Al Implantation and Post Annealing Effects in n-Type 4H-SiC

2020 ◽  
Vol 15 (7) ◽  
pp. 777-782
Author(s):  
Woo-Young Son ◽  
Myeong-Cheol Shin ◽  
Michael Schweitz ◽  
Sang-Kwon Lee ◽  
Sang-Mo Koo
Keyword(s):  
Energy Level ◽  
Ion Implantation ◽  
Cross Section ◽  
Epitaxial Layer ◽  
Capture Cross Section ◽  
Deep Level ◽  
Capture Cross ◽  
Trap Concentration ◽  
Post Annealing ◽  
Measurement Results

We investigated the post annealing effect of Al implantation in n-type 4H-SiC by using deep level transient spectroscopy (DLTS). The Schottky contacts were deposited on n-type epitaxial layer on 4H-SiC substrates and the effect of Al-implantation on the structures has been examined with and without post-annealing process. n-type epitaxial layer on a 4H-SiC substrate was implanted with Al-ion at an energy of 300 keV and a dose of 1.0 × 1015 cm–2. The effect of annealing has been studied by annealing the structures at 1700 C after ion implantation. DLTS measurements were performed before and after ion implantation, in order to determine the characteristics and magnitudes of the resulting electrical defects. Based on the DLTS measurement results, typical Z1/2 peak of SiC is obtained in reference samples without implantation. Z1/2 of the non-annealed samples had an energy level of 0.831 eV. The energy level was found to be deeper after the implantation whereas the capture cross section is about 60 times smaller and the trap concentration increases by a factor of 10. In other words, the Al-ion implantation clearly influenced the electrical characteristics of the sample and consequently also the DLTS measurement results. After post-implantation annealing, a new shallow defect (I2Al-A) was identified (∼0.028 eV) with a capture cross section of 1.9 × 10–21 cm –2 and a trap concentration of 4.8 × 1015 cm–3.

Effect of Sacrificial AlN (Aluminum Nitride) Layer on the Deep Surface States of 4H-SiC

2021 ◽  
Vol 21 (3) ◽  
pp. 1904-1908
Author(s):  
Woo-Young Son ◽  
Jeong Hyun Moon ◽  
Wook Bahng ◽  
Sang-Mo Koo
Keyword(s):  
Cross Section ◽  
Deep Level Transient Spectroscopy ◽  
Capture Cross Section ◽  
Deep Level ◽  
Surface States ◽  
Nitride Layer ◽  
Double Negative ◽  
Capture Cross ◽  
Trap Energy ◽  
Transient Spectroscopy

We investigated the effect of a sacrificial AlN layer on the deep energy level states of 4H-SiC surface. The samples with and without AlN layer have been annealed at 1300 °C for 30 minutes duration using a tube furnace. After annealing the samples, the changes of the carbon vacancy (VC) related Z1/2 defect characteristics were analyzed by deep level transient spectroscopy. The trap energy associated with double negative acceptor (VC(2-/0)) appears at ˜0.7 eV and was reduced from ˜0.687 to ˜0.582 eV in the sacrificial AlN layer samples. In addition, the capture cross section was significantly improved from ˜2.1×10-14 to ˜3.8×10−16 cm−2 and the trap concentration was reduced by approximately 40 times.

scholarly journals Majority‐carrier capture cross‐section determination in the large deep‐trap concentration cases

1986 ◽  
Vol 59 (5) ◽  
pp. 1562-1569 ◽  
Author(s):  
J. R. Morante ◽  
J. Samitier ◽  
A. Cornet ◽  
A. Herms ◽  
P. Cartujo
Keyword(s):  
Cross Section ◽  
Capture Cross Section ◽  
Deep Trap ◽  
Capture Cross ◽  
Carrier Capture ◽  
Trap Concentration ◽  
Majority Carrier

