Date of Award

2021

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy in Materials Science and Engineering (PhD)

Administrative Home Department

Department of Materials Science and Engineering

Advisor 1

Joshua M. Pearce

Committee Member 1

Paul L. Bergstrom

Committee Member 2

Stephen A. Hackney

Committee Member 3

Kathryn A. Perrine

Abstract

While hardware innovations in micro/nano electronics and photonics are heavily patented, the rise of the open-source movement has significantly shifted focus to the importance of obtaining low-cost, functional and easily modifiable research equipment. This thesis provides a foundation of open source development of equipment to aid in the micro/nano electronics and photonics fields.

First, the massive acceptance of the open source Arduino microcontroller has aided in the development of control systems with a wide variety of uses. Here it is used for the development of an open-source dual axis gimbal system. This system is used to characterize optoelectronic properties of thin transparent films at varying angles.

Conventionally, the ubiquity of vacuum systems in semiconductor fabrication has precluded the development of an open-source development in the “fab” environment and thus has high foundational and operational costs. In order to make vacuum systems and their components cost-effective in a research environment there has been a paradigm shift towards refurbishing and repairing instead of replacing legacy systems. These legacy systems are built, and operate on the principle that the vacuum industry is a small industry, and hence only a small number of sizes and types of parts may be used to reduce costs. The assumption that the vacuum industry is a small industry is no longer valid. The semiconductor industry alone, which is a subset of the vacuum industry, was worth over USD 481b and increasing. Hence,there is a need to not only introduce new methods but also new materials that make up these systems. Additive manufacturing is a low-waste, low-capital cost way to make custom equipment. The most popular materials used in additive manufacturing processes are polymer blends. 3-D printing using Fused Filament Fabrication (FFF) methods has been used to create custom objects for laboratories. However, the use of polymer-based materials is conspicuously absent in the development of vacuum systems, especially those that are used for semiconductor fabrication. There are two major problems identified when polymeric materials are used to make vacuum systems: finding a way to prevent outgassing (which can subsequently lead to contamination), and sealing them so that they can hold a vacuum. This work has demonstrated how an inorganic barrier layer introduced via Atomic Layer Deposition (ALD) can alleviate outgassing to a large extent under high vacuum levels (1E-6 to 1E-7 torr).

Recognizing the importance of ALD alumina in back end of the line (BEOL) semiconductor processing, films were deposited on 3-D printed polymer-based substrates with differing constituents. These samples were tested in a bespoke gas analysis chamber for outgassing characterization. Surface and bulk characterization was completed using various tools such as scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), x-ray photoelectron spectroscopy (XPS), attenuated total reflectance - Fourier transform infrared spectroscopy (ATR-FTIR) and others. Additionally, spectroscopic ellipsometry (SE) was used to understand how the concept of thickness of a film deposited on a porous polymer-based sample does not correlate directly with its conventional definition. Also, an effort is made to understand the mechanism of ALD alumina deposition on porous plastic surfaces.It was concluded that this deposition is a complex amalgamation of physical and chemical properties of both the polymer and the precursor gases. Finally, recommendations are made for AM materials to be used in vacuum systems.

Available for download on Monday, April 18, 2022

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