Digital projection photochemical etching defines gray-scale features

Chris Edwards, Kaiyuan Wang, Renjie Zhou, Basanta Bhaduri, Gabriel Popescu, Lynford L. Goddard

Research output: Contribution to journalArticlepeer-review


We demonstrate a maskless photochemical etching method that is capable of performing one-step etching of multi-level structures. This method uses a digital projector to focus an image onto the sample and define the etching pattern. By combining digital projection photochemical etching with diffraction phase microscopy, etch heights can be measured in situ in a non-destructive manner. This method is single shot, eliminating the need for expensive gray-scale masks or laser scanning methods. The etch rate is studied as a function of the wavelength and irradiance of the projected light. A lateral etch resolution of 2 μm is demonstrated by etching selected portions of the USAF-1951 target. Micropillars, multi-level plateaus, and an Archimedean spiral are etched, each in a single processing step, to illustrate the unique capabilities.

Original languageEnglish (US)
Pages (from-to)13547-13554
Number of pages8
JournalOptics Express
Issue number11
StatePublished - Jun 3 2013

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics


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