Growth of InN and Related Alloys Using Droplet Elimination by Radical Beam Irradiation
|Tomohiro Yamaguchi , Yasushi Nanishi|
Ritsumeikan University, 1-1-1, Noji-higashi, Kusatsu, Shiga 525-8577, Japan
InN is the most difficult binary material to grow among group III nitride semiconductors. It is known that the growth under a N-rich condition results in a poor-quality film with a rough surface. The growth under an In-rich condition leads to a high-quality InN film, but In droplets are formed on the surface. Once In droplets are formed on the surface during growth, the elimination of droplets is essentially impossible by thermal treatment, since InN decomposes before In droplets are evaporated.
In this talk, a new method using droplet elimination by radical beam irradiation (DERI) is proposed for a reproducible growth of high-quality InN. This growth method is composed of In-droplet formation and elimination steps. In In-droplet formation step, In droplets are formed on a surface by either InN growth under an In-rich condition or simple In irradiation. These droplets are eliminated by transforming to InN epitaxially on the underlayer in In-droplet elimination step, consisting of simple nitrogen radical beam irradiaiton. This method supplies simple and reproducible growth of high-quality InN film, since DERI process can be monitored in situ by RHEED intensity variation. This method can be useful for the growth of not only polar c-plane but also non-polar m-plane InN.
The growth of InGaN using DERI process is also demonstrated. In the case of InGaN, Ga is preferentially captured from Ga and In mixture into the growing InGaN layer and In is preferentially swept out to the surface, especially when they are grown under a metal-rich condition. The swept In was transformed to InN epitaxially on an InGaN underlayer during the DERI process.
This work was supported by the MEXT through Grant-in-Aids for Scientific Research in Priority Areas “Optoelectronics Frontier by Nitride Semiconductor” #18069012 and Scientific Research (A) #21246004. One of the authors (T. Y.) was also supported by Grant-in-Aid for Young Scientist (B) #21760237 from the MEXT.
Presentation: Invited oral at E-MRS Fall Meeting 2009, Symposium A, by Tomohiro Yamaguchi
See On-line Journal of E-MRS Fall Meeting 2009
Submitted: 2009-05-06 04:51 Revised: 2009-06-07 00:48