Papers by Keyword: Dangling Bond

Abstract: We present an electrically detected electron-spin-resonance (ESR) study on SiO2-SiC interface regions of n-channel lateral 4H-SiC MOSFETs with hydrogen annealing. This characterization technique can reveal electrically active defects that interact with channel currents of the MOSFETs. The defects were observed at 20 K, and were labeled “PH0” and “PH1”, one of which (PH1) exhibited a 1H hyperfine splitting of 5.3 mT.

Abstract: We have investigated the techniques to improve the channel mobility of SiC MOSFETs and found that the hydrogen termination of dangling bonds at a MOS interface is very effective in improving the channel mobility, particularly that of the interface fabricated on a (11-20) face wafer. A high channel mobility of MOSFET on the (11-20) face was achieved to 244cm2/Vs by new process which can terminate dangling bonds by hydrogen. The vertical MOSFET, which is prepared using this process, has a low on-resistance of 5.7 mΩcm2 and a breakdown voltage of 1100 V. The channel resistance is estimated at 0.58 mΩcm2.

Abstract: We report a density functional theory study of N and NO passivation of surface dangling bonds at the Si-face of (0001) 4H-SiC. Results agree with many key experimental findings in nitrogen processed devices including: observed interface N coverage and characteristic changes in Dit. Dangling bonds at the SiC surface are fully passivated by 1/3 ML N or NO coverage. Upon passivation the surface is found to incur negligible strain and no reconstruction. Allowing atomic O to interact with the 1/3 ML N or NO passivated surface, we find oxygen prefers to incorporate into SiO2 rather than adsorb to the surface. This indicates the possibility of oxide deposition onto nitrogen passivated (0001) 4H-SiC surfaces.

Abstract: This paper mainly describes that nano-scale surface structure change in dangling bond density related to free volume caused the reinforcement of inorganic glass irradiated by electron beam. Based on the results of electron spin resonance experiments, EB irradiation enhanced the density of dangling bonds at the glass surface. To confirm the strengthening principle, we have employed EB irradiation of inorganic glass. The EB reinforcement was explained as caused by stress relaxation induced by dangling bonds formation in the tight network structure of silica and soda glasses.

Abstract: Properties of defects encountered at the oxidized surfaces of silicon carbide (SiC) suggest their origin to be different from the dangling-bond-type defects commonly observed in the oxidized silicon. Among different models of these SiC/oxide interface states advanced during the past decade, two have received substantial experimental support. This first one is the “carbon cluster” model, which ascribes the traps with energy levels in the SiC bandgap to inclusions of elemental carbon formed during the SiC surface treatment and subsequent oxidation. The second model invokes intrinsic defects of SiO2 to account for the high density of interface states in the energy range close to the conduction band of SiC. Achievements in reducing the SiC/SiO2 defect density are discussed.