Controllable Fabrication Of AlN Periodic Micro/Nano Arrays

As the third generation wide band gap semiconductor material,aluminum nitride(AlN)has many excellent characteristics,such as wide band gap,small dielectric constant,high electron drift rate,high thermal conductivity,stable chemical properties,etc.,which is the core of the third generation semiconductor industry,such as deep UV optoelectronic devices,high temperature,high frequency and high power microwave devices,especially in military,satellite,national defense and security fields The future of application.Through the study of AlN material etching,we can lay a solid foundation for the later device manufacturing and development of application fields.In this paper,through the combination of pattern mask and wet etching,the anisotropy limitation of unshielded AlN etching has been successfully suppressed.The controllable display of micro nano structure with periodic arrangement has been realized on the 2-inch AlN/sapphire template,and its process has been studied.It is found that no matter whether the strip mask is parallel to or perpendicular to the positioning edge,the wet etching will not show anisotropy under the mask effect,but will be etched along the strip window to the sapphire substrate,and the lateral etching rate in the mask coverage area is constant and low.It is found that the surface shape of the micro nano structure etched by the dot mask(circular)follows the mask shape.The periodic micro nano array prepared by this method has good boundary shape.Based on the successful preparation of micro/nano column array,the device preparation technology of single nano column was further studied,and an AlN micro/nano column piezoelectric device was prepared.Firstly,a single nanopillar is removed from the substrate by mechanical method and transferred to the flexible substrate.By making mark on the flexible substrate,we can determine the specific position of the micro/nano column,and then through the electron beam exposure system,we can make electrode patterns at both ends of a single micro/nano column.After the deposition of metal by electron beam evaporation,we can measure and study its piezoelectric properties through the electrochemical workstation.Because there is no precedent for this experimental scheme,and the operation involved in the specific experimental process needs a high degree of proficiency,the time reason failed to successfully prepare a good device.However,it provides a feasible scheme for the study of micro nano AlN optoelectronic devices.