Ryosuke Inagaki

HiSIM2: Advanced MOSFET Model Valid for RF Circuit Simulation

The compact MOSFET model development trend leads to models based on the channel surface potential, allowing higher accuracy and a reduced number of model parameters. Among these, the Hiroshima University Semiconductor Technology Academic Research Center IGFET Model (HiSIM) solves the surface potentials with an efficient physically correct iteration procedure, thus avoiding additional approximations without any computer run-time penalty. It is further demonstrated that excellent model accuracy for higher-order phenomena, which is a prerequisite for accurate RF circuit simulation, is achieved by HiSIM without any new model parameters in addition to those for describing the current-voltage characteristics

A GIDL-Current Model for Advanced MOSFET Technologies without Binning

A GIDL (Gate Induced Drain Leakage) current model for advanced MOSFETs is proposed and implemented into HiSIM2, complete surface potential based MOSFET model. The model considers two tunneling mechanisms, the band-to-band tunneling and the trap assisted tunneling. Totally 7 model parameters are introduced. Simulation results of NFETs and PFETs reproduce measurements for any device size without binning of model parameters. The influence of the GIDL current is investigated with circuits, which are sensitive to the change of the stored charge due to the GIDL current.

Efficient non-quasi-static MOSFET model for both time-domain and frequency-domain analysis

A consistent non-quasi-static MOSFET model for time-domain and frequency-domain circuit simulation is developed. The model takes into account the time delay for carriers to form the channel, which is neglected in conventional quasi-static models. The model, as implemented into the surface-potential-based MOSFET model HiSIM, is verified to calculate correct Y-parameters in the frequency domain. The computational runtime cost of the model is comparable to a conventional quasi-static modeling approach

Second-Order Polynomial Expressions for On-Chip Interconnect Capacitance

Simple closed-form expressions for efficiently calculating on-chip interconnect capacitances are presented. The formulas are expressed with second-order polynomial functions which do not include exponential functions. The runtime of the proposed formulas is about 2--10 times faster than those of existing formulas. The root mean square (RMS) errors of the proposed formulas are within 1.5%, 1.3%, 3.1%, and 4.6% of the results obtained by a field solver for structures with one line above a ground plane, one line between ground planes, three lines above a ground plane, and three lines between ground planes, respectively. The proposed formulas are also superior in accuracy to existing formulas.

A GIDL-Current Model for Advanced MOSFET Technologies Implemented into HiSIM2

A GIDL (Gate Induced Drain Leakage) current model for advanced MOSFETs has been proposed and implemented into HiSIM2, first complete surface potential based model. The model consists of one tunneling mechanism considering two tunneling currents, band to band tunneling (BTBT) and trap assisted tunneling (TAT), and requires totally 7 model parameters covering all bias conditions. Simulation results of NFETs and PFETs reproduce measurements for any device size without binning. Validity of the model has been tested with a circuit, which is sensitive to the change of the stored charge due to tunneling current.

STARC's Semiconductor Design Technology Research Activities and the HiSIM2 Advanced MOSFET Model Project

STARC (Semiconductor Technology Academic Research Center) is a research consortium co-founded by major Japanese semiconductor companies, whose mission is to contribute to the growth of the Japanese semiconductor industry by developing leading-edge SoC design technologies. One of the achievements enabled by the academia collaboration is HiSIM (Hiroshima University STARC IGFET Model) an advanced MOSFET Model. The HiSIM2 version includes required features in modeling for the 45 nm technology node and beyond such as the STI effect. A major development is an improved model consistency, which enables even modeling of the technology variation accurately. HiSIM2 realizes both accurate and fast circuit simulation.