Use of Vanadium Doping for Compensated and Semi-Insulating SiC Epitaxial Layers for SiC Device Applications

2012 ◽  
Vol 717-720 ◽  
pp. 133-136 ◽  
Author(s):  
Bharat Krishnan ◽  
Rooban Venkatesh K.G. Thirumalai ◽  
Siva Prasad Kotamraju ◽  
Joseph Neil Merrett ◽  
Yaroslav Koshka
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Epitaxial Growth ◽  
Growth Rates ◽  
Reverse Bias ◽  
Epitaxial Layers ◽  
Pin Diodes ◽  
Vanadium Doping ◽  
Device Applications ◽  
Epilayer Surface

Vanadium doping from SiCl4 source during epitaxial growth with chlorinated C and Si precursors was investigated as a mean of achieving compensated and semi-insulating epitaxial 4H-SiC layers for device applications. Thin epilayers were grown at 1450°C with a growth rate of ~6 μm/h. Experiments at 1600°C resulted in the growth rates ranging from 60 to 90 µm/h producing epilayers with thickness above 30 µm. V concentrations up to about 1017cm-3 were found safe for achieving defect-free epilayer surface morphology, however certain degradation of the crystalline quality was detected by XRD at V concentrations as low as 3-5x1015 cm-3. Controllable compensation of nitrogen donors with V acceptors provided low-doped and semi-insulating epitaxial layers. Mesa isolated PiN diodes with V-acceptor-compensated n- epilayers used as drift regions showed qualitatively normal forward- and reverse-bias behavior.

Homoepitaxial Growth on Si-Face (0001) On-Axis 4H-SiC Substrates

2019 ◽  
Vol 954 ◽  
pp. 31-34
Author(s):  
Guo Guo Yan ◽  
Xing Fang Liu ◽  
Feng Zhang ◽  
Zhan Wei Shen ◽  
Wan Shun Zhao ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Epitaxial Growth ◽  
Growth Temperature ◽  
Epitaxial Layers ◽  
Homoepitaxial Growth ◽  
Influence Mechanism

Homoepitaxial growths of 4H-SiC were performed on Si-face (0001) on-axis substrates in a SiH4-C2H4-H2-HCl system by using our home-made vertical hot wall CVD reactor. The influence mechanism of the growth temperature and C/Si ratio on the morphology and growth rate was studied. It is found that the steps in the epilayer become more clear with the increasing temperatures. The result indicates that the C/Si ratio window of on-axis epitaxial growth is very narrow. Only when the C/Si ratio was 1.2, a slightly improved surface morphology can be achieved. The results indicate that 4H-SiC epitaxial layers were obtained on on-axis substrates and the films were highly-oriented 4H-SiC.

Very High Growth Rate of 4H-SiC Using MTS as Chloride-Based Precursor

2008 ◽  
Vol 600-603 ◽  
pp. 115-118 ◽  
Author(s):  
Henrik Pedersen ◽  
Stefano Leone ◽  
Anne Henry ◽  
Franziska Christine Beyer ◽  
Vanya Darakchieva ◽  
...  
Keyword(s):  
Growth Rate ◽  
Linear Dependence ◽  
Growth Rates ◽  
Molar Fraction ◽  
High Growth ◽  
High Growth Rate ◽  
Epitaxial Layers ◽  
Single Precursor ◽  
Very High

The chlorinated precursor methyltrichlorosilane (MTS), CH3SiCl3, has been used to grow epitaxial layers of 4H-SiC in a hot wall CVD reactor, with growth rates as high as 170 µm/h at 1600°C. Since MTS contains both silicon and carbon, with the C/Si ratio 1, MTS was used both as single precursor and mixed with silane or ethylene to study the effect of the C/Si and Cl/Si ratios on growth rate and doping of the epitaxial layers. When using only MTS as precursor, the growth rate showed a linear dependence on the MTS molar fraction in the reactor up to about 100 µm/h. The growth rate dropped for C/Si < 1 but was constant for C/Si > 1. Further, the growth rate decreased with lower Cl/Si ratio.

4H-SiC Homoepitaxial Growth on Vicinal-Off Angled Si-Face Substrate

2010 ◽  
Vol 645-648 ◽  
pp. 99-102 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Sachiko Ito ◽  
Junji Senzaki ◽  
Hajime Okumura
Keyword(s):  
Surface Morphology ◽  
Epitaxial Growth ◽  
Growth Temperature ◽  
Growth Conditions ◽  
Step Bunching ◽  
Homoepitaxial Growth ◽  
Blocking Voltage ◽  
Basal Plane Dislocation ◽  
Epilayer Surface

We have carried out detailed investigations of 4H-SiC homoepitaxial growth on vicinal off-angled Si-face substrates. We found that the surface morphology of the substrate just after in-situ H2 etching was also affected by the value of the vicinal-off angle. Growth conditions consisting of a low C/Si ratio and a low growth temperature were effective in suppressing macro step bunching at the grown epilayer surface. We also demonstrated epitaxial growth without step bunching on a 2-inch 4H-SiC Si-face substrate with a vicinal off angle of 0.79o. Ni Schottky barrier diodes fabricated on an as-grown epilayer had a blocking voltage above 1000V and a leakage current of less than 5x10-7A/cm2. We also investigated the propagation of basal plane dislocation from the vicinal off angled substrate into the epitaxial layer.

