Process-Induced Defects in High-Purity GaAs

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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CW Laser Induced Deep Level Defects in Virgin Silicon.

MRS Proceedings ◽

10.1557/proc-4-325 ◽

1981 ◽

Vol 4 ◽

Cited By ~ 1

Author(s):

A. Chantre ◽

M. Kechouane ◽

D. Bois

Keyword(s):

High Temperature ◽

Point Defects ◽

Deep Level Transient Spectroscopy ◽

Solid Phase ◽

Deep Level ◽

Deep Levels ◽

Cw Laser ◽

Temperature State ◽

Transient Spectroscopy ◽

Induced Defects

ABSTRACTDeep Level Transient Spectroscopy has been used to investigate cw laser induced defects in virgin silicon. Two main regimes have been found. In the solid phase regime, two well defined deep levels at Ec−0.19 eV and Ec−0.45 eV are observed. This point defect introduction is proposed to be involved in the degradation of ion-implanted cw laser annealed junctions. The mechanism leading to point defects generation is likely to involve trapping of in–diffused vacancies, quenched–in from the high temperature state. In the slip lines or melt regimes, additionnal deep levels are detected, which are ascribed to dislocations.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.615-617.365 ◽

2009 ◽

Vol 615-617 ◽

pp. 365-368 ◽

Cited By ~ 1

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.

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Deep Levels in 4H Silicon Carbide Epilayers Induced by Neutron-Irradiation up to 1016 n/cm2

MRS Proceedings ◽

10.1557/proc-0911-b06-01 ◽

2006 ◽

Vol 911 ◽

Cited By ~ 4

Author(s):

Anna Cavallini ◽

Antonio Castaldini ◽

Filippo Nava ◽

Paolo Errani ◽

Vladimir Cindro

Keyword(s):

Deep Level ◽

Collection Efficiency ◽

Deep Levels ◽

Charge Collection ◽

Charge Collection Efficiency ◽

Temperature Range ◽

Order Of Magnitude ◽

Irradiation Level ◽

Transient Spectroscopy ◽

Induced Defects

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.

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Deep Level Transient Spectroscopy Study Of High-Temperature Aluminum Implanted 6H-SiC

MRS Proceedings ◽

10.1557/proc-442-649 ◽

1996 ◽

Vol 442 ◽

Author(s):

Yuri A. Stotski ◽

Igor O. Usov ◽

Alexander V. Suvorov

Keyword(s):

High Temperature ◽

Carrier Concentration ◽

Deep Level Transient Spectroscopy ◽

Deep Level ◽

Deep Levels ◽

Epitaxial Layers ◽

Spectroscopy Study ◽

Four Levels ◽

Transient Spectroscopy ◽

The Relationship

AbstractDeep levels in 6H-SiC wafers implanted with Al+ ions at high-temperature were studied using current deep level transient spectroscopy (iDLTS). Aluminum was implanted at a temperature of 1800 °C with an energy of 40 keV and a dose of 2 × 1016 cm−2 into n-type epitaxial layers with different carrier concentration. Four levels were found, at Ec−0.12, Ec−0.13, Ec−1.06 and Ev+0.35 eV. It was established that modification of the carrier concentration in original ntype 6H-SiC epitaxial layers affects the deep levels concentration. The relationship between the thickness of the space charge region and the relative deep level concentration was considered.

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Effects of Thermal Oxidation on Deep Levels Generated by Ion Implantation into n-Type and p-Type 4H-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.645-648.651 ◽

2010 ◽

Vol 645-648 ◽

pp. 651-654 ◽

Cited By ~ 2

Author(s):

Koutarou Kawahara ◽

Giovanni Alfieri ◽

Toru Hiyoshi ◽

Gerhard Pensl ◽

Tsunenobu Kimoto

Keyword(s):

Ion Implantation ◽

Thermal Oxidation ◽

Deep Level Transient Spectroscopy ◽

Low Dose ◽

Deep Level ◽

Deep Levels ◽

High Temperature Annealing ◽

Bulk Region ◽

Transient Spectroscopy ◽

P Type

The authors have investigated effects of thermal oxidation on deep levels in the whole energy range of bandgap of 4H-SiC which are generated by ion implantation, by deep level transient spectroscopy (DLTS). The dominant defects in n-type samples after ion implantation and high-temperature annealing at 1700oC, IN3 (Z1/2: Ec – 0.63 eV) and IN9 (EH6/7: Ec – 1.5 eV) in low-dose-implanted samples, can be remarkably reduced by oxidation at 1150oC. However, in p-type samples, the IP8 (HK4: Ev + 1.4 eV) survives and additional defects, several defects such as IP4 (HK0: Ev + 0.72 eV) appear after thermal oxidation in low-dose-implanted samples. The defects except for the IP8 center can be reduced by subsequent annealing at 1400oC. These phenomena are explained by a model that excess interstitials are generated at the oxidizing interface and diffuse into the bulk region.

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