Point Defects in a Directly-Bonded Wafer, and its Comparison with the Bonded Soi Wafers

1993 ◽  
Vol 302 ◽  
Author(s):  
Akira Usami ◽  
Keisuke Kaneko ◽  
Akira Ito ◽  
Shun-ichiro Ishigami ◽  
Takao Wada

ABSTRACT<Directly-bonded wafers were characterized using capacitance-voltage (C-V) and deep level transient spectroscopy (DLTS) measurements. We also studied silicon on insulator (SOI) wafers with different interfacial oxide thicknesses. In the active layers of the directly bonded wafer, two dominant electron traps (Ec-0.16eV, Ec-0.24eV) were observed at 23 μμμμm from the bonded interface. Both trap densities are almost constant (about 2 × 1011cm−3) at distances larger than about 10 μm. In the substrate, the density of the shallower electron trap increases (about 8 × 1011 cm−3) within about 20 μm from the interface, while the other trap concentration is almost constant and nearly equal to that in the active layers. No trap was observed near the wafer backside. These traps were also observed in the bonded SO1 wafers. Both the trap concentrations depend on the thickness of the bonded interfacial oxide. The shallower trap concentration increases with increasing oxide thickness, and the deeper one decreases.

2007 ◽  
Vol 994 ◽  
Author(s):  
Jinggang Lu ◽  
Yongkook Park ◽  
George A Rozgonyi

AbstractExamination of dislocations in the as-grown and annealed SiGe/Si heterostructures by DLTS indicates the three strong DLTS bands from 70 to 270K in the as-grown sample are likely related to intrinsic point defects or dislocation trails. A small amount of Fe at dislocations dramatically increases their electrical activity, and the trap concentration due to Fe-decorated dislocations can well exceed the total Fe impurities presented along dislocations. Through examining the competitive trapping of Fe at boron and dislocations, it is suggested that Fe trapping only happens at disordered sites along dislocations, such as kinks.


1992 ◽  
Vol 262 ◽  
Author(s):  
Akira Usami ◽  
Taichi Natori ◽  
Akira Ito ◽  
Shun-ichiro Ishigami ◽  
Yutaka Tokuda ◽  
...  

ABSTRACTSilicon-on-insulator films fabricated by the wafer bonding technique were studied with capacitance-voltage (c-V) and deep-level transient spectroscopy (DLTS) measurements. For our experiments, two kinds of SOI wafers were prepared. Many voids were present in one sample (void sample), but few voids were in the other sample (no void sample). Before annealing, two DLTS peaks (E-0.48 eV and Ec-0.38 eV) were observed in the SOI layer of the void sample. For the no void sample, different two DLTS peaks (Ec-0.16 eV and Ec-0.12 eV) were observed. The trap with an activation energy of 0.48 eV was annealed out after 450 °C annealing for 24 h. On the other hand, other traps were annealed out after 450 °C annealing for several hours. During annealing at 450 °C, thermal donors (TDs) were formed simultaneously. In usual CZ sil icon, a DLTS peak of TD was observed around 60 K. In the no void sample, however, a TD peak was observed at a temperature lower than 30 K. This TD was annihilated by rapid thermal annealing. This suggests that the TD with a shallower level was formed in the no void sample after annealing at 450 °C.


1996 ◽  
Vol 442 ◽  
Author(s):  
Akira Ito ◽  
Hiroyuki Iwata ◽  
Yutaka Tokuda

AbstractThe change of the concentration of electron traps in n-type Si induced by P+ implantation (300keV, l×109 cm−2) with subsequent H+-implantation has been studied by deep level transient spectroscopy. H+-implantation is performed at room temperature to a dose of 2×1010cm−2 in the range 30 to 120keV. First P+ implantation induces six electron traps (Ec-0.12, 0.15, 0.21, 0.26, 0.39, 0.49eV). H+-implantation additionally induces an electron trap (Ec-0.32eV) which is related to hydrogen. The subsequent H+-implantation partly decreases the concentration of the electron traps induced by P+ implantation, although it increases the concentrations near the H+ projected range. 30 keV H+-implantation is mdst effective to reduce the trap concentration. The reduction of the concentration of the traps is ascribed to the reaction of pre-existing defects with interstitial or vacancy defects formed by subsequent H+-implantation.


