Resonant tunnelling diode epitaxial wafer design manufacture and characterisation

Cito, Michele (2022) Resonant tunnelling diode epitaxial wafer design manufacture and characterisation. PhD thesis, University of Glasgow.

Abstract

Resonant tunnelling diodes realised using the AlAs/InGaAs lattice match to InP substrates have demonstrated promising performance as THz sources. The main limitations to deployment are imposed by the device output power, which is critically dependent on the structural quality of the epitaxial material. Future design and growth optimization require tools to characterize the thin RTD active region on different length scales and to create a link between design variables and device performance. This thesis reports a combined non-destructive characterisation scheme based on photoluminescence spectroscopy (PL), X-ray diffraction (XRD), and photoluminescence excitation (PLE) spectroscopy. The scheme improves the accuracy and reproducibility of all the RTD design parameters to provide accurate feedback for future epitaxy optimization both in R&D and in future manufacturing. A new PL technique is also proposed to investigate RTD structural imperfection on a length scale comparable with the RTD device mesa area, allowing an investigation into important growth imperfections affecting the device performance and reproducibility. Alternative RTD designs made by substituting the ternary InGaAs well with an InAs/GaAs superlattice are proposed and demonstrated in the last part of the thesis. Design criteria and simulations are reported and improvements in the structure epitaxial quality are highlighted by PL.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: T Technology > T Technology (General)
• Colleges/Schools: College of Science and Engineering > School of Engineering
• Supervisor's Name: Hogg, Prof. Richard A.
• Date of Award: 2022
• Depositing User: Theses Team
• Unique ID: glathesis:2022-83238
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 16 Jan 2023 09:06
• Last Modified: 16 Jan 2023 09:09
• Thesis DOI: 10.5525/gla.thesis.83238
• URI: https://theses.gla.ac.uk/id/eprint/83238

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