Solid State Science and Technology, Vol. 14, No 1 (2006) 160-165

ISSN 0128-7389




A. M. Ahmmed1, A. M. Alwan1, N. M. Ahmed2

1School of Applied Science/ University of Technology, Baghdad-IRAQ

2School of physics/ Universiti Sains Malaysia/ 11800/ Pinang



In this work, electrical properties of porous silicon (PS) structure fabricated by using the photochemical etching process in HF acid under different etching times was investigated. (111) n-type silicon wafers with two different resistivities (ρ1 = 3.25 x 10-4 Ωcm and ρ2 = 4.3-5.6 Ωcm) were used. The wafers were etched in 40% HF acid by using 100 W quartz tungsten halogen lamp integral with ditchroic ellipsoidal mirror for two different etching times (t1 = 1800 s and t2 = 5400 s). The current-voltage characteristics for all Al/PS/n-Si/Al structures show a rectifying behavior with different values of ideality factor and barrier height. The forward and reverse current show Schottky-like behavior and the presence of an inflection point in reverse a characteristic is explained by energy band gap difference between porous silicon and crystalline silicon substrates.




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