1. English ability would save life English ability gives you opportunities http://www.youtube.com/watch?v=tcseWVNmda8 e.g. Job opening in TSMC http://www.tsmc.com/chinese/careers/jobs.html Why English is Important http://www.youtube.com/watch?v=GT86iWiH2mI

2. Read largely - preview textbook before class - review textbook and note after class Increase your vocabulary Invest your time to learn English regularly - Reading CNN, yahoo, newspaper - Listening radio youtube watching TV What should you do to learn English in this class?

3. Ch.1 Introduction Optoelectronic devices: - devices deal with interaction of electronic and optical processes Solid-state physics: - study of solids, through methods such as quantum mechanics, crystallography, electromagnetism and metallurgy Elemental semiconductors: - Si, Ge,..etc. - indirect bandgap, low electric-optics conversion efficiency Compound semiconductors - III-V (e.g. GaN, GaAs), II-VI - direct bandgap, high electric-optics conversion efficiency GaAs, InP - higher mobility than Si, Ge, - energy band gap, Eg: 1.43 (GaAs), 1.35 (InP) - most common substrate, used to grow up compound semiconductors

4. Periodic Table

5. Band structure Band structure: - results of crystal potential that originates from equilibrium arrangement of atoms in lattice - directed from potential model and electron wave equation (Schrodinger equation) time-dependent Schrodinger equation E: electron energy, φ:wave equation, m: electron mass, ħ: Plank constant

6. Electron energy band diagram v.s. wave number

7. Energy bandgap v.s. lattice constant

8. Wavelength (Bandgap) Engineering Reference article: http://www.tf.uni-kiel.de/matwis/amat/semi_en/kap_5/backbone/r5_1_4.html

9. Energy bandgap v.s. lattice constant Constrains for forming compound semiconductors: (1) requirement of lattice match, (2) availability of suitable substrates GaAs and InP are most common substrates used to grow up compound semiconductors (Note: InAs, InSb and GaSb substrates are availabe, but not as readily as GaAs and InP, moreover, all the ternary and quaternary alloys of interest are mis-matched to these substrates) only In x Ga 1-x As and In x Al 1-x As lattice-matched on InP substrate all Al x Ga 1-x As can lattice-match on GaAs substrate

11. Bonding in solids Van der Waals bonding: attractions between atoms, molecules, and surfaces. e.g.: inert gas (like Ar), the ability of gecko to hang on a glass surface Ionic bonding: electron exchange between atoms produces positive and negative ions which attract each other by Coulomb-type interactions e.g. NaCl, KCl covalent bonding sharing of electrons between neighboring atoms e.g.: elemental and compound semiconductors Metallic bonding: valence electrons are shared by many atoms (bonding not directional, electron free or nearly free contributed to conductivity) e.g.: Zn

12. Body-Centered Cubic (BCC) structure http://stokes.byu.edu/bcc.htm e.g. iron, chromium, tungsten, niobium

13. Face-Centered Cubic (FCC) structure http://stokes.byu.edu/fcc.htm e.g.: aluminum, copper, gold, silver

14. Diamond Cubic (FCC) structure http://zh.wikipedia.org/zh-tw/File:Diamond_Cubic-F_lattice_animation.gif

15. Diamond structure v.s. Zincblende structure Diamond structure, Zincblende structure e.g.: GaAs, and some many binary compound semiconductors e.g.: Si, Ge

16. Atomic arrangement in different solids

17. Dislocation & strain Dislocation occurs if - epitaxial layer thickness > h c (critical thickness), or - epitaxial layer thickness < h c, but with large mismatch Strain occurs if - epitaxial layer thickness < h c, and with small mismatch

18. Strain semiconductor a) lattice match b) compressive strain c) tensile strain Strain offers flexibility for restriction of lattice mismatch Pseudomorphic: thin film take on morphology (lattice constant) of the substrate

19. Crystal Growth Bulk growth: - furnace growth - pulling technique e.g. Czochralski Epitaxial growth: - Liquid Phase Epitaxy (LPE) - Vapor Phase Epitaxy (VPE), or termed Chemical Vapor Deposition (CVD) - Molecular Beam Epitaxy (MBE)

20. Epitaxy epi means “above” taxis means “in order manner” epitaxy can be translated to “to arrange upon” with controlled thickness and doping subtract acts as a seed crystal, deposited film takes on a lattice structure and orientation identical to the subtract different from thin film deposition that deposit polycrystalline or amorphous film - homoepitaxy: epi and subtract are with the same material epi layer more pure than subtract and have different doping level - hetroepitaxy: epi and subtract are with different material Examples includes - Si-based process for BJT and CMOS, or - compound semiconductors, such as GaAs

21. Epitaxy Material Growth Methods Liquid Phase Epitaxy Vapor Phase Epitaxy (VPE), or termed Chemical Vapor Deposition (CVD) - formation of condensed phase from gas of different chemical composition - distinct from physical vapor deposition (PVD) such as sputtering, e-beam deposition, MBE (condensation occurs without chemical change) - gas stream through a reactor and interact on a heated subtract to grow epi layer Molecular Beam Epitaxy

22. Doping of Compound Semiconductors Intrinsic materials: undoped - Undoped materials by epitaxy technology have more carriers than in intrinsic material. e.g. GaAs: 10 13 /cm 3 (instrinsic carrier concentration: 1.8x10 6 /cm 3 ) - impurity comes from source materials, carrier gases, process equipment, or subtract handle Extrinsic materials: - n-type: III sub-lattice of III-V compound is substituted by IV elements: impurity terms “donor” - p-type: V sub-lattice of III-V compound is substituted by IV elements: impurity terms “acceptor” http://www.siliconfareast.com/sigegaas.htm

23. Optical fiber -Silica optical fibers have a lowest loss at 1.55 um, and a lowest dispersion at 1.3 um -In 0.53 Ga 0.47 As (E g =0.47ev)/In 0.52 Al 0.48 As (E g =1.45ev) heterojunction on InP can be used for optical fiber because Eg of InGaAs is close to 1.55 and 1.3 um -Note: Why GaAs/AlGaAs can’t be used here?

24. Energy band theory