4H-SiC ohmic contacts, where x = 25, 50 or 75 nm, was investigated. Two-dimensional X-ray diffraction, hard X-ray photoelectron spectroscopy and transmission electron microscopy analyses indicated that a relatively high Ni concentration had a strong influence on low specific contact resistance due to the greater formation of Ni2Si at the contact interface, whereas a higher density of Nb improved the ability to collect excess carbon atoms by the formation of Nb6C5 at the interface, ensuring high-temperature reliability of the contacts. The experimental results showed that the Ni(50)/Nb(50)/4H-SiC ohmic contact is a potential candidate for high-temperature and harsh environment applications.

show abstract

A Novel Tungsten–Nickel Alloy Ohmic Contact to SiC at 900 $^{\circ}\hbox{C}$

Cited by 28 publications

References 11 publications

Characterization of tungsten–nickel simultaneous Ohmic contacts to p- and n-type 4H-SiC

Characterization of tungsten–nickel simultaneous Ohmic contacts to p- and n-type 4H-SiC

Effects of annealing temperature on the structure and electrical properties of tungsten contacts to n-type silicon carbide

Influence of Ni and Nb thickness on low specific contact resistance and high-temperature reliability of ohmic contacts to 4H-SiC

Contact Info

Product

Resources

About