Dr. D.A. Thompson

Dr D. Thompson

Dr. D.A. Thompson     

Professor Emeritus
Department of Engineering Physics

McMaster University
1280 Main Street West, Hamilton
Ontario, Canada  L8S 4L7

office: JHE/A317
email: dathomp@mcmaster.ca
voice: (905) 525-9140 x 24932
fax: (905) 527-8409

B.Sc., Ph.D. (Reading)

http://epic.mcmaster.ca/foswiki/bin/view/Main/DavidThompson

Research Interests :


Molecular Beam Epitaxy (MBE)
A MBE system is available that allows growth of a wide range of III-V semiconductors involving Al, Ga, In, P, As and Sb. With these semiconductor materials a wide range of studies are undertaken involving hetero-structure quantum well (QW), quantum wire (QWR) and quantum dot (QD) growths, research into device processing involving these material structures and in the fabrication and characterization of various semiconductor photonic devices. The flexibility of the MBE system allows us to undertake research into devices operating over a large range of wavelengths from the visible to mid-infrared.

Current projects:

My research is currently focused on the growth, fabrication and characterization of semiconductor heterojunction light sources operating in the 1.5 – 3µm wavelength range for applications in telecommunications, remote trace gas detection, and industrial and medical instrumentation. In particular, it is my goal to develop such devices using the well established InGaAsP materials system in which the wavelength is normally limited to ~1.6 µm when grown on InP or GaAs substrates. To attain these goals it is necessary to grow the device active layer on a substrate with a controllable lattice constant in order to achieve the targeted emission wavelength. This involves growing strain relaxed ternary or quaternary III-V semiconductor layers, specifically InxGa1-xAs with a variable In content on GaAs or InP substrates (an alternative being InAsyP1-y with variable As content on InP substrates), having the desired lattice constant on top of a standard GaAs or InP substrate. Such layers are called metamorphic pseudo-substrates (MSL). My ongoing research involves studies of the growth, by MBE, of quantum structures; QWs, QWRs, and QDs on MSLs with the objective of fabricating light emitting devices; lasers or broad spectral output superluminescent diodes (SLD), with wavelengths exceeding 1.5µm.

Growth of quantum structures on MSLs.

Quantum well device structures are grown using either InAsyP1-y on InP substrates or InGa(Al)As on GaAs or InP. The choice is dictated by the device wavelength requirements and the ultimate design of the device active layer taking into consideration the QW/barrier band offsets and refractive index desired for the light waveguiding. Applications under consideration include tunable lasers for application in trace gas detection.
Quantum wires and quantum dot structures typically involve the growth of thin, highly strained InAs layers (2 – 7 monolayers thick) which nucleate into quantum dots on GaAs substrates, where the strain is 7.2%, or quantum wires on InP, where the strain is 3.2%, via the Stranski-Krastanov growth mechanism. For InAs QD structures on GaAs the emission is usually limited to ~1.2µm which as we showed recently is the result of Ga out-diffusion from the substrate and layers covering the QDs. However, we have recently to achieve 1.7µm emission from the deposition of single and multiple layer InAs quantum structures on InxGayAl1-x-yAs MSLs grown on GaAs substrates.
 

Device design, fabrication and characterization.

Complete facilities are available through the Centre for Emerging Device Technologies for the fabrication and testing of a wide range of photonic devices. Past students have produced and analyzed semiconductor optical amplifiers, Fabry-Perot lasers, distributed feedback lasers, electroabsorption modulators, and broadband light sources; also, more ambitious integrated systems have been achieved. Currently we are interested in sources that have medical and gas detection applications, and others as may be identified.
Recent publications:
Students and research associates under my supervision are shown in bold type.

