An Investigation of the Stresses Causing the Spontaneous Delamination of Titanium-Platinum Bilayers Leading to The Formation of Nanogaps

  • Afnan AlBatati

Student thesis: Master's Thesis

Abstract

Adhesion lithography has been used to pattern nanogaps between two electrodes of the same or different metals onto a substrate. Patterning Al and Ti/Pt bilayer electrodes have been shown to form nanogaps leaving behind relatively consistent nanogaps of less than 12 nm between the electrodes. These nanogaps are formed without the need for adhesion lithography due to the bilayer spontaneously delaminating from the aluminum electrodes, In this study, the stresses in the Ti/Pt bilayer are investigated to determine the amount of stress required for delamination and the properties causing it. The goal is to recreate this stress mechanism in other patterned metals such as Au and Al. Heat cycling is used to induce high stress in other metal electrode combinations in an attempt to induce spontaneous delamination in Al and Au but fails up to 310°C annealing temperature. Theoretical methods are used to determine the stress: searching for an appropriate mathematical model and using finite element analysis in ABAQUS software to create a simulation of the delaminating Ti/Pt bilayer. The stress is found to be caused by the residual stresses in platinum and the high energy e-beam deposition method. An experimental value for the stress and the ability to recreate it in other metals remains elusive.
Date of AwardJul 23 2020
Original languageEnglish (US)
Awarding Institution
  • Physical Science and Engineering
SupervisorThomas Anthopoulos (Supervisor)

Keywords

  • Nanogaps
  • Microelectronics
  • Stress
  • Platinum
  • Titanium
  • Adhesion Lithography

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