Gan Film Structure Of High-resolution X-ray Diffraction Characterization And Electrical Properties

As an importantⅢ-Ⅴgroup's nitride,GaN has been applied in many fields such as photo-electricity devices,light detectors and novel microelectronics devices etc because it almost owns all the typical merits of wide-band-gap semiconductors. Nowadays,GaN has become a focus in the development of semiconductor technology all over the world.However,just because some special properties of this material,it is very difficult to attain perfect p-GaN or n-GaN,the doping conditions account for the complicated changes of the crystal structures and electrical properties,the relationships between them are hard to understand completely,some essential correlated phenomena and mechanisms have still not obtain comprehensive and reasonable explanations as yet.Consequently,making some more systemic and deep corresponding research on GaN is valuable.In the Introduction of this master thesis,the potential applications of the GaN thin films,preparation methods and the current research on the relationship between the microstructure and properties of GaN thin films are reviewed.On the basis of the review,the investigation of the structure-properties of GaN thin films by X-ray diffraction methods is proposed.Main content of the thesis are also given in the Introduction.The thesis focused on using different measure methods of HRXRD(High Resolution X-ray diffraction) to figure the microstructures about Mg-doped p type GaN,Si-implanted n type GaN,and high Al content AIGaN,moreover,researched and discussed the dependences of electrical properties on microstructures detailedly.We found that the epitaxial strain in the Mg-doped GaN thin film was directly influenced by active-Mg and its correlative self-compensation effect besides thermal stress.In the analysis of Si-implanted GaN,the implantation-induced damages in GaN thin film were found complicate with the increase of implanted dose,when the dose increased to 1×10¹⁶ cm^-2,there was amorphous layer appeared in the area closed to the surface of GaN thin film,on the other hand,the temperature of RTA greatly influenced the electrical activation efficiency and carrier mobility,but the detailed relationship between dose and electrical activation efficiency was still not straightforward.The triple axis crystal X-ray diffraction performed on the high AI content A1GaN epitaxial layer showed that AIN template was more suitable to grow high AI content A1GaN than GaN template due to their lattice matching degree.These results obtained in these researches are complementary to the current study on the relationships between the microstructures and electrical properties of the GaN thin films.