Journal of Crystal Growth 251 (2003) 596–601 High quality ZnTe heteroepitaxy layers using low-temperature buffer layers Jiho Chang a, *, Kenji Godo a , Junsuk Song a , Dongcheol Oh a , Changwoo Lee b , Takafumi Yao a a IMR, Tohoku University, Katahira 2-1-1, Aoba-ku, Miyagi, Sendai 980-8577, Japan b VBL, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan Received 24 December 2002; accepted 12 February 2003 Abstract Low dislocation density ZnTe heteroepitaxial layers are achieved by inserting a thin ZnTe buffer layer at low growth temperature (LT-buffer) followed by annealing. The ZnTe heteroepitaxy layer with a LT-buffer shows a narrow line width of X-ray rocking curve as narrow as 42 arcsec in (0 0 4) reflection and the dislocation density is estimated as 1:3  10 6 cm 2 : A cross-sectional view of transmission electron microscopy shows high structural quality of ZnTe layer with LT-buffers. r 2003 Elsevier Science B.V. All rights reserved. PACS: 85.60.Jb; 81.05.Zx; 81.15. Hi Keywords: A1. Defect density; A3. Heteroepitaxy; A3. Molecular beam epitaxy; A3. ZnTe thin films 1. Introduction Heteroepitaxy provides a wide range of freedom for the epitaxial growth of mismatched systems. However, to grow high quality heteroepitaxial films, one should understand how to accommo- date the mismatches between substrates and epitaxial layers. Buffer layers are widely used technique not for heteroepitaxy but for homo- epitaxy to accommodate mismatches and to grow high quality films, respectively. It is understood that the buffer layer performs four important roles such as, (1) heterointerface formation: it is especially important for the epitaxy of hetero- valent layers, (2) accommodation of lattice mis- match: actually it is the main role of a buffer for most of heteroepitaxy, (3) dislocation reduction: it is obtained through various ways such as interac- tion, bending, and looping of dislocations during the buffer growth, (4) provides optimum surface for epitaxial layers: smooth surface enhances 2- dimensional growth which is indispensable for high quality epitaxial layers. There have been many reports on the effects of buffer layers. It is well known that high quality heteroepitaxial layers are achieved by the *Corresponding author. Tel.: +81-222-152-074; fax: +81- 222-152-073. E-mail address: jamaica@imr.edu (J. Chang). 0022-0248/03/$ - see front matter r 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0022-0248(03)00974-6