Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

Deep x-ray lithography with the SU-8 resist

[+] Author Affiliations
Laurence Singleton

Institut fuer Mikrotechnik Mainz GmbH (Germany)

Alexei L. Bogdanov, Serguei Peredkov, Oliver Wilhelmi

Lunds Univ. (Sweden)

Andreas Schneider

Rutherford Appleton Lab. (United Kingdom)

Carsten Cremers, Stephan Megtert

Univ. Paris-Sud XI (France)

Andreas Schmidt

PDF Solutions (Germany)

Proc. SPIE 4343, Emerging Lithographic Technologies V, 182 (August 20, 2001); doi:10.1117/12.436647
Text Size: A A A
From Conference Volume 4343

  • Emerging Lithographic Technologies V
  • Elizabeth A. Dobisz
  • Santa Clara, CA | February 25, 2001

abstract

Although the process of deep x-ray lithography with PMMA achieves good resolution, it requires significant exposure times because of the low sensitivity of PMMA to x-rays. Therefore resist materials, which can achieve high resolution, but which are inherently more sensitive than PMMA, are desirable. Here it is shown, that x-ray exposures of the SU-8 resist can achieve high resolution with substantially reduced exposure times. Irradiation at the synchrotron source of DCI at Lure (Paris) and MAXLAB (Lund, Sweden) demonstrated a reduced exposure time for a 600 micrometers thick SU-8 relative to PMMA. The does needed to obtain standing structures was 30 J/Cm3 for DCI and 52 J/CM3 for MAXLAB. A 600 micrometers thick PMMA resist requires a typical bottom does of 4 kJ/cm3, so Su-8 is considerably more sensitive to x-rays than PMMA. Preliminary critical dimension measurements (CD) of the 600 micrometers SU-8 resist structures have been obtained for the entire height of the structure, which was exposed at DCI. The CD measurements were made in a Scanning Electron Microscope (SEM) using 10 micrometers wide structures, which have a 20micrometers pitch, this being used to calibrate the measurements. These measurements show that the gain in the critical dimension per structure edge is dependent on the bottom dose. Doses of 30 J/cm3 achieved a CD gain per edge of +0.5 micrometers , while doses of 40 J/cm3 Yielded a CD gain per edge of 0.9 micrometers . However, the gain in the CD per edge is critically dependent on the solvent content in the resist. Doses of 40 J/cm3 into a resist with a 2% residual solvent content yielded CD gains per edge of 0.3micrometers . In addition, the dose profile in the resist does not change the CD values significantly. It has been shown that the resolution of the x-ray exposed SU-8 structures compare quite favorable with PMMA, but the exposure time for SU-8 is approximately 100 times less than that for PMMA. This significantly improves throughput for deep x-ray lithography processes.

© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Citation

Laurence Singleton ; Alexei L. Bogdanov ; Serguei Peredkov ; Oliver Wilhelmi ; Andreas Schneider, et al.
"Deep x-ray lithography with the SU-8 resist", Proc. SPIE 4343, Emerging Lithographic Technologies V, 182 (August 20, 2001); doi:10.1117/12.436647; http://dx.doi.org/10.1117/12.436647


Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement


  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.