Low Trap Concentration and Low Basal-Plane Dislocation Density in 4H-SiC Epilayers Grown at High Growth Rate

Author(s):  
T. Hori ◽  
Katsunori Danno ◽  
Tsunenobu Kimoto
2007 ◽  
Vol 556-557 ◽  
pp. 129-132 ◽  
Author(s):  
T. Hori ◽  
Katsunori Danno ◽  
Tsunenobu Kimoto

Fast homoepitaxial growth of 4H-SiC has been carried out on off-axis (0001) substrates by horizontal hot-wall CVD at 1600οC. High growth rate up to 24 μm/h has been achieved with mirror-like surface in the C/Si ratio range of 1.0-2.0. The Z1/2 and EH6/7 concentrations can be kept as low as 7 × 1011 cm-3 and 3 × 1011 cm-3, although an unknown trap (UT1) is observed with the concentration in the 1011 cm-3 range. The photoluminescence spectra are dominated by strong free exciton peaks, and the L1 peak is not observed. The basal-plane dislocation (BPD) density has decreased with increase in growth rate, and it can be reduced to 22 cm-2 when epilayers are grown on Chemical Mechanically Polished (CMP) substrates at a growth rate of 24 μm/h.


2008 ◽  
Vol 1069 ◽  
Author(s):  
Jie Zhang ◽  
Swapna Sunkari ◽  
Janice Mazzola ◽  
Becky Tyrrell ◽  
Gray Stewart ◽  
...  

ABSTRACTEpitaxial growth on 3-in, 2° off-axis 4H SiC substrates has been conducted in a horizontal hot-wall CVD reactor with HCl addition. The thickness of the epiwafers ranges from 3m to 11 m and the growth rate is 7 − 7.5 m/h. Although a rougher surface and a higher triangular defect density is observed using the standard process for 4° growth, an improved process has resulted in reduced triangular defect density down to around 4 cm−2 and a smoother surface with the roughness of 1.1 nm for a 3.7 m thick epiwafer. Most interestingly, the basal plane dislocation density in the 2° off-axis epiwafers has been reduced to "negligible" levels, as confirmed by both the non-destructive UVPL mapping technique and the molten KOH etching on 2° epiwafers with thickness of around 10 m.


2019 ◽  
Vol 963 ◽  
pp. 123-126
Author(s):  
Tobias Höchbauer ◽  
Christian Heidorn ◽  
Nikolaos Tsavdaris

The future challenges for SiC device technology are cost reduction and increased reliability. A key point to achieve that is the increase of yield during epitaxial layer growth through the reduction of structural defects (such as basal plane dislocations and triangle defects), an increased thickness and doping uniformity, and a high growth rate. Despite significant advancements in SiC epitaxial growth technology, it still constitutes a big challenge to find the optimum working point at which all those requirements are fulfilled. By implementing a new epitaxial layer growth process, we are able to grow basal plane dislocation free epitaxial layers, while the density of other structural defects remains low. Additionally, intra-wafer thickness and doping uniformities of the epitaxial layers are further improved.


2013 ◽  
Vol 740-742 ◽  
pp. 323-326
Author(s):  
Kassem Alassaad ◽  
François Cauwet ◽  
Davy Carole ◽  
Véronique Soulière ◽  
Gabriel Ferro

Abstract. In this paper, conditions for obtaining high growth rate during epitaxial growth of SiC by vapor-liquid-solid mechanism are investigated. The alloys studied were Ge-Si, Al-Si and Al-Ge-Si with various compositions. Temperature was varied between 1100 and 1300°C and the carbon precursor was either propane or methane. The variation of layers thickness was studied at low and high precursor partial pressure. It was found that growth rates obtained with both methane and propane are rather similar at low precursor partial pressures. However, when using Ge based melts, the use of high propane flux leads to the formation of a SiC crust on top of the liquid, which limits the growth by VLS. But when methane is used, even at extremely high flux (up to 100 sccm), no crust could be detected on top of the liquid while the deposit thickness was still rather small (between 1.12 μm and 1.30 μm). When using Al-Si alloys, no crust was also observed under 100 sccm methane but the thickness was as high as 11.5 µm after 30 min growth. It is proposed that the upper limitation of VLS growth rate depends mainly on C solubility of the liquid phase.


2008 ◽  
Vol 600-603 ◽  
pp. 115-118 ◽  
Author(s):  
Henrik Pedersen ◽  
Stefano Leone ◽  
Anne Henry ◽  
Franziska Christine Beyer ◽  
Vanya Darakchieva ◽  
...  

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.


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