AVS 51st International Symposium
    Electronic Materials and Processing Monday Sessions
       Session EM-MoP

Paper EM-MoP12
Optical properties of Zn@sub1-x@Mn@subx@S epilayers by Spectroscopic Ellipsometry

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: D.-J. Kim, Mokwon University, Korea
Authors: D.-J. Kim, Mokwon University, Korea
S.-H. Eom, Mokwon University, Korea
Y.-M. Yu, Mokwon University, Korea
Y.D. Choi, Mokwon University, Korea
M.-Y. Yoon, Joongbu University, Korea
I.-H. Choi, Chung-Ang University, Korea
Correspondent: Click to Email
II-VI compounds with transition metal Mn are generally referred to as diluted magnetic semiconductors (DMS), and they can be crystallized in the NaCl, zincblende and wurzite structure defined by the binary host crystal structure. ZnMnS is one of the widely studied systems among the DMS groups and is led to a wide range of technological applications as functional layers in electronic and optoelectronic devices, solar cells and sensors. Therefore, these materials have attracted much interest because of their various structural and optical properties. ZnMnS epilayers were grown on GaAs (100) by hot-wall epitaxy. The grown films had zincblende structure, which was confirmed from x-ray diffraction spectra. The Mn composition ratios of the epilayers were determined using the electron probe x-ray micro analyzer. The surface morphologies with Mn compositions were observed by atomic force microscopy. And a spectroscopic ellipsometry was used to know the optical properties by dielectric constants. The measured dielectric function spectra reveal distinct structures at energies of E@sub0@, E@sub0@+@delta@@sub0@, E@sub1@, E@sub1@+@delta@@sub1@, and E@sub2@ critical points (CPs). The complex refractive index n*=n+ik, the absorption coefficient @alpha@, and the normal incidence reflectivity R were deduced from dielectric constants @epsilon@@sub1@ and @epsilon@@sub2@. Also, a shifting and a broadening of the CPs can be observed. A new CP appears in the vicinity of 7.0 eV with the increasing Mn composition.