An Assessment of ECR Argon Plasma Etching Damage on Si and SiO2 Interfaces

1992 ◽  
Vol 279 ◽  
Author(s):  
C. W. Nam ◽  
S. Ashok ◽  
W. Tsai ◽  
M. E. Day

ABSTRACTElectron cyclotron resonance (ECR) argon plasma has been used (to etch the native oxide on Si and thermal SiO2. The Schottky barrier height modification on both n- and p-Si has been studied as a function of substrate bias and etch time. Deep Level Transient Spectroscopy (DLTS) measurements show clear peaks on both p- and n-Si, but wish low levels of trap concentrations (1012-1013cm−3), and decreasing with depth from the surface. The effects of thermal oxide etching on the Si/SiO2 interface have been estimated with MOS capacitors. Negative flat-voltage shift is observed after argon plasma exposure, which removes the thermal oxide at a rate of over 100 Å/min at 50 V bias. C-V measurements show an order of magnitude increase in interface trap density.

2008 ◽  
Vol 1074 ◽  
Author(s):  
Jeffrey McCallum ◽  
Michael L. Dunn ◽  
Eric Gauja

ABSTRACTIon implantation doping of Si through an SiO2 overlayer is of interest for fabrication of a range of devices on the pathway to development of a solid–state quantum computer (SSQC). The fabrication requirements of devices based on the Kane architecture typically involve implantation through a pre-existing thin device–quality thermal oxide at low fluences ∼1011 cm−2 and ion energies in the range 10 – 20 keV. Here we present results from a deep level transient spectroscopy studies of ion–implanted MOS capacitors in which interface–trap densities have been measured in as–grown and H–passivated thermal oxides and in ion implanted and rapid–thermally processed devices. For thin oxides of 5nm or less and low ion fluences we find that implantation does not significantly increase interface trap densities and somewhat surprisingly that it can even be beneficial when the interface trap density is abnormally high, (∼ 1 × 1011cm−2.eV−1) in the as-grown oxide.


2019 ◽  
Vol 963 ◽  
pp. 465-468
Author(s):  
Stephan Wirths ◽  
Giovanni Alfieri ◽  
Alyssa Prasmusinto ◽  
Andrei Mihaila ◽  
Lukas Kranz ◽  
...  

We investigated the influence of forming gas annealing (FGA) before and after oxide deposition on the SiO2/4H-SiC interface defect density (Dit). For MOS capacitors (MOSCAPs) that were processed using FGAs at temperatures above 1050°C, CV characterization revealed decreased flat band voltage shifts and stretch-out for different sweep directions and frequencies. Moreover, constant-capacitance deep level transient spectroscopy (CC-DLTS) was performed and showed Dit levels below 1012 cm-2eV-1 for post deposition FGA at 1200°C. Finally, lateral MOSFETs were fabricated to analyze the temperature-dependent threshold voltage (Vth) shift.


1998 ◽  
Vol 535 ◽  
Author(s):  
Daewon Kwon ◽  
R. J. Kaplar ◽  
J. J. Boeckl ◽  
S. A. Ringel ◽  
A. A. Allerman ◽  
...  

AbstractDeep level defects in MOCVD-grown, unintentionally doped p-type InGaAsN films lattice matched to GaAs were investigated using deep level transient spectroscopy (DLTS) measurements. As-grown p-InGaAsN showed broad DLTS spectra suggesting that there exists a broad distribution of defect states within the band-gap. Moreover, the trap densities exceeded 1015 cm−3. Cross sectional transmission electron microscopy (TEM) measurements showed no evidence for threading dislocations within the TEM resolution limit of 107 cm−2. A set of samples was annealed after growth for 1800 seconds at 650 °C to investigate the thermal stability of the traps. The DLTS spectra of the annealed samples simplified considerably, revealing three distinct hole trap levels with energy levels of 0.10 eV, 0.23 eV, and 0.48 eV above the valence band edge with trap concentrations of 3.5 × 1014 cm−3, 3.8 × 1014 cm−3, and 8.2 × 1014 cm−3, respectively. Comparison of as-grown and annealed DLTS spectra showed that post-growth annealing effectively reduced the total trap concentration by an order of magnitude across the bandgap. However, the concentration of a trap with an energy level of 0.48 eV was not affected by annealing indicating a higher thermal stability for this trap as compared with the overall distribution of shallow and deep traps.


2006 ◽  
Vol 911 ◽  
Author(s):  
Anna Cavallini ◽  
Antonio Castaldini ◽  
Filippo Nava ◽  
Paolo Errani ◽  
Vladimir Cindro

AbstractWe investigated the electronic levels of defects introduced in 4H-SiC α-particle detectors by irradiation with 1 MeV neutrons up to a fluence equal to 8x1015 n/cm2. As well, we investigated their effect on the detector radiation hardness. This study was carried out by deep level transient spectroscopy (DLTS) and photo-induced current transient spectroscopy (PICTS). As the irradiation level approaches fluences in the order of 1015 n/cm2, the material behaves as highly resistive due to a very great compensation effect but the diodes are still able to detect with a acceptably good charge collection efficiency (CCE) equal to 80%. By further increasing fluence, CCE decreases reaching the value of ≈ 20% at fluence of 8x1015 n/cm2.The dominant peaks in the PICTS spectra occur in the temperature range [400, 700] K. Enthalpy, capture cross-section and order of magnitude of the density of such deep levels were calculated. In the above said temperature range the deep levels associated to the radiation induced defects play the key role in the degradation of the CCE. Two deep levels at Et = 1.18 eV and Et = 1.50 eV are likely to be responsible of such dramatic decrease of the charge collection efficiency. These levels were reasonably associated to an elementary defect involving a carbon vacancy and to a defect complex involving a carbon and a silicon vacancy, respectively.


