Fin field effect transistors (FinFETS) are silicon-on-insulator (SOI) transistors with three-dimensional structures. As a result of some fabrication-process limitations (as nonideal anisotropic overetch) some FinFETs have inclined surfaces, which results in trapezoidal cross sections instead of rectangular sections, as expected. This geometric alteration results in some device issues, like carrier profile, threshold voltage, and corner effects. This work analyzes these consequences based on three-dimensional numeric simulation of several dual-gate and triple-gate FinFETs. The simulation results show that the threshold voltage depends on the sidewall inclination angle and that this dependence varies according to the body doping level. The corner effects also depend on the inclination angle and doping level.

Electronic systems functionality degrades when these systems are operating in harsh environments such as those where they are exposed to ionizing radiation. Understanding and measuring these effects is extremely important in order to design systems that can operate reliably. This work discusses experimental data of heavy ion and x-ray radiation effects on a Commercial-Off-The-Shelf (COTS) low-cost microprocessor. The heavy ions test results suggest that, in this technology, the SRAM is more sensitive to SEE than flash memory. Ions with a LET higher than 5 MeV/mg/cm² may disrupt the device's proper operation.

This paper proposes a new and refined bio-amplifier design, which associates DC offset cancellation, adequate frequency response and buffered outputs to a significant reduction of the signal recovery time. A MOS-Bipolar pseudo-resistor integrated to the feedback network of a single-stage Operational Transconductance Amplifier and the source-follower buffers give to the new topology its main advantages. This architecture makes use of the high resistance values of these pseudo-resistors to eliminate the offset DC level input preserving the low cut-off frequency, without the need of high capacitances, thereby significantly reducing the active die area, which enables its use as a front-end pre-amplifier assembled directly on the acquisition probes. The recovery time after an input voltage transitory of high-amplitude is an important characteristic of the bio-potential amplifiers due to their very low cut-off frequency. The proposed bio-amplifier utilizes the non-linear characteristics of the pseudo-resistor in the recovery time reduction. This time was evaluated and the topology presented a significant contribution in this aspect, assuming values 90% lower when compared with the same topology using a constant resistance. The new amplifier allows voltage gain of 30dB from 0.6 Hz to 2 kHz, and Total Harmonic Distortion (THD) of 0.19% for an input signal of 10Hz. This work also provides a behavioral spice model for MOS-Bipolar pseudo-resistor, which allows an accurate simulation of the linear and nonlinear pseudo-resistor characteristics, obtained through an experimental method of indirect characterization. This method is based on the transitory response from a first order RC low pass filter. The experimental characterization method is of fundamental importance, due to the absence of appropriate SPICE models that describe with precision the pseudo-resistance behavior. The circuits were manufactured by MOSIS on 8HP SiGe BiCmos Global Foundries 0.13μm technology.

Since the use of pseudo‐resistors became popular in of bio‐amplifiers research, several works have been published, but a lack of knowledge about accurate experimental characterisation and simulation of these non‐linear devices remains. An innovative experimental procedure concerning the characterisation of pseudo‐resistors is presented. The proposed experimental procedure proves the existence of a linear operation region, where the device can operate like a very high resistance, which is mainly applied on bio‐amplifier designs. The main experimental results of the electrical characterisation of pseudo‐resistors are described in detail and compared with the SPICE results. The pseudo‐resistor experimental curve response including the non‐linear operation region is presented. Finally, a new non‐linear polynomial resistor model to use in SPICE simulator, replacing with success the electrical representation model based on transistors models is proposed. The presented simulations were performed with Mentor Graphics Eldo ^TM SPICE simulator, using BSIM3V3.1 and PSP103.1 models. The MOSIS Educational Program fabricated the samples used in this work.