1997 Fiscal Year Final Research Report Summary
Low-Temperature Processing Technology of SiC Devices
| Project/Area Number |
08455143
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
NAKASHIMA Kenshiro Nagoya Institute of Technology, Dept.of Engineering, Professor, 工学部, 教授 (80024305)
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| Co-Investigator(Kenkyū-buntansha) |
ERYU Osamu Nagoya Institute of Technology, Dept.of Engineering, Assoc.professor, 工学部, 助教授 (10223679)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Silicon carbide / laser doping / excimer laser / Aluminum / Nickel / Tungsten / ohmic electrode / ohmic contact / laser ablation |
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| Research Abstract |
(1) Results in 1996
(a) Aluminum atoms have been doped in n type 6H-SiC (n= 1.4x10^<18>cm^<-3>) and 4H-SiC substrates set in doping chamber containing mixed gases of tri-methyl aluminum and hydrogen with a pressure of 100 Torr. Al atoms are distributed in the range of 50 nm, and the doped region showed p type conduction in as-doped conditions. Hole concentration and the mobility are estimated to be 2-4x10^<18>cm^<-3>,1-2x10^2cm^2/Vsec, and 2-4x10^<18>cm^<-3>,70-100cm^2/Vsec, respectively.
(b) Ni-ohmic electrodes have been fabricated on n-type 6H-SiC substrates (n= 1.5x10^<18>cm^<-3>) by KrF excimer laser irradiation during Ni deposition. A shallow Ni-doped layr 120nm deep was formed by room temperature processes (laser energy density 1.0J/cm^2 and 1,000 pulses). Contact resistivity was estimated to be 6x10^<-3>OMEGAcm^2.
Results in 1997
(c) Boron-doping has been examined in n-type 6H-SiC substrates set in the gas mixture of tri-methyl boron and hydrogen by using KrF excimer laser irradiation processes. Inconditions of the laser energy density 0.8J/cm^2 and number of laser shots 1000-5000, SIMS analysis shows B atoms are doped in the range of 10-20 nm. P-type conduction with Hall measurements has not been assured due to shallow depth of the doped region
(d) Tungsten ohmic contacts stable at 1000ﾟC (2 hours) have been fabricated on n-type 6H-SiC (n= 1.8x10^<18>cm^<-3>) substrates using both laser ablation of W pellets (purity 99.9%), and laser doping of deposited W with a KrF excimer laser inthe same process chamber. Shallow and abrupt contacts formed 10-20 nm deep in the substrates showed good ohmic characteristics without post-heat treatments (contact resistivity 2.2x10^<-4>OMEGAcm^2). The surface was found to be very smooth even after laser irradiation of the energy density 2.0J/cm^2.
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