Anjani Challa

Publication Date


Document Type


First Advisor

Haji-Sheikh, Michael J.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Electrical Engineering


Diodes; Schottky-barrier; Porous silicon


The thesis work mainly focuses on the Design, Fabrication & characterization and testing of the device using porous silicon. The two wafers used for this work are the silicon wafer coated with silicon nitride on the both sides. To prepare a mask, a design is drawn using AutoCAD software. The photoresist is coated on the front side of the wafer using spin coating technique and the silicon nitride which is coated on the back side of the wafer is removed by Dry chemical etching process. Windows are opened on the front side of the wafer using positive photoresist technique. Silicon nitride is etched on the front side of the wafer where the windows are opened. For the first wafer, Gold/Chromium is deposited on the back side before the porous silicon formation and for the second wafer Titanium/Gold is deposited after porous silicon formation. The wafers are then diced in to small pieces to form porous silicon. Porous silicon is formed by electrochemical etching of silicon. The electrolytes used to form porous silicon are the mixtures of HF:Ethanol and HF:Acetonitrile of both 1:3 ratios. The process is carried out by varying the etching time, current density and keeping the concentration of electrolyte constant. The results are analyzed using Scanning Electron Microscope (SEM) and UV-Vis spectrometer. The metal is deposited on top and bottom of the samples using Titanium/Gold. When the device is exposed to light, the Schottky diode characteristics are observed.


Advisors: Michael J. Haji-Sheikh.||Committee members: Martin Kocanda; Suma Rajashankar; Donald S. Zinger.


xii, 66 pages




Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type