Low-pressure Chemical Vapour Deposition of Silicon Nanoparticles:Synthesis and Characterisation

A. Kumar; Pankaj B. Agarwal; Sachin Kumar; B. C. Joshi; H. Chander

doi:10.14429/dsj.58.1676

A. Kumar Central Electronics Engineering Research Institute, Pilani
Pankaj B. Agarwal Central Electronics Engineering Research Institute, Pilani
Sachin Kumar The Technological Institute of Textile and Sciences, Bhiwani
B. C. Joshi Central Electronics Engineering Research Institute, Pilani
H. Chander National Physical Laboratory, New Delhi

DOI: https://doi.org/10.14429/dsj.58.1676

Keywords: Silicon nanoparticles, coulomb blockade, quantum confinement, tip artifacts, convolution, deconvolution, surface reconstruction, single electron transistor, single electron memories

Abstract

emiconductor nanostructures such as quantum wells, quantum wires or quantum dots exhibit superior properties in comparison to their bulk forms. Quantum dots are described aszero-dimensional electron gas system, as carriers are confined in all the three directions. Densityof states is discrete function of energy. Allowed energy spectrum is discrete like in an atom.Energy band gap is broadened due to carriers confinement. Semiconductor quantum dots exhibittypical coulomb blockade characteristic which is exploited for development of new generationof nanoelectronic devices namely single-electron transistor, memories, etc, whose operationdepends on quantum mechanical tunneling of carriers through energy barriers. Thesesemiconductor nanostructures emit light in visible range upon excitation by optical means. Inrecent years, research has been focused on different nano-scale materials; metals (Au, Ag, Fe,Mn, Ni), metal oxides (SnO2, ZnO2), compound semiconductors (GaAs, GaAlAs, CdSe, CdS,GaN), and elemental semiconductors (silicon and germanium). As silicon is the most favouredmaterial in the established integrated circuits manufacturing technology, research is being donefor controlled synthesis and characterisation of Si nanoparticles. The Si nanoparticles havebeen synthesised on oxide and nitride layers over Si substrate by IC technology compatiblelow-pressure chemical vapour deposition technique. Atomic force microscopy (AFM)characterisation has been extensively carried out on the samples. It is shown that the tip radiusand shape of tip lead to less accurate estimate of the actual size. The AFM images have been evaluated based on the real surface topography and shape of the tip. Photolumine scence (PL) studies have been performed to characterise the samples. The PL measurements showed visiblelight emission from synthesised silicon nanoparticles.

Defence Science Journal, 2008, 58(4), pp.550-558, DOI:http://dx.doi.org/10.14429/dsj.58.1676