Characteristics of silicon nanostructures produced by high power lasers

Dissertant

Mekeef, Qasim Ahmad

Thesis advisor

Rashid, Bassam Ghalib

University

University of Technology

Faculty

-

Department

Applied Sciences Department

University Country

Iraq

Degree

Master

Degree Date

2010

English Abstract

Silicon nanostructures with various morphologies have been produced by relatively high power laser.

The localized heating established by the laser beam initiates a chemical reaction between the silicon wafer and the fluorine ions, which subsequently form a nanostructured layer of large surface area.

This technique demonstrates porous samples of higher hardness than the porous structure synthesized by a common iodization technique.

We found that large surface area could be obtained when proper numbers of laser pulses were used.

Moreover, the laser parameters play a significant role in there process, increasing the laser power leads to increase the particle size and decrease the surface area.

Furthermore, high laser power could be employed to drill a brittle wafer such as silicon.

The surface morphology investigation reveals that the porous layer characteristics are determined by the amount of the temperature raised due to the laser influence.

A variety of laser wavelengths (512, 532, 1064 nm) have been used to produce porous silicon structure, by high power laser etching of in n-type and p-type silicon which immersed in HF (48 %wt) and ethanol solutions Scanning Electron Microscope, Atomic Force Microscope and Optical Microscope were used to monitor the changes in the structure of porous silicon which involves surface morphology and surface area for the prepared samples.

It has been found that a large surface can be obtained with longer wavelength.

The etching rate studies were found to be increased with increasing the laser wavelength.

Main Subjects

Physics

Topics

• Nanotechnology
• Silicon

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305231