Deep Levels Induced by SiCI4 Reactive Ion Etching in GaAs

1993 ◽  
Vol 325 ◽  
Author(s):  
N.P. Johnson ◽  
M. A. Foad ◽  
S. Murad ◽  
M. C. Holland ◽  
C. D. W. Wilkinson
Keyword(s):  
Deep Level ◽  
Reactive Ion Etching ◽  
Depth Profiling ◽  
Deep Levels ◽  
Small Concentration ◽  
Conduction Band Edge ◽  
Experimental Conditions ◽  
Ion Etching ◽  
Self Bias ◽  
Transient Spectroscopy

AbstractDeep Level Transient Spectroscopy (DLTS) is used to investigate the effect of SiC14 Reactive Ion Etching (RIE) on GaAs. At high power (150-80 W) with high DC self bias (380-240 V), five deep levels trapping electrons are observed at energies of 0.30, 0.42, 0.64, 0.86 and ∼0.8 eV below the conduction band edge. Depth profiling reveals an approximate exponential decay of the concentration of the deep levels. At low power the induced concentration falls, the small concentration of remaining deep levels is close to control (no etching) samples. The induced deep levels can account for reduced conductances in n+GaAs wires defined by RIE under similar experimental conditions.

Reactive-Ion-Etching Induced Deep Levels Observed in n-Type and p-Type 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 759-762
Author(s):  
Koutarou Kawahara ◽  
Giovanni Alfieri ◽  
Michael Krieger ◽  
Tsunenobu Kimoto
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Reactive Ion Etching ◽  
Deep Levels ◽  
Total Density ◽  
Ion Etching ◽  
Initial Concentration ◽  
Grown Sample ◽  
Transient Spectroscopy ◽  
P Type

In this study, deep levels are investigated, which are introduced by reactive ion etching (RIE) of n-type/p-type 4H-SiC. The capacitance of as-etched p-type SiC is remarkably small due to compensation or deactivation of acceptors. These acceptors can be recovered to the initial concentration of the as-grown sample after annealing at 1000oC. However, various kinds of defects remain at a total density of ~5× 1014 cm-3 in a surface-near region from 0.3 μm to 1.0 μm even after annealing at 1000oC. The following defects are detected by Deep Level Transient Spectroscopy (DLTS): IN2 (EC – 0.35 eV), EN (EC – 1.6 eV), IP1 (EV + 0.35 eV), IP2 (HS1: EV + 0.39 eV), IP4 (HK0: EV + 0.72 eV), IP5 (EV + 0.75 eV), IP7 (EV + 1.3 eV), and EP (EV + 1.4 eV). These defects generated by RIE can be significantly reduced by thermal oxidation and subsequent annealing at 1400oC.

Influence of CH4/H2 Reactive Ion Etching on Deep Levels in Si-Doped AlxGa1−xAs (x=0.25)

1993 ◽  
Vol 300 ◽  
Author(s):  
R. Pereira ◽  
M. Van Hove ◽  
M. de Potter ◽  
K. Van Rossum
Keyword(s):  
Electron Capture ◽  
Deep Level ◽  
Reactive Ion Etching ◽  
Deep Levels ◽  
Ion Etching ◽  
Hall Measurements ◽  
First Order Kinetics ◽  
Si Doped ◽  
Transient Spectroscopy ◽  
Kinetics Of

The effect of CH4/H2 reactive ion etching (RIE) on Si-doped AlxGa1−xAs (x=0.25) is studied by deep level transient spectroscopy (DLTS) and Hall measurements. After RIE exposure, the samples were annealed between 250 and 500°C in order to study the recovery kinetics of deep and shallow levels. Non-etched reference samples showed broad DLTS spectra which were deconvoluted in two different emission peaks. We assigned them to DX1 and DX2 centers. The different deep levels are characierized by different aluminium configurations, one or two aluminium atoms, surrounding the silicon donor which are responsible for the DX centers. After RIE exposure and subsequent thermal annealing, a third emission peak is observed. This emission is attributed to the DX3 center, which is characterized by three aluminium atoms neighbouring the silicon donor. The recovery activation energy is calculated based on first-order kinetics. The activation energies are found to be around 1.9 eV in all cases.Complementary Hall measurements as a function of temperature (4-300 K) were used to characterize the electron capture of deep levels in Si-doped AlGaAs exposed to CH4/H2 RIE. We observed that the samples exposed to RIE and annealed at temperatures higher than 400°C exhibit electron capture in the 120-150 K temperature range. On the other hand, samples annealed at lower temperatures, showed additional capture features between 200 and 230 K.

Defects Induced by Reactive Ion Etching in Ge Substrate

2014 ◽  
Vol 896 ◽  
pp. 241-244
Author(s):  
Kusumandari ◽  
Noriyuki Taoka ◽  
Wakana Takeuchi ◽  
Mitsuo Sakashita ◽  
Osamu Nakatsuka ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Defect Formation ◽  
Deep Level ◽  
Reactive Ion Etching ◽  
The Other ◽  
Ion Etching ◽  
Ar Plasma ◽  
Transient Spectroscopy ◽  
Electron And Hole Traps ◽  
Dlts Spectra

We investigated impacts of the Ar and CF4　plasma during reactive ion etching (RIE) on defect formation in the Ge substrates using the deep-level-transient-spectroscopy (DLTS) technique. It was found that the Ar plasma causes the roughening of the Ge surface. Moreover, the Ar plasma induces a defect with an energy level of 0.31 eV from the conduction band minimum in the Ge substrate, confirming by DLTS spectra. On the other hand, the CF4plasma hardly induces the surface roughness of Ge. However, the CF4plasma induces many kinds of electron and hole traps. It should be noted that the defects associated with Sb and interstitials are widely distributed to around 3-µm.

