Investigation of the nanoscale features fabricated on the HOPG surface induced by STM electric lithography under different voltage regions in ambient conditions

► Nanometer-scale pits and line were generated under different voltage regions. ► 10 nm or so uniform pits were fabricated around 3 V. ► Exfoliation of the graphite flakes was observed when voltage was above 5 V or so. ► Mechanisms in distinct regions were discussed experimentally and analytically.