Thesis

Nanoscale 3D transfer printing for hybrid photonic device fabrication

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2025
Thesis identifier
  • T17367
Person Identifier (Local)
  • 201876603
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • This thesis presents the development of gallium nitride (GaN) and other III-V nitride semiconductor material fabrication protocols to create transfer printable device coupons, such as light emitting diodes (LEDS) and distributed Bragg reflectors (DBRs), for use in the construction of vertically stacked hybrid devices. The epilayer material is refined using systematic processing and metrology of a series of epitaxially grown wafers to determine optimal ammonia dosage in growth to create flatter devices with the goal to minimise the air-gaps introduced from stacking. A thicker strain managed buffer structure succeeds in reducing the bow by a factor of three compared to devices from commercially available material. The novel structures had a radius of curvature of 2.98mm and 3.13mm compared to the commercial material’s 0.88 mm. The geometry of the tethers suspending the devices was assessed with a systematic study; two tethers with a width of 3 µm and a straight shape being determined optimal for this particular material platform by the success rate of transfer printing the resultant suspended devices. A two stage lithography process was developed to successfully fabricate DBR coupons for transfer printing and use in hybrid devices; overcoming the difficulties of device release and wet-etch damage presented by using a novel porous GaN material. Using finite difference time domain (FDTD) simulation software the optimal LED layer structure for a 450nm resonant cavity LED (RCLED) was determined for combining with the aforementioned DBRs. The design was to be used by transfer printing the LED onto a DBR or metal bottom mirror and then stacking an exit DBR mirror on top, although has yet to be realised.
Advisor / supervisor
  • Dawson, Martin
  • Strain, Michael
Resource Type
DOI

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