Author(s):  
М.М. Соболев ◽  
Ф.Ю. Солдатенков

The results of experimental studies of capacitance– voltage characteristics, spectra of deep-level transient spectroscopy of graded high-voltage GaAs p+−p0−i−n0 diodes fabricated by liquid-phase epitaxy at a crystallization temperature of 900C from one solution–melt due to autodoping with background impurities, in a hydrogen or argon ambient, before and after irradiation with neutrons. After neutron irradiation, deep-level transient spectroscopy spectra revealed wide zones of defect clusters with acceptor-like negatively charged traps in the n0-layer, which arise as a result of electron emission from states located above the middle of the band gap. It was found that the differences in capacitance–voltage characteristics of the structures grown in hydrogen or argon ambient after irradiation are due to different doses of irradiation of GaAs p+−p0−i−n0 structures and different degrees of compensation of shallow donor impurities by deep traps in the layers.


2011 ◽  
Vol 109 (6) ◽  
pp. 064514 ◽  
Author(s):  
A. F. Basile ◽  
J. Rozen ◽  
J. R. Williams ◽  
L. C. Feldman ◽  
P. M. Mooney

2011 ◽  
Vol 295-297 ◽  
pp. 777-780 ◽  
Author(s):  
M. Ajaz Un Nabi ◽  
M. Imran Arshad ◽  
Adnan Ali ◽  
M. Asghar ◽  
M. A Hasan

In this paper we have investigated the substrate-induced deep level defects in bulk GaN layers grown onp-silicon by molecular beam epitaxy. Representative deep level transient spectroscopy (DLTS) performed on Au-GaN/Si/Al devices displayed only one electron trap E1at 0.23 eV below the conduction band. Owing to out-diffusion mechanism; silicon diffuses into GaN layer from Si substrate maintained at 1050°C, E1level is therefore, attributed to the silicon-related defect. This argument is supported by growth of SiC on Si substrate maintained at 1050°C in MBE chamber using fullerene as a single evaporation source.


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.


1989 ◽  
Vol 4 (2) ◽  
pp. 241-243 ◽  
Author(s):  
Yutaka Tokuda ◽  
Nobuji Kobayashi ◽  
Yajiro Inoue ◽  
Akira Usami ◽  
Makoto Imura

The annihilation of thermal donors in silicon by rapid thermal annealing (RTA) has been studied with deep-level transient spectroscopy. The electron trap AO (Ec – 0.13 eV) observed after heat treatment at 450 °C for 10 h, which is identified with the thermal donor, disappears by RTA at 800 °C for 10 s. However, four electron traps, A1 (Ec 0.18 eV), A2 (Ec – 0.25 eV), A3 (Ec – 0.36 eV), and A4 (Ec – 0.52 eV), with the concentration of ∼1012 cm−3 are produced after annihilation of thermal donors by RTA. These traps are also observed in silicon which receives only RTA at 800 °C. This indicates that traps A1–A4 are thermal stress induced or quenched-in defects by RTA, not secondary defects resulting from annealing of thermal donors.


1993 ◽  
Vol 312 ◽  
Author(s):  
P. Krispin ◽  
R. Hey ◽  
H. Kostial ◽  
M. Höricke

AbstractWe report on a detailed investigation of MBE-grown isotype silicon-doped heterostructures by capacitance/voltage (C/V) technique and deep-level transient spectroscopy (DLTS). A sequence of electrically active defects is found. By depth profiling of the density of the dominant levels it is demonstrated that the corresponding defects are concentrated at the GaAs-on-AlAs (inverted) interface. By comparison with studies on irradiation-induced levels in LPE- or VPE-grown AlGaAs we conclude that the defects at the GaAs/AlAs interface are most probably linked to different charge states of the arsenic vacancy VAs and VAs−ASi pairs.


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