Excess Carrier Lifetime in a Bulk p-Type 4H–SiC Wafer Measured by the Microwave Photoconductivity Decay Method

2007 ◽  
Vol 46 (8A) ◽  
pp. 5057-5061 ◽  
Author(s):  
Masashi Kato ◽  
Masahiko Kawai ◽  
Tatsuhiro Mori ◽  
Masaya Ichimura ◽  
Shingo Sumie ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Excess Carrier ◽  
Photoconductivity Decay ◽  
P Type ◽  
Sic Wafer

Excess Carrier Lifetimes in a Bulk p-Type SiC Wafer Measured by the Microwave Photoconductivity Decay Method

2007 ◽  
Vol 556-557 ◽  
pp. 359-362 ◽  
Author(s):  
Masahiko Kawai ◽  
Tatsuhiro Mori ◽  
Masashi Kato ◽  
Masaya Ichimura ◽  
Shingo Sumie ◽  
...  
Keyword(s):  
Time Constant ◽  
Minority Carrier ◽  
Slow Component ◽  
Structural Defects ◽  
Excess Carrier ◽  
Carrier Lifetimes ◽  
Photoconductivity Decay ◽  
Increasing Temperature ◽  
P Type ◽  
Sic Wafer

We carried out mapping of the excess carrier lifetime for a bulk p-type 4H-SiC wafer by the microwave photoconductivity decay (μ-PCD) method, and we compared the lifetime map with structural defect distribution. Several small regions with short lifetimes compared with surrounding parts are found, and they correspond to regions with high-density structural defects. Excess carrier decay curves for this wafer show a slow component, which originates from minority carrier traps. From temperature dependence of the excess carrier decay curve, we found decrease of the time constant of the slow component with increasing temperature. We compared the activation energy of the time constant with that obtained from the numerical simulation, and concluded that the energy level for the minority carrier trap would be 125 meV from the conduction band.

Excess Carrier Lifetimes in a Bulk p-Type SiC Wafer Measured by the Microwave Photoconductivity Decay Method

2007 ◽  
pp. 359-362
Author(s):  
Masahiko Kawai ◽  
Tatsuhiro Mori ◽  
Masashi Kato ◽  
Masaya Ichimura ◽  
Shingo Sumie ◽  
...  
Keyword(s):  
Excess Carrier ◽  
Carrier Lifetimes ◽  
Photoconductivity Decay ◽  
P Type ◽  
Sic Wafer

Correlation between Strain and Excess Carrier Lifetime in a 3C-SiC Wafer

2012 ◽  
Vol 717-720 ◽  
pp. 305-308 ◽  
Author(s):  
Atsushi Yoshida ◽  
Masashi Kato ◽  
Masaya Ichimura
Keyword(s):  
Raman Spectroscopy ◽  
Optical Microscopy ◽  
Carrier Lifetime ◽  
Structural Defects ◽  
Free Standing ◽  
Excess Carrier ◽  
Carrier Lifetimes ◽  
Photoconductivity Decay ◽  
Sic Wafer

We obtained excess carrier lifetime maps by the microwave photoconductivity decay (µ-PCD) method in a free-standing n-type 3C-SiC wafer, and then we compared the lifetime maps with distributions of strains and defects observed by the optical microscopy and the Raman spectroscopy. We found that the excess carrier lifetimes are short in a strained region in 3C-SiC, which indicates that structural defects exist around a strained region.

Characterization of the Excess Carrier Lifetime of As-Grown and Electron Irradiated Epitaxial p-Type 4H-SiC Layers by the Microwave Photoconductivity Decay Method

2010 ◽  
Vol 645-648 ◽  
pp. 207-210 ◽  
Author(s):  
Yoshinori Matsushita ◽  
Masashi Kato ◽  
Masaya Ichimura ◽  
Tomoaki Hatayama ◽  
Takeshi Ohshima
Keyword(s):  
Cross Sections ◽  
Carrier Lifetime ◽  
Excitation Density ◽  
Excess Carrier ◽  
Carrier Lifetimes ◽  
Photoconductivity Decay ◽  
Recombination Centers ◽  
P Type ◽  
Capture Cross Sections

We measured the excess carrier lifetimes in as-grown and electron irradiated p-type 4H-SiC epitaxial layers with the microwave photoconductivity decay (-PCD) method. The carrier lifetime becomes longer with excitation density for the as-grown epilayer. This dependence suggests that e ≥h for the dominant recombination center, where e andh are capture cross sections for electrons and holes, respectively. In contrast, the carrier lifetime does not depend on the excitation density for the sample irradiated with electrons at an energy of 160 keV and a dose of 1×1017 cm-2. This may be due to the fact that recombination centers with e <<h were introduced by the electron irradiation or due to the fact that the acceptor concentration was decreased significantly by the irradiation.

