scholarly journals High-temperature annealing behavior of deep levels in 1MeV electron irradiated p-type 6H-SiC

2008 ◽  
Vol 93 (3) ◽  
pp. 032108 ◽  
Author(s):  
Giovanni Alfieri ◽  
Tsunenobu Kimoto
Keyword(s):  
High Temperature ◽  
Deep Levels ◽  
High Temperature Annealing ◽  
Annealing Behavior ◽  
P Type

Deep Levels Generated by Ion-Implantation in n- and p-Type 4H-SiC

2009 ◽  
Vol 615-617 ◽  
pp. 365-368 ◽  
Author(s):  
Koutarou Kawahara ◽  
Giovanni Alfieri ◽  
Tsunenobu Kimoto
Keyword(s):  
High Temperature ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
High Temperature Annealing ◽  
Implantation Damage ◽  
Transient Spectroscopy ◽  
P Type ◽  
Two Peaks ◽  
Dlts Spectra

The authors have investigated deep levels in the whole energy range of bandgap of 4H-SiC, which are generated by N+, P+, Al+ implantation, by deep level transient spectroscopy (DLTS). Ne+-implanted samples have been also prepared to investigate the pure implantation damage. In the n-type as-grown material, Z1/2 (Ec – 0.63 eV) and EH6/7 (Ec – 1.6 eV) are dominant deep levels. When the implant dose is low, seven peaks (IN1, IN3 ~ IN6, IN8, IN9) have emerged by implantation and annealing at 1000oC in the DLTS spectra from all n-type samples. After high-temperature annealing at 1700oC, however, most DLTS peaks disappeared, and two peaks, Z1/2 and EH6/7 survive. In the p-type as-grown material, D center (Ev + 0.40 eV) and HK4 (Ev + 1.4 eV) are dominant. When the implant dose is low, two peaks (IP1, IP3) have emerged by implantation and annealing at 1000oC, and four traps IP2, IP4 (Ev + 0.72 eV), IP7 (Ev + 1.3 eV), and IP8 (Ev + 1.4 eV) are dominant after annealing at 1700oC.

Annealing Behavior of Electrical Resistivities Perpendicular and Parallel to the Basal Plane of Heavily Nitrogen-Doped 4H-SiC Crystals

2018 ◽  
Vol 924 ◽  
pp. 293-296 ◽  
Author(s):  
Kiyo Okawa ◽  
Yuina Mannen ◽  
Kentaro Shioura ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
...  
Keyword(s):  
High Temperature ◽  
Basal Plane ◽  
Stacking Fault ◽  
High Temperature Annealing ◽  
Annealing Behavior ◽  
Nitrogen Doped ◽  
Electrical Resistivities ◽  
C 30 ◽  
Induced Changes

The annealing behavior of electrical resistivities perpendicular and parallel to the basal plane of heavily nitrogen-doped 4H-SiC crystals was investigated. The temperature dependencies of the resistivities exhibited characteristic behaviors after multiple rounds of high-temperature annealing (1100°C, 30 min). High-temperature annealing induced stacking fault formation to various extents in heavily nitrogen-doped 4H-SiC crystals. Based on these results, we discuss the cause and mechanism of the observed annealing-induced changes in electrical resistivities of the crystals.

Correlation Study of Morphology, Electrical Activation and Contact formation of Ion Implanted 4H-SiC

2009 ◽  
Vol 156-158 ◽  
pp. 493-498
Author(s):  
Ming Hung Weng ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Corrado Bongiorno ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Morphology ◽  
Electrical Activation ◽  
Structural Defects ◽  
High Resistivity ◽  
Al Alloy ◽  
High Temperature Annealing ◽  
Capping Layer ◽  
P Type ◽  
Ion Implanted

This paper reports a detailed study of the electrical activation and the surface morphology of 4H-SiC implanted with different doping ions (P for n-type doping and Al for p-type doping) and annealed at high temperature (1650–1700 °C) under different surface conditions (with or without a graphite capping layer). The combined use of atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning capacitance microscopy (SCM) allowed to clarify the crucial role played by the implant damage both in evolution of 4H-SiC surface roughness and in the electrical activation of dopants after annealing. The high density of broken bonds by the implant makes surface atoms highly mobile and a peculiar step bunching on the surface is formed during high temperature annealing. This roughness can be minimized by using a capping layer. Furthermore, residual lattice defects or precipitates were found in high dose implanted layers even after high temperature annealing. Those defects adversely affect the electrical activation, especially in the case of Al implantation. Finally, the electrical properties of Ni and Ti/Al alloy contacts on n-type and p-type implanted regions of 4H-SiC were studied. Ohmic behavior was observed for contacts on the P implanted area, whilst high resistivity was obtained in the Al implanted layer. Results showed a correlation of the electrical behavior of contacts with surface morphology, electrical activation and structural defects in ion-implanted, particularly, Al doped layer of 4H-SiC.

Influence of Cooling Rate after High Temperature Annealing on Deep Levels in High-Purity Semi-Insulating 4H-SiC

2007 ◽  
Vol 556-557 ◽  
pp. 371-374 ◽  
Author(s):  
Andreas Gällström ◽  
Björn Magnusson ◽  
Patrick Carlsson ◽  
Nguyen Tien Son ◽  
Anne Henry ◽  
...  
Keyword(s):  
High Temperature ◽  
Cooling Rate ◽  
High Purity ◽  
Room Temperature ◽  
Deep Levels ◽  
High Temperature Annealing ◽  
Cooling Rates ◽  
Silicon Vacancy

The influence of different cooling rates on deep levels in 4H-SiC after high temperature annealing has been investigated. The samples were heated from room temperature to 2300°C, followed by a 20 minutes anneal at this temperature. Different subsequent cooling sequences down to 1100°C were used. The samples have been investigated using photoluminescence (PL) and IV characteristics. The PL intensities of the silicon vacancy (VSi) and UD-2, were found to increase with a faster cooling rate.

Process-Induced Defects in High-Purity GaAs

1982 ◽  
Vol 14 ◽  
Author(s):  
P. H. Campbell ◽  
O. Aina ◽  
B. J. Baliga ◽  
R. Ehle
Keyword(s):  
High Temperature ◽  
High Purity ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Schottky Contacts ◽  
High Temperature Annealing ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Induced Defects

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.

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