Chloride-based Silicon Carbide CVD

Silicon carbide (SiC) is a promising material for high power and high frequency devices due to its wide bandgap, high break down field and high thermal conductivity. The most established technique for growth ofepitaxial layers of SiC is chemical vapor deposition (CVD) at around 1550 °C using silane, SiH4, and lighthydrocarbons e g propane, C3H8, or ethylene, C2H4, as precursors heavily diluted in hydrogen. For high-voltagedevices made of SiC thick (> 100 μm), low doped epilayers are needed. Normal growth rate in SiC epitaxy is~ 5 μm/h, rendering long growth times for such SiC device structures. The main problem when trying to achievehigher growth rate by increasing the precursor flows is the formation of aggregates in the gas phase; for SiCCVD these aggregates are mainly silicon droplets and their formation results in saturation of the growth ratesince if the gas flow does not manage to transport these droplets out of the growth zone, they will eventuallycome in contact with the crystal surface and thereby creating very large defects on the epilayer making theepilayer unusable….


Part I: An introduction to the field
1. Silicon Carbide
1.1 Crystal structure
1.2 History of SiC
1.3 SiC as a semiconductor
2. Crystal Growth
2.1 Bulk Crystal Growth
2.2 Epitaxial Growth
2.3 Chemical Vapor Deposition
3. Chloride-based Growth
3.1 Growth of Silicon epilayers
3.2 Growth of Silicon Carbide epilayers
3.3 Growth of Silicon Carbide bulk crystals
3.4 Simulations of Chloride-based growth
4. Characterization
4.1 Optical Microscopy
4.2 Thickness measurements
4.3 Doping measurements
4.4 X-ray diffraction (XRD)
4.5 Atomic Force Microscopy (AFM)
5. Main results
Part II: Papers
My contribution to the papers

Author: Pedersen, Henrik

Source: Linköping University

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