Final Report Summary - COMON (COmpact MOdelling Network (COMON))
The objectives of COMON have been to develop complete compact models and parameter extraction techniques for three types of advanced electron devices and also to make them suitable for industrial circuit design, by incorporating them in design tools.
Analytical, compact models, which balance accuracy and computational complexity, are the type of device models needed for circuit simulation tools. Compact modelling is the only feasible path for a practical implementation of a generalized integrated circuit (IC) design flow.
The COMON project has addressed the full development chain of Compact Modeling (CM) of advanced CMOS and III-V technologies, from the technology level to the system level.
COMON has targeted three types of the semiconductor devices, i.e. device technologies, that are currently considered as “state-of-the-art” and are the most promising for capturing future digital, analog and high frequency communication IC markets: Multi-Gate MOSFETs, high voltage (HV) MOSFETs and advanced GaAs and GaN HEMTs. In the COMON consortium there were industrial partners who fabricated these devices.
The COMON partnership consisted of eight universities, three industrial device foundries, three Electron Design Automation (EDA) tool vendors and one design company. Therefore, the Consortium has been a communication platform for foundries, software vendors, circuit designers and universities regarding compact modelling issues. COMON established a joint programme that enabled research through intersectorial and multidisciplinary collaboration, including researcher exchanges (secondments), recruitment of external researchers, between academia and industry, as well as dissemination and training activities.
According to the number and type of the approximations done to obtain analytical expressions, different compact models with different levels of complexity can be developed. Each level of complexity may be useful for certain purposes. Simpler models use to be purely design oriented. Strongly physically-base models, which use more complex equations and require higher computation time, are particularly suitable for predictive analysis of device and circuit techniologies.
In the framework of COMON, partners developed three models for Multi-Gate MOSFETs, one model for High Voltage MOSFETs and two type models for HEMTs. Experimental measurements and with 2D/3D TCAD (Technology Computer Aided Design) numerical simulations were instrumental to thoroughly analyze and understand the behavior of the targeted devices (identifying the main electrostatic, transport, dynamic and noise effects), which allow to develop the compact expressions of the models.
The three Multi-Gate MOSFET models were developed following three modelling schemes:
1) A fully physical 2D/3D predictive model, based on isomorphic expressions and conformal mapping, which uses semi-analytical expressions and only physical parameters.
2) A quasi-2D/3D predictive design-oriented model. It uses very few fitting parameters and only explicit expressions. It is based on using a suitable quasi-2D/3D electrostatic analysis to find fully explicit expressions.
3) A purely design-oriented model. It is based on a 1D electrostatic analysis with semi-empirical equations with fitting parameters for short-channel effects.
These three types of models have been validated by comparison with 2D/3D TCAD numerical simulations and experimental measurements for devices with channel lengths in the sub-50 nm range. Parameter extraction techniques for these models were also developed. Besides, a gate level model for logic gates designed with Multi-Gate MOSFETs was also developed
One physically based analytical model for the High Voltage MOSFET was developed by COMON partners . It is valid for both Lateral double-Diffused (LD) MOS and Vertical double-Diffused (VD) MOS devices.The models splits the HV transistor into a low voltage section and a high voltage one, for which suitable explicit models were developed. The final model includes short-channel effects, geometry dependences, temperature and self-heating effects and noise.. Very good agreement was obtained between the model and TCAD simulations, as well as with experimental data, confirming the validity of the approach used.
Finally, two types of models were developed for GaN and GaAs HEMTs. One of the models, is strongly physically-based (from the band structure of the material) and uses different expressions for GaN and GaAs HEMTs. The other model, developed by TU-Ilmenau, of empirical type, with relatively simple expressions and a number of empirical parameters. Parameter extraction methodologies were developed for both models.
The design-oriented models developed for Multi-Gate MOSFETs, HV MOSFETs and HEMTs were implemented in EDA vendors’ design tools by means of the Verilog-A language, and their implementation was evaluated their implementation by means of circuit simulations.
Finally, the circuit simulation performances of some of the models were validated by simulating some basic circuits, and by means of comparisons with some experimental performances.
The research done in the framework to the COMON project has led to 57 papers published or accepted in international journals (including the most prestigious ones in the field), 104 conference presentations, and four book chapters. Two COMON participants have also edited a book on advanced device modeling.
As a result of the research work carried out, the main goals of COMON have been achieved. Very accurate models for the targeted devices have been developed and their implementation in EDA tools have made them available for the industry.
Industrial partners can start applying the new tools for production shortly after the end of the project.
The incorporation of the new models in the design kits of the foundries will lead to faster and cost effective IC development cycles and higher integration levels.
COMON has also included special dissemination actions, such as a Workshop on Compact Modeling (the so-called MOS-AK Workshop), held twice a Year in Europe, and two editions of a Training Course on Compact Modeling, consisting of 12 lectures conducted by top experts in compact modeling. These events have been very useful to disseminate results related top compact device modeling and to provide training in the field to young researchers and engineers from both academia and industry. Participation to these events was quite important.
A COMON project website was created (www.compactmodelling.com) to announce events related to device modeling, not necessary organized by the COMON consortium, and to present the main results obtained in the framework of the project.