Vincent Pouget

Investigation of the Propagation Induced Pulse Broadening (PIPB) Effect on Single Event Transients in SOI and Bulk Inverter Chains

The propagation of single event transients (SET) is measured and modeled in SOI and bulk inverter chains. The propagation-induced pulse broadening (PIPB) effect is shown to determine the SET pulse width measured at the output of long chains of inverters after irradiation. Initially, narrow transients, less than 200 ps at the struck inverter, are progressively broadened into the nanosecond range. PIPB is induced by dynamic floating body effects (also called history effects) in SOI and bulk transistors, which depend on the bias state of the transistors before irradiation. Implications for SET hardness assurance, circuit modelling and hardening are discussed. Floating body and PIPB effects are usually not taken into account in circuit models, which can lead to large underestimation of SET sensitivity when using simulation techniques like fault injection in complex circuits.

Backside laser testing of ICs for SET sensitivity evaluation

A new experimental approach combining backside laser testing and analog mapping is presented. A new technique for integrated circuits (ICs) backside preparation by laser ablation is evaluated. The methodology is applied to the study of single-event transient (SET) sensitivity on a linear IC.

Time-resolved scanning of integrated circuits with a pulsed laser: application to transient fault injection in an ADC

This paper presents an experimental system for integrated circuits testing with a pulsed laser beam. The system is fully automated and simultaneously provides interesting spatial and temporal resolutions for various applications like fault injection, radiation sensitivity evaluation, or default localization. In the presented application, the system is used to visualize signal propagation in an 8 bit half-flash ADC.

Pulsed-Laser Testing for Single-Event Effects Investigations

The application of pulsed lasers to the study of Single-Event Effects (SEEs) in integrated circuits and devices is described. The role of a pulsed laser is to provide spatial and temporal information about SEEs, information that is not available when broad-beam ion sources are used. A detailed description is given of the mechanisms involved, including light propagation and absorption by both linear and non-linear processes. Numerous examples highlight the versatility and usefulness of the technique in the study of SEEs.

Investigation of single-event transients in voltage-controlled oscillators

The responses of voltage-controlled oscillators (VCOs) to single-event transients (SETs) are investigated. Laser testing and simulations indicate that ion strikes on critical transistors cause distortions in the oscillating output. The time it takes for the circuit to resume its normal operating condition is limited by the recovery time of the affected transistor(s) and the oscillator startup time. These limits to circuit recovery time are the primary causes of the frequency dependence of SET responses in VCOs.

Influence of Laser Pulse Duration in Single Event Upset Testing

Device simulations of laser induced SEU in an SRAM cell are performed with pulse durations from 100 fs to 100 mus. SEU threshold energy is notably dependent on the pulse duration. Two regimes are identified and modeled analytically and electrically

Dynamic behavior of a chemical sensor for humidity level measurement in human breath

This paper presents a model of the transient response of a short response time capacitive humidity sensor to evaluate its ability to measure the humidity level in exhaled air. This sensor will be used to increase diagnosis accuracy of pulmonary deficiencies. A dedicated humid air blower was developed to measure the transient response of the humidity sensor exposed to abrupt humidity variations. The model is proposed for extraction of humidity data from experiments or for the sensor response prediction in any humidity conditions. This model relies on the theory of gas diffusion in polymer films. It describes a bidimensional diffusion process as the combination of two one-dimensional mechanisms.

Investigation of millisecond-long analog single-event transients in the LM6144 op amp

A new category of analog single-event transients (SETs) with millisecond-long durations have been experimentally observed in the LM6144 operational amplifier. It is the first time that events with such extreme widths are under investigation in a linear integrated circuit. Relying on heavy-ion broadbeam tests, picosecond pulsed lasers diagnostics, and computer-assisted circuit modeling, we uncover the mechanisms and causes of these anomalous voltage transients. The identification of the problematic area of the IC reveals that the bias/startup circuitry is sensitive to energetic ionizing particles and can be responsible for corrupted circuit operations when subjected to a heavy-ion strike. A circuit hardening solution with minimal impact on the layout and the electrical performances of the op amp are proposed to mitigate this effect.

Validation of radiation hardened designs by pulsed laser testing and SPICE analysis

Abstract A new pulsed laser system dedicated to the simulation of radiation effects on integrated circuits is presented. On-line testing capabilities are detailed and two SPICE models of radiation induced transient currents are proposed to be used for results analysis.

Laser-Induced Current Transients in Silicon-Germanium HBTs

Device-level current transients are induced by injecting carriers using two-photon absorption from a subbandgap pulsed laser and recorded using wideband transmission and measurement equipment. These transients exhibit three distinct temporal trends that depend on laser pulse energy as well as the transverse and vertical charge generation location. The nature of the current transient is controlled by both the behavior of the subcollector-substrate junction and isolation biasing. However, substrate potential modulation, due to deformation of the subcollector-substrate depletion region, is the dominant mechanism affecting transient characteristics.