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Top-down fabrication of horizontally-aligned gallium nitride nanowire arrays for sensor development



Guannan Liu, Baomei Wen, Ting Xie, Audie M. Castillo, Ratan K. Debnath, Albert Davydov


This paper describes a method for mass production of CMOS compatible gallium nitride (GaN) nanowire (NW) arrays for sensors and other application. The method uses a top-down etching technique starting from a thin-film GaN layer. The etching process on a fixed substrate creates the horizontally aligned GaN NWs. This contrasts with conventional methods involving vertical growth, sonication detachment and subsequent horizontal alignment of a single NW. The detachment-alignment free method described here is shown to provide reliable and repeatable NWs and NW arrays. Furthermore, the length of the NW can be precisely defined and customized. This is difficult to achieve in the current commonly practiced approaches. Surface defect structure and electrical behavior of nanowires fabricated using the new technique are reported. In this study, we successfully delivered 300nm and 500nm wide GaN NW arrays, the total length can be accurately controlled from short (5um) single wire runs to extremely long (5mm) meander shaped arrays. NWs (in parallel or interdigitated) aligned between two electrodes arrays are achievable as well. The wet etching method is shown to provide surfaces of lower defect density. This was ascertained through both photoluminescence (PL) and Field Emission Scanning Electron Microscopy (FESEM) studies. These NWs can be used to create many high-sensitivity sensors (chemical, gas, biological and physical) and can be integrated with other CMOS and MEMS devices.
Microelectronic Engineering


Gallium nitride, nanowire, top-down approach, surface treatment, and sensors


Liu, G. , Wen, B. , Xie, T. , Castillo, A. , Debnath, R. and Davydov, A. (2015), Top-down fabrication of horizontally-aligned gallium nitride nanowire arrays for sensor development, Microelectronic Engineering (Accessed April 20, 2024)
Created July 1, 2015, Updated March 17, 2017