Self-Assembly and Chemical Patterning on Germanium(100)

Open Access
- Author:
- Lawrence, Jeffrey Alan
- Graduate Program:
- Engineering Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Paul S Weiss, Thesis Advisor/Co-Advisor
Paul S Weiss, Thesis Advisor/Co-Advisor
Mark William Horn, Thesis Advisor/Co-Advisor - Keywords:
- soft lithography
chemical patterning
Self-Assembly - Abstract:
- Abstract The focus on faster, smaller, and more diverse electronic devices has prompted research into new materials. The search is on for semiconductor substrates with superior electronic capabilities. Germanium has emerged as a semiconductor material capable of producing desired performance. Current methods of thin-film deposition, once intended for applications involving alternative substrates, must be altered to improve upon germanium’s inherently unstable surface. This thesis investigates the adolescent mechanism of self-assembly and chemical patterning on Ge(100). Our preliminary research offers insight into applicable techniques for depositing stabilizing and chemically functionalized, patterned adsorbate layers on germanium. It is our belief that the examination of sample preparation will lead to reproducible and cost-efficient techniques for use in industry. This dissertation will address possible candidates for successful monolayer deposition on germanium, and the appearance of and possible solutions to additional limitations. Germanium suffers from an inherently unstable surface, a result of its native oxide layer. Until this time, instability has limited germanium’s capacity for integration into electronic devices. Self-assembled monolayers (SAMs) offer a method for controlling interfacial properties, through formation of highly ordered, single-molecule thick structures on surfaces, transferring their chemical attributes to the interface. Successful deposition of SAMs on germanium can address its intrinsic limitations. Through manipulation of SAM deposition techniques, used primarily for patterning alkanethiols on gold, formation of high-quality monolayers becomes possible, improving the surface stability of germanium. High-dielectric materials, due to their ability to resist leakage resulting from electron tunneling, are necessary for producing functional components of nanoscale dimensions. These materials may be limited in their ability to interact with relevant substrates, making device fabrication difficult. Chemical patterning techniques exhibit the ability to place an array of species selectively, otherwise limited by surface diffusion, bonding capacity, etc., onto semiconductor surfaces. This dissertation describes the utilization and manipulation of soft lithography methods for successful patterning on germanium.