Simultaneous formation of p- and n-type ohmic contacts to 4H-SiC using the ternary Ni/Ti/Al system

Tsukimoto, Susumu; Sakai, T.; Onishi, Toshitake; Ito, Kazuhiro; Murakami, Masanori

doi:10.1007/s11664-005-0255-6

Cited by 34 publications

(14 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The neutron conversion materials are usually 10 B or 6 LiF solids, while the SiC diode detectors are usually composed of front ohmic contact electrode solids, SiC material solids, and back ohmic contact electrode solids [7], [20], [38]. In actual manufacturing, the front p-type ohmic contact electrode of the SiC diode was usually made of Ti with a thickness of 30 nm and Al with a thickness of 100 nm, and the backside n-type ohmic contact electrode was usually made of Ni with a thickness of 150 nm [41], [42], [43], [44], [45]. Also, the surface area of the SiC neutron detector was 1 × 1 cm 2 [9], [10], [15].…”

Section: B Detector Modeling Methodology In Geant4mentioning

confidence: 99%

Improving Detection Efficiency of Silicon Carbide Neutron Detector Using Double Trench

et al. 2023

View full text Add to dashboard Cite

In this article, we propose a double-trenchtype silicon carbide (SiC) neutron detector and model it using the concept of a unit cell on the GEANT4 platform. When the low-level discriminator (LLD) value was fixed at 300 keV, the structural parameters of this double-trench-type SiC neutron detector were optimized to maximize the intrinsic detection efficiency. Compared with the single trench type, the doubletrench-type SiC neutron detector can significantly improve the neutron intrinsic detection efficiency within a limited trench depth, which was especially suitable for the current technological status that SiC materials can only be used for shallow trench etching. Apart from optimizing the structural parameters, the energy deposition spectra in the SiC detector region by the generated secondary charged particles upon thermal neutron interaction in neutron conversion materials ( 10 B and 6 LiF) have also been estimated. It can be found that the double-trench-type SiC neutron detector counts significantly increased in the low-energy range, while the counts in the high-energy range are only slightly decreased. This is also the essential reason why the intrinsic detection efficiency of the double-trench-type SiC neutron detector was significantly improved compared to the single-trench-type SiC neutron detector.

show abstract

Section: B Detector Modeling Methodology In Geant4mentioning

confidence: 99%

Improving Detection Efficiency of Silicon Carbide Neutron Detector Using Double Trench

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Tanimoto et al 8 reported simultaneous formation of Ni-based contacts to both n-and p-type heavily doped SiC (N D > 10 20 cm -3 and N A > 10 20 cm -3 ) after annealing at 1000°C. Tsukimoto et al 9 also reported that a Ni/Ti/Al ternary contact showed ohmic behavior after annealing at 800°C to both n-and p-type SiC in which N and Al were doped at 10 19 cm -3 and 4.5 9 10 18 cm -3 , respectively. However, the mechanisms responsible for the simultaneous formation of ohmic contacts to both n-and p-type SiC using the same material have not yet been clarified.…”

Section: Introductionmentioning

confidence: 95%

Simultaneous Formation of Ni/Al Ohmic Contacts to Both n- and p-Type 4H-SiC

Ito

Onishi

Takeda

et al. 2008

Journal of Elec Materi

Self Cite

View full text Add to dashboard Cite

The fabrication procedure for silicon carbide power metal oxide semiconductor field-effect transistors can be improved through simultaneous formation (i.e., using the same contact materials and a one-step annealing process) of ohmic contacts on both the n-source and p-well regions. We have succeeded in the simultaneous formation of Ni/Al ohmic contacts to n-and p-type SiC after annealing at 1000°C for 5 min in an ultrahigh vacuum. Ohmic contacts to n-type SiC were found when the Al-layer thickness was less than about 6 nm, while ohmic contacts to p-type SiC were observed for an Al-layer thickness greater than about 5 nm. Only the contacts with an Al-layer thickness in the range of 5 nm to 6 nm exhibited ohmic behavior to both n-and p-type SiC, with a specific contact resistance of 1.8 9 10 -4 X cm 2 and 1.2 9 10 -2 X cm 2 for n-and p-type SiC, respectively. An about 100-nm-thick contact layer was uniformly formed on the SiC substrate, and polycrystalline d-Ni 2 Si(Al) grains were formed at the contact/SiC interface. In the samples that exhibited ohmic behavior to both n-and p-type SiC, the distribution of the Al/Ni ratios in the d-Ni 2 Si(Al) grains was larger than that observed for any of the samples that showed ohmic behavior to either n-or p-type SiC. Furthermore, the grain size of the d-Ni 2 Si(Al) grains in the samples showing ohmic behavior to both n-and p-type SiC was smaller than the grains in any of the samples that showed ohmic behavior to either n-or p-type SiC. Thus, the large distribution in the Al/Ni ratios and a fine microstructure were found to be characteristic of the ohmic contacts to both n-and p-type SiC. Grains with a low Al concentration correspond to ohmic contacts to n-type SiC, while grains with a high Al concentration correspond to ohmic contacts to p-type SiC.

show abstract

“…Thierry-Jebali et al have reported the formation of Ni/Ti/Al contacts on highly p-type 4H-SiC with low Specific Contact Resistance (SCR = 2.8×10 −6 Ω•cm 2 ), but this result was not reproducible [18]. Another study reported the formation of contacts on highly p-type 4H-SiC after annealing at 800ºC (relatively low temperature) for 30 min, but such long annealing time can be detrimental for MOSFET fabrication process [19]. On the other hand, a great attention is given to Al-Ti alloy which has shown stable low SCRs on the order of 10 −3 -10 −5 Ω•cm 2 on p-type SiC [20,21].…”

Section: Introductionmentioning

confidence: 99%

Stable and reliable ohmic contact on p-type 4H-SiC up to 1500 h of aging at 600 °C

Hamad

Tannous

Soueidan

et al. 2020

Microelectronics Reliability

View full text Add to dashboard Cite

The stability and reliability at high temperature of Ti3SiC2 based ohmic contacts on ptype 4H-SiC (0001) 4°-off substrates were studied. The contact was grown from Ti100-xAlx alloys annealed at high temperature (from 900°C to 1200°C). The Specific Contact Resistance (SCR) at room temperature and at high temperature (up to 600°C) was in the 10 -4 -10 -5 Ω.cm 2 range. A Schottky barrier height of 0.71 to 0.85 eV was calculated for the set of samples. After aging period at 600°C for 1500h, the SCR was very stable for Al contents x < 80 at%. This was correlated with chemical and physical stability of these contacts, where the residual stress located on 4H-SiC/Ti3SiC2 interface decreased after aging, for which the Ti3SiC2 phase was preserved. Whereas, in the case of x = 80 at%, the Ti3SiC2 phase disappeared and the contacts were not ohmic anymore after long time aging. The obtained results showed that Ti3SiC2/4H-SiC system is thermodynamically stable at high temperatures and can therefore be a good candidate, with high potential, for high power and high temperature electronic applications.

show abstract

Simultaneous formation of p- and n-type ohmic contacts to 4H-SiC using the ternary Ni/Ti/Al system

Cited by 34 publications

References 13 publications

Improving Detection Efficiency of Silicon Carbide Neutron Detector Using Double Trench

Improving Detection Efficiency of Silicon Carbide Neutron Detector Using Double Trench

Simultaneous Formation of Ni/Al Ohmic Contacts to Both n- and p-Type 4H-SiC

Stable and reliable ohmic contact on p-type 4H-SiC up to 1500 h of aging at 600 °C

Contact Info

Product

Resources

About