A printable form of single-crystalline gallium nitride for flexible optoelectronic systems

The procedures for generating printable forms of single-crystalline inorganic semiconductors with applications, was investigated. Microribbons of GaN were generated and fabricated onto plastic substrates, which was done using GaN thin films supported on sacrificial handle wafers, materials grown by a metal-organic chemical vapor deposition (MOCVD) process. The protocol used conventional photolithography and plasma etching of GaN thin films supported on Si (111) wafers to generate the structures, and soft lithography to print them onto a target substrate. High quality Si-doped GaN (0001)thin films were grown by MOCVD onto a Si(111) substrate having a 0.1-μm-thick AlN buffer layer. Then photolithography was used to define an etch mask of photoresist (PR) and an inductively coupled plasma (ICP) was used to etch the unmasked regions of GaN/AlN through underlying silicon substrate. After stripping the PR, an isotropic wet etchant was used to undercut the GaN/AlN and release it.