Lidia Lukasiak

Low temperature mobility in hafnium-oxide gated germanium p-channel metal-oxide-semiconductor field-effect transistors

Effective mobility measurements have been made at 4.2 K on high performance high-k gated germanium p-type metal-oxide-semiconductor field effect transistors with a range of Ge/gate dielectric interface state densities. The mobility is successfully modelled by assuming surface roughness and interface charge scattering at the SiO2 interlayer/Ge interface. The deduced interface charge density is approximately equal to the values obtained from the threshold voltage and subthreshold slope measurements on each device. A hydrogen anneal reduces both the interface state density and the surface root mean square roughness by 20%.

A review of SOI transistor models

Several SOI MOSFET models based on 1-D solution of Poissons equation are compared in terms of their accuracy. A brief discussion of the simplifying assumptions leads to a conclusion that the methods used for surface potential evaluation strongly influence the accuracy of a model. An analytical approximation for the front surface potential is presented and then introduced into the fully analytical Lim-Fossum model [1]. The accuracy of the modified model is better than that of the original Lim-Fossum model [1].

The Influence of Selected Material and Transport Parameters on the Accuracy of Modeling Early Voltage in SiGe-Base HBT

Using a new model of Early voltage (VA), it is demonstrated that diffusion coefficient dependence on electric field and carrier velocity saturation at the collector end of the base has to be taken into account for accurate modeling of VA in SiGe-based heterojunction bipolar transistors. The need to incorporate the dependence of SiGe material parameters on the local Ge content in the base is also addressed

The effects of high doping on the I-V characteristics of a thin-film SOI MOSFET

Modifications of the Ortiz-Conde et al., model which take into account either apparent or physical bandgap narrowing have been presented. The influence of high doping effects is investigated by means of a comparison of the modified models with their original, version for various device parameters. It is shown that the inclusion of bandgap narrowing is essential for accurate simulation of I-V characteristics of a SOI MOSFET in the subthreshold and near-threshold regions. A new analytical model with bandgap narrowing has been derived for the subthreshold region.

The influence of nonuniform doping profile on I-V characteristics of MOS transistors

The influence of nonuniform doping on I-V characteristics of a MOS transistor is estimated. A modification of the Pao-Sah model (1966) is presented, which extends its validity on a box doping profile. >

FDSOI MOSFET threshold voltage characterization based on AC simulation and measurements

A method for extraction of the threshold voltage corresponding to the front and back interface in FDSOI MOSFETs is proposed. The approach is based on the nonlinear behavior of the capacitances between the source and front/back gate. The method has been discussed using the numerical simulation results and has been demonstrated using the C-V characteristics of the experimental FDSOI devices manufactured in ITE.

A novel fast and flexible technique of radical kinetic behaviour investigation based on pallet for plasma evaluation structure and numerical analysis

This paper describes a new, fast, and case-independent technique for sticking coefficient (SC) estimation based on pallet for plasma evaluation (PAPE) structure and numerical analysis. Our approach does not require complicated structure, apparatus, or time-consuming measurements but offers high reliability of data and high flexibility. Thermal analysis is also possible. This technique has been successfully applied to estimation of very low value of SC of hydrogen radicals on chemically amplified ArF 193 nm photoresist (the main goal of this study). Upper bound of our technique has been determined by investigation of SC of fluorine radical on polysilicon (in elevated temperature). Sources of estimation error and ways of its reduction have been also discussed. Results of this study give an insight into the process kinetics, and not only they are helpful in better process understanding but additionally they may serve as parameters in a phenomenological model development for predictive modelling of etching for ultimate CMOS topography simulation.

Sticking coefficient of hydrogen radicals on ArF photoresist estimated by parallel plate structure in conjunction with numerical analysis

Investigation of radicals kinetic behavior and estimation of radical sticking coefficient become indispensable for establishing plasma processing control by its internal parameters. This approach is required for plasma processing of single-nanometer gate length field effect transistors and 3-diemnsional gates in particular. In our works we have developed new technique for radicals kinetic behavior investigation and its sticking coefficient estimation. Our approach is based on application of parallel plate structure in conjunction with numerical analysis. This approach allows for radicals behavior investigation apart from ions and ultraviolet photons. Moreover this approach allows for analysis role of radical direct and indirect fluxes. By comparison of measured profile thickness and simulated stuck radicals profile we were able to estimate hydrogen radical sticking probability to ArF photoresist.