磷化鋁銦鎵、氮化銦鎵與碳化矽半導體 之光學特性研究

Optical Studies of AlInGaP, InGaN and SiC Semiconductors and Heterostrcutures

施宇承(Yu-Cheng Shin)

指導教授 ： 馮哲川

國立臺灣大學/電機資訊學院/光電工程學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.00427

摘要

光學量測對於分析半導體材料具有很重要的地位，尤其是對於材料的結構、特性，甚至是物理機制。而近幾年的寬能隙半導體材料，由於它的材料特性非常適合應用在現今生活的電器設備用品上，譬如：發光二極體、積體電路原件…等，所以被廣泛而且深入的研究，縱使已經有不少上市產品應用寬能隙半導體為材料，但是仍然有許多的問題與困難需要被解答被突破，因此，我們將針對目前的許多挑戰做出研究。在這篇論文中，我們將藉由上述各項技術進行研究。
在半導體雷射開始崛起以後，已經有許多的物質成功地被研究出能發出紅光。而這其中又以AlInGaP最具代表性，因為它能在室溫底下發出波長為0.6

關鍵字

氮化銦鎵 ； 碳化矽

並列摘要

A series of optical characterization techniques, including Raman scattering, Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL), Photoreflectance (PR) and X-ray diffraction (XRD), were employed to assess wide band gap semiconductors which are semiconductor materials with electronic band gaps larger than an electron volt (eV) or two. They have been expected to be applied to various optoelectronic devices such as light emitting diodes (LED), lasers, and electron-beam sources. In this thesis, we study the optical properties, especially on Raman scattering, of aluminum indium gallium phosphorus (AlInGaP), indium gallium nitride (InGaN), silicon carbide (SiC) and indium arsenic phosphorus antimony (InAsPSb).
The quaternary alloy (AlxGa1-x)0.5In0.5P, lattice-matched to GaAs and with a direct band-gap transition in the green-red light wavelength range, is an important material in visible light emitting diodes (LEDs), laser diodes, heterojunction bipolar transistors (HBT), matrix for the growth of self-assembled quantum dots (QDs) [13] and devices for 630-700 nm wavelength range applications such as laser pointers, barcode readers, digital versatile disk (DVD) players and solid-state lighting. Metalorganic chemical vapor deposition (MOCVD) technology has been widely employed for the growth and industry production of this quaternary and related material. Atomic ordering may occur under certain conditions during the epitaxial growth of AlInGaP by MOCVD, which forms a Cu-Pt ordered structure, i.e. the group-III In, Ga and Al atoms spontaneously segregate into alternating {111} monolayers during growth rather than forming a disordered alloy with the In, Ga and Al atoms randomly distributed on all the group III sublattices. This ordering results in the reduction of alloy bandgap and the negative effects in the subsequently grown devices. It is important to control and optimize the growth conditions to avoid or depress the appearance of ordering and other types of defects, to acquire high quality AlInGaP layers.
ZnO has been considered as a substrate for epitaxial growth of III-Nitrides due to its close lattice and stacking order match. My works cover the growth of InxGa1-xN and GaN epitaxial layers on lattice-matched ZnO substrates by metal-organic chemical vapor deposition (MOCVD). Since MOCVD is the dominant growth technology for GaN-based materials and devices, there is a need to more fully explore this technique for ZnO substrates. However, there are a number of issues that need to be addressed for the MOCVD growth of GaN on ZnO. The thermal stability of the ZnO substrate, out-diffusion of Zn from the ZnO into the GaN, and H2 back etching into the substrate can cause growth of poor quality GaN. High-resolution X-ray diffraction (HRXRD) confirmed the epitaxial growth of GaN and InGaN films on ZnO. The optical and structural characterization of InGaN epilayer on ZnO substrates was measured by room temperature photoluminescence, temperature-dependent photoluminescence. In addition, a transition layer of Al2O3 on ZnO substrates have been employed for InGaN growth to help prevent Zn and O diffusion into the epilayers as well as assist nitride epilayer growth. HRXRD results show a single crystal InGaN film has been successfully grown on annealed Al2O3 coated ZnO substrates.
We study Raman scattering on 6H-SiC with two varied factors: temperature and free carrier concentration. There are many journals and reports of LOPC modes on high doping samples. And there are also many discussions about temperature-dependent Raman scattering. But we find out an unusual dependence of the LOPC mode shift with temperature in chapter 4. We suppose that it results from excited plasma by increasing temperature.
Finally, InAsPSb is one of the important center infrared compound semi conducting materials. Cause the InAsPSb crystal lattice match above the InAs or GaSb substrates by adjustment ingredient. Samples with rich arsenic composition which are located away from miscibility gap in quaternary composition plane show better surface morphology and crystal quality. Power dependent and temperature dependent optical measurements were performed on these samples. We have successfully grown InAsPSb samples on n+ (100) InAs substrates by gas-source molecular beam epitaxy.

並列關鍵字

InGaN ； SiC

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