Two-dimensional Layered Dielectric Materials And Their Synchrotron Radiation Characterizations

In recent years,with the rapid development of the global semiconductor industry,silicon-based materials have increasingly approached their physical limits.Due to the unique crystal structure and physical properties,two-dimensional(2D)materials as new semiconductor materials to next generation of high-performance semiconductors are expected to become a continuation of Moore's law.From the transistor level,compared with silicon-based semiconductor materials,the interface contact(semiconductor-insulator's interface,semiconductor-metal's interface)has a very large impact on the performance of the 2D electronic devices.Therefore,it is very important to find low-dimensional dielectric materials for 2D electronic devices' application.Compare with traditional dielectric layer materials such as silicon oxide,the two-dimensional dielectric material can form a van der Waals heterojunction with the two-dimensional layered channel,and the dielectric constant can be achieved by adjusting the chemical composition and interlayer coupling.2D dielectric material is a new system of dielectric materials with great potential of application.From the system integration level,the using of two-dimensional layered materials as the system of integrated circuits requires low-k materials as the the interconnection layer to reduce the power consumption of the system.In current,silicon-based low-k materials are difficult to reduce the k value,so it is very important to explore new types of low-k materials.In this thesis,we controlled the synthesis of transition metal oxyhalide single crystals and boron oxide nanoribbons structure materials by chemical vapor transport(CVT)and chemical vapor deposition(CVD).The X-ray single crystal diffraction,Raman spectroscopy and synchrotron radiation methods were used to reveal the crystal structure of the material,the phonon behavior and the coordination information of the material atoms.Combine the information of the internal structure of the materials and the electrical properties of the materials,the structure-activity relationship of the materials has been revealed.The specific research contents of this paper are showed as follows:1.The two-dimensional layered VOCl single crystal was synthesized by chemical vapor transport method,combined with X-ray single crystal diffraction and synchrotron radiation spectroscopy,the ternary crystal structure and atomic coordination information were determined.Using micro-nano processing methods,a MoSe2/VOCl/graphene heterojunction device was constructed,the dielectric constant of VOCl(about 11.7)was measured,and it was proved that it can significantly improve the dielectric layer characteristics of two-dimensional electronic devices.2.The two-dimensional layered CrOCl single crystal with weaker interlayer force was synthesized by chemical vapor transport method,combined with X-ray single crystal diffraction and synchrotron radiation spectroscopy,the ternary crystal structure and atomic coordination information were determined.Using micro-nano processing methods,a MoSe2/CrOCl/graphene heterojunction device was constructed,the dielectric constant of CrOCl(approximately 10.6)was measured,and its potential advantage as a two-dimensional dielectric layer material was pointed out,and easier to prepare the dielectric layer than VOC1.3.The N-BO_x nanoribbons were synthesized by chemical vapor deposition method,and combined with electron microscopy and synchrotron radiation spectroscopy,the amorphous crystal structure and diversified composition of the material were confirmed.Using micro-nano processing methods,electronic devices were constructed,and the low dielectric constant characteristics of nitrogen-doped boron oxide nanoribbons(approximately 2.39)were measured,verifying its potential application in the interconnection layer of integrated circuits.