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
First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester
Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy