Hui-Feng Li

INTERFACIAL CHARACTERISTICS OF N2O AND NO NITRIDED SIO2 GROWN ON SIC BY RAPID THERMAL PROCESSING

Interfacial characteristics of Al/SiO2/n-type 6H–SiC metal–oxide–semiconductor capacitors fabricated by rapid thermal processing (RTP) with N2O and NO annealing are investigated. Interface state density was measured by a conductance technique at room temperature. RTP oxidation in pure O2 leads to an excellent SiO2/n-type 6H–SiC interface with interface state density in the order of 1010–1011 eV−1 cm−2. NO annealing improves the SiO2/n-type 6H–SiC interface, while N2O annealing increases the interface state density.

Nitridation of silicon-dioxide films grown on 6H silicon carbide

This letter addresses the question of why it is possible to grow high-quality oxide films on N-type but not on P-type SiC. It provides results which indicate that the oxide/SiC interface would be inferior to the oxide/Si interface for both N-type and P-type SiC, if it were not for the beneficial effects of nitrogen incorporation. The letter presents, for the first time, results on nitridation of thermally grown oxides in NO and N/sub 2/O. The results demonstrate that the oxides grown on P-type can be improved by NO annealing, but not by N/sub 2/O annealing.

Investigation of nitric oxide and Ar annealed SiO2/SiC interfaces by x-ray photoelectron spectroscopy

Silicon dioxide (SiO2)/silicon carbide (SiC) structures annealed in nitric oxide (NO) and argon gas ambiences were investigated using x-ray photoelectron spectroscopy (XPS). The XPS depth profile analysis shows a nitrogen pileup of 1.6 at. % close to the NO annealed SiO2/SiC interface. The results of Si 2p, C 1s, O 1s, and N 1s core-level spectra are presented in detail to demonstrate significant differences between NO and Ar annealed samples. A SiO2/SiC interface with complex intermediate oxide/carbon states is found in the case of the Ar annealed sample, while the NO annealed SiO2/SiC interface is free of these compounds. The Si 2p spectrum of the Ar annealed sample is much broader than that of the NO annealed sample and can be fitted with three peaks compared with the two peaks in the NO annealed sample, indicating a more complex interface in the Ar annealed sample. Also the O 1s spectrum of the NO annealed samples is narrow and symmetrical and can be fitted with only one peak whereas that of the Ar an...

Improved reliability of NO-nitrided SiO 2 grown on p-type 4H-SiC

This letter demonstrates that the reliability of oxides grown on p-type 4H-SiC can be dramatically improved by NO nitridation. High field (-8 Mv/cm) room-temperature stressing and high-temperature negative-bias (250/spl deg/C, -4 MV/cm) testing were used to investigate the reliability of NO nitrided oxides. Relatively small changes in the flat-band voltage, interface-trap density and leakage current were observed after 5000 s in the case of NO nitrided oxides, while shorter stressing shifted these parameters dramatically in the case of N annealed control samples.

Analysis of Fowler–Nordheim injection in NO nitrided gate oxide grown on n-type 4H–SiC

Abstract Fowler–Nordheim injection in NO nitrided gate oxides, grown on n-type 4H–SiC, has been investigated at room temperature and 300°C. The results show that NO increases the electron injection barrier height to a value which is very close to the theoretical value at room temperature. Excessive temperature dependence of the electron injection barrier height is also significantly reduced by the nitridation.

Analysis of Fowler-Nordheim injection in NO nitrided gate oxide grown on n-type 4H-SiC

F-N injection in NO nitrided gate oxides, grown on n-type 4H-SiC, has been investigated at room temperature and 300/spl deg/C. The results show that NO nitridation has a positive effect on the Fowler-Nordheim electron injection at high electric fields. The electron injection barrier height is very close to the theoretical value at room temperature. The temperature dependence of the electron injection barrier height is reduced by nitridation.

Nitrogen in Ultra Thin Dielectrics

Gas phase growth or annealing of pre-grown oxides in nitrous oxide (N2O) on silicon produces desirable dielectric layer properties. However since this gas is really a dilute form of nitric oxide (NO) it could be expected that it would give such properties as well. In this paper we consider the use of NO as both a growth environment and as an annealing gas firstly on silicon and then briefly on silicon carbide. We note that unlike N2O, NO has some unique properties for silicon applications that may be useful for future generation integration. Its as grown self limiting growth properties for example may be helpful in layer thickness control. However we also see that the NO can have deleterious effects through the introduction of too much nitrogen at the interface transition layer. The paper explores both the physical and electrical properties of as grown and annealed layers exposed to NO for silicon. We also proposed a growth model that has particular relevance, and then presents some results for fine geometry MOSFET devices. Finally a brief consideration of silicon carbide shows some similarities in properties to that of silicon when oxides grown on it are annealed in NO and N2O. In the case of SiC only annealing is considered, but in this case NO does show superior properties to those gained through the use of N2O.

Electrical characteristics of NO nitrided SiO/sub 2/ grown on p-type 4H-SiC

This paper presents the results of NO nitridation of SiO/sub 2/ grown on p-type 4H-SiC. NO nitridation has a beneficial effect on the quality of the oxides grown on p-type 4H-SiC. The C-V curves become smoother and sharper after NO annealing. Frequently observed interface ledge is also removed from NO annealed samples.

Distribution and chemical bonding of N at NO nitrided SiC/SiO/sub 2/ interface

This paper presents results of the physical characterization of NO nitrided SiC/SiO/sub 2/ interfaces by XPS analysis. The results show different interface chemistries between NO nitrided and Ar annealed SiC/SiO/sub 2/ interfaces. After NO nitridation, N builds up at the SiC/SiO/sub 2/ interface forming Si/spl equiv/N bonds. The NO nitrided SiC/SiO/sub 2/ interface is free of the complex interface oxide/carbon compounds which are suggested to be the reason for the inferiority of the SiC/SiO/sub 2/ interface compared to the Si/SiO/sub 2/ interface.

Effect Of No On The Electrical Characteristics Of SiO 2 Grown On P-Type 4H SiC

In this paper the effect of NO nitridation on the electrical characteristics of the oxides grown on p-type 4H SiC has been investigated. The results show that NO nitrided oxide has a lower interfacial trap density and a lower net oxide charge compared to N 2 annealed oxides.