Krystian Król

Influence of Phosphorus Implantation on Electrical Properties of Al/SiO2/4H-SiC MOS Structure

This paper describes the effects of phosphorus implantation into n-type 4H-SiC substrate prior to standard dry oxidation process. Phosphorus incorporation has been reported to be one of the most efficient means of increasing SiC MOSFET field mobility however the physical basis of this phenomenon is still not clear. The aim of this research is to investigate the influence of phosphorus implantation on trap density profile close to conduction band of silicon carbide and to gain understanding of physical processes responsible for observed trap density improvement in phosphorus related oxidation technologies of silicon carbide.

The Influence of Post-Oxidation Annealing Process in O2 and N2O on the Quality of Al/SiO2/n-Type 4H-SiC MOS Interface

The effect of the n-type 4H-SiC (0001) oxidation in wet O2 at temperature of 1175 °C followed by low temperature annealing in N2O at temperature of 800°C for 2 or 4 hours followed by high temperature annealing in nitrogen ambient on nitrogen distribution in silicon dioxide was investigated. It was shown that the oxidation and annealing have a strong impact on the behavior of electrical parameters of MOS capacitors using the oxides as gate dielectric what is probably an effect of nitrogen incorporation. The explanation of the observed electrical properties is included.

Influence of Nitrogen Implantation on Electrical Properties of Al/SiO2/4H-SiC MOS Structure

In this article, an influence of nitrogen implantation dosage on SiC MOS structure is analyzed using wide range of nitrogen implantation dose (between ~1013 – 1016). Authors analyzed electrical and material properties of investigated samples using C-V, I-V measurements, Raman spectroscopy, and XPS profiling. It has been shown that surface state trap density is directly connected to implantation damage and thus implantation conditions. Using research results a trap origin at given energy can be concluded.

Selective deep wet etching of fused silica optical fibers for sensing applications

In the paper we discuss crucial aspects of selective deep wet etching technology of fused silica optical fibers. The technology includes preparation of the fiber, photolithography aiming to create a mask for etching, wet etching process and photoresist removal. We also discuss the influence of removing polyimide layer from the fiber, photoresist type, thickness of the photoresist and etching time. The developed technology allows for obtaining periodic variations in the fiber diameter resulting in formation of corrugated long-period grating (LPG). Introduction of strain induces appearing of attenuation peak in the transmission spectrum of the fiber. The developed technology can be also applied for fabrication of other optical fiber devices.