Atomic Layer Deposition of Two Dimensional MoS2 on 150 mm Substrates Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/sb397c47d

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Two-dimensional transition metal dichalcogenides (TMDs) have recently come under intense investigation as building blocks for van der Waals heterostructure electronics. One of the most promising TMDs is MoS₂, which transitions from an indirect bandgap (1.3 eV) in its bulk state to a direct band gap (1.8 eV) in its single layer state making it suitable for optoelectronic and transistor applications. The synthesis of high quality single layer MoS₂ on large substrates, however, remains a challenge. Although, mechanical exfoliation is capable of producing the highest quality material, it is limited by small surface areas and is not scalable. Chemical vapor deposition (CVD) is also widely utilized but exhibits a lack of thickness control, poor process stability, and requires high deposition temperatures (typically above 650 °C). Atomic layer deposition (ALD) is natural technique for the synthesis of 2D materials. ALD is a CVD technique in which reactants are introduced to the chamber sequentially rather than simultaneously. Sequential self-limiting surface reactions allow for precise thickness control, high conformality, and scalability to large surface areas. The objective of this work is to demonstrate low temperature atomic layer deposition (ALD) of monolayer to few layer MoS₂ uniformly across 150 mm diameter SiO₂/Si and quartz substrates. Purge separated cycles of MoCl₅ and H₂S precursors were used at reactor temperatures of up to 475 °C. Raman scattering studies show clearly the in-plane (E¹₂g) and out-of-plane (A₁g) modes of MoS₂. The separation of the E¹₂g and A₁g peaks is shown to be a function of the number of ALD cycles, shifting closer together with fewer layers. X-ray photoelectron spectroscopy (XPS) indicates that stoichiometry is improved by post deposition annealing in a sulfur ambient. High resolution transmission microscopy (TEM) confirmed the atomic spacing of monolayer MoS₂ thin films signaling successful deposition of monolayer to few layer MoS₂ thin films.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Non-Academic Affiliation
Keyword
Subject
Rights Statement
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Laura Wilson(laura.wilson@oregonstate.edu) on 2016-07-20T23:09:31Z (GMT) No. of bitstreams: 2 ValdiviaArturoH2016.pdf: 1371172 bytes, checksum: efe00e4021afb3ceb0b0462c5af43f10 (MD5) license_rdf: 1223 bytes, checksum: d127a3413712d6c6e962d5d436c463fc (MD5)
  • description.provenance : Rejected by Julie Kurtz(julie.kurtz@oregonstate.edu), reason: I thought I would check your submission while I am waiting for the ETD submission approval form. It looks like all the revisions I noted on your pretext pages were not made. The revisions required are- 1) Copyright page, your name has to be the same throughout your thesis so add your middle name Herrera. 2) Title page- remove the underline under your title 3) Approval page - second signature line needs to be changed so it reads - Director of the Material Science Program 4) L on 2016-07-01T21:53:57Z (GMT)
  • description.provenance : Submitted by Arturo Valdivia (valdivia@oregonstate.edu) on 2016-07-08T17:07:52Z No. of bitstreams: 2 license_rdf: 1223 bytes, checksum: d127a3413712d6c6e962d5d436c463fc (MD5) ValdiviaArturoH2016.pdf: 1335603 bytes, checksum: 57ac031e43859bdc96aa17538db576e1 (MD5)
  • description.provenance : Made available in DSpace on 2016-07-20T23:09:31Z (GMT). No. of bitstreams: 2 ValdiviaArturoH2016.pdf: 1371172 bytes, checksum: efe00e4021afb3ceb0b0462c5af43f10 (MD5) license_rdf: 1223 bytes, checksum: d127a3413712d6c6e962d5d436c463fc (MD5) Previous issue date: 2016-03-04
  • description.provenance : Submitted by Arturo Valdivia (valdivia@oregonstate.edu) on 2016-07-13T23:53:04Z No. of bitstreams: 2 ValdiviaArturoH2016.pdf: 1371172 bytes, checksum: efe00e4021afb3ceb0b0462c5af43f10 (MD5) license_rdf: 1223 bytes, checksum: d127a3413712d6c6e962d5d436c463fc (MD5)
  • description.provenance : Submitted by Arturo Valdivia (valdivia@oregonstate.edu) on 2016-06-10T19:44:58Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: bb87e2fb4674c76d0d2e9ed07fbb9c86 (MD5) Arturo Valdivia Thesis March 4 2016.pdf: 1309865 bytes, checksum: befdffcb96805b87b3690a57dcb65f59 (MD5)
  • description.provenance : Rejected by Julie Kurtz(julie.kurtz@oregonstate.edu), reason: Rejecting because the title on the Abstract page should be underlined and it was removed and the title on the Title page, where it is at the top and centered, is not underlined. So add the underline back on the first page, Abstract, and remove the underline on the Title page. Everything else looks good. Once revised, log back into ScholarsArchive and go to the upload page. Replace the attached file with the revised PDF and resubmit. Thanks, Julie on 2016-07-11T21:46:16Z (GMT)
  • description.provenance : Approved for entry into archive by Julie Kurtz(julie.kurtz@oregonstate.edu) on 2016-07-14T14:57:21Z (GMT) No. of bitstreams: 2 ValdiviaArturoH2016.pdf: 1371172 bytes, checksum: efe00e4021afb3ceb0b0462c5af43f10 (MD5) license_rdf: 1223 bytes, checksum: d127a3413712d6c6e962d5d436c463fc (MD5)

Relationships

In Administrative Set:
Last modified: 08/22/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items