DLTS Study on Al+ Ion Implanted and 1950°C Annealed p-i-n 4H-SiC Vertical Diodes

2017 ◽  
Vol 897 ◽  
pp. 279-282 ◽  
Author(s):  
Hussein M. Ayedh ◽  
Maurizio Puzzanghera ◽  
Bengt Gunnar Svensson ◽  
Roberta Nipoti
Keyword(s):  
Cross Section ◽  
Deep Level Transient Spectroscopy ◽  
Capture Cross Section ◽  
Deep Level ◽  
Electron Trap ◽  
Double Negative ◽  
Capture Cross ◽  
Carrier Traps ◽  
Transient Spectroscopy ◽  
Post Implantation

A vertical 4H-SiC p-i-n diode with 2×1020cm-3 Al+ implanted emitter and 1950°C/5min post implantation annealing has been characterized by deep level transient spectroscopy (DLTS). Majority (electron) and minority (hole) carrier traps have been found. Electron traps with a homogeneous depth profile, are positioned at 0.16, 0.67 and 1.5 eV below the minimum edge of the conduction band, and have 3×10-15, 1.7×1014, and 1.8×10-14 cm2 capture cross section, respectively. A hole trap decreasing in intensity with decreasing pulse voltage occurs at 0.35 eV above the maximum edge of the valence band with 1×1013 cm2 apparent capture cross section. The highest density is observed for the refractory 0.67 eV electron trap that is due to the double negative acceptor states of the carbon vacancy.

scholarly journals Extracting bulk defect parameters in silicon wafers using machine learning models

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Yoann Buratti ◽  
Quoc Thong Le Gia ◽  
Josef Dick ◽  
Yan Zhu ◽  
Ziv Hameiri
Keyword(s):  
Machine Learning ◽  
Energy Level ◽  
Cross Section ◽  
Capture Cross Section ◽  
Complex Data ◽  
Capture Cross ◽  
Cross Section Ratio ◽  
Defect Energy ◽  
Section Ratio ◽  
The Impact

Abstract The performance of high-efficiency silicon solar cells is limited by the presence of bulk defects. Identification of these defects has the potential to improve cell performance and reliability. The impact of bulk defects on minority carrier lifetime is commonly measured using temperature- and injection-dependent lifetime spectroscopy and the defect parameters, such as its energy level and capture cross-section ratio, are usually extracted by fitting the Shockley-Read-Hall equation. We propose an alternative extraction approach by using machine learning trained on more than a million simulated lifetime curves, achieving coefficient of determinations between the true and predicted values of the defect parameters above 99%. In particular, random forest regressors, show that defect energy levels can be predicted with a high precision of ±0.02 eV, 87% of the time. The traditional approach of fitting to the Shockley-Read-Hall equation usually yields two sets of defect parameters, one in each half bandgap. The machine learning model is trained to predict the half bandgap location of the energy level, and successfully overcome the traditional approach’s limitation. The proposed approach is validated using experimental measurements, where the machine learning predicts defect energy level and capture cross-section ratio within the uncertainty range of the traditional fitting method. The successful application of machine learning in the context of bulk defect parameter extraction paves the way to more complex data-driven physical models which have the potential to overcome the limitation of traditional approaches and can be applied to other materials such as perovskite and thin film.

Behavior of Electron Traps Induced by Phosphidization and Nitridation of GaAs Surfaces

1998 ◽  
Vol 510 ◽  
Author(s):  
Satoshi Nozu ◽  
Koichiro Matsuda ◽  
Takashi Sugino
Keyword(s):  
Energy Level ◽  
Cross Section ◽  
Capture Cross Section ◽  
Conduction Band Edge ◽  
Capture Cross ◽  
Electron Traps ◽  
Plasma Treatments ◽  
Transient Spectroscopy ◽  
Capacitance Transient ◽  
Isothermal Capacitance Transient Spectroscopy

AbstractGaAs is treated with remote PH3 and N2 plasmas. Electron traps induced by plasma treatments are investigated by isothermal capacitance transient spectroscopy measurements. The EL2 trap is detected in the as-grown GaAs. The TP1 trap(Ec-0.26eV) is generated in GaAs phosphidized for 10min, while the TN1 trap(Ec-0.66eV) is induced in GaAs nitrided for 30min. It is found that the TP1 trap is changed to the another trap with an energy level as shallow as 0.16eV below the conduction band edge and a capture cross section as small as 1.8×10−21cm2 by treating with N2 plasma subsequently after PH3 plasma treatment.

