Molecular beam epitaxial growth and characterization of extended short wavelength infrared mercury cadmium telluride detectors

Download
2017
Şaşmaz, Emrah
This thesis reports the growth, fabrication and characterization of extended short wavelength infrared (SWIR) mercury cadmium telluride (Hg1-xCdxTe) photodiodes with a cut off wavelength of 2.17 µm at room temperature. HgCdTe layers were grown on home-polished cadmium zinc telluride, CdZnTe, substrates by molecular beam epitaxy (MBE). Test arrays were fabricated in order to evaluate the electrical and optical characteristics of the photodiodes. Test array consists of mesa type pixels with 30 µm pitch. The test array was hybridized with silicon fan-out with flip-chip bonder. Electrical and optical characterization performed on 28x28 µm2 detectors yielded a room temperature dark current density of 100 µA/cm2 which is diffusion limited. The peak responsivity of the test diodes without anti-reflection coating is 1.0 A/W corresponding to a quantum efficiency of 62%. Dark current limited peak detectivity of the detectors is 1.17x10^11 Jones at room temperature. Deep level transient spectroscopy (DLTS) measurements were performed on the detectors in order to identify the performance limiting material characteristics. DLTS measurements yielded a hole trap with activation energy of 267 meV, capture cross section of 2.0x10^-17 cm2 and trap density of 3x10^13 cm-3. The trap does not display extended defect characteristics suggesting that it originates from isolated defects in the material  

Suggestions

Molecular beam epitaxy growth of inp/ingaas structures for short wavelength infrared photodetectors
Temel, Oğuzhan; Beşikci, Cengiz; Parlak, Mehmet; Department of Micro and Nanotechnology (2014)
Indium Gallium Arsenide (In0.53Ga0.47As) is a suitable compound semiconductor for photodetector applications in the Short Wavelength Infrared (SWIR) band with its ~1.7 µm cut-off wavelength. In this work, lattice-matched InxGa1-xAs compounds (x~0.53) were grown on InP (001) substrates by the molecular beam epitaxy (MBE) method. Unintentional doping level as low as 1.96E15 cm-3 was obtained in the In0.53Ga0.47As epilayers. The X-ray diffraction full width at half maximum values were as low as 45 arc-sec disp...
High performance near/short wavelength infrared megapixel InGaAs focal plane array fabrication development and new design proposals
Karaca, Utku; Kocaman, Serdar; Department of Electrical and Electronics Engineering (2018)
In0.53Ga0.47As is the most appropriate material system for Short Wavelength Infrared (SWIR) detection at ~1.7 μm cutoff wavelength with its relatively lower cost and high performance. Ultra-low dark current (~ nA/cm2) has been recently demonstrated in InGaAs photodetectors with planar type process by eliminating surface leakage current. Here, a fabrication procedure for planar InGaAs photodetectors with unique pixel isolation methods has been developed and ~10 nA/cm2 dark current density levels were obtaine...
Numerical modeling and optimization of HgCdTe infrared photodetectors for thermal imaging
Koçer, Hasan; Beşikci, Cengiz; Department of Electrical and Electronics Engineering (2011)
This thesis presents a detailed investigation of the performance limiting factors of long wavelength infrared (LWIR) and very long wavelength infrared (VLWIR) p on n HgCdTe detectors through numerical simulations at 77 K incorporating all considerable generation-recombination mechanisms including trap assisted tunneling (TAT), Shockley-Read-Hall (SRH), Auger and radiative processes. Numerical simulations under dark and illuminated conditions were performed with different absorber layer thicknesses, material...
Heat-damage assessment of carbon-fiber-reinforced polymer composites by diffuse reflectance infrared spectroscopy
Dara, IH; Ankara, A; Akovali, G; Suzer, S (2005-05-15)
Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy was used to assess the effects of heat damage on carbon-fiber-reinforced polymer composites. Moisture-saturated graphite-epoxy laminates with a quasi-isotropic lay-up were heat-damaged above their upper service temperatures. The loss of matrix-dominated mechanical properties due to heat exposure was investigated in the laboratory under environmental testing conditions with mechanical tests, ultrasonic C-scanning, and DRIFT spectroscopy. The...
Molecular-dynamics simulation of radiation damage on copper clusters
Erkoç, Şakir (2000-07-01)
The effect of radiation damage on copper clusters has been investigated by performing molecular-dynamics simulation using empirical potential energy function for interaction between copper atoms. The external radiation is modeled by giving extra kinetic energy in the range of 5- 50 eV to initially chosen atom in the cluster. It has been found that the atom having extra kinetic energy dissociates independently from the amount of given energy in the studied range.
Citation Formats
E. Şaşmaz, “Molecular beam epitaxial growth and characterization of extended short wavelength infrared mercury cadmium telluride detectors,” M.S. - Master of Science, Middle East Technical University, 2017.