Hyperscript

Defects in Crystals

Topics for the Seminar

Hyperscripts of AMAT:
General Information

Index

Topics			Group	Date
	Thermodynamics of Point Defects in Ionic Crystals
		Explain the different formal concepts of looking at point defects with the "metallurgist" approach and the "chemical potential" approach
		Deal with a few examples in both approaches
		Expand the chemical potential approach to some specific examples as e.g. an oxygen sensors.
	Point Defect Complexes in Silicon Crystals
		Start from point defects in thermal equilibrium; consider their agglomeration during cooling
		Historical/Experimental: The A-,B-,C,-, D-defects, the interstitial controversy
		Present view; simulation and role of oxygen/carbon Overviews [1] and [2]
	Point Defects and Diffusion in Silicon
		The self-diffusion problem; role of interstitials; unknown parameters
		Diffusion of dopants and other substitutional impurities
		Interstitialcy mechanism and significance
		State of the art: Complete simulation of all point defect reactions.
	Dislocations and Plastic Deformation in Hexagonal Crystals
		Describe the specialities of plastic deformation in hex. crystals as a function of the crystal and defect symmetry
		Give examples, discuss the technical importance.
	Dislocations and Plastic Deformation in bcc Crystals
		Describe the specialities of plastic deformation in bcc crystals. Consider glide systems, the role of screw dislocations
		Consider low temperature deformation; twinning as a deformation mode
	Memory Shape Alloys
		History, basic structures and mechanisms
		Reversible deformation - defects and defect mechanisms involved
		Applications, state of the art, outlook
	Defects in Quasicrystals
		History, general background for periodic tilings in 2 Dimensions
		Quasicrystal as projections from 6-dim. crystals
		Point defects and diffusion
		Phasons and quasi-dislocations
		State of the art and problems
	X-Ray Methods for Investigating Defects
		General considerations
		Looking at Bragg peaks and in between Bragg peaks
		Defect imaging with x-rays (Berg-Barrett, x-ray topography); Advantages and limitations
	Oxidation Induced Stacking Faults in Si (OSF)
		General aspects; historical development
		Role of metal impurities for nucleation
		Growth kinetics, present status and state of the art in avoidance of OSFs
	Epitaxial Silicides
		Overview of epitaxial Silicides
		Special role of Ni- and Co-Silicides
		Kinetics and phase diagrams
		Interface structure
	Compliant Substrates
		Problem of misfit, basic concept of compliant substrates
		Techniques of waferbonding, special conditions for compliant substrates
		State of the art, possibilities and problems
		Models for interface reactions and dislocation reshuffling