Investigating Pulsed X-ray Induced SEE in Analog Microelectronic Devices

Abstract

We investigate analog single event transient (ASET) generation in an LM124 operational amplifier using focused pulsed x-rays and 800 nm femtosecond laser pulses. We report improvements that have been made to the pulsed x-ray experimental apparatus which include normal incidence geometry and a high speed x-ray chopper that allows us to reduce the pulse repetition frequency of the synchrotron derived x-ray pulse train. The addition of the chopper allows us to measure ASETs that have long relaxation times. We show that ASETs can be generated through metallization on the LM124, and that for equivalent pulse energy incident on the part, the x-ray response from areas covered by metal (and inaccessible to the laser) are different than the x-ray response from areas with no metallization, i.e. “metal-free”. We use the laser pulses to generate ASETs at the same metal-free locations of x-ray induced ASETs. The shapes of the ASETs generated by the two methods are compared. We use the differences seen from the two generation methods to estimate the charge generation/collection produced by the pulsed x-rays and then estimate what LET this would correspond to for heavy ions. This work shows that pulsed x-rays can be used to characterize analog devices for single event effects.