Morphology Control, Dopant Incorporation, and Selective Epitaxial Growth of 4H-SiC at Low Temperatures Using CH3Cl Growth Precursor

2006 ◽  
Vol 911 ◽  
Author(s):  
Yaroslav Koshka ◽  
Bharat Krishnan ◽  
Huang-De Lin ◽  
Galyna Melnychuk
Keyword(s):  
Growth Rate ◽  
Low Temperature ◽  
Epitaxial Growth ◽  
Growth Surface ◽  
Epitaxial Layers ◽  
Selective Epitaxial Growth ◽  
Dopant Incorporation ◽  
Nitrogen Donor ◽  
Order Of Magnitude ◽  
Silicon Vapor

AbstractLow-temperature homoepitaxial growth of 4H-SiC using halo-carbon precursors was further investigated to address the problems limiting increase of the growth rate of the defect-free epilayers at growth temperatures below 1300°C. Enhanced etching of Si clusters in the gas phase was achieved by adding HCl during the low-temperature growth. The effective Si/C ratio above the growth surface was increased as a result of reduced depletion of silicon vapor species by cluster condensation, which resulted in drastically improved epilayer morphology and significant increase of the growth rate. An intentional insitu nitrogen doping of epitaxial layers during 1300°C growth on Si and C faces revealed more than an order of magnitude higher nitrogen donor incorporation in the C-face epitaxial layers. Finally, a feasibility of selective epitaxial growth using low-temperature masking materials such as SiO2 was demonstrated.

Effect of C/Si Ratio and Nitrogen Doping on 4H-SiC Epitaxial Growth Using Dichlorosilane Precursor

2015 ◽  
Vol 821-823 ◽  
pp. 129-132 ◽  
Author(s):  
Hai Zheng Song ◽  
M.V.S. Chandrashekhar ◽  
T.S. Sudarshan
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Nitrogen Doping ◽  
Gas Flow ◽  
Gas Flow Rate ◽  
Wide Range ◽  
N Doping ◽  
Morphological Defects ◽  
Defect Densities ◽  
Epilayer Surface

Application of dichlorosilane (DCS) in 4H-SiC epitaxial growth on 4° off-cut substrates has been studied. The effect of C/Si ratio and N2gas flow rate on epilayer properties is investigated in detail. It is found that the C/Si ratio has a significant influence on the growth rate, epilayer surface roughness (step-bunching), conversion of basal plane dislocations (BPDs), and generation of morphological defects and in-grown stacking faults. A wide range of doping concentration from p- to n+ can be controlled in DCS growth. High quality 4° off-cut SiC epilayers are achieved for C/Si=1.3 – 1.8. Addition of N2has no obvious influence on growth rate and defect densities. The BPD conversion greater than 99.8% is achieved independent of N doping without any pretreatment.

In-Situ Dry Etching of InP Using Phosphorus Tri-Chloride and Re-Growth Inside a Chemical Beam Epitaxial Growth Chamber

1993 ◽  
Vol 300 ◽  
Author(s):  
K M. Kapre ◽  
W. T. Tsang ◽  
P. F. Sciortino
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Epitaxial Growth ◽  
Substrate Surface ◽  
Etching Rate ◽  
Growth Chamber ◽  
Dramatic Improvement ◽  
First Time ◽  
Substrate Temperatures

ABSTRACTWe have extended the capability and versatility of a chemical beam epitaxial (CBE) system by demonstrating reactive chemical beam etching (RCBE) of InP using phosphorus tri chloride (PCl3)as the gaseous etching beam injected directly into the growth chamber. This permits instant switching from etching to growth (and vice versa) in the same run for the first time in CBE. We investigated RCBE of InP at various substrate temperatures between 400 °C and 580°C, under different PCl3 fluences, and etching conditions. Excellent surface morphology was obtained at high temperatures (> 530°C - 570°C) and under an etching rate of < 6 Å/sec. We also found that upon addition of trimethylindium flow equivalent to a growth rate of 1 Å/sec during RCBE a dramatic improvement in surface morphology was obtained even at a high net etching rate of 10 Å/sec. The surface morphology obtained under such conditions is indistinguishable from that of the original substrate surface. Using Si02 as a mask, in-situ etching of laser mesas followed immediately by regrowth of blocking layers with excellent wetting characteristics was obtained.

