Photolithographic patterning of polymer-encapsulated optical oxygen sensors

• Published in: Microelectronic engineering Vol. 87; no. 5; pp. 814 - 816
• Main Authors: Nock, Volker, Alkaisi, Maan, Blaikie, Richard J.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2010; Elsevier
• Subjects: Applied sciences; Compatibility; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Glass; Masks; Materials science; Microelectronic fabrication (materials and surfaces technology); Microelectronics; Optical oxygen sensor; Optoelectronic devices; Other materials; Patterning; Photolithography; Physics; PtOEPK/PS; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Sensor patterning; Sensors; Specific materials; Surface treatments; Sensor patterning; PtOEPK/PS; Photolithography; Optical oxygen sensor; Patterning; Oxygen; Multisensor; Semiconductor materials; Lithography; Measurement sensor; Glass; Optical sensor; Polymer; System on a chip; Thin film; Microelectronic fabrication; Manufacturing process; Integrated circuit; Wafer; Sacrificial layer
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2009.11.076

In this paper we show a novel fabrication process capable of yielding arbitrarily-shaped optical oxygen sensor patterns at micron resolution. The wafer-level process uses a thin-film sacrificial metal layer as intermediate mask, protecting the sensor material and enabling the use of conventional semiconductor patterning techniques. Feature sizes down to 3 μm are demonstrated and only limited by the lithographic process. Gaseous oxygen detection using the patterned sensors shows Stern–Volmer behaviour with a measured intensity ratio I 100/ I 0 of 10.8, the highest reported for a lab-on-a-chip compatible glass substrate. The process has the potential to enable the integration of multiple sensor patches underneath single cells for laterally registered oxygen sensing in cell-culture applications.