Direct machining and imprinting of Si are beneficial for simplifying the fabrication of microelectromechanical systems, nanoelectromechanical systems, optical devices, and fin field-effect transistors, and for reducing process costs. Electrochemical micromachining has been introduced for highly doped Si, but complex structures cannot be imprinted directly. With chemical imprinting, complex nano/micropatterns can be imprinted even on low-doped Si, but the physical contact can damage the templates. In this study, we demonstrated an electrochemical local etching (ELE) method for fabricating nano/micrometer structures on semiconductors in a noncontact manner. Polygon tips were prepared as templates on highly doped n-type Si via etching in KOH. A constant space is maintained between the template and the target Si using a gap layer to prevent damage and contamination. In the etchant vapor, the voltage bias between the template and the target Si leads to condensation of the etchant. Because the etching region is localized by the condensation of the etchant, even low-doped semiconductors can be imprinted in submicrometer patterns in a single step. When the etchant condensation is suppressed, the etching area is reduced and the resolution is increased, allowing direct imprinting of the polygonal submicrometer pattern. ELE has the potential to produce complex nano/micrometer structures in a single step without photoresists and physical contact.
Bibliographical noteFunding Information:
This research was supported by MSIT (Ministry of Science and ICT), Korea, under the “ICT Consilience Creative Program” (IITP-2019-2017-0-01015) supervised by the IITP (Institute for Information & Communications Technology Promotion). This research was also supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology (NRF-2016R1D1A1A09918647) and by Korea Electric Power Corporation (Grant number 3): R19XO01-22.
© 2020 The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Materials Science(all)