Material development for double patterning and double exposure

Acronym: MD3
Title: Material development for double patterning and double exposure
Status: Active
Funding Organization: European Union

ICT – 214948



Leader in charge : E. Goggolidis
Start Date: 01/12/2007
Duration: 24 months

Summary       Double patterning lithography has been identified as the only viable solutions to support the development of the 32nm half pitch generation in a within the time limits defined by ITRS roadmap.

      Its main advantage consists in enabling the definition of structures beyond resolution capability of existing lithographic tools without drastic changes in manufacturing infrastructures. For the moment, several issues still need to be addressed ahead of the introduction of the Double Patterning process in production such as layout decomposition, topography at wafer level, overlay control, Line Edge Roughness and process throughput.  

      For example, the conventional double patterning process requires two different exposure and etching steps which cumbersomely reduce productivity and increase the cost of ownership. 

      In that perspective, the two year project MD3 aims to suppress the additional etching or exposure steps by developing new strategies and new processes for double pattering or double exposure.  

Three main strategies are currently evaluated:

  • Self aligned spacers deposited directly on the resist patterns. Specific resist materials are developed to be able to withstand the high temperature CVD processes used for the spacers deposition.

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Cross sections of the CVD spacers on resist: after deposition on the left and after transfer in the amorphous carbon layer on the carbon layer.

  • Dual layer patterning approach based on a resist freezing step which allows a second resist coating over the first developed resist layer.

Your browser may not support display of this image.Cross sections of the dual layer: after the two litho steps on the left and after transfer into the spin on carbon on the right  

  - Double exposure based on two consecutives exposures on non linear materials

Each strategy is going to be compared to a reference double patterning process in terms of technical performances as well as cost of ownership.   

      In order to reach its objectives, MD3 brings together a multidisciplinary team of 7 partners from with complementary skills and strong backgrounds in: photo-resist development (RHEM), lithography simulation (Fraunhofer-IISB, WIAS, NCSR-D), lithography process development and characterization (ST, CEA-LETI) and etching process development (CNRS-LTM).