Nondestructive measurements of depth distribution of carrier lifetimes in 4H-SiC thick epitaxial layers using time-resolved free carrier absorption with intersectional lights
| Autor: | Akira Miyasaka, Tomohisa Kato, Hajime Okumura, Kazutoshi Kojima, Takashi Hirayama, Masashi Kato, Keisuke Nagaya |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science business.industry System of measurement Resolution (electron density) Carrier lifetime Epitaxy 01 natural sciences 010305 fluids & plasmas Cross section (physics) 0103 physical sciences Optoelectronics Free carrier absorption Diffusion (business) business Instrumentation Voltage |
| Zdroj: | The Review of scientific instruments. 91(12) |
| ISSN: | 1089-7623 |
| Popis: | To achieve low on-state and switching losses simultaneously in SiC bipolar devices, the depth distribution of the carrier lifetime within the voltage blocking layer and the techniques used for observing the carrier lifetime distribution are important considerations. We developed a measurement system of the time-resolved free carrier absorption with intersectional lights (IL-TRFCA) for the nondestructive measurements of the depth distribution of the carrier lifetime in 4H-SiC thick epilayers. To confirm the reliability of the measurement results, we also performed TRFCA measurements to the cross section of the samples. As a result, although the lifetimes are underestimated owing to an inevitable diffusion of the carriers from the measurement region, the system was able to observe a carrier lifetime distribution up to a depth of 250 μm. Our IL-TRFCA system demonstrated a depth resolution of ∼10 μm, which is the best resolution among previously reported nondestructive measurement techniques. We consider the proposed system to be useful for the development of SiC bipolar devices. |
| Databáze: | OpenAIRE |
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