Selective dry etch process for step and flash imprint lithography

• Published in: Microelectronic engineering Vol. 78; pp. 464 - 473
• Main Authors: Le, Ngoc V., Dauksher, William J., Gehoski, Kathy A., Resnick, Douglas J., Hooper, A.E., Johnson, Steve, Willson, Grant
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2005; Elsevier Science
• Subjects: Acoustic wave devices, piezoelectric and piezoresistive devices; Ammonia; Applied sciences; Electronics; Etch; Exact sciences and technology; Imprint lithography; Microelectronic fabrication (materials and surfaces technology); S-FIL; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; S-FIL; Imprint lithography; Ammonia; Etch; Surface acoustic wave filters; Patterning; Lithography; Dry process; Mechanical properties; Microelectronic fabrication; Imaging; Resist; Selective etching; Photolithography
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2005.01.013

In order for Step and Flash Imprint Lithography (S-FIL) to be considered a viable printing technology to produce sub-100 nm geometries, a reliable pattern transfer etch process needs to be established. Unlike optical lithography processes, imprinting features via S-FIL creates a residual layer of several hundred angstroms thick, which requires a break-through etch prior to etching the transfer layer. Of greater concern is the etch barrier used as the imaging layer for S-FIL technology. The incorporated silicon content is limited to approximately nine percent, and the formulation is geared toward achieving mechanical properties for the imprinting process. As a result, typical oxygen-based plasmas used for transferring more conventional bi-layer structures are not compatible with the current S-FIL resist stack. A reducing chemistry using ammonia (NH 3) plasma has been developed in providing a selective etch process for pattern transfer using S-FIL technology. The development of this NH 3-based process was a key enabler in the fabrication of the world’s first surface acoustic wave filters patterned via S-FIL technology.