Fabrication The Non-polar Preferred Orientation ZnO Thin Films On Modified P-type Si Substrate

At the present stage the study of non-polar ZnO thin films have attracted more and more attention both in the nation and abroad, that is because the intrinsic direction along the growth of the ZnO can cause piezoelectric effect and spontaneous polarization effect due to its own structure, thus greatly limit the ZnO thin film device of practical application. On the contrary, non-polar preferred orientation ZnO thin film has a natural advantage in the structure and properties, therefore, in this paper to obtain the high quality of non-polar preferred orientation ZnO thin film is the final experimental purposes. This article is divided into two parts, the first part is through using wet chemical etching technology for surface modification on the single crystal p-type Si(100) substrate to obtain the desired substrate, the surface has continuous V-groove and it is expected that according using this method to get random arrangement of ZnO thin film; Secondly is that through using CBD method on single crystal p-type Si substrate to grow non-polar ZnO thin films, and then in order to test its electrical properties as pn junctions. The main working content includes the following aspects:Firstly using anisotropic wet etching technology,5 mol/L KOH and 1 mol/L IPA as etching agent, mixed solution preparation TiO2 thin films by magnetron sputtering method as etching mask, in the single crystal Si (100) substrate we can get the neat rows of "V" shaped groove structure. And we discuss the different etching time, different cleaning method and other factors which affect final etching morphology. The experimental results show that with the increasing of etching time, depth and width of "V" shaped groove are increasing gradually, at the same time, TiO2 mask is consuming. When the mask was consumed totally,it has formed the tip of the groove structure which began to deterioration caused by corrosion structure. Water bath temperature should be controlled in 55 ?, after 35 minutes of etching in the thickness of 120 nm.TiO2mask can protect the underlying surfaces of Si.The surface has smooth and flat structure of "V" type grooves. Si substrate for "V" shaped groove structure is the foundation of the follow-up work, for the next step of nonpolar ZnO nanostructures membrane preparation of deposit provides a good substrate material.Secondly, fabrication of non-polar ZnO thin film, starting from the fabrication conditions of seed layer first, in ZnO,the zinc ion concentration, and sol-gel machine's speed,preheat temperature and sintering temperature are the optimal parameters. By changing the seed layer of spin frequency to change the polarity of the surface grain size in the seed layer, based on in-depth analysis to the polarity of the seed layer and the relationship between the polarity of the ZnO thin films and seed layers, we can get the conclusion that the polarity of the ZnO thin film increases with the increasing polarity of the seed layer. Then, from the perspective of the changing polarity in the CBD solution, by changing the types of organic solvents and alcohols ratio between water, alcohol and cyclohexane to alter the polarity of the subsequent growth mode in ZnO thin films and the growth mechanism and on this basis to determine the best ratio of all these solutions. The tentative in nonpolar ZnO thin film on etched Si(100) substrate which is prepared and determined by the substrate's pattern.The non-polar ZnO thin film's electrical properties remains to be further explored.