Controlled electroplating for high-aspect-ratio zone plate fabrication
2006 (English)In: Journal of Vacuum Science & Technology B, ISSN 1071-1023, E-ISSN 1520-8567, Vol. 24, no 6, 2592-2596 p.Article in journal (Refereed) Published
The authors report a method for monitoring, control, and end-point detection of electroplating in nanostructures. The method is demonstrated on nickel plating into polymer molds, which is an important process in the fabrication of soft x-ray zone-plate diffractive optics. The lack of reproducibility presently limits the achievable nickel aspect ratio and, thus, reduces the zone-plate diffraction efficiency. The reported method provides reproducible plating via real-time control of the plating rate. It combines in situ light transmission measurements with current measurements to determine the thickness of the growing layer. The accuracy of the thickness prediction was better than ±4% (1) for 100–300 nm nickel layers. Furthermore, a slight change in the light transmission signal indicates when a gratinglike zone-plate structure is slightly overplated and the plating should be stopped. This end-point detection provides the optimal filling of high-aspect-ratio molds for improved diffraction efficiency.
Place, publisher, year, edition, pages
2006. Vol. 24, no 6, 2592-2596 p.
X-RAY MICROSCOPY; HIGH-EFFICIENCY; CONDENSER; OPTICS
IdentifiersURN: urn:nbn:se:kth:diva-5987DOI: 10.1116/1.2362761ISI: 000243324400017ScopusID: 2-s2.0-33845257285OAI: oai:DiVA.org:kth-5987DiVA: diva2:10543
QC 201006162006-06-082006-06-082010-12-06Bibliographically approved