Simulator to host single event effect testing

Precision Solutions' new SEREEL 2 facility has been officially opened by Lord Sainsbury of Turville.

Precision Solutions' new SEREEL 2 facility has been officially opened by Lord Sainsbury of Turville.

The SEREEL2 (single event radiation effects in electronics laser, 2nd generation) simulator, based within the Radiation Effects Group of the Precision Solutions business unit of MBDA UK allows single event effect (SEE) testing to be carried out using pulsed laser excitation.

Single event effects are faults due to the interactions of high-energy radiation particles with microchip cells.

They range from "soft" errors involving both single and multiple bit upsets in digital devices that corrupt data stored in memory cells (until they are reset), to "hard" catastrophic errors that may lead to a destructive failure of the integrated circuit.

Testing electronic component designs for susceptibility to single event effects forms an important part of the system design process, and can prevent potentially expensive discoveries during system qualification.

SERREL 2 uses very short pulses of light from an ultra fast Ti- Sapphire laser system that are focused through a microscope objective to induce a column of ionisation (1um diameter) that propagates into the surface of the silicon die after the top surface of the package is removed).

The column of charge can cause a memory cell to gain or lose charge, resulting data bits "flips" known as a single event upset (SEU).

SEREEL2 has computer controlled nanostep x-y-z positioners to allow an IC to be positioned in front of the focused laser pulses to an accuracy of 1um.

During normal operation the IC is moved within the focus of the laser, while the laser fires pulses at a range of repetition rates from 100Hz to a single shot.

Using a scanning action, the entire IC (or a specific section) is bombarded with laser pulses that strike the IC die at discrete locations.

A pulse energy CCD camera on the three-axis positioning system, an adjustable pulse attenuator, and computer-controlled goniometers ensure that the die remains in the focal plane of the laser.

The contents of the device are examined after the scan is completed and any data values that are found to be in error can be saved for further analysis along with their respective addresses.

The energy of the laser pulses can be altered, which in turn changes the number of errors observed.

Techniques have also been developed for laser memory mapping and threshold contour mapping.

Depth-wise SEE sensitivity profiling can reveal funnelling of charge from the substrate, if the ionisation path penetrates deep into the substrate.

SEREEL 2 automation of the techniques for laser memory mapping and multiple-wavelength SEE sensitivity profiling makes such studies quicker and more practical.

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