Fundamentals Of Modern Vlsi Devices

In this paper, the analog properties of advanced GaN/AlGaN High-Electron-Mobility Transistors (HEMTs) are studied as a function of temperature (T). The drain current, the threshold voltage, the transconductance and the output conductance are experimentally investigated under saturation operation. Moreover, important figures of merit for the analog performance, such as transconductance-over-drain current, Early voltage and intrinsic voltage gain are analyzed for different channel lengths in the temperature range of 25 °C till 200 °C. The results indicate that due to change in the Fermi potential, the analog parameters reduce with increasing T. Furthermore, the performance increase for longer channel devices is correlated directly with the lower drain electric field penetration.

Analog performance of GaN/AlGaN high-electron-mobility transistors

In this work, the influence of proton-irradiation in the voltage gain of two-stage operational transconductance amplifier (OTA) designed with silicon-on-insulator (SOI) fin field effect transistors (FinFETs) is studied. The OTA simulations were performed using Verilog-A approach based on experimental data extracted from the SOI FinFET electrical characterization, before and after proton-irradiation. The OTA is designed with SOI FinFETs of fin widths (W fin) of 20 nm, 120 nm, and 870 nm, all in the same predefined inversion region (g m/I D = 8 V−1). All evaluated OTA circuits exposed to proton-irradiation presented a voltage gain increase (compared with pre-irradiation circuits), of 0.87 dB, 1.19 dB, and 6.16 dB for fin widths of 20 nm, 120 nm, and 870 nm, respectively. The results show that despite the typical radiation effect of degradation of the individual transistors (it being more severe for larger fin width SOI FinFET), these effects combined in OTA circuits result in an unexpected improvement in DC voltage gain, especially for wider fins. Focusing on the fin width impact on the OTA voltage gain, before and after proton-irradiation, it is much greater for narrow fin width SOI FinFET thanks to the better Early voltage.

Voltage gain improvement of the operational transconductance amplifier designed with silicon-on-insulator fin field effect transistor after being exposed to proton-irradiation

This paper presents an evaluation of omega-gate nanowire n- and p-type SOI MOSFETs performance focusing on the main analog figures of merit. The different channel widths (WNW) and channel lengths (L) were also evaluated. These devices presented values of subthreshold slope near the theoretical limit at room temperature (60 mV/dec) and in the worst case a DIBL value smaller than 70 mV/V showing its immunity to short channel effects (SCEs) in the range studied. The narrowest device showed great electrostatic coupling, improving transconductance (gm), presenting an unit gain frequency over 200 GHz and intrinsic voltage gain over 80 dB. These values suggests that this device is capable of achieving good performance on new applications such as 5G communications and Internet-of-Things (IoT).

http://ojs.fei.edu.br/ojs/index.php/JICS/article/download/113/52

Analysis of Omega-Gate Nanowire SOI MOSFET Under Analog Point of View

This paper studies the proton radiation influence on SOI FinFET analog parameters based on the device inversion coefficient (IC). The analysis focuses on some figures of merit in analog design like the transistor efficiency, the unity gain frequency and the intrinsic voltage gain. Although the proton radiation affects the device performance, it is possible to define an optimal analog condition by basing the analysis on the inversion coefficient, even considering the radiation impact. N-channel devices are affected in a different manner when compared to p-channel counterparts, which can be decisive depending on the application.

Proton radiation influence on SOI FinFET trade-off between transistor efficiency and unit gain frequency

/pdf/analysis-of-proton-irradiated-n-and-p-type-strained-finfets-3iffchhygu.pdf

Analysis of proton irradiated n- and p-type strained FinFETs at low temperatures down to 100 K

This paper studies for the first time the low temperature characteristics of strained SOI FinFETs submitted to proton irradiation. Both types of transistors, nMOS and pMOS, were analyzed from room temperature down to 100K, focusing on the threshold voltage (V TH ), subthreshold swing (SS), the Early voltage V EA and the intrinsic gain voltage (A V ). The effects of strain techniques are also studied. The p-channel devices showed a greater immunity to radiation when looking at their digital parameters while nFinFETs had a better response to proton radiation from an analog parameters point of view.

Luis Felipe Vicentis Caparroz

Papers

Proton radiation influence on SOI FinFET trade-off between transistor efficiency and unit gain frequency

Analysis of proton irradiated n- and p-type strained FinFETs at low temperatures down to 100 K

Low temperature performance of proton irradiated strained SOI FinFET