Reklaitis, IgnasIgnasReklaitisGrinys, TomasTomasGrinysTomašiũnas, RolandasRolandasTomašiũnasPuodžiunas, TomasTomasPuodžiunasMažulė, LinaLinaMažulėSirutkaitis, Valdas A.Valdas A.SirutkaitisLin, ChunhanChunhanLinCHIH-CHUNG YANG2018-09-102018-09-102015http://www.scopus.com/inward/record.url?eid=2-s2.0-84930211868&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/391500A new original method to reduce time and resource consuming photolithography mask production operations has been suggested. By means of femtosecond laser direct writing, thus, gaining cleaner surrounding than for nano- and pico-second pulse processing, a 45° angle ablation geometry has been proven. LED chip separation trenches and n-GaN layer exposure were made simultaneously saving from one fundamental processing and alignment step without adverse effect from the laser-processing on the quantum well region. © 2015 Elsevier Ltd. All rights reserved.Femtosecond laser; GaN; Light-emitting diode; Processing; Trenchjournal article10.1016/j.optlaseng.2015.05.0022-s2.0-84930211868