A Modular End-to-End Framework for Secure Firmware Updates on Embedded Systems

Firmware refers to device read-only resident code which includes microcode and macro-instruction-level routines. For Internet-of-Things (IoT) devices without an operating system, firmware includes all the necessary instructions on how such embedded systems operate and communicate. Thus, firmware updates are essential parts of device functionality. They provide the ability to patch vulnerabilities, address operational issues, and improve device reliability and performance during the lifetime of the system. This process, however, is often exploited by attackers in order to inject malicious firmware code into the embedded device. In this article, we present a framework for secure firmware updates on embedded systems. This approach is based on hardware primitives and cryptographic modules, and it can be deployed in environments where communication channels might be insecure. The implementation of the framework is flexible, as it can be adapted in regards to the IoT device’s available hardware resources and constraints. Our security analysis shows that our framework is resilient to a variety of attack vectors. The experimental setup demonstrates the feasibility of the approach. By implementing a variety of test cases on FPGA, we demonstrate the adaptability and performance of the framework. Experiments indicate that the update procedure for a 1183-kB firmware image could be achieved, in a secure manner, under 1.73 seconds.

Investigation of SiC Trench MOSFETs’ Reliability under Short-Circuit Conditions

In this paper, the short-circuit robustness of 1200 V silicon carbide (SiC) trench MOSFETs with different gate structures has been investigated. The MOSFETs exhibited different failure modes under different DC bus voltages. For double trench SiC MOSFETs, failure modes are gate failure at lower dc bus voltages and thermal runaway at higher dc bus voltages, while failure modes for asymmetric trench SiC MOSFETs are soft failure and thermal runaway, respectively. The shortcircuit withstanding time (SCWT) of the asymmetric trench MOSFET is higher than that of the double trench MOSFETs. The thermal and mechanical stresses inside the devices during the short-circuit tests have been simulated to probe into the failure mechanisms and reveal the impact of the device structures on the device reliability. Finally, post-failure analysis has been carried out to verify the root causes of the device failure.

Performance Improvement in E-Gun Deposited SiOx- Based RRAM Device by Switching Material Thickness Reduction

A performance improvement by reduction in switching material thickness in a e-gun deposited SiOx based resistive switching memory device was investigated. Reduction in thickness cause thinner filamentary path formation during ON-state by controlling the vacancy defects. Thinner filament cause lowering of operation current from 500 μA to 100 μA and also improves the reset current (from >400 μA to <100 μA). Switching material thickness reduction also cause the forming free ability in the device. All these electrical parametric improvements enhance the device reliability performances. The device show >200 dc endurance, >3-hour data retention and >1000 P/E endurance with 100 ns pulses.

GaN power IC normally-on and normally-off transistors technology and simulation

GaN technology has been waiting to be widely adopted because of its specific technical requirements. Integration of transistor and driver in a single die will enable to overcome problems with gate driving, high cost of circuit and low device reliability. This paper demonstrates technology of GaN-on-Si normally-on and normally-off transistor with different p-GaN cap-layer thickness as well as simulation of these devices. The simulation data confirm experimental results. P-GaN cap-layer thickness affects the current channel density: the more p-GaN thickness, the less channel density. The fabricated transistors have a maximum drain current in open state of about 800 mA/mm.

Mechanical Reliability of Silicon Microstructures

In this article, an overview of the mechanical reliability of silicon microstructures for micro-electro-mechanical systems (MEMS) is given to clarify what we now know and what we still have to know about silicon as a high-performance mechanical material on the microscale. Focusing on the strength and fatigue properties of silicon, attempts to understand the reliability of silicon and to predict the device reliability of silicon-based microstructures are introduced. The effective parameters on the strength and the mechanism of fatigue failure are discussed with examples of measurement data to show the design guidelines for highly reliable silicon microstructures and devices.

Accuracy and Reliability of Inertial Devices for Load Assessment During Flywheel Workout

There is currently an increase in inertial flywheel application in strength training; thus, it must be monitored by an accurate and reliable device. The present study tested: (1) the accuracy of an inertial measurement device (IMU) to correctly measure angular velocity and (2) its inter-unit reliability for the measurement of external load. The analysis was performed using Pearson Correlation and Intraclass Correlation Coefficient (ICC). The IMU accuracy was tested using Bland-Altman and the reliability with the coefficient of variation (CV). Ten elite-level football players performed ten series of 5 repetitions in a one-hand standing row exercise (5 series with each arm). A nearly perfect accuracy (ICC=.999) and a very good between-device reliability (Bias=-.010; CV=.017%) was found. IMU is a reliable and valid device to assess angular velocity in inertial flywheel workout objectively.

Early Fault-Analysis Using In-Line Raman Spectroscopy Metrology

As semiconductor device dimensions scale down, process variation impact on reliability becomes increasingly severe. This trend stems from the high-reliability requirements typical for advanced system applications, the narrowing process margins and the high sensitivity of devices to material and dimensional variations. At the process level, many deviations from nominal conditions can degrade the devices' reliability. Examples are induced charge traps in the various types of memory cells, electrical performance inhibitors due to lattice defects or poor stress management and poor data retention due to contamination by killer elements. We claim that monitoring and correcting deviations throughout the fabrication process provides an effective approach for preventing reliability failures. By restricting deviations below specific threshold levels and screening out reliability and End Of line (EOL) related parameters, eventual device reliability can be safeguarded. This paper addresses the relationship between various process parameters and reliability, and reviews the enablers of preventive, early-detection inline metrology in the fab.

Numerical Study of Joule Heating Effects on Microfluidics Device Reliability in Electrode Based Devices

In electrode-based microfluidic devices, micro channels having narrow cross sections generate undesirable temperature inside the microfluidic device causing strong thermal distribution (joule heating) that eventually leads to device damage or cell loss. In this work, we investigate the effects of joule heating due to different electrode configuration and found that, electrodes with triangular arrangements produce less heating effect even at applied potential of 30 V, without compromising the performance of the device and separation efficiency. However, certain electrode materials have low thermal gradients but erode the channel quickly thereby affecting the reliability of the device. Our simulation also predicts optimal medium conductivity (10 mS/m with 10 V) for cells to survive inside the channel until they are selectively isolated into the collection outlet. Our investigations will aid the researchers in the designing of efficient and reliable microfluidic devices to overcome joule heating inside the microchannels.