Boron nitride and graphene for thermal management : from fundamentals to devices
Abstract/Contents
- Abstract
- Decades of advances in semiconductor technology have led to the scaling of silicon transistors towards nanometer scale dimensions, culminating in physical limitations to transistor size, and the concurrent issue of thermal degradation and excessive energy consumption. As the semiconductor industry moves towards continuously increasing computational density, for example from planar to 3-dimensional (3D) vertical stacking, the ability to effectively regulate temperature and manage heat has become a pressing bottleneck to the realization of these dense architectures. Thermal challenges in high-density memory and computation require new thermal and material considerations at the nanoscale. Accurate knowledge of temperature and heat transport within a complex system is the essential first step to successful thermal management. To this end, experimental validation of material thermal conductivity is fundamental both to understanding thermal transport and to implementing solid state thermal management approaches. The complexity of thermal transport within a dense system also necessitates novel thermal management tactics including active methods of routing heat, such as thermal switching. This dissertation evaluates the intersection of nanoscale thermal transport and nanomaterials, assessing materials that show promise for low-temperature integration in semiconductor-based systems. The studies presented in this thesis range from fundamental thermal, electrical, and material characterization thin films to the design, demonstration, and characterization of an active thermal switch. We first present thermal characterization of nanoscale boron nitride thin films transferred and deposited at low temperature (< 500 °C) for back-end of the line (BEOL) temperature compatible processes. We report the in-plane thermal conductivity measurement of large area hexagonal boron nitride thin films grown using chemical vapor deposition (CVD) and transferred at room temperature to be 55-78 W/m/K from 300-400 K. We also evaluate the complementary thermal and electrical properties of low thermal conductivity boron nitride films deposited at room temperature using electron enhanced atomic layer deposition (EE-ALD). These electrically insulating films have very low cross-plane thermal conductivities (< 0.6 W/m/K) with 10 nm thick films approaching the amorphous thermal limit of BN (~0.13 W/m/k). Finally, we present the fabrication and thermal characterization of graphene-based thermal switches for active thermal management, reporting the first thermal switch based on flexible, collapsible graphene membranes with low operating voltage (~2V).
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2023; ©2023 |
| Publication date | 2023; 2023 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Chen, Michelle Ellen |
|---|---|
| Degree supervisor | Pop, Eric |
| Degree supervisor | Salleo, Alberto |
| Thesis advisor | Pop, Eric |
| Thesis advisor | Salleo, Alberto |
| Thesis advisor | Howe, Roger Thomas |
| Degree committee member | Howe, Roger Thomas |
| Associated with | Stanford University, School of Engineering |
| Associated with | Stanford University, Department of Materials Science and Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Michelle Ellen Chen. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2023. |
| Location | https://purl.stanford.edu/xf541bh8413 |
Access conditions
- Copyright
- © 2023 by Michelle Ellen Chen
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