Atomic force microscopy observation of threading dislocation density reduction in lateral epitaxial overgrowth of galliu
- PDF / 1,018,148 Bytes
- 8 Pages / 792 x 792 pts Page_size
- 7 Downloads / 175 Views
Internet Journal of Nitride Semiconductor Research:
Email alerts: Click here Subscriptions: Click here Commercial reprints: Click here Terms of use : Click here
Atomic force microscopy observation of threading dislocation density reduction in lateral epitaxial overgrowth of gallium nitride by MOCVD H. Marchand, J.P. Ibbetson, Paul T. Fini, Peter Kozodoy, S. Keller, Steven DenBaars, J. S. Speck and U. K. Mishra MRS Internet Journal of Nitride Semiconductor Research / Volume 3 / January 1998 DOI: 10.1557/S1092578300000752, Published online: 13 June 2014
Link to this article: http://journals.cambridge.org/abstract_S1092578300000752 How to cite this article: H. Marchand, J.P. Ibbetson, Paul T. Fini, Peter Kozodoy, S. Keller, Steven DenBaars, J. S. Speck and U. K. Mishra (1998). Atomic force microscopy observation of threading dislocation density reduction in lateral epitaxial overgrowth of gallium nitride by MOCVD . MRS Internet Journal of Nitride Semiconductor Research, 3, pp e3 doi:10.1557/ S1092578300000752 Request Permissions : Click here
Downloaded from http://journals.cambridge.org/MIJ, IP address: 165.123.34.86 on 13 Oct 2015
MRS
Internet Journal Nitride Semiconductor Research
Atomic force microscopy observation of threading dislocation density reduction in lateral epitaxial overgrowth of gallium nitride by MOCVD H. Marchand1, J.P. Ibbetson1, Paul T. Fini 1, Peter Kozodoy 1, S. Keller1, Steven DenBaars 1, J. S. Speck1 and U. K. Mishra1 1Electrical
and Computer Engineering and Materials Departments, University of California, Santa Barbara,
(Received Sunday, February 8, 1998; accepted Tuesday, February 24, 1998)
Extended defect reduction at the surface of GaN grown by lateral epitaxial overgrowth (LEO) on large-area GaN/Al2O3 wafers by low pressure MOCVD is demonstrated by atomic force microscopy. The overgrown GaN has a rectangular cross section with smooth (0001) and {1120} facets. The density of mixed character threading dislocations at the surface of the LEO GaN is reduced by at least 3-4 orders of magnitude from that of bulk GaN. Dislocation-free GaN surfaces exhibit an anisotropic step structure that is attributed to the orientation dependence of the dangling bond density at the step edges.
1 Introduction The lateral epitaxial overgrowth (LEO) technique consists of partially masking a substrate or "seed" layer and subsequently regrowing over the masked substrate. The potential of LEO for extended defect reduction in the heteroepitaxial growth of III-V semiconductors has been demonstrated in materials systems such as GaAs on Si [1], [2], InGaAs on GaAs [3], and InP on Si [4]. Recently, LEO has been utilized in the deposition of GaN, both by MOCVD [5], [6], [7] and HVPE [8], [9]. Transmission electron microscopy (TEM) studies have shown that threading dislocation (TD) reduction may occur not only by mask blocking of vertically-propagating dislocations, but also by a change in propagation direction of some dislocations at the LEO growth front [6], [9]. Such dislocations continue to propagate lateral
Data Loading...