MS Thesis Defense: The Influence of Oxygen Partial Pressure on the Properties of Evaporated Alumina Thin Film

MS Thesis Defense
The Influence of Oxygen Partial Pressure on the Properties of Evaporated Alumina Thin Film

Tsion Teklemarim
Materials Science and Engineering MS Candidate
School of Chemistry and Materials Science, RIT
Faculty Mentor: Dr. Michael Pierce

Ms. Teklemarim will discuss her thesis work involving Al2O3 thin film synthesis using varying oxygen partial pressures to investigate specific optical properties of the resulting films.

Abstract:
Alumina (Al2O3) thin films are used in anti-reflection and high reflection mirror coatings from deep UV to near infrared. The films' optical, mechanical, and structural properties are dependent on the deposition technique and the desired film performance can be achieved by manipulating the deposition parameters. Such deposition parameters are substrate temperature, deposition rate, and oxygen partial pressure. For laser mirror performance applications, it is desirable to optimize the films with regards to laser damage threshold and film stress. To these ends, this thesis work studies Al2O3 thin films synthesized with electron beam evaporation technique as a function of oxygen partial pressure. As the oxygen partial pressure increases the laser damage resistance improves with absorption of the film in the UV region. At the same time, the residual stress is observed to shift towards less tensile stress, likely due to water absorption. Additionally, the study included the optical performance of Al2O3 monolayer films, showing the refractive index decreases with increasing oxygen pressure.

Speaker Bio:
Tsion Teklemarim is a graduate student in the material Science and Engineering department. She received her undergraduate degree in Civil engineering from Bahirdar University, Ethiopia. She has been working at Optimax Systems Inc. Ontario, NY, in the field of optical coating for almost five years. Her work has been an inspiration for her thesis research which achieved a significant finding in the field of thin film material property.

Intended Audience:
Undergraduates, graduates, and experts. Those with interest in the topic.