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Identifier

000446157

Title

Study of dielectric deposition in two-dimensional semiconductors by the method of atomic layer deposition

Alternative Title

Μελέτη εναπόθεσης διηλεκτρικού σε δισδιάστατους ημιαγωγούς με τη μέθοδο εναπόθεσης ατομικών στρωμάτων

Author

Φανουράκης, Γεώργιος

Thesis advisor

Σαββίδης, Παύλος
Δεληγεώργης, Γεώργιος

Reviewer

Κιοσέογλου, Γεώργιος

Abstract

Semiconductors have been crucial in the advancement of technology. As technology advances, devices continue to shrink in size, and have now shrunk to the nanometer scale. This resulted in the quantum confinement of semiconductors and a corresponding degradation of device properties. Fortunately, this rapid scaling down of three-dimensional semiconductors occurred within the same decade as the isolation of graphene, the first two-dimensional material. Due to the fact that two-dimensional materials are by nature two-dimensional make them good candidates to replace conventional three-dimensional semiconductors. The interface between those novel materials and high-k dielectrics is critical for nanoelectronics and optoelectronics. Atomic Layer Deposition (ALD) can deposit thin films that are uniform and pinhole-free at the atomic level. This indicates that ALD can be employed for this purpose; however, the primary disadvantage is that ALD relies on self-limiting surface reactions to achieve dielectric deposition, whereas the surface of an ideal 2D material is completely self-passivated. This work seeks to study dielectric performance and deposition conditions on 2D-materials. To do so, we first investigate the deposition of Hafnium Oxide on Platinum using Atomic Layer Deposition. We tested the dielectric growth at 250 °C, at 200 °C, and at 150 °C. We also investigated the ALD growth at 250 °C using HfO2 and Yttria (Y2O3) as buffer layers. Based on our findings, we then investigated ALD growth of Hafnium Oxide on Molybdenum Disulphide monolayers using the optimal conditions. The results contribute to better understanding of high-k material development on inert surfaces of sensitive 2D materials.

Language

English

Subject

2D materials

High-K dielectrics

Issue date

2022-03-18

Collection

School/Department--School of Sciences and Engineering--Department of Materials Science and Technology--Post-graduate theses

Type of Work--Post-graduate theses

Permanent Link

https://elocus.lib.uoc.gr//dlib/e/9/e/metadata-dlib-1645692725-385229-17866.tkl