Wafer-scale 3D shaping of high aspect ratio structures by multistep plasma etching and corner lithography

Shu Ni*, Erwin J.W. Berenschot, Pieter J. Westerik, Meint J. de Boer, René Wolf, Hai Le-The, Han J.G.E. Gardeniers, Niels R. Tas*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Scopus)
121 Downloads (Pure)


The current progress of system miniaturization relies extensively on the development of 3D machining techniques to increase the areal structure density. In this work, a wafer-scale out-of-plane 3D silicon (Si) shaping technology is reported, which combines a multistep plasma etching process with corner lithography. The multistep plasma etching procedure results in high aspect ratio structures with stacked semicircles etched deep into the sidewall and thereby introduces corners with a proper geometry for the subsequent corner lithography. Due to the geometrical contrast between the gaps and sidewall, residues are left only inside the gaps and form an inversion mask inside the semicircles. Using this mask, octahedra and donuts can be etched in a repeated manner into Si over the full wafer area, which demonstrates the potential of this technology for constructing high-density 3D structures with good dimensional control in the bulk of Si wafers.

Original languageEnglish
Article number25
JournalMicrosystems and Nanoengineering
Issue number1
Publication statusPublished - 23 Mar 2020


Dive into the research topics of 'Wafer-scale 3D shaping of high aspect ratio structures by multistep plasma etching and corner lithography'. Together they form a unique fingerprint.

Cite this