Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Brominated chemistry for chemical vapor deposition of electronic grade SiC
Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.ORCID iD: 0000-0001-8116-9980
Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
Show others and affiliations
2015 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, no 3, 793-801 p.Article in journal (Refereed) Published
Abstract [en]

Chlorinated chemical vapor deposition (CVD) chemistry for growth of homoepitaxial layers of silicon carbide (SiC) has paved the way for very thick epitaxial layers in short deposition time as well as novel crystal growth processes for SiC. Here, we explore the possibility to also use a brominated chemistry for SiC CVD by using HBr as additive to the standard SiC CVD precursors. We find that brominated chemistry leads to the same high material quality and control of material properties during deposition as chlorinated chemistry and that the growth rate is on average 10 % higher for a brominated chemistry compared to chlorinated chemistry. Brominated and chlorinated SiC CVD also show very similar gas phase chemistries in thermochemical modelling. This study thus argues that brominated chemistry is a strong alternative for SiC CVD since the deposition rate can be increased with preserved material quality. The thermochemical modelling also suggest that the currently used chemical mechanism for halogenated SiC CVD might need to be revised.

Place, publisher, year, edition, pages
2015. Vol. 27, no 3, 793-801 p.
National Category
Chemical Sciences Physical Sciences
Identifiers
URN: urn:nbn:se:liu:diva-111075DOI: 10.1021/acs.chemmater.5b00074ISI: 000349934500016OAI: oai:DiVA.org:liu-111075DiVA: diva2:753046
Available from: 2014-10-07 Created: 2014-10-07 Last updated: 2017-12-05Bibliographically approved
In thesis
1. Precursors and defect control for halogenated CVD of thick SiC epitaxial layers
Open this publication in new window or tab >>Precursors and defect control for halogenated CVD of thick SiC epitaxial layers
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Silicon carbide (SiC) is a very hard semiconductor material with wide band gap, high breakdown electric field strength, high thermal conductivity and high saturation electron drift velocity making it a promising material for high frequency and high power devices. The performance of electrical devices is strongly dependent on the quality, doping level and thickness of the grown epitaxial layers. The SiC epitaxial layers are usually grown by chemical vapor deposition (CVD), using silane (SiH4) and light hydrocarbons (C2H4 or C3H8) as precursors, diluted in a massive flow of hydrogen (H2), at growth temperatures and pressures of 1500-1600 °C and 100-300 mbar, respectively. A Silicon Carbide (SiC) device with a high breakdown voltage (> 10 kV) requires thick (> 100 μm) and low doped (1014cm-3) epitaxial layers. The typical growth rate is usually 5-10 μm/h, rendering very long growth times which result in a high cost for the final device. It is hard to increase the growth rate without running into problems with homogeneous gas phase nucleation, which badly affects the surface morphology and the usefulness of the epitaxial layers for devices. This problem can be avoided by lowering the growth pressure and/or increasing the carrier gas flow (H2) to minimize the homogeneous gas phase nucleation or by increasing the growth temperature to evaporate the silicon droplets. On the other hand introducing chlorine into the gas mixture, by adding HCl or using some chlorinated silicon precursor, such as trichlorosilane (SiHCl3) or tetrachlorosilane (SiCl4), or by methyltrichlorosilane (CH3SiCl3) as a single molecule will prevent nucleation in the gas phase. In this thesis a detailed study of the chloride-based processes and an investigation of a bromide-based CVD process is made using a horizontal hot wall reactor. Focus has been mainly on the study of various precursor molecules but also the effect of process parameters on the growth of thick epitaxial layers (100-200 μm). In paper 1 the growth of SiC epitaxial layers on 4° off-axis substrates manifesting very good morphology when using methane (CH4) as carbon precursor is demonstrated. A comparative study of SiCl4, SiHCl3, SiH4+HCl, C3H8, C2H4 and CH4 in an attempt to find the optimal precursor combination is presented in Paper 2 for growth of 4H-SiC epitaxial layers on 4° off-axis substrates with very good morphology. Paper 3 presents a direct comparison between chloride-based and bromide-based CVD chemistries for growth of SiC epitaxial layers using SiH4 and C2H4 as Si- respectively C-precursors with HCl or HBr as growth additives. The influence of temperature ramp up conditions on the carrot defect density on 8° off-axis 4H-SiC epitaxial layers using the single molecule precursor methyltrichlorosilane (MTS) as growth precursor is studied in Paper 4. In paper 5 growth of about 200 μm thick epitaxial layers with very good morphology at growth rates exceeding 100 μm/h using SiCl4+C2H4 and SiH4+HCl+C2H4 precursor approaches is reported. The effect of growth conditions on dislocation density by decorating the dislocations using KOH etching is reported in Paper 6. In Paper 7 the effect of varying parameters such as growth  temperature, C/Si ratio, Cl/Si ratio, Si/H2 ratio and in situ pre-growth surface etching time are studied in order to reduce the formation of step bunching and structural defects, mainly triangular defects for growth of about 100 μm thick epitaxial layers on 4° off-axis substrates with very good morphology at growth rates up to 115 μm/h.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2014. 61 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1625
National Category
Physical Sciences Chemical Sciences
Identifiers
urn:nbn:se:liu:diva-111076 (URN)10.3384/diss.diva-111076 (DOI)978-91-7519-213-0 (ISBN)
Public defence
2014-10-31, Plank, Fysikhuset, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2014-10-07 Created: 2014-10-07 Last updated: 2015-03-11Bibliographically approved

Open Access in DiVA

fulltext(3376 kB)171 downloads
File information
File name FULLTEXT01.pdfFile size 3376 kBChecksum SHA-512
1e5918738095270e0034c0f75514f68020c9b4d7a5ca5ea5b9e959b9ed02da1fa2ba82bc0d873b2d2d731c0ec98d39b3eedfe5318de5394f6fe6d0e4695bbb28
Type fulltextMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Yazdanfar, MilanKalered, EmilDanielsson, ÖrjanKordina, OlleNilsson, DanielIvanov, Ivan GueorguievOjamäe, LarsJanzén, ErikPedersen, Henrik
By organisation
Semiconductor MaterialsThe Institute of TechnologyChemistry
In the same journal
Chemistry of Materials
Chemical SciencesPhysical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 171 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 181 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf