Fabrication and Characterization of 4H-SiC Planar MESFET Using Ion- Implantation

et al. 2007

SSP

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4H-SiC planar MESFETs were fabricated using ion-implantation on high-purity semi-insulating substrate, and their DC and RF performances were characterized. A modified RCA method was used to clean the substrate before each procedure. Sacrificial oxide was grown after channel layer etching to eliminate plasma damage to the gate region. A thin, thermal oxide layer was grown to passivate the surface and then a thick field oxide was deposited by CVD. The maximum oscillation frequency of 26.4 GHz and the cut-off frequency of 7.2 GHz were obtained. The power gain was 8.4 dB and the output power was 2.8 W/mm at 2 GHz.

Section: Methodsmentioning

confidence: 99%

Fabrication of 4H-SiC Planar MESFETs on High-Purity Semi-Insulating Substrates

Yim

et al. 2007

SSP

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“…For lateral power microwave devices application of silicon carbide (SiC), a very high resistivity substrate is required because the substrate conductivity limits the maximum frequency and efficiency of SiC microwave MESFETs [1]. However, the background doping concentration of SiC is still relatively high and it is difficult to grow SiC having high resistivity for the purpose of maximizing its potential.…”

Section: Introductionmentioning

confidence: 99%

Homoepitaxial Growth of Vanadium-Doped 4H-SiC Using Bis-Trimethylsilylmethane and Verrocene Precursors

Seo

et al. 2007

MSF

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The authors attempted to grow a semi-insulating SiC epitaxial layer by in-situ vanadium doping. The homoepitaxial growth of the vanadium-doped 4H-SiC layer was performed by MOCVD using the organo-silicon precursor, bis-trimethylsilylmethane (BTMSM, [C7H20Si2]) and the metal-organic precursor, bis-cyclopentadienylvanadium (Verrocene, [C10H10V]). Vanadium doping effect on crystallinity of epilayer was very destructive. Vanadium-doped epilayers grown on normal condition had various surface or crystal defects such as micropipes, polytype inclusions. But this crystallinity degradation was overcome by high growth temperature. For the measurement of the resistivity of the highly resistive vanadium-doped 4H-SiC epilayers, the authors used the on-resistance technique. Based on the measurements of the on-resistance of the epilayers using the current-voltage technique, it is shown that the residual donor concentration of the epilayers was decreased with increasing partial pressure of verrocene. The resistivity of the vanadium-doped 4H-SiC epilayer was about 107 /cm.

“…In spite of recent progress in SiC epitaxial and bulk growth technique, the background doping concentration is still relatively high. Because semi-insulating SiC should be used as a substrate for many SiC-based devices such as SiC MESFET [1] and GaN HEMT [2] to reduce device parasitics, growth of semi-insulating SiC is a key technique for the application of SiC on many electrical devices. Conventionally, vanadium doping [3] was widely used for semi-insulating bulk SiC growth.…”

Section: Introductionmentioning

confidence: 99%

Homoepitaxial Growth of Iron-Doped 4H-SiC Using BTMSM and t-Butylferrocene Precursors for Semi-Insulating Property

Yim

et al. 2006

MSF

In this paper, we attempted to grow semi-insulating SiC epitaxial layer by in-situ iron doping. Homoepitaxial growth of iron-doped 4H-SiC layer was performed by MOCVD using organo-silicon precursor, bis-trimethylsilylmethane (BTMSM, [C7H20Si2]) and metal organic precursor, t-butylferrocene ([C14H17Fe]). Doping-induced crystallinity degradation showed different tendency depending on conducting type of substrate. The crystal quality of epilayer grown on n-type substrate was not degraded significantly despite of the Fe doping but in case of semi-insulating substrate, crystallinity was remarkably degraded as increasing iron contents. For measurement of resistivity of highly resistive iron-doped 4H-SiC epilayer, we used the on-resistance technique which is firstly attempted for measuring resistivity of epilayer. From on-resistance of epilayer measured by I-V, it is shown that the residual donor concentration of epilayer was decreased as increasing partial pressure of t-butylferrocene. The resistivity of iron-doped 4H-SiC epilayer was about 107 Ωcm. From this result, it is concluded that Fe could effectively act as a compensation center in the iron-doped 4H-SiC.