Ti–Ni ohmic contacts on 3C–SiC doped by nitrogen or phosphorus implantation

Bazin, Anne-Elisabeth; Michaud, Jean-François; Autret-Lambert, Cécile; Cayrel, Frédéric; Chassagne, Thierry; Portail, Marc; Zieliński, Marcin; Collard, Emmanuel; Alquier, Daniel

doi:10.1016/j.mseb.2010.03.084

Cited by 16 publications

(23 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can be noticed that regardless of the dose levels, all groups experienced a surface degradation, although the high dose sample surfaces were degraded more severely, indicating higher lattice damage [5,18]. The SiO 2 capped samples were left with a higher roughness compared with the uncapped ones in all batches.…”

Section: Surface Roughness Evolutionmentioning

confidence: 91%

Section: Methodsmentioning

confidence: 99%

“…A series of energies with increasing total doses were applied during implantation to form box profile at 3 doping levels, which will be called high dose, medium dose and low dose samples in following text. Nitrogen was selected as the dopant rather than phosphorous since it does less damage to the 3C-SiC film [17,18], although it saturates more readily [8]. Prior to the PIA process, 1μm thick SiO 2 was deposited on the surface of half samples from each batch via plasma enhanced chemical vapour deposition (PECVD).…”

Section: Methodsmentioning

confidence: 99%

“…For 3C-SiC on Si wafers, the PIA temperature is limited by the melting point of Si (1412°C), well below that of SiO 2 (1610°C) [9] so a SiO 2 capping layer can be a good choice. Previously, n-type heavily implanted 3C-SiC was studied for different annealing conditions with [17] and without [18,19] a graphite cap. A study of using deposited SiO 2 as the PIA capping layer for 3C-SiC on Si is demonstrated here.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Electrical activation of nitrogen heavily implanted 3C-SiC(1 0 0)

Sharma

Shah

et al. 2015

Applied Surface Science

View full text Add to dashboard Cite

A degenerated wide bandgap semiconductor is a rare system. In general, implant levels lie deeper in the bandgap and carrier freeze-out usually takes place at room temperature. Nevertheless, we have observed that heavily doped n-type degenerated 3C-SiC films are achieved by nitrogen implantation level of ~6x10 20 cm -3 at 20K. According to temperature dependent Hall measurements, nitrogen activation rates decrease with the doping level from almost 100% (1.5x10 19 cm -3 , donor level 15meV) to ~12% for 6x10 20 cm -3 . Free donors are found to saturate in 3C-SiC at ~7x1019 cm -3 . The implanted film electrical performances are characterized as a function of the dopant doses and post implantation annealing (PIA) conditions by fabricating Van der Pauw structures. A deposited SiO 2 layer was used as the surface capping layer during the PIA process to study its effect on the resultant film properties. From the device design point of view, the lowest sheet resistivity (~1.4mΩ.cm) has been observed for medium doped (4x10 19 cm -3) sample with PIA 1375°C 2h without a SiO 2 cap.Keywords: 3C-SiC; post-implantation activation; Van der Pauw; Hall; degenerated film IntroductionSilicon carbide (SiC) has been considered as the future power devices materials attributed to its superior electrical, mechanical and thermal properties. 3C-SiC has a smaller bandgap (2.3eV) than 4H-SiC (3.2eV), but still 2 times higher than Si (1.1eV) and can be grown directly on large area Experimental ProceduresThe materials studied in this work was a 10μm thick unintentionally doped (<1x10 16 cm -3 ) 3C-SiC film epitaxial grown on a 4 inch Si(100) substrate by NOVASiC. The wafer went through a chemical-mechanical polishing process [20] after the CVD growth with an initial surface RMS roughness ~0.2nm determined from atomic force microscopy (AFM) measurements. A Veeco multimode AFM with Nanonis controller was used to evaluate the surface roughness. The overall roughness value was determined by scanning three 10x10μm 2 areasand averaging the results. The wafer was cut into 30 8x8mm 2 pieces and equally divided into 3 batches. An onaxis nitrogen implantation process was conducted on the plain surface of all samples at room temperature. A series of energies with increasing total doses were applied during implantation to form box profile at 3 doping levels, which will be called high dose, medium dose and low dose samples in following text. Nitrogen was selected as the dopant rather than phosphorous since it does less damage to the 3C-SiC film [17,18] SIMS profilesAfter the PIA process, Second Ion Mass Spectrometry (SIMS) analysis was conducted on samples from each dose batch for the toughest PIA condition (1375°C, 2 hours) as shown in Fig 2. The profiles before PIA were not shown here but were expected to be much like the annealed ones due to the unlikely observable diffusion of nitrogen in 3C-SiC below 1800°C [17,24]. High dose and medium dose samples both achieved an implantation depth of ~300nm with peak values around 6x10 20 cm -3 and 4x10 1...

show abstract

Section: Surface Roughness Evolutionmentioning

confidence: 91%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Electrical activation of nitrogen heavily implanted 3C-SiC(1 0 0)

Sharma

Shah

et al. 2015

Applied Surface Science

View full text Add to dashboard Cite

show abstract

“…The most studied metals for n-type 3C-SiC Ohmic contacts are Al [2][3][4], Ti [3][4][5] and Ni [2,4,6,7], and the resultant ρ c Manuscript submitted July 20, 2016 ) n-type 3C-SiC back in 1995 [3], although with a considerable resistivity spread of over 6x10 -5 Ω.cm -2 . The literature shows that Al contacts generally have the lowest ρ c value, which can be explained by the negligible SBH between Al and 3C-SiC (~0 eV) compared with Ti (0.4 eV) and Ni (0.55 eV) [4].…”

Section: Introductionmentioning

confidence: 99%