Phase mode nanomachining on ultra-thin films with atomic force microscopy

Fabrication of Sub‐Micrometer‐Sized MoS2 Thin‐Film Transistor by Phase Mode AFM Lithography

“…AFM Lithography and Imaging : The experimental system of phase mode of AFM lithography consisted of a commercial AFM (Dimension Icon, Bruker), a piezoceramic disk (NCE51, Noliac), a lock‐in amplifier including a function generators and a PID controller (HF2LI, Zurich Instruments AG), and a signal subtractor (custom design). The phase setpoint value used in the phase mode nanomachining was pre‐determined by simply scratching a groove on the polymer thin film . The force mode of AFM lithography was carried out by maintaining a constant cantilever deflection.…”

“…The phase response signal of cantilever vibration is extracted by the lock‐in amplifier and sent to the PID controller to control the machining depth by regulating the probe position in Z direction, which is the machining force. Because the phase response only related to the machining depth and was not affected by the debris in the machining process, the machining depth and state is much more stable than the force mode . In addition, the phase setpoint at the interface can be easily pre‐determined by a simple scratching on the polymer thin film with an increasing applied force.…”

“…Using this pre‐determined phase setpiont value, the polymer thin film will be cut through without over‐cut and under‐cut. In conventional force mode, the huge applied force is used to ensure the valid machining results …”

Tip-Based Nanomachining on Thin Films: A Mini Review

“…To date, nanodots/pits, nanogrooves/lines, and even three-dimensional (3D) complex structures have been achieved on these films by using the TBN method. Various types of nanomachining methods based on tips involving static scratch [33][34][35], DPL [9,13,14,36,37], and vibration-assisted approach [22,[38][39][40][41][42][43][44][45][46], especially the ultrasonic vibration-assisted (UV-assisted) method, have been used to machine nanopatterns on polymer films (Table 1). Heated tips have been found to offer important advantages in machining polymer film materials.…”

“…Nanopatterns of varying dimensions, including nanopits/dots [9,13], nanogrooves/lines [14,15], and bundles [16], have been achieved on polymer films via TBN and have been applied to data storage [17], etch masks [18], sacrificial layers for lift-off [19], and so on. As for machining on metal films, numerous TBN methods have been employed, and they include constant force mode [20], dynamic plowing lithography (DPL) [21], phase mode nanofabrication [22], vibration-assisted nanomachining [23], AFM electric lithography [24], and coupling AFM lithography [25]. Reports have shown that 2DMs demonstrate immense potential in the fabrication of nanobiosensors [26] and nanoelectronic sensors [2].…”