Cubic boron nitride (cBN) is a synthetic and an intrinsically super-hard material with the second highest hardness and thermal conductivity next to diamond. Cubic BN with its tetrahedral sp3 structure is isostructural and isoelectronic to diamond. Diamond is far the most extreme material but cBN surpasses diamond in some properties. Unlike diamond, cBN is chemically inert to molten ferrous materials and resistant to oxidation up to 1200 °C at atmospheric conditions. These properties make cBN more attractive than diamond in many mechanical and tribological applications. Cubic BN has the widest bandgap (6.2 ± 0.2 eV) among III-V semiconductors, high electron mobility and hole mobility. In contrast to diamond it maintains high resistivity even at extreme temperatures. It can be doped for both p- and n-type conductivities and is piezoelectric. Therefore cBN is a potential candidate for construction of high-temperature, high power and high-speed electronic devices operating in harsh environment. Although cBN films are very attractive they have not been implemented into practical applications because of many accoutered problems like poor quality, low phase purity, high compressive stress (up to 20 GPa), poor adhesion to the substrates, small deposited area and limited film thickness (≤200 nm)…
Contents
Chapter 1. Properties of BN polymorphs
1.1 Structural properties of BN
1.2 Vibrational properties of crystalline BN structures
1.3 Electrical and electronic properties of cBN
1.4 Thermal properties of cBN
Chapter 2. High pressure high temperature synthesis of cBN
2.1 Milestones in cBN synthesis
2.2 Direct transformation at static pressure
2.3 BN conversion at static pressure with catalytic assistance
2.4 BN conversion at dynamic pressure
2.5 Summary to high pressure high temperature BN conversion
Chapter 3. Low pressure synthesis of cBN
3.1 Foundations on technology of thin film cBN films
3.2 Low pressure synthesis by PECVD
3.3 Low pressure synthesis of cBN by PVD
Chapter 4. Thermodynamics and kinetics of BN
Chapter 5. Experimental methods and characterization techniques
5.1 Deposition systems used in BN syntheses
5.2 Characterization techniques in analysis of cBN films
Chapter 6. Deposition of cBN on Si − a parametric study towards
high quality film
6.1 Methods of cBN synthesis
6.2 Effect of helium additives in plasma on cBN deposition
6.3 Effect of substrate bias and role of ion bombardment
6.4 Evolution of cubic phase of BN
6.5 H2/BF3 ratio as the deposition parameter
6.6 Synergetic effect of temperature and fluorine chemistry at cBN growth.
6.7 Uniformity of cBN films over large area
6.8 Phase structure of BN films
6.9 Summary to the parametric study of cBN growth on Si
Chapter 7. Deposition of cBN on diamond − the route to elimination of graphitic boron nitride layer
7.1 Experience in diamond and cBN coatings
7.2 Significance of substrate in deposition of cBN
7.3 Effect of diamond interfacial layer on nucleation and growth of cBN
7.4 Growth mechanism of cBN − role of diamond
7.5 Summary to cBN growth
Chapter 8. Growth mechanism of cBN films by PECVD
8.1 Briefing on diamond and cBN nucleation/growth
8.2 Examination of the substrate − aBN/tBN interface
8.3 Study of tBN and cBN interface by HRTEM
8.4 Analysis of cBN layer by HRTEM
8.5 Investigation of cBN surface by HRTEM
8.6 Growth species involved in cBN growth
8.7 Growth mechanism of cBN films by PECVD using fluorine chemistry
8.8 Summary to the growth mechanism of cBN films synthesized by PECVD using fluorine chemistry
Chapter 9. Parametric study of cBN deposited by PVD
9.1 Benchmark in cBN synthesis
9.2 Infrared spectral analysis of BN grown on scratched Si substrates
9.3 Morphological study of BN films grown on scratched Si surfaces
9.4 Microstructural investigation of BN on scratched Si surfaces
9.5 XANES analysis of BN films synthesized on scratched Si substrates
9.6 Nucleation and growth mechanism induced by surface roughness
9.7 Summary of surface roughness affecting cBN quality
Chapter 10. Mechanical characterization of cBN films
10.1 Accounting problems at mechanical applications
10.2 Nanoindentation measurement performed on cBN films
10.3 Pain-view hardness and elastic modulus of cBN films
10.4 Cross-sectional hardness and elastic modulus of cBN films
10.5 Final remarks to hardness measurement
Chapter 11. Applications of cBND composite in cutting tools
11.1 Incentives behind cBN coating of cutting tools
11.2 Deposition and performance of cBND coated cutting tools
11.3 Summary to cBND coating of cutting tools
Chapter 12. Conclusions
References
Publications
Abstract of Publications
Author: Chan, Chit-yiu
Source: City University of Hong Kong
Download URL 2: Visit Now