Preparation of Schottky devices  (Al-GaAs &Ni-GaAs) and study of some photoelectronic properties

Yahya Kadem, Burak

	Preparation of Schottky devices (Al-GaAs &Ni-GaAs) and study of some photoelectronic properties
Journal of University of Babylon
Article 1, Volume 22, Issue 2, 2014, Pages 873-884
Author
Burak Yahya Kadem
Abstract
Four samples of metal (n-type) semiconductor contact had been prepared as a form of Schottky contact, Aluminum and Nickel metals and semiconductor substrate GaAs (donor) where used. The Ohmic contact has been firstly made with thickness (500 nm) using Aluminum for two samples and Nickel for other two, four samples were collected. These samples were annealed under the temperature of (450 K) and pressure (10-4Torr) for (30 min.) to avoid the interfacial layers. Then Schottky contact where made using Aluminum twice and Nickel twice with (120 nm) thickness and then we annealed the samples under temperature (450 K) and pressure (10-4Torr) , the samples are as follows:(Al/GaAs/Al Ohmic, Al/GaAs/Ni Ohmic, Ni/GaAs/Al Ohmic , Ni/GaAs/Ni Ohmic). The photocurrent as a function of wavelength was calculated and it was found that the maximum value for the sample (Al/GaAs/Al Ohmic) in the wavelength (800 nm), the dark current is (1.9 x 10-9Ampere). The detector coefficients of the samples where calculated, the maximum Response at the wavelength (800 nm) was (0.157 Ampere/ Watt) and maximum Specific Directivity at the same wavelength is ( 63.7 x1011 Hz ½ Watt-1), the maximum Noise Equivalent Power is (0.157 Watt Hz -½ ) and the maximum Efficiency is (24.4 %) at the same wavelength, the photocurrent and Response values depended on the absorption coefficients of metals and work functions the samples operated within the area under the near- infrared .
Keywords
Thin films; Schottky devices; GaAs; optoelectronics properties

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