Electrically detected magnetic resonance of carbon dangling bonds at the Si-face 4H-SiC/SiO2_2 interface

SiC based metal-oxide-semiconductor field-effect transistors (MOSFETs) have gained a significant importance in power electronics applications. However, electrically active defects at the SiC/SiO$_2$ interface degrade the ideal behavior of the devices. The relevant microscopic defects can be identified by electron paramagnetic resonance (EPR) or electrically detected magnetic resonance (EDMR). This helps to decide which changes to the fabrication process will likely lead to further increases of device performance and reliability. EDMR measurements have shown very similar dominant hyperfine (HF) spectra in differently processed MOSFETs although some discrepancies were observed in the measured $g$-factors. Here, the HF spectra measured of different SiC MOSFETs are compared and it is argued that the same dominant defect is present in all devices. A comparison of the data with simulated spectra of the C dangling bond (P$_\textrm{bC}$) center and the silicon vacancy (V$_\textrm{Si}$) demonstrates that the P$_\textrm{bC}$ center is a more suitable candidate to explain the observed HF spectra.Comment: Accepted for publication in the Journal of Applied Physic

Effect of Asphyxia on Thrombotest Values in Low Birthweight Infants

Thrombotest was used as a measure of coagulation status in 55 low birthweight infants. The initial levels were similar in both babies who were asphyxiated at birth and in those who had uncomplicated deliveries. On the other hand, 24 hours after giving vitamin K(1), a rise in the mean percentage thrombotest activity was confined to the normal delivery group. No significant rise occurred in the babies who suffered from hypoxia. It is suggested that fresh frozen plasma should be given particularly to asphyxiated low birthweight infants in an effort to diminish their liability to haemorrhage