13 May 2010


Fraunhofer ENAS orders second Altatech liquid-precursor CVD system

Fraunhofer Research Institution for Electronic Nano Systems (Fraunhofer ENAS) in Chemnitz, Germany has ordered an AltaCVD system from liquid-vaporization chemical vapor deposition (CVD) equipment maker Altatech Semiconductor S.A. of Montbonnot near Grenoble, France for the deposition onto 200mm wafers of silicon stressor materials, which are used to increase the channel mobility of transistors (enabling higher processing speeds).

This marks Fraunhofer ENAS’ second order for a CVD tool from Altatech. The previous system is being used to deposit diffusion barrier and copper layers for copper damascene interconnects and through-silicon-via (TSV) features.

Fraunhofer ENAS is scheduled to install the new system in its back-end-of-line (BEOL) cleanroom facility in Chemnitz during second-quarter 2010. Applications support will be provided by Altatech in Berlin.

The AltaCVD system uses liquid precursors to create highly uniform thin films. As outlined in the International Technology Roadmap for Semiconductors (ITRS), virtually all next-generation precursors required for advanced wafer processing (such as 3D integration) are available only in liquid form. This includes ruthenium (Ru), hafnium (Hf), copper (Cu), and a ternary alloy of germanium, tin and tellurium (GeTeSn).

“We’re developing nanometric thin films to advance the state of semiconductor processing,” says professor Stefan E. Schulz, head of back-end-of-line operations at Fraunhofer ENAS. “The use of liquid-phase precursor injection and evaporation is a key enabling technology for this work.”

The AltaCVD platform uses direct injection of liquid precursors and a flash-vaporization system in processing wafers up to 300 mm. The modular system can accommodate a wide range of vaporization and deposition temperatures, enabling selection of the optimal process windows for a specific application, which can include deposition of materials for high- k gate dielectrics, metal gate electrodes, capacitors and 3D integration. For thermal CVD or RF-enhanced deposition steps, a low-frequency plasma enables tuning of the thin film’s mechanical, electrical and optical properties.

“Through our partnerships with Fraunhofer ENAS and other leading research centers, we are continuing to develop liquid-precursor deposition processes for high- k/metal gates, through-silicon-vias, memory and capacitor applications,” says Altatech’s president Jean-Luc Delcarri. “We’re also working with IDMs and foundries to bring liquid-precursor deposition to their high-volume 300mm fabs,” he adds. “And we’ve begun applying our CVD technology to create advanced thin films for solar cells, high-brightness LEDs and other microelectronics markets.”

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