Impact of n-Type versus p-Type Doping on Mechanical Properties and Dislocation Evolution during SiC Crystal Growth

The origin of dislocation evolution during SiC crystal growth is usually related to lattice relaxation mechanisms caused by thermal stress. In this paper we discuss dislocation generation and dislocation propagation related to doping and suppression of basal plane dislocations, the latter being of particular interest for bipolar electronic devices. We have prepared alternating p-/n-/pdoped SiC crystals using the donor nitrogen and the acceptors aluminum or boron. In addition we determined the mechanical properties of n-type and p-type SiC; in particular we measured the critical shear stress by nano-indentation on c-plane and a-plane 6H-SiC surfaces. A considerably lower basal plane dislocation density is found in aluminum as well as in boron doped p-type SiC compared to nitrogen doped n-type SiC. It is concluded that the explanation of the reduced basal plane dislocation density in p-type SiC needs the consideration of electronic as well as mechanical effects.

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Basal Plane Dislocation Dynamics in Highly p-Type Doped versus Highly n-Type Doped SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.527-529.79 ◽

2006 ◽

Vol 527-529 ◽

pp. 79-82 ◽

Cited By ~ 4

Author(s):

Peter J. Wellmann ◽

Desirée Queren ◽

Ralf Müller ◽

Sakwe Aloysius Sakwe ◽

Ulrike Künecke

Keyword(s):

Basal Plane ◽

Stacking Fault ◽

Dislocation Dynamics ◽

Dislocation Generation ◽

Basal Plane Dislocation ◽

Substrate Wafer ◽

P Type ◽

Long Term Performance ◽

Term Performance

The long term performance of today’s SiC based bipolar power devices suffer strongly from stacking fault formation caused by slip of basal plane dislocations, the latter often originating from the n-type doped SiC substrate wafer. In this paper, using sequentially p-type / n-type / p-type doped SiC crystals, we address the question, whether basal plane dislocation generation and annihilation behaves differently in n-type and p-type SiC. We have found that basal plane dislocations are absent or at least appear significantly less pronounced in p-type doped SiC, which may become of great importance for the stacking fault problem in SiC.

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Fast homoepitaxial growth of 4H-SiC with low basal-plane dislocation density and low trap concentration by hot-wall chemical vapor deposition

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2007.05.009 ◽

2007 ◽

Vol 306 (2) ◽

pp. 297-302 ◽

Cited By ~ 51

Author(s):

Tsutomu Hori ◽

Katsunori Danno ◽

Tsunenobu Kimoto

Keyword(s):

Chemical Vapor Deposition ◽

Dislocation Density ◽

Vapor Deposition ◽

Basal Plane ◽

Chemical Vapor ◽

Trap Concentration ◽

Homoepitaxial Growth ◽

Basal Plane Dislocation

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Techniques for Minimizing the Basal Plane Dislocation Density in SiC Epilayers to Reduce Vf Drift in SiC Bipolar Power Devices

Silicon Carbide and Related Materials 2005 - Materials Science Forum ◽

10.4028/0-87849-425-1.141 ◽

2006 ◽

pp. 141-146 ◽

Cited By ~ 6

Author(s):

Joseph J. Sumakeris ◽

J.Peder Bergman ◽

Mrinal K. Das ◽

Christer Hallin ◽

Brett A. Hull ◽

...

Keyword(s):

Dislocation Density ◽

Basal Plane ◽

Power Devices ◽

Basal Plane Dislocation

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The Interplay of Thermo-Mechanical Properties in the Growth and Processing of III-V Materials

MRS Proceedings ◽

10.1557/proc-226-117 ◽

1991 ◽

Vol 226 ◽

Author(s):

A. S. Jordan ◽

V. Swaminathan

Keyword(s):

Mechanical Properties ◽

Shear Stress ◽

Dislocation Density ◽

Semiconductor Device ◽

Electronic Devices ◽

Device Fabrication ◽

Device Performance ◽

Bulk Crystals ◽

Dislocation Generation ◽

Critical Resolved Shear Stress

AbstractThe thermo-mechanical properties of III-V semiconductors, in general, and of GaAs and InP in particular, are reviewed. They play an important role in many aspects of semiconductor device fabrication starting from the growth of bulk crystals. Dislocation generation in GaAs and InP are discussed with the emphasis on the theoretical and experimental aspects of reducing the dislocation density in these materials. Such mechanical properties as glide systems, critical resolved shear stress and impurity hardening are covered. The effects of dislocations on device performance are illustrated with examples from photonic and electronic devices. Finally, the effect of thermomechanical stresses in the degradation and reliability of GaAs/AlGaAs and InP/InGaAsP based opto-electronic devices is considered.

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Characterization of 100 mm Diameter 4H-Silicon Carbide Crystals with Extremely Low Basal Plane Dislocation Density

Materials Science Forum ◽

10.4028/www.scientific.net/msf.645-648.291 ◽

2010 ◽

Vol 645-648 ◽

pp. 291-294 ◽

Cited By ~ 14

Author(s):

Michael Dudley ◽

Ning Zhang ◽

Yu Zhang ◽

Balaji Raghothamachar ◽

Sha Yan Byrapa ◽

...

Keyword(s):

Silicon Carbide ◽

Dislocation Density ◽

Basal Plane ◽

X Ray ◽

Repetitive Process ◽

Basal Plane Dislocation ◽

And Behavior ◽

New Generation ◽

Edge Dislocations

Synchrotron White Beam X-ray Topography (SWBXT) studies are presented of basal plane dislocation (BPD) configurations and behavior in a new generation of 100mm diameter, 4H-SiC wafers with extremely low BPD densities (3-4 x 102 cm-2). The conversion of non-screw oriented, glissile BPDs into sessile threading edge dislocations (TEDs) is observed to provide pinning points for the operation of single ended Frank-Read sources. In some regions, once converted TEDs are observed to re-convert back into BPDs in a repetitive process which provides multiple BPD pinning points.

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Demonstration of High Quality 4H-SiC Epitaxial Growth with Extremely Low Basal Plane Dislocation Density

Materials Science Forum ◽

10.4028/www.scientific.net/msf.778-780.91 ◽

2014 ◽

Vol 778-780 ◽

pp. 91-94 ◽

Cited By ~ 8

Author(s):

Takanori Tanaka ◽

Naoyuki Kawabata ◽

Yoichiro Mitani ◽

Nobuyuki Tomita ◽

Masayoshi Tarutani ◽

...

Keyword(s):

Dislocation Density ◽

Basal Plane ◽

Growth Conditions ◽

Conversion Ratio ◽

Lateral Growth ◽

High Quality ◽

Basal Plane Dislocation ◽

Ratio Condition ◽

High Conversion Ratio ◽

Edge Dislocations

SiC epitaxial layer with low basal plane dislocation (BPD) density of 0.2/cm2 was successfully grown under higher C/Si ratio, which is found on the investigation about growth conditions. In order to study conversion mechanism of BPDs to threading edge dislocations (TEDs), angles between directions of BPD lines on a substrate and that of moving edges of steps ([11-2) during growth were examined. Consequently, it was revealed that almost 98% of BPDs are converted to TEDs for the case of the absolute angles above 45°. This high conversion ratio is considered to be induced by enhanced lateral growth under the higher C/Si ratio condition.

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Growth of Low Basal Plane Dislocation Density SiC Epitaxial Layers

Silicon Carbide and Related Materials 2005 - Materials Science Forum ◽

10.4028/0-87849-425-1.243 ◽

2006 ◽

pp. 243-246

Author(s):

Ze Hong Zhang ◽

Tangali S. Sudarshan

Keyword(s):

Dislocation Density ◽

Basal Plane ◽

Epitaxial Layers ◽

Basal Plane Dislocation

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Epitaxial Growth on 2° Off-axis 4H SiC Substrates with Addition of HCl

MRS Proceedings ◽

10.1557/proc-1069-d07-10 ◽

2008 ◽

Vol 1069 ◽

Cited By ~ 5

Author(s):

Jie Zhang ◽

Swapna Sunkari ◽

Janice Mazzola ◽

Becky Tyrrell ◽

Gray Stewart ◽

...

Keyword(s):

Growth Rate ◽

Dislocation Density ◽

Epitaxial Growth ◽

Basal Plane ◽

Defect Density ◽

Mapping Technique ◽

Standard Process ◽

Basal Plane Dislocation ◽

Non Destructive ◽

Koh Etching

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.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.556-557.129 ◽

2007 ◽

Vol 556-557 ◽

pp. 129-132 ◽

Cited By ~ 5

Author(s):

T. Hori ◽

Katsunori Danno ◽

Tsunenobu Kimoto

Keyword(s):

Growth Rate ◽

Dislocation Density ◽

Basal Plane ◽

Free Exciton ◽

High Growth ◽

High Growth Rate ◽

Photoluminescence Spectra ◽

Homoepitaxial Growth ◽

Basal Plane Dislocation ◽

Ratio Range

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.

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