Top-down process, comprising lithography and plasma etching is widely used in very-large-scale integration due to its scalability, has the greatest potential to fabricate graphene nanoribbon based nanoelectronic devices for large-scale intergraded circuits. However, conventional plasma etching inevitably introduces plenty of damage or defects to the etched materials, which drastically degrades the performance of nano materials. In this study, extremely low-damage neutral beam etching (NBE) is applied to fabricate ultra-low-defect graphene nanoribbon array (GNR). The ultra-low-edge-defect GNRs are fabricated by E-beam lithography followed by oxygen NBE from large-scale chemical-vapor-deposition-grown graphene. AFM images clearly shows the GNRs patterned by NBE and E-beam lithography, and Raman spectroscopy exhibits extremely low ID/IG of GNRs, which indicate that high-quality GNRs can be successfully fabricated by neutral beam. We also demonstrated bottom-gated field-effect transistor with the high-quality GNR and observed a high carrier mobility (>200 cm2V-1 s -1) at room temperature.