Pulsed laser-induced single event upset and charge collection measurements as a function of optical penetration depth

Abstract

We use picosecond laser pulses to investigate single event upsets and related fundamental charge collection mechanisms in semiconductor microelectronic devices and circuits. By varying the laser wavelength the incident laser pulses deposit charge tracks of variable length, which form an approximation to the charge tracks resulting from high energy space particle strikes. We show how variation of the charge track length deposited by laser pulses allows the mechanisms of charge collection in semiconductor devices to be probed in a sensitive manner. With the aid of computer simulations, new insight into charge collection mechanisms for metal–semiconductor field effect transistor (MESFET) devices and heterojunction bipolar transistor devices is found. In the case of the MESFET we point out the correlation between charge collection in the device and the ensuing single event upset in the composite circuit. In favorable cases, we show how probing circuits with tunable laser pulses can estimate a charge collection depth, which is a circuit parameter important for the prediction of error rates for circuits operating in a space-radiation environment.

Comparison of SETs in bipolar linear circuits generated with an ion microbeam, laser light, and circuit simulation

“…These results are consistent with a model in which Q20 contains two competing junctions at different depths below the surface, and suggest that the more sensitive junction is at the greater depth. At low laser pulse energies the amount of charge deposited near the top junction exceeds the SET threshold for that junction, whereas the amount of charge deposited at the lower junction is small due to the exponential decay of the light intensity with depth in the material [15]. As a result, the SETs are dominated by charge deposited near the top junction, giving rise to a negativegoing transient.…”

Single event effects in circuit-hardened SiGe HBT logic at gigabit per second data rates

“…Briefly, laser SEU measurements were performed with nominally 1 ps duration optical pulses centered at 590 nm (2.1 eV) at a pulse repetition rate of 1 KHz. The optical pulses are focused onto the DUT with a microscope objective resulting in a measured Gaussian FWHM (intensity) spot size of 1.2 microns [21]. The DUT is mounted on a motorized xyz stage with 0.1 micrometer resolution.…”

“…8. Details of the system are described elsewhere [20], [21]. Briefly, laser SEU measurements were performed with nominally 1 ps duration optical pulses centered at 590 nm (2.1 eV) at a pulse repetition rate of 1 KHz.…”

Modeling single-event effects in a complex digital device

“…Two pulse repetition frequencies were used: 100 Hz and 1 KHz. Optics between the laser source and the device-under-test focus the beam to a spot size of approximately 1.5 [29]. This allows the targeting of a single transistor.…”