Effects of CF4, Reactive ion Etching on Si-Doped Al0.2Ga0.8As

1998 ◽  
Vol 535 ◽  
Author(s):  
Akira Ito ◽  
Atsuyoshi Sakai ◽  
Yutaka Tokuda
Keyword(s):  
Deep Level ◽  
Reactive Ion Etching ◽  
Forward Bias ◽  
Electrical Characteristics ◽  
Plasma Exposure ◽  
Ion Etching ◽  
Post Annealing ◽  
Capacitance Voltage ◽  
Si Doped ◽  
Transient Spectroscopy

AbstractEffects of CF4 reactive ion etching on electrical characteristics of Si-doped Al0.2Ga0.8As layers were studied with capacitance-voltage and deep level transient spectroscopy measurements. Plasma exposure for about 30 s drastically degrades the electrical characteristics. Post-annealing at 360 °C for 20 s partially recovers the carrier concentrations. After the post-annealing, some electron traps were observed. Two of the traps show bi-stability. The concentrations of the two traps increase with forward bias temperature annealing and decrease with reverse bias temperature annealing.

Deep Level Transient Spectroscopy of Defects Induced by the Combination of CF4 Reactive Ion Etching and Oxidation in Metal-Oxide-Silicon Capacitors.

1989 ◽  
Vol 148 ◽  
Author(s):  
Dominique Vuillaume ◽  
Jeff P. Gambino
Keyword(s):  
Metal Oxide ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Reactive Ion Etching ◽  
Interface States ◽  
Ion Etching ◽  
Mos Capacitors ◽  
Metal Oxide Silicon ◽  
Transient Spectroscopy ◽  
Induced Defects

ABSTRACTMetal-Oxide-silicon (MOS) capacitors have been fabricated on CFb reactive ion etched silicon (n and p types) in order to study the defects at the Si-Si02 interface and in the bulk of the substrate, produced by the combination of reactive ion etching (RIE) and oxidation. Bulk defects and fast interface states are analysed by Deep Level Transient Spectroscopy (DLTS) and the slow interface states in the oxide layer near the interface are probed by Tunnel-DLTS. A density of fast interface states in the range 1010-1011 cm−2 eV−1 is observed for capacitors (both n and p types) fabricated with either dry or wet oxidations, and is probably due to disrupted or strained bonds at the Si-SiO2 interface. The observation of bulk defects in the wet-RIE oxide samples but not in the dry-RIE oxide samples may be related to the shorter oxidation time for wet oxides (31mn) compared to dry oxides(190mn) and explained by a greater annealing of RIE induced defects during the dry oxidation. The bulk traps are identified to be related to carbon contamination, in SiC form, introduced during RIE. Finally, an increase of the slow interface states density is observed for the n-type dry oxide samples.

EXPERIMENTAL VERIFICATION OF DLTS MODELS

2019 ◽  
Author(s):  
Nataliya Mitina ◽  
Vladimir Krylov
Keyword(s):  
Activation Energy ◽  
Gallium Arsenide ◽  
Data Processing ◽  
Experimental Verification ◽  
Deep Level ◽  
Deep Levels ◽  
Transient Spectroscopy

The results of an experiment to determine the activation energy of a deep level in a gallium arsenide mesastructure, obtained by the method of capacitive deep levels transient spectroscopy with data processing according to the Oreshkin model and Lang model, are considered.

Evaluation of On-State Resistance and Boron-Related Levels in n-Type 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 425-428 ◽  
Author(s):  
R.R Ciechonski ◽  
Samuele Porro ◽  
Mikael Syväjärvi ◽  
Rositza Yakimova
Keyword(s):  
Minority Carrier ◽  
Deep Level ◽  
Schottky Diodes ◽  
Depth Profiling ◽  
Thermionic Emission ◽  
Barrier Heights ◽  
Transient Spectroscopy ◽  
State Resistance ◽  
Thick Layers

Specific on-resistance Ron estimated from current density-voltage characteristics of Schottky diodes on thick layers exhibits variations from tens of mW.cm2 to tens of W.cm2 for different doping levels. In order to understand the occurrence of high on-state resistance, Schottky barrier heights were first estimated for both forward and reverse bias with the application of thermionic emission theory and were in agreement with a literature reported values. Decrease in mobility with the temperature was observed and its dependencies of T–1.3 and T–2.0 for moderately doped and low doped samples respectively were estimated. From deep level measurements by Minority Carrier Transient Spectroscopy, an influence of shallow boron related levels and D-center on dependence of on-state resistance was observed, being more pronounced in low doped samples. Similar tendency was observed in depth profiling of Ron. This suggests a major role of boron in a compensation mechanism thus resulting in high Ron.

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