Increased Growth Rate in a SiC CVD Reactor Using HCl as a Growth Additive

2005 ◽  
Vol 483-485 ◽  
pp. 73-76 ◽  
Author(s):  
Rachael L. Myers-Ward ◽  
Olof Kordina ◽  
Z. Shishkin ◽  
Shailaja P. Rao ◽  
R. Everly ◽  
...  
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Gas Phase ◽  
Hydrogen Chloride ◽  
Growth Rates ◽  
Growth Process ◽  
Cluster Formation ◽  
Film Morphology ◽  
Hydrogen Carrier ◽  
Low Crystalline

Hydrogen chloride (HCl) was added to a standard SiC epitaxial growth process as an additive gas. A low-pressure, hot-wall CVD reactor, using silane and propane precursors and a hydrogen carrier gas, was used for these experiments. It is proposed that the addition of HCl suppresses Si cluster formation in the gas phase, and possibly also preferentially etches material of low crystalline quality. The exact mechanism of the growth using an HCl additive is still under investigation, however, higher growth rates could be obtained and the surfaces were improved when HCl was added to the flow. The film morphology was studied using SEM and AFM and the quality with LTPL analysis, which are reported.

High Uniformity with Reduced Surface Roughness of Chloride Based CVD Process on 100mm 4° Off-Axis 4H-SiC

2012 ◽  
Vol 717-720 ◽  
pp. 93-96 ◽  
Author(s):  
Hrishikesh Das ◽  
Swapna G. Sunkari ◽  
Timothy Oldham ◽  
Janna R. B. Casady ◽  
Jeff B. Casady
Keyword(s):  
Surface Roughness ◽  
Epitaxial Growth ◽  
Growth Rates ◽  
Growth Process ◽  
Process Conditions ◽  
Epitaxial Layers ◽  
High Uniformity ◽  
Highly Uniform ◽  
Reduced Surface

In this work we present the epitaxial growth of 4H-SiC on 100mm 4° off-axis substrates grown in a multi-wafer CVD planetary reactor. Highly uniform epitaxial layers having thickness and doping uniformities of 1.7% and 1.4% respectively were grown in the production reactor with optimized process conditions at 8µm/hr and 30µm/hr growth rates. Process optimizations resulted in epitaxial layers with surface roughness (RMS) of 0.32nm. Epitaxial layers with a thickness of 53µm grown with a 30µm/hr growth process had minimal degradation in surface roughness (RMS of 0.39nm).

Formation and Reduction of Large Growth Pits on 100 mm 4° 4H-SiC

2016 ◽  
Vol 858 ◽  
pp. 193-196 ◽  
Author(s):  
Yong Qiang Sun ◽  
Gan Feng ◽  
Jun Yong Kang ◽  
Wei Ning Qian ◽  
Li Ping Lv ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Epitaxial Growth ◽  
Process Parameters ◽  
Growth Process ◽  
High Quality ◽  
Substrate Quality ◽  
Large Growth

The large growth pits (LGPs) dependence of substrate quality, growth rate, and C/Si ratio have been discussed in the 4H-SiC epitaxial growth on 100 mm N-type 4H-SiC Si-face substrates misoriented by 4° toward [11-20] with a warm-wall planetary reactor. The formation and reduction of LGPs have been investigated by adjusting the growth process parameters. With the optimized process, the perfect surface morphology with lower LGPs density has been obtained on the high quality substrate.

Cleaning during Initial Stages of Epitaxial Growth in an Ultrahigh Vacuum Rapid Thermal Chemical Vapor Deposition Reactor

1993 ◽  
Vol 334 ◽  
Author(s):  
Mahesh K. Sanganeria ◽  
Katherine E. Violette ◽  
Mehmet C. ÖZtÜRk ◽  
Gari Harris ◽  
C. Archie Lee ◽  
...  
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Oxygen Concentration ◽  
Growth Rates ◽  
Oxygen Absorption ◽  
Substrate Interface ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Si Films ◽  
Water Rinse

AbstractIn this paper, we report our results on surface preparation for the growth of epitaxial Si films. Hydrogen passivated surfaces are currently being investigated for application in Si epitaxy to eliminate the high temperature in-situ bake necessary to remove the native oxide. Hydrogen passivation is obtained by a dilute HF dip before the substrate is loaded in the process chamber. However the passivation is partially lost when the HF dip is followed by a water rinse which results in oxygen absorption on the substrate. It was found that the peak oxygen concentration at the epitaxy substrate interface increase by an order of magnitude due to a five minute water rinse. We report here that oxygen and carbon at the epitaxy substrate interface can be desorbed during initial stage of epitaxial growth by reducing epitaxial growth rate. In this work, epitaxial Si films were deposited over a wide range of growth rates obtained by varying Si2H6 flow rates. The peak oxygen concentration decreases by an order of magnitude by changing the growth rate from 3000 to 700Å/kminute for a deposition temperature of 800°C. We believe that at higher growth rates Si overgrows on absorbed oxygen maintaining epitaxial alignment reflected in the good electrical quality of the epitaxial films. However, at low growth rates oxygen has sufficient time to desorb before overgrowth can take place, improving the epitaxy substrate interface quality.

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