DOI Number : 10.5614/itbj.sci.2008.40.1.8
Hits : 10

Photoemission Studies of Si Quantum Dots with Ge Core: Dots formation, Intermixing at Si-clad/Ge-core interface and Quantum Confinement Effect

Yudi Darma1

1Quantum Semiconductor and Devices Laboratory,

Study Program of Physics, Bandung Institute of Technology,

Ganesha 10 Bandung Indonesia 40132 yudi@fi.itb.ac.id


Abstract. Spherical Si nanocrystallites with Ge core (~20nm in average dot diameter) have been prepared by controlling selective growth conditions of low-pressure chemical vapor deposition (LPCVD) on ultrathin SiO2 using alternately pure SiH4 and 5% GeH4 diluted with He. XPS results confirm the highly selective growth of Ge on the pregrown Si dots and subsequently complete coverage by Si selective growth on Ge/Si dots. Compositional mixing and the crystallinity of Si dots with Ge core as a function of annealing temperature in the range of 550-800oC has been evaluated by XPS analysis and confirms the diffusion of Ge atoms from Ge core towards the Si clad accompanied by formation of GeOx at the Si clad surface. The first subband energy at the valence band of Si dot with Ge core has been measured as an energy shift at the top of the valence band density of state using XPS. The systematic shift of the valence band maximum towards higher binding energy with progressive deposition in the dot formation indicate the charging effect of dots and SiO2 layer by photoemission during measurements.

Keywords: charging effect; compositional mixing; Ge core; LPCVD; photoemission; Si dot; Thermal stability.

Download Article
 
Bahasa Indonesia | English
 
 
 

Notification:

Begin on 10 October 2014 this website is no longer activated for article process in Journal of Mathematical and Fundamental Sciences, Journal of Engineering and Technological Sciences, Journal of ICT Research and Applications and Journal of Visual Art and Design. The next process will be proceeded under new website at http://journals.itb.ac.id.

For detail information please contact us to: journal@lppm.itb.ac.id.

 
       
       
       ITB Journal Visitor Number #13737724       
       Jl. Tamansari 64, Bandung 40116, Indonesia Visitor IP Address #       
       Tel : +62-22-250 1759 ext. 121 2011 Institut Teknologi Bandung       
       Fax : +62-22-250 4010, +62-22-251 1215 XHTML + CSS + RSS       
       E-mail : journal@lppm.itb.ac.id or proceedings@lppm.itb.ac.id Developed by AVE