Large area low temp. nanofabric. of ordered low dimensional matl.s & semicond. quantum strctrs.

IV-4: Large area, low temperature Nanofabrication of ordered low dimensional materials and semiconducting quantum structures

School of Physical and Mathematical Sciences, and Plasma Sources and Applications Centre, Natural Sciences and Science Education, NIE

Abstract

This talk focus on large area, low temperature nanofabrication of ordered low dimensional materials and quantum structures by means of chemically active RF plasmas. Two forms of plasma reactors are developed for producing aligned carbon nanotubes, ordered zero-dimensional semiconductor quantum dots, one-dimensional nanowires and two-dimensional superlattices. In the first type, a high density, highly uniform plasma is produced by low-frequency inductively coupled RF fields generated by distinctive antenna configurations. The second type of plasma is created by purpose-designed multiple RF and/or DC magnetron electrodes. Both types of plasma sources have successfully been employed for various applications, including growth of vertically aligned single crystal carbon nanotubes and nanocorns, fabrication of periodical SiC/AlN superlattice quantum wells, self-assembly of optoelectronically SiC and Al1-xInxN quantum dots with controllable bandgaps, as well as synthesis of III-V and IV-IV quantum wires. First Principles calculations based on the local density approximation to the density functional theory are employed to study the geometrical structures and stabilities of the nanostructure. The main properties of the rf plasma deposited nanomaterials can be efficiently controlled by the plasma parameters and discharge conditions. The techniques for tailoring the species composition using the electron energy distribution functions are also discussed. The results offer exciting opportunities for research and applications in nanoscience and nanotechnology.