Micro Electrolithography System Development

Electric field induced patterning in Cr film under ambient conditions: A chemical reaction based perspective

“…In practice, various types of SPL techniques have been invented depending on the nature of the interaction, such as mechanical, electrical, thermal, and chemical, between the tip and the substrate surface [1]. In particular, SPL techniques involving electric field or currents (SPL-E), such as electro-lithography (ELG) [2,3], etc., are quite attractive, as they work under ambient conditions and produce patterns of widths ranging from a few nanometers to hundreds of micrometers using the same setup [3]. SPL-E may be implemented by a scanning tunneling microscope (STM), wherein a tunneling current can be used in the non-contact mode for oxidizing metals locally [4,5], or an atomic force microscope (AFM), wherein a bias between the probe and the substrate is used to induce the desired surface modification, including oxidation, etc., in the contact mode [6].…”

“…created using SPL-E [9][10][11]. However, as explained next in the context of ELG, all SPL-E techniques suffer from lack of repeatability of patterns [2,3,9], that is often attributed to the lack of unambiguous understanding of the mechanism through which electric field or current interacts with the substrate surface. Resolving this ambiguity is the primary goal of this study.…”

“…ELG is a new SPL-E technique that is based on the electric current induced liquefaction of Cr film around the cathode tip [2,3,12]. As shown in Fig.…”

“…1b has a width of ~100 μm, patterns as narrow as <10 nm in polymer and ~40 nm in transferred metal have been obtained using ELG [3]. Given the ease of operation of ELG, the faster rate of liquefaction of material and the excellent resolution of the patterns achieved by controlling the force applied onto the tip, electric field applied, etching of polymer layer placed in between Cr film and substrate, etc., ELG appears to be quite promising in terms of a unique combination of throughput and resolution [2,3].…”

Introducing Water Electrolithography

“…The basic working principle of all SPL techniques is the modification of the surface of a substrate using a sharp probe tip. , Therefore, various SPL techniques have evolved depending on the nature of the interaction between the tip and the surface, such as oxidation-SPL, thermal-SPL, field-emission SPL, mechanical-SPL, dip-pen nanolithography (DPN), electrolithography (ELG), etc. , The flexibility in manipulating the tip-substrate surface interaction proffers SPL to be suitable for both direct writing (such as DPN, ELG in oxidation mode, , etc.) and indirect patterning (such as ELG in the trench-creation mode, , etc.) that can be used to transfer the pattern to the material of choice, e.g., metal, semiconductor, ceramic, polymer, protein, etc. ,− In addition, SPL techniques, which are often inexpensive to establish and maintain as compared to EBL , EUV, etc., allow parallelization of processing: Herein, numerous tips can be independently controlled to write complex patterns in high throughput fashion as well as with enormous flexibility (or batch customizability). , Due to these advantages, SPL has become one of the most researched lithography techniques in the last few decades …”