Ph.D. Research Talks
Monishmurali M
(Indian Institute of Science)
Talk Title:
Addressing design challenges for current uniformity in Fin-based SCRs
Abstract:
This talk presents advancements in designing Fin-based Silicon-Controlled Rectifiers (SCRs) for ESD protection, focusing on addressing critical challenges in ESD current localization, failure current scalability, and current filament formation. It explores tap engineering techniques to improve conduction uniformity across anode and cathode junctions. These techniques include various n-Tap and p-Tap configurations, leading to the development of new Fin-based SCR schemes. Additionally, 2D and 3D current filament dynamics within these SCRs are discussed, highlighting enhancements in turn-on uniformity and filament spreading dynamics. These findings promise significant improvements in SCR performance and reliability under ESD stress.
Rasik Rashid Malik
(Indian Institute of Science)
Talk Title:
Interplay of Surface Passivation and Electric Field Distribution in Determining ESD Behaviour of p-GaN Gated AlGaN/GaN HEMTs
Abstract:
This paper presents the dependence of ESD robustness on the electric field distribution in p-GaN gated HEMTs. The Al% in the bilayer AlxTi1-xO/SiO2 passivation is used as a tuning parameter to modulate the electric field distribution. It was observed that the ESD robustness of the devices increased as the electric field intensity near the gate edge decreased. Two distinct failure modes related to the electric field distribution were identified through leakage behavior, electroluminescence microscopy, Raman spectroscopy, and SEM imaging of ESD-damaged devices. Devices with higher electric field peaks near the gate edge exhibited tensile stress buildup in the gate-source access region, leading to a sudden rise in TLP leakage at snapback and gate-driven failures. Conversely, devices with lower electric field peak intensity showed compressive stress buildup in the gate-source and gate-drain access regions, a gradual increase in leakage after snapback, and are susceptible to drain-to-source driven failure mechanism.
Mitesh Goyal
(Indian Institute of Science)
Talk Title:
Load-line Dependent Current Filament Dynamics in Nanoscale SCR Devices
Abstract:
In this presentation physics of experimentally observed abnormal behavior in STI bounded Silicon-Controlled-Rectifier (SCR) structures is investigated and explained using basic principles and 3D electrothermal TCAD simulations. The device physics during ESD event is thoroughly simulated and the behaviour is observed. The SCR device is found to show pulse to pulse instability in the negative resistance (snapback) region during the 100ns pulse width TLP measurement. The instabilities were independent of SCR geometrical design variations but were dependent on the load line conditions used in the TLP measurement. The physical insights and device physics has been explored using well calibrated 3D process and device TCAD.
Mohammad Ateeb Munshi
(Indian Institute of Science)
Talk Title:
Understanding Temperature Dependence of ESD Reliability in AlGaN/GaN HEMTs.
Abstract:
In this work we report the role of temperature on the ESD reliability of AlGaN/GaN HEMTs, emulating a system level scenario. We compared two stacks with different carbon doping concentration, LC (low carbon doping) and HC (high carbon doping). The trigger voltage (Vtr) was seen to decrease with increasing temperature in LC, while as Vtr remained independent of the temperature for HC. The modulation of field due to the temperature is seen to govern the ESD behavior of the LC. While as in HC, hot holes due to avalanche and hole emission in the high carbon doped buffer determine the breakdown behavior. This study shows the need of an optimum buffer to ensure the ESD robustness of AlGaN/GaN HEMTs with temperature.