Effect of NO Annealing on 6H- and 4H-SiC MOS Interface States

2010 ◽  
Vol 645-648 ◽  
pp. 499-502 ◽  
Author(s):  
Alberto F. Basile ◽  
John Rozen ◽  
X.D. Chen ◽  
Sarit Dhar ◽  
John R. Williams ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Cross Section ◽  
Deep Level Transient Spectroscopy ◽  
Capture Cross Section ◽  
Deep Level ◽  
Capture Cross ◽  
Temperature Dependent ◽  
Band Energy ◽  
Transient Spectroscopy ◽  
Semiconductor Traps

The electrical properties of the SiC/SiO2 interface resulting from oxidation of the n-type 6H-SiC polytype were studied by hi-lo CV, temperature dependent CV and constant capacitance deep level transient spectroscopy (CCDLTS) techniques. Several trap species differing in energy and capture cross section were identified. A trap distribution at 0.5 eV below the 6H-SiC conduction band energy and a shallower density of states in both the 6H and 4H polytyes are passivated by post-oxidation NO annealing. However, other ultra-shallow and deeper defect distributions remain after nitridation. The latter may originate from semiconductor traps.

The Effect of Si Planar Doping on DX Centers in Al.20Ga.74As

1991 ◽  
Vol 240 ◽  
Author(s):  
G. S. Solomon ◽  
G. Roos ◽  
E. Muñoz-Merino ◽  
J. S. Harris
Keyword(s):  
Cross Section ◽  
Capture Cross Section ◽  
Deep Level ◽  
Biaxial Stress ◽  
Capture Cross ◽  
Biaxial Stress State ◽  
Si Doped ◽  
Dx Center ◽  
Transient Spectroscopy ◽  
Planar Doping

ABSTRACTThe effect of planar Si doping on the DX center in AlGaAs is investigated using Capacitance-Voltage and Deep Level Transient Spectroscopy techniques. We observe an increase of approximately six orders of magnitude in the DX center capture cross section in Al.26Ga.74As with planar doped Si spikes of 2×1012cm−2 as compared to conventional homogeneous Si doped Al.26Ga.74As. We also observe a small increase in the DX activation energy which was initiated at a lower planar doping of 4×1011 cm−2 and remained constant for the higher planar doping case. We believe the DX center concentration is not changed by the planar doping levels studied here. A model is proposed to explain the increase in capture cross section based on a biaxial stress state in the planar doped AlGaAs region.

Oxidation Induced ON1, ON2a/b Defects in 4H-SiC Characterized by DLTS

2014 ◽  
Vol 778-780 ◽  
pp. 281-284 ◽  
Author(s):  
Ian D. Booker ◽  
Hassan Abdalla ◽  
Louise Lilja ◽  
Jawad ul Hassan ◽  
Peder Bergman ◽  
...  
Keyword(s):  
Correlation Function ◽  
Energy Level ◽  
Electron Capture ◽  
Cross Section ◽  
Cross Sections ◽  
Capture Cross Section ◽  
Capture Cross ◽  
Electron Capture Cross Section ◽  
Pulse Measurement ◽  
Capture Cross Sections

The deep levels ON1and ON2a/bintroduced by oxidation into 4H-SiC are characterized via standard DLTS and via filling pulse dependent DLTS measurements. Separation of the closely spaced ON2a/bdefect is achieved by using a higher resolution correlation function (Gaver-Stehfest 4) and apparent energy level, apparent electron capture cross section and filling pulse measurement derived capture cross sections are given.

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