Online information source for semiconductor professionals

Product Briefing Outline: Sopra has launched a new version of its spectroscopic metrology tool called the GES5 Evolution (GES5-E). The system is based on Ellipsometric porosimetry (EP), used to characterize CVD and spin coated porous ultra low-k materials. EP measures the change of the optical properties and thickness of the materials during adsorption and desorption of an organic solvent. The new system allows the complete characterization of porous thin layers for applications related to micro-electronics as well as new organic technologies.

Problem: Lowering the low-k film density by introducing porosity has become an important part of R&D into future generations of ultra low-K ILD materials. The need for non-destructive characterisation of porous low-K dielectric films is required. EP simpler and faster than Positronium Annihilation Lifetime Spectroscopy (PALS) and Small Angle Neutron Scattering combined with X-ray Reflectivity (SANS/XR), which have traditionally been used for characterisation of porous films.

Solution: Equipped with very significant improvements on its spectrometers and spectrographs, the GES-E makes it possible to cover the range from UV to near Infra-Red with unequalled specifications on the market in terms of quality of signal, speed of measurement on the entire spectrum and particularly at 190nm, according to the company. Analysis during adsorption and desorbtion of an organic solvent gives the porosity of the low-k. Pore size distribution of both microporous and mesoporous, cumulative surface area, pore interconnectivity, Young modulus, thickness and refractive index data is given within 2 hours. EP qualifies the sealing layer of both patterned and blanket wafers. The tool detects the diffusion of the solvent through the sealing layer. The diffusion of the solvent leads to a change in refractive index of the layer that the spectroscopic ellipsometer easily detects. EP gives structural information and qualifies how the material can be integrated in the dual damascene process.

Applications: EP allows the measurement of PSD at room temperature in thin films directly deposited on Si or any smooth solid substrate. A small surface area (<1 mm 2) is sufficient. It is also suited to characterize other materials like: membranes, fuel cells, Sensors, Catalysis surfaces,Nano-structure and nano-composite materials, Hybrid organic & inorganic interfaces.

Platform: IMEC patented the EP technology and has granted an exclusive license to SOPRA in 2004. SOPRA holds several patents on EP.

Availability: June 2006 onwards.