 

  1. K. Cui. M. D. Robertson, B. J. Robinson, C. M. Andrei, D. A. Thompson, and G. A. Botton (2010). “InAs quantum wire induced compositional modulation in an In0.53Ga0.47As barrier layer grown on an InP substrate”, (2010) J. Appl. Phys. 108, 034321 1-8
  2. K.Cui, B. J. Robinson, D. A. Thompson, and G. A. Botton  “Stacking pattern of multi-layer InAs quantum wires embedded in In0.53Ga0.47-xAlx As matrix layers grown on lattice-matched InP substrate”, (2010)  J. Crystal Growth.312, 2637 - 2646
  3. J A Czaban and D A Thompson, (2010). “Semiconductor optical amplifiers grown on a metamorphic substrate for long wavelength applications” Nanotechnology 21, 134005, 1-4.
  4. M. A. Naser, M.J. Deen and D.A. Thompson, (2010). “Photocurrent modeling and detectivity optimization in a resonant tunneling quantum dot infrared photodetector”, IEEE J. Quantum Electron.  46, 849 – 859
  5. J. Caram, C. Sandoval, M. Tirado, D. Comedi, J. Czaban, D. A. Thompson and R. R. LaPierre, (2010). “Electrical characteristics of core-shell p-n GaAs nanowire structures with Te as the n-dopant”, Nanotechnology 21, 134007, 1-7.
  6. Shahram Ghanad-Tavakoli, Mohamed A. Naser, David A Thompson and M. Jamal Deen, (2009). “Experimental characterization and theoretical modeling of the strain effect on the evolution and interband transitions on InAs quantum dots grown on InxGa1-xAs (0.0≤x≤0.3) metamorphic pseudosubstrates on GaAs wafers”, J. Appl. Phys. 106, 063533 1-8.
  7. O. Hulko, D. A. Thompson, B. J. Robinson and J. G. Simmons, (2009). “Quantum well intermixing of a quantum well structure grown on an InAsP metamorphic pseudosubstrate on InP”, J. Appl. Phys. 105, 073507 1-6.
  8. K. Cui, M. D. Robertson, B. J. Robinson, C. M. Andrei, D. A. Thompson and G. A. Botton, (2009). “Quantitative compositional analysis and strain study of InAs quantum wires with InGaAlAs barrier layers”, J. Appl. Phys. 105, 094313 1-8.
  9. O. Hulko, D. A. Thompson and J. G. Simmons, (2009). “Quantitative compositional  profiles of enhanced intermixing in GaAs/AlGaAs quantum well heterostructures annealed with and without a SiO2 cap layer”, Semicond. Sci. Technol. 24, 045015, 1 – 6.
  10. F. M. Mohammedy, M. J. Deen and D. A. Thompson, (2009). “Extraction of electron and hole ionization coefficients from metamorphically grown InGaSb diodes”, IEEE Trans. Electron. Devices 56, 523 – 528 .
  11. Josef A Czaban, David A Thompson and Ray PaPierre, (2009). “GaAs core-shell nanowires for photovoltaic applications”, Nano Letters 9, 148-154.
  12. J. A. Czaban and D. A. Thompson, (2008). “The response of semiconductor optical amplifiers containing lateral composition modulation in the quantum wells”, J. Appl. Phys. 104, 093114 1-6.
  13. M. A. Naser, M. J. Deen and D. A. Thompson, (2008). “Theoretical modelling of dark current in quantum dot infrared photodetectors using non-equilibrium Green’s function”, J. Appl. Phys. 104, 104511 1-11.
  14. J. A. Czaban and D. A. Thompson, (2008). “The consequence of lateral composition modulation on the anisotropic emission for transitions to the heavy hole sub-bands in InGaAs QWs “ , J. Appl. Phys. 104, 023107 1-7.
  15. Shahram Ghanad Tavakoli, Oksana Hulko, David A. Thompson, (2008). “Tilt generation in step-graded InxGa1-xAs metamorphic pseudosubstrate on a singular GaAs substrate using a low-temperature grown InGaP inter-layer”, Journal of Applied Physics, 103, 103527 1-8.
  16. O. Hulko, D. A. Thompson and J. G. Simmons, (2008). “Comparison of quantum well interdiffusion on group III, group V and combined groups III and V sub-lattices in GaAs-based structures”, IEEE Journal of Selected Topics in Quantum Electronics 14, 1104-1112.