Improvement in the aspect ratio of fabricated minute dots by the volume change thermal lithography technique

M. Kuwahara, J. H. Kim, P. Fons, J. Tominaga

Research output: Contribution to journalConference articlepeer-review

3 Citations (Scopus)


Volume change thermal lithography has been developed as a low cost and simple lithography technique for application in optical mastering. The combination of the temperature distribution induced by a focused laser spot with a Gaussian distribution and a special multilayer consisting of TbFeCo and ZnS-SiO2 are utilized. Application of heat to these materials induces interdiffusion and as a result local volume expansion leading to the formation of a convex surface region. This technique was used to fabricate nano-dots with dimensions less them 100 nm on the sample surface. Typical nano-dot height, however, was less than 20 nm and this value is not sufficient for the pit height of an optical master disk. To address this problem, a PtOx film was inserted between the TbFeCo and ZnS-SiO2 layers. Laser irradiated PtOx decomposed to Pt and oxygen leading to additional surface protrusion due to the combination of the thermally induced interdiffusion of the TbFeCo and ZnS-SiO2 region and PtOx decomposition induced compressive stress. Nano-dots of 110 nm diameter and 37 nm height were successfully fabricated. Transmission electron microscope (TEM) observations of the nano-dot structure are reported.

Original languageEnglish
Pages (from-to)359-363
Number of pages5
JournalMicroelectronic Engineering
Issue number1-4
Publication statusPublished - 2005 Mar
Externally publishedYes
EventProceedings of the 30th International Conference on Micro- and Nano-Engineering -
Duration: 2004 Sept 192004 Sept 22


  • Mastering
  • Optical ROM disk
  • The diffraction limit
  • Thermal lithography
  • Visible laser light
  • Volume change material

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering


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