Low threshold voltage (Vt) is achieved by applying a thin dielectric cap between the gate dielectric and metal gate. In addition, the use of laser-only annealing for gate stack engineering resulted in a significant reduction of the minimum sustainable gate length and improved short-channel effect control. The same processes were applied on FinFETs and resulted in a possible candidate technology for the 22nm node.
A major challenge in using high-k dielectrics for CMOS devices is the high threshold voltage resulting in low performance. Dual metal gates in combination with dual dielectrics can solve this problem but have the drawback that extra processing steps are required resulting in a higher processing cost. IMEC developed a simpler, lower-cost integration scheme using only one dielectric stack and one metal. A thin dielectric cap is deposited between the gate dielectric and metal gate which effectively modulates the work function towards the optimal operating zone. Laser anneal instead of spike anneal is applied to reduce the effective oxide thickness. Using laser-only annealing higher activated and shallow junctions could be achieved.
Both a lanthanium- (La2O3) and dysprosium-based (Dy2O3) capping layer was used for nMOS and an aluminum-based capping layer for pMOS. Symmetric low Vt of +/-0.25V were achieved and drive currents of 1035µA/µm and 505µA/µm for nMOS and pMOS respectively at VDD of 1.1V and Ioff of 100nA/µm. Successful CMOS integration was illustrated by a ring oscillator delay of less than 15ps.
Since thin gate dielectrics suffer from soft breakdown before the specified lifetime and the failure is difficult to forecast, IMEC developed a time-dependent dielectric breakdown model to completely predict the reliability of the devices. The model is based on the statistical analysis of hard breakdown including multiple soft breakdown and wear out. By applying the model on the high-k/metal gate devices, the excellent quality of the gate dielectrics has been demonstrated.
In strong collaboration with NXP and TSMC, excellent performance (drive current of 950µA/µm and Ioff of 50nA/µm at VDD of 1V for nMOS FinFETs) and short channel effect control were achieved for tall, narrow FinFETs without mobility enhancement. Physical vapor deposition (PVD) and atomic layer deposition (ALD) were compared as metal deposition technique. Since PVD metals are denser and less porous, PVD of titanium nitride (TiN) electrodes on hafnium oxide (HfO2) dielectrics gave improved nMOS performance compared to ALD TiN. IMEC also applied the dysprosium-based (Dy2O3) capping process on FinFETs resulting in a possible candidate technology for the 22nm node.
These results were obtained in collaboration with IMEC’s (sub-)32nm CMOS core partners including Infineon, Qimonda, Intel, Micron, NXP, Panasonic, Samsung, STMicroelectronics, Texas Instruments and TSMC, and IMEC’s key CMOS partners including Elpida and Hynix.
Katrien Marent | alfa
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The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
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The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
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Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
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