Minority Carrier Lifetime Measurements in Specific Epitaxial 4H-SiC Layers by the Microwave Photoconductivity Decay

2009 ◽  
Vol 615-617 ◽  
pp. 295-298 ◽  
Author(s):  
Laurent Ottaviani ◽  
Olivier Palais ◽  
Damien Barakel ◽  
Marcel Pasquinelli
Keyword(s):  
Absorption Spectra ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
Optical Excitation ◽  
Minority Carrier Lifetime ◽  
Lifetime Measurements ◽  
Recombination Processes ◽  
Photoconductivity Decay ◽  
P Type ◽  
Non Destructive

We report on measurements of the minority carrier lifetime for different epitaxial 4H-SiC layers by using the microwave photoconductivity decay (µ-PCD) method. This is a non-contacting, non-destructive method very useful for the monitoring of recombination processes in semiconductor material. Distinct samples have been analyzed, giving different lifetime values. Transmittance and absorption spectra have also been carried out. The n-type layers, giving rise to a specific absorption peak near 470 nm, are not sensitive to optical excitation for the used wavelengths, as opposite to p-type layers whose lifetime values depend on thickness and doping.

Excess carrier lifetime of 3C–SiC measured by the microwave photoconductivity decay method

1997 ◽  
Vol 70 (13) ◽  
pp. 1745-1747 ◽  
Author(s):  
M. Ichimura ◽  
H. Tajiri ◽  
Y. Morita ◽  
N. Yamada ◽  
A. Usami
Keyword(s):  
Carrier Lifetime ◽  
Excess Carrier ◽  
Photoconductivity Decay

Excess Carrier Lifetime in p-Type 4H-SiC Epilayers with and without Low-Energy Electron Irradiation

2012 ◽  
Vol 51 (2R) ◽  
pp. 028006 ◽  
Author(s):  
Masashi Kato ◽  
Yoshinori Matsushita ◽  
Masaya Ichimura ◽  
Tomoaki Hatayama ◽  
Takeshi Ohshima
Keyword(s):  
Electron Irradiation ◽  
Carrier Lifetime ◽  
Low Energy ◽  
Energy Electron ◽  
Excess Carrier ◽  
Low Energy Electron ◽  
P Type

Non-linear injection level dependence of the excess carrier lifetime of p-type GaSb thin films: A two-layer model

2012 ◽  
Vol 111 (11) ◽  
pp. 113104 ◽  
Author(s):  
M. W. Shura ◽  
V. Wagener ◽  
J. R. Botha ◽  
M. C. Wagener
Keyword(s):  
Thin Films ◽  
Carrier Lifetime ◽  
Injection Level ◽  
Layer Model ◽  
Excess Carrier ◽  
Non Linear ◽  
Two Layer Model ◽  
P Type

Passivation of Silicon Surfaces Using Atomic Layer Deposited Metal Oxides

2009 ◽  
Vol 1153 ◽  
Author(s):  
Jun Wang ◽  
Mahdi Farrokh Baroughi ◽  
Mariyappan Shanmugam ◽  
Roohollah Samadzadeh-Tarighat ◽  
Siva Sivoththaman ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Surface Passivation ◽  
Atomic Layer ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
Excess Carrier ◽  
Si Substrates ◽  
Layer Deposition ◽  
Deposited Metal ◽  
Photoconductivity Decay

AbstractSurface passivation of silicon substrates using atomic layer deposited Al2O3 and HfO2 thin films are assessed. Al2O3 and HfO2 dielectric layers with various thicknesses were deposited on both sides of n-type (100) FZ-Si substrates (resistivity 4 – 6 Ω-cm) at 200°C by atomic layer deposition (ALD) system. The effective excess carrier lifetime of as-deposited oxide/Si/oxide structure was measured by microwave-photoconductivity-decay (MWPCD) measurement technique and it was observed that the thicker ALD dielectrics lead to higher effective excess carrier lifetime and better surface passivation. The measurements showed average excess carrier lifetime values of 302 μs and 347 μs for as-deposited Al2O3 and HfO2 passivated Si substrates with 150 ALD cycles, respectively. MWPCD and capacitance-voltage (C-V) measurements suggest that as-deposited ALD HfO2 layer leads to a better surface passivation compared to as-deposited ALD Al2O3 layer. Further, the results suggest that there exist fixed negative charges in the bulk of the ALD dielectrics and this contributes to the field effect passivation of the silicon surfaces.

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