ISSN:
1432-0630
Schlagwort(e):
PACS: 61.70; 68.55; 78.70
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
,
Physik
Notizen:
Abstract. Positron lifetime measurements on bulk samples of single crystal SiC wafers have shown that both 6H and 4H polytypes exhibit a bulk lifetime of 150±2 ps. All samples contained a second, defect-related lifetime component, ranging in value from 250 to about 300 ps with rather low intensities. The defect structure exhibited by the nanocrystalline samples is, not unexpectedly, much more complex. Positron beam experiments on Electron Cyclotron Resonance Chemical Vapour Deposited (ECR-CVD) SiC thin films showed that the positrons are very sensitive to changes in important film parameters as a function of the deposition conditions. It was found that the film density is lower than expected, probably due to hydrogen incorporation; variations in composition among different films were detected through variations in the S parameters, and differences were observed in the electric field at the film–substrate interface due to hydrogen passivation of dangling bonds and different substrate resistivities.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01538211
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