Properties of the EL2 Level in Organometallic Ga1−xAlxAs

1987 ◽  
Vol 104 ◽  
Author(s):  
A. Ben Cherifa ◽  
R. Azoulay ◽  
G. Guillot

ABSTRACTWe have studied by means of deep level transient spectroscopy and photocapacitance measurements deep electron traps in undoped Ga1−xAlxAs of n-type grown by metalorganic chemical vapor deposition with 0≤x≤ 0.3. A dominant deep electron trap is detected in the series of alloys. Its activation energy is found at EC-0.8 eV in GaAs and it increases with x. Its concentration is found nearly independent of x. For the first time we observed for this level in the Ga1−xAlxAs alloys, the photocapacitance quenching effect typical for the EL2 defect in GaAs thus confirming clearly that EL2 is also created in MOCVD Ga1−xAlxAs.

1995 ◽  
Vol 378 ◽  
Author(s):  
Z. C. Huang ◽  
Bing Yang ◽  
H. K. Chen ◽  
J. C. Chen

ABSTRACTWe have achieved deep-level-free Al0.22Ga0.78As epitaxial layers using low selenium (Se)-doping (8.4 × l016 cm−3) grown by metalorganic chemical vapor deposition (MOCVD). Deep levels in various Al0.22Ga0.78As layers grown on GaAs substrates were measured by deep level transient spectroscopy (DLTS). We have found that the commonly observed oxygen contamination-related deep levels at EC-0.53 and 0.70 eV and germanium-related level at EC-0.30 eV in MOCVD-grown Al0.22Ga0.78 As can be eliminated by low Se-doping. In addition, a deep hole level located at Ev+0.65 eV was found for the first time in highly Se-doped Al0.22Ga0.78 As epilayers. We suggest that low Se-doping (<2 × 1017 cm−3) produces a passivation effect and then deactivates other deep levels in Al0.22Ga0.78As.


2004 ◽  
Vol 831 ◽  
Author(s):  
M. Ahoujja ◽  
S. Elhamri ◽  
R. Berney ◽  
Y.K. Yeo ◽  
R. L. Hengehold

ABSTRACTElectrical properties of As, Si, and [As+Si] doped GaN films grown on sapphire substrates by low temperature metalorganic chemical vapor deposition have been investigated using temperature dependent Hall-effect and deep level transient spectroscopy measurements. The Hall measurements from the GaN layers show that the concentration decreases with arsine flow (4, 40, and 400 sccm) at all temperatures. The carrier concentration of the Si-doped GaN, on the other hand, increases with the incorporation of arsine flow. This behavior is attributed to the formation of AsGa antisites which act as double donors. A deep level at around 0.82 eV below the conduction in the band gap of As doped GaN is measured by DLTS and is tentatively assigned to arsenic on gallium antisite.


2001 ◽  
Vol 40 (Part 2, No. 4B) ◽  
pp. L404-L406 ◽  
Author(s):  
Takahira Miyagi ◽  
Tomoyuki Ogawa ◽  
Masayuki Kamei ◽  
Yoshiki Wada ◽  
Takefumi Mitsuhashi ◽  
...  

1995 ◽  
Vol 378 ◽  
Author(s):  
Z. C. Huang ◽  
Bing Yang ◽  
H. K. Chen ◽  
J. C. Chen

AbstractInxGai-xP (x=0.49) layers lattice-matched to GaAs have been grown by metalorganic chemical vapor deposition (MOCVD). We did not observe any deep levels in the temperature range of 30-380K by deep level transient spectroscopy (DLTS) in undoped In0.49Ga0.51P layers which have a background concentration of 3.1×1015 cm−3. The deep levels, if they exist, have a concentration of less than 5×1011 cm−3, which is the lowest deep level concentration found so far in InxGa1-xP materials. Moreover, lattice-mismatched InxGa1-xP/GaAs heterojunctions were deliberately grown by varying the In-composition ranging from 0.43 to 0.57. No deep levels were created in 1-μm-thick InxGa1-xP layers due to lattice mismatch when 0.469 < x < 0.532. However, we have observed a shallow electron trap at EC - 60 meV in InxGa1-xP layers with x < 469, and a deep electron trap located at Ec - 0.85 eV in the samples with x > 0.532. We suggest that the lattice-mismatch-induced-defects in InxGa1-xP are either electrically inactive or resided outside the bandgap when In content ranging from 0.469 to 0.532.


2005 ◽  
Vol 891 ◽  
Author(s):  
Steven W. Johnston ◽  
Sarah R. Kurtz ◽  
Richard S. Crandall

ABSTRACTDilute-nitrogen GaNAs epitaxial layers grown by metal-organic chemical vapor deposition were characterized by deep-level transient spectroscopy (DLTS). For all samples, the dominant DLTS signal corresponds to an electron trap having an activation energy of about 0.25 to 0.35 eV. The minority-carrier trap density in the p-type material is quantified based on computer simulation of the devices. The simulations show that only about 2% of the traps in the depleted layer are filled during the transient. The fraction of the traps that are filled depends strongly on the depth of the trap, but only weakly on the doping of the layers and on the conduction-band offset. The simulations provide a pathway to obtain semi-quantitative data for analysis of minority-carrier traps by DLTS.


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