Mark W. Savage

Demonstration of single-event effects induced by through-wafer two-photon absorption

The first demonstration of through-wafer two-photon absorption (TPA) single-event effects (SEEs) testing is presented. We interrogate the single-event transient (SET) response of several different nodes of the LM124 operational amplifier via TPA carrier injection through both the front and back (substrate) chip surfaces. The results reveal that the SETs and sensitivities produced in several different nodes by front-side and back-side irradiation are effectively identical, confirming the validity of this approach for SEE studies.

Critical charge for single-event transients (SETs) in bipolar linear circuits

The critical charge for single-event transients (SETS) from heavy ions has been simulated and measured in bipolar linear circuits under several bias conditions. Although in many cases the threshold linear energy transfer is less than 2 MeV-cm/sup 2//mg, the minimum critical charge is of the order of 0.3-1 pC.

The role of parasitic elements in the single-event transient response of linear circuits

Parasitic elements can play an important role in the single-event transient sensitivity of a circuit. This work describes how parasitics can affect the simulation response of linear circuits and shows how parasitics have been identified using a pulsed laser.

Circuit modeling of the LM124 operational amplifier for analog single-event transient analysis

This work presents the development of a transistor-level circuit model of the LM124 operational amplifier specifically engineered and calibrated for analog single-event transient (ASET) computer simulations. The techniques presented rely heavily on datasheet specifications for electrical parameterization and experimental laser probing for dc and transient calibration. The resulting circuit model proves to be suitable for broad-beam SET predictions and fault diagnostics for space applications.

Comparison of single-event transients induced in an operational amplifier (LM124) by pulsed laser light and a broad beam of heavy ions

A comparison of single-event transients (SETs) from heavy-ion and pulsed-laser irradiation of the LM124 operational amplifier shows good agreement for different voltage configurations. The agreement is illustrated by comparing both individual transient shapes and plots of transient amplitude versus width.

Variations in SET pulse shapes in the LM124A and LM111

We present a paper that shows remarkable variation in single-event transient (SET) pulse signal shape for the LM124 operational amplifier, and the LM111 voltage comparator. Both the data and the test methods used are presented.

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.

An improved stripe-cell SEGR hardened power MOSFET technology

A new single-event gate rupture radiation-hardened power MOSFET is reported. It is based upon a well-established radiation-hardened technology described in 1996. The hexagonal cells used in prior work are replaced with a stripe-cell structure producing demonstrated performance improvements.

Total-dose hardening of a bipolar-voltage comparator

A radiation-tolerant bipolar-voltage comparator experienced severe degradation of radiation hardness when layout of the part was redrawn and the process moved from a 4-in wafer to a 6-in wafer line. The reasons for the loss in hardness are identified, and it is shown that modifications to the design layout eliminate the problem.

Characterization of SET response of the LM124A the LM111, and the LM6144

We present a paper that characterizes the single event transient response of the LM124, LM111, and LM6144 in a heavy ion environment. In the paper both the test methods used and the data are presented.