Cooperative Activity Ion Printing Technology

IONPRINTEX - EC-US049

Keywords: ion printing, CMOS technology, lithography

Start Date: 1 January 95 / Status: finished / Duration: 24 months

Objectivies and Approach

This cooperative project addresses open stencil mask fabrication and development of resist processes for ion projection lithography, to complement work in the US on the development of a new ion projector, and so support the development of 0.18 micron CMOS technology. This project will bring together experts by exchange of scientists, who will be able to use the specialised equipment in the different locations. In addition workshops will be organised to promote development in this field.

European links: ESPRIT project NOVA (9159).

Progress and Results

Design parameters have been investigated with the existing ion projector at ISiT to support the developmentof the new ion projector and consequently higher total ion currents. It could be demonstrated that Coulomb interactions in the charged particle beam do not disturb the resolution of 0.18 µm. A comparative study of radiation damage in metal-oxide-semiconductor varactor cells showed that damage is less with 74 keV H2⁺ ions compared to 50 keV electron beams or 1 nm synchrotron radiation, because ions can be stopped in a proper buffer layer of resist and Poly-Silicon whereas electrons and X-rays penetrate deeper into the substrate.

Ion projection lithography in a mix and match procedure with optical lithography would need a resist which is sensitive to both kind of radiation. A positive tone photoresist HPR 506 (Olin Microelectronics Materials) fulfils these requirements with a good ion sensitivity of 1.2x10¹³ H⁺ions/cm² and a contrast of 3.3. At the moment, advanced i-line and Deep UV optical resists are tested for exposure with H⁺ and He⁺ ions.

Information Dissemination Activities and/or Exploitation

The partners organised workshops within the MNE conference in Europe and the EIBP Symposia in the USA. The first workshop took place at the EIPB-95 in Arizona, in May 1995. The subject was Mask Technology for Ion Projection Lithography and the focus was on the problem of stress engineering of open stencil masks. The second workshop, Resist Technology for Ion Projection Lithography, was organised at the MNE95 in France, in 1995 and brought together representatives of resist manufacturers and scientists working on ion lithography. The third workshop, EIPBN-96, Atlanta, USA, May 1996, was about Electron and Ion Beam Induced Processes for Device Modification and Mask Repair. Results of the projects have been presented at these conferences and also published in scientific journals.

Coordinator

Fraunhofer-Gesellschaft, ISiT
Fraunhoferstr. 1
D-25524 Itzehohe, D

EU Partners

Fraunhofer-Gesellschaft, ISiT, D
Technical University of Vienna, A

Non-EU Partners

University of Maryland-LIBRA, USA
University of Houston, USA
U.S. DOD, MRL, Columbia MD, USA

CONTACT POINT

Dr. Wilhelm H. Brünger
Tel.: +49 4821 17 45 42
Fax: +49 4821 17 42 50
E-mail: bruenger@isit.fhg.de