POLDER · Porous Low-K Deposition and Characterization Research
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2006-05-01 → 2008-04-30
- EU contribution
- €80,000
- Participants
- 1
- Scheme
- IRG
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - POLDER (Porous Low-K Deposition and Characterization Research)
In the first month of the project, new equipment, the ASM Eagle #174; 12, was delivered at IMEC. It was installed and the basic processes accepted within the original chronogramme. Initially, two types of low-k films were studied. The first one, Aurora #174; ELK HM, is a film with a dielectric constant of 2.55 and a Young's modulus of 9 GPa, compatible with integration in the 45 nm node. The second one, Aurora #174; ELK, is a film with a dielectric constant of 2.3 and a Young's modulus of 4 GPa, compatible with integration in the 32 nm node. The final films are obtained after a two-step process: the first process consists of the deposition of a film, which contains a porogen within a Si-O-C type of skeleton; the second process consists of a UV cure in which this porogen is removed (and nanopores are created) and the skeleton is restructured in such a way that the mechanical characteristics (as characterized by E modulus and hardness) are improved. Both deposition and cure processes had to be optimised for both films during the course of the project and eventually the final material and film characteristics were state of the art. In the same equipment and in another, similar equipment (also an Eagle #174; 12 cluster system), barrier layers were developed and characterised. The interaction of the UV cure with these films was characterised. A special hermeticity test was developed which showed that the standard barrier is excellent against moisture diffusion. All these films were used for integration in single and dual damascene flows. This integration proved to be quite difficult and special optimisation of the etch, strip and clean steps were necessary to limit the increase of the effective dielectric constant. The final processes showed good electrical results and EFTEM analysis showed very little carbon depletion in the low k films.
Data: CORDIS, © European Union
Project objective
As microelectronic device dimensions continue to shrink, system performance is becoming limited by the interconnect delay. A major component of this delay arises from intra-level capacitance. The dielectric must therefore have a low dielectric constant in order to minimize the capacitance between the lines and maximize performance at reduced dimensions. Silicon oxycarbides with dielectric constant of 2.7-3.0 are already being used in advanced production processes. In order to reduce the dielectric constant further, porosity has to be introduced into the film. Initial research, performed on spin-on dielectrics, already revealed many integration issues related to the porosity of these materials. In order to achieve production-worthy processes, chemical vapour deposition is the preferred way to fabricate these films.In this project, plasma enhanced chemical vapour deposition (PECVD) is used to develop processes for ultra-low K deposition. This research project makes use of the most advanced production-compatible equipment on 300mm Si wafers. Through selection of the optimum precursors and process conditions, suitable films will be developed. The project will investigate the impact of the plasma parameters on film properties, such as uniformity, composition, dielectric constant, pore size and pore distribution, elastic modulus and strength. The films will be integrated in IMEC's back-end of line processes to investigate etch behaviour, CMP compatibility and reliability properties. Specific plasma characterization of the deposition and clean recipes will be performed to optimise both.
Original text from CORDIS.
Participants
- INTERUNIVERSITAIR MICRO-ELECTRONICA CENTRUM VZW · LEUVENCoordinatorBelgium
Links
Data: CORDIS, © European Union