Files in this item
Files | Description | Format |
---|---|---|
application/pdf ![]() ![]() | (no description provided) |
Description
Title: | Ohmic Metallizations to Aluminum Gallium Nitride/gallium Nitride High Electron Mobility Transistors: Electrical and Microstructural Studies |
Author(s): | Wang, Liang |
Doctoral Committee Chair(s): | Adesida, Ilesanmi |
Department / Program: | Materials Science and Engineering |
Discipline: | Materials Science and Engineering |
Degree Granting Institution: | University of Illinois at Urbana-Champaign |
Degree: | Ph.D. |
Genre: | Dissertation |
Subject(s): | Engineering, Materials Science |
Abstract: | Major findings of this work include: (1) Elucidated the interfacial reactions between Al, Ti, AlTi alloy, and Ti/Al/Mo/Au on GaN. (2) Explained the electrical performance of Ti/Al/Mo/Au on AlGaN/GaN based on microstructural investigations. Proposed a "spike" mechanism. (3) Identified the role of other metals, i.e. V, Mo, and Ta, as the first layer for X/Al/Mo/Au contacts. (4) Correlated the surface roughness, lateral encroachment, and contact performance of the Ti/Al/X/Au (X=Ni, Pt, Ir, Mo, Ti and NM) contacts for AlGaN/GaN HEMTs. (5) Tailored the interfacial reaction pathways and electrical performance of Ti/Al/Mo/Au on AlGaN/GaN by incorporating Si into the metallization. Obtained low-resistance contact schemes having wide processing window. (6) Investigated the electrical performance and microstructure of the Ti/Al/Mo/Au contacts on all-binary AlN/GaN HEMTs. Optimized the Ti/Al/Mo/Au contacts on n+-GaN capped AlGaN/AlN/GaN by combined surface treatment and solid state interfacial reaction. (7) Evidenced ultra-shallow Si plasma implantation and dry etch effects of SiCl4 pre-metallization treatment. Demonstrated the best performance by side-way direct contact of the metal with the 2DEG channel. (8) Characterized the carrier transport mechanism by variable temperature measurement between 100 and 375 K. |
Issue Date: | 2008 |
Type: | Text |
Language: | English |
Description: | 291 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008. |
URI: | http://hdl.handle.net/2142/82821 |
Other Identifier(s): | (MiAaPQ)AAI3314931 |
Date Available in IDEALS: | 2015-09-25 |
Date Deposited: | 2008 |
This item appears in the following Collection(s)
-
Dissertations and Theses - Materials Science and Engineering
-
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois