AVS 49th International Symposium
    Dielectrics Wednesday Sessions
       Session DI+EL-WeP

Paper DI+EL-WeP2
Remote Plasma-assisted Cleaning, Oxidation and Oxidation/Nitridation of GaN for Low Defect Density GaN-SiO@sub 2@ Interfaces

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Poster Session
Presenter: C. Bae, North Carolina State University
Authors: C. Bae, North Carolina State University
G.B. Rayner, North Carolina State University
G. Lucovsky, North Carolina State University
Correspondent: Click to Email
In previous studies, device quality Si-SiO@sub 2@ interfaces and dielectric bulk films (SiO@sub 2@) were prepared using a two-step process; i) remote plasma-assisted oxidation (RPAO) to form a superficially interfacial oxide (~0.6 nm) and ii) remote plasma enhanced chemical vapor deposition (RPECVD) to deposit the oxide film. The same approach has been applied to GaN-SiO@sub 2@ system. After a 300 °C remote N@sub 2@/He plasma treatment of the GaN surface, residual C and Cl were reduced below Auger electron spectroscopy (AES) detection, and the AES peak ratio of O KLL and N KLL was ~0.06 or ~0.1 monolayer of oxygen. RPAO of GaN surfaces using O@sub 2@, N@sub 2@O, and N@sub 2@O in N@sub 2@ source gases was investigated by AES and x-ray photoelectron spectroscopy (XPS) to determine the oxidation kinetics, chemical composition of the interfacial oxide and oxidation state of interfacial Ga. Without an RPAO step, subcutaneous oxidation of GaN takes place RPECVD deposition of SiO@sub 2@, and on-line AES indicate a ~0.6-0.8 nm subcutaneous oxide. Compared to single step SiO@sub 2@ deposition, significantly reduced defect state densities are obtained at the GaN-SiO@sub 2@ interface by independent control of GaN-GaO@sub x@ interface formation by RPAO and SiO@sub 2@ deposition by RPECVD.