Electrical properties of stacking faults and bounding partial dislocations in 4H-SiC Schottky diode were investigated by using electron-beam-induced current ͑EBIC͒ and cathodoluminescence ͑CL͒ techniques. EBIC images show that basal plane dislocation is easily dissociated into two partial dislocations ͓Si ͑g͒ 30°and C ͑g͒ 30°partials͔, with a stacking fault between them. The EBIC contrast of C ͑g͒ 30°partial is always several percent higher than that of Si ͑g͒ 30°partial. The stacking fault is brighter than the background, having the negative EBIC contrast. CL spectrum shows that a new peak ͑417 nm͒ appears at stacking fault position. The origin of bright stacking fault in EBIC image is discussed according to its quantum-well state.

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Minority-carrier lifetime is one of the key parameters governing the performance of semiconductor devices. Here, we report on tuning the minority-carrier lifetime through stacking fault (SF) defects in polytypic SiC. The SFs are distinguished in terms of their characteristic luminescence peaks at 482 nm, 471 nm, and 417 nm, respectively. Different from general point, linear, and volume defects, the planar SFs demonstrate the interesting phenomena of either decreasing or increasing the minority-carrier lifetime, which depend on the SF-related energy levels. The mechanism for the down/up modulation of the carrier lifetime through the SFs is discussed.

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Stacking faults ͑SFs͒ in semiconductors are generally regarded as the electrically active defects that reduce the minority carrier lifetime. In contrast to this typical phenomenon, here we report that the SFs in SiC functionalize as the ideal quantum well ͑QW͒ structure for electrons. Due to the QW effect, an increase of minority carrier lifetime is observed at the SF regions. The reason for the lifetime increment is discussed with the electron dissipation along the SF plane. Our results suggest that this is a general mechanism regarding the increase of minority carrier lifetime at the defects.Stacking faults ͑SFs͒ are one of the most fundamental planar defects in crystalline solids. The SFs occur in a number of crystal structures, but the common example is in close-packed structures. In Si material, the SFs are usually formed on ͕111͖ planes by the application of a shear stress and are regarded as the electrically active defects. 1,2 In a compound semiconductor, such as SiC, the situation becomes complicated since SiC is known to have hundreds of different polytypes. 3-5 Especially, the polymorphism of SiC is particular in that all its different crystalline forms have a same atomic plane in common and differ only in the stacking sequence along the direction normal to this plane. It has been reported that SiC has a very low SF energy. 6 Therefore, various kinds of SFs are expected to appear if the local stacking sequence is interrupted somewhat with respect to the host material.Indeed, several types of SFs differing in the stacking arrangement have been already observed in SiC. 7-11 Since SiC is a promising wide-bandgap semiconductor aimed at highpower, high-frequency, and high-temperature applications, many investigations of the SFs are related to the devices ͑p-i-n diodes͒, such as the following aspects: ͑i͒ the degradation of SiC devices; 12,13 ͑ii͒ the nucleation sites of the SFs; 14-16 ͑iii͒ the driving force for the SF expansion under forward bias stressing; 17-19 ͑iv͒ partial dislocations ͑PDs͒ bounding the SFs 20-22 and ͑v͒ theoretical calculation of the electronic state of the SFs. 23-25 However, the fundamental/ intrinsic properties of the SFs in SiC have not been clarified very well. The clarification may provide fundamental knowledge of SF behavior in polytypic materials as well as further facilitate the understanding of SF effect on device properties.In this paper, we report on the intrinsic feature of the SFs in SiC. Different from the common feature in Si, we show that the SFs in SiC act as the ideal quantum-well ͑QW͒ structure for electrons. We also observe an increase of minority carrier lifetime at the SFs, which is not generally expected. We thus propose that the lifetime increment is associated with the QW-related "pump effect" dissipating the majority carriers, which would be a general mechanism regarding the increase of minority carrier lifetime at the defects.The common polytype of SiC, 4H, was used in this work. The 4H-SiC epi-films ͑6 m thick͒ were grown on the n + -type 4H-SiC ͑0001͒ off...