First Threshold Voltage in the Process of Electrostatic Field Induced Reorientation of Diblock Copolymers

In recent advancements in soft-semiconductor manufacturing, a pivotal phenomenon pertinent to nano-lithographic techniques involves the reorientation of parallel lamellae in lamellar diblock copolymers confined between two parallel plates. This reorientation results in a transition to a perpendicular lamellar alignment when an electric field, applied perpendicular to the plates, surpasses a critical threshold value. Such electric field-induced reorientation is of paramount importance for nanolithographic applications. During this structural transition, two distinct characteristic voltages are identified: the first corresponds to the onset of reorientation, where the parallel lamellae begin to tilt toward an upright configuration; and the second marks the completion of reorientation, where the lamellae achieve full perpendicular alignment. Through rigorous stability analysis, we have derived an analytical expression for the first characteristic voltage, providing a theoretical framework that enhances the understanding of the underlying experimental phenomena and offers valuable insights for industrial applications.