Thermal decomposition of indium phosphide: Monitoring of metallic cluster growth
Contributors: M. Himmerlich, M. Eremtchenko, S. Krischok, Th. Stolz, M.C. Zeman, M. Gubisch , Robert J. Nemanich, and J.A. Schaefer
ABSTRACT
Indium phosphide has attracted high technological and scientific interest as a semiconductor material because of its applications in many electronic and photonic devices (1,2). The well known instability of this material under annealing and/or hydrogenation reveals itself in the formation of metallic indium clusters on the surface as a consequence of phosphorus evaporation by thermal decomposition of the semiconductor material (3 [4][5][6]–7).As a widespread structural defect, metallic droplets strongly affect the properties of semiconductor surfaces and need to be considered for the design of electronic devices as well as for the growth of layered semiconducting structures. At the same time, these clusters can serve as purposeful modification of the surface properties, which strongly modifies the contact properties of electronic circuits and is an important issue for the development of technological applications in nanoelectronics, There the coupled plasmon-phonon modes in InP are of high relevance for the transport properties and the relaxation dynamics in the material (8).
A combined microscopic and spectroscopic characterisation of the surface before and after ion bombardment and subsequent annealing cycles was performed, enabling us to correlate changes in the microscopic surface structure with changes in the electronic properties.
The microscopic data presented here has allowed us to study the dynamics of indium cluster formation on the InP surface. Reported results in the literature are mainly data from electron microscopy (3 [4]–5). In this work we combine the data obtained from electron microscopy, scanning probe microscopy, and photoelectron emission microscopy. In addition to microscopic investigations a spectroscopic examination by photoelectron spectroscopy and high resolution electron energy loss spectroscopy was performed. This combination of various techniques allows us to correlate changes in the microscopic surface structure with changes in the electronic and vibronic structure.