High‐frequency electrical properties tomography at 9.4T as a novel contrast mechanism for brain tumors

Abstract A variant of electroencephalogram (EEG) power spectral mapping called power ratio index (PRI) mapping was used to monitor 15 patients with malignant brain tumors. This index is generated by dividing the low frequency (delta, theta) power by the high frequency (alpha, beta) power. Because the nonparoxysmal effect of a brain tumor on the EEG is reflected as a relative loss of high frequency power and a gain in low frequency power, utilization of the PRI has the effect of placing the epicenter of the “power dysfunction” coincident with the epicenter of the tumor.

Download Full-text

Thick Oxide Layers on N and P SiC Wafers by a Depo-Conversion Technique

MRS Proceedings ◽

10.1557/proc-572-57 ◽

1999 ◽

Vol 572 ◽

Cited By ~ 1

Author(s):

Q. Zhang ◽

V. Madangarli ◽

I. Khlebnikov ◽

S. Soloviev ◽

T. S. Sudarshan

Keyword(s):

Electrical Properties ◽

Effective Charge ◽

High Frequency ◽

Breakdown Field ◽

Mos Capacitors ◽

Mos Capacitor ◽

Oxide Layers ◽

Oxide Breakdown ◽

Thermal Oxide ◽

Capacitance Voltage

ABSTRACTThe electrical properties of thick oxide layers on n and p-type 6H-SiC obtained by a depoconversion technique are presented. High frequency capacitance-voltage measurements on MOS capacitors with a ∼ 3000 Å thick oxide indicates an effective charge density comparable to that of MOS capacitors with thermal oxide. The breakdown field of the depo-converted oxide obtained using a ramp response technique indicates a good quality oxide with average values in excess of 6 MV/cm on p-type SiC and 9 MV/cm on n-type SiC. The oxide breakdown field was observed to decrease with increase in MOS capacitor diameter.

Download Full-text

Nitrogen-Atom Bonding at Sio2/SI Interfaces in Metalinsulator-Semiconductor (MIS) Stacked Gates Made by Integration of Plasma Assisted Oxidation-Deposition and Rapid Thermal Processing

MRS Proceedings ◽

10.1557/proc-303-325 ◽

1993 ◽

Vol 303 ◽

Cited By ~ 1

Author(s):

Y. Ma ◽

T. YAsuda ◽

G. Lucovsky

Keyword(s):

Electrical Properties ◽

Thermal Processing ◽

High Frequency ◽

Electron Spectroscopy ◽

Auger Electron ◽

Rapid Thermal Processing ◽

Atom Concentration ◽

Bonding Structure ◽

Static Capacitance ◽

Capacitance Voltage

ABSTRACTSiO2 thin films were deposited by remote PECVD on Si surfaces exposed to species generated in O2/N2 and O2/NH3 plasmas. The surface chemistry was studied by Auger Electron Spectroscopy, AES, and the electrical properties of the SiO2/Si interface by high frequency and quasi-static Capacitance-Voltage, C-V, measurements. The AES results showed that Ccontamination was removed by exposure to both plasma-excited gas mixtures, but that N-atoms were incorporated into the SiO2 film, and Si-N bonds were formed at the SiO2/Si interface. C-V measurements indicated that the Si-N bonding structure, rather than the N-atom concentration, is critical in determining the interface electrical properties. The effects of Rapid Thermal Annealing, RTA, on the electrical properties of these SiO2/Si interfaces were also studied.

Download Full-text