1997 ◽  
Vol 500 ◽  
Author(s):  
S. Dueñas ◽  
R. Peláez ◽  
E. Castán ◽  
J. Barbolla ◽  
I. Mártil ◽  
...  

ABSTRACTWe have obtained Al/SiNx:H/Si and Al/SiNx:H/InP Metal-Insulator-Semiconductor devices by directly depositing silicon nitride thin films on silicon and indium phosphide wafers by the Electron Cyclotron Resonance Plasma method at 200°C. The electrical properties of the structures were first analyzed by Capacitance-Voltage measurements and Deep-Level Transient Spectroscopy (DLTS). Some discrepancies in the absolute value of the interface trap densities were found. Later on, Admittance measurements were carried out and room and low temperature conductance transients in the silicon nitride/semiconductor interfaces were found. The shape of the conductance transients varied with the frequency and temperature at which they were obtained. This behavior, as well as the previously mentioned discrepancies, are explained in terms of a disorder-induced gap-state continuum model for the interfacial defects. A perfect agreement between experiment and theory is obtained proving the validity of the model.


1995 ◽  
Vol 396 ◽  
Author(s):  
A. Tanabe ◽  
S. Ashok

AbstractAn exploratory deep level transient spectroscopy (DLTS) study on the possible role of illumination during thermal annealing has been carried out on Si with extended defects generated by Ar implantation and electron cyclotron resonance (ECR) hydrogen plasma. Experiments with rapid thermal anneal (RTA) using quartz-halogen lamps show only a minor role for illumination on anneal of defects generated by Ar ion damage as well as thermal generation of defects under post-hydrogenation anneal. However, significant differences are evident relative to conventional furnace anneal and it appears likely that recombination-assisted defect reactions may be quite significant in Si processing when high intensity sources such as arc lamps are adapted in RTA systems.


1982 ◽  
Vol 14 ◽  
Author(s):  
P. H. Campbell ◽  
O. Aina ◽  
B. J. Baliga ◽  
R. Ehle

ABSTRACTHigh temperature annealing of Si 3 N4 and SiO2 capped high purity LPE GaAs is shown to result in a reduction in the surface carrier concentration by about an order of magnitude. Au Schottky contacts made on the annealed samples were found to have severely degraded breakdown characteristics. Using deep level transient spectroscopy, deep levels at EC–.58eV, EC–.785eV were detected in the SiO2, capped samples and EC–.62eV, EC–.728eV in the Si3N4 capped Samples while none was detected in the unannealed samples.The electrical degradations are explained in terms of compensation mechanisns and depletion layer recombination-generation currents due to the deep levels.


2018 ◽  
Vol 83 (1) ◽  
pp. 10101 ◽  
Author(s):  
Zeeshan Najam Khan ◽  
Ahmed Shuja ◽  
Muhammad Ali ◽  
Shoaib Alam

A combination of two powerful techniques, namely, charge deep level transient spectroscopy and spectroscopic ellipsometry is employed on atomic layer deposited Si-metal oxide semiconductor capacitors (MOSCAPs) to investigate the energy efficiency of the physical process. Ultra-thin TiN/HfSiO acted as gate-dielectric stack on Si substrate was carefully subjected to rapid thermal processing and subsequent spectroscopic measurements to determine the transient behaviour of charges and electro-optical characteristics. Some key parameters such as trap concentration, activation energy required to surmount the traps, capture cross section, refractive index and extinction coefficient are found to play an important role in order to assess the energy efficiency of the devices both in terms of post-process quality of the retained surface and residual efficiency of the process by virtue of dynamics at atomistic scales. The results may provide a useful insight to the Si manufacturing protocols at ever decreasing nodes with desirable energy efficiency.


2010 ◽  
Vol 1246 ◽  
Author(s):  
Alberto F Basile ◽  
Sarit Dhar ◽  
John Rozen ◽  
Xudong Chen ◽  
John Williams ◽  
...  

AbstractSilicon Carbide (SiC) Metal-Oxide-Semiconductor (MOS) capacitors, having different nitridation times, were characterized by means of Constant Capacitance Deep Level Transient Spectroscopy (CCDLTS). Electron emission was investigated with respect to the temperature dependence of emission rates and the amplitude of the signal as a function of the filling voltage. The comparison between the emission activation energies of the dominant CCDLTS peaks and the filling voltages, led to the conclusion that the dominant trapping behavior originates in the Silicon-dioxide (SiO2) layer. Moreover, a model of electron capture via tunneling can explain the dependence of the CCDLTS signal on increasing filling voltage.


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