Speaker
Description
In the field of single-event effects (SEE) testing, laser testing [1] is commonly used for different purposes. The most well-known application is probably the accurate mapping of SEE sensitive areas in a device, especially in the context of radiation-hardening of an integrated circuit (IC) design. Another application consists in screening different components against critical events like single-event latch-up (SEL). Providing an estimation of the sensitive area (cross section) for specific types of events is also a result that is commonly expected from a laser test campaign. For practical reasons related especially to the duration of the test campaign, it is usually not possible to scan a complete chip at the highest available resolution (i.e. smallest scanning step). Thus, a trade-off needs to be found between the scanning resolution and the scanning time. The result of this trade-off depends on several factors like the priority objectives of the test, the time needed to acquire data from the device-under-test (DUT), and the scanning method, which we define as the way to deliver the laser pulse to the DUT vs space and time.
We present a comparison of the various scanning methods available with our Pulsys-Rad industrial laser system for SEE testing [2]. Beyond the classical method that consists in doing a stop-and-go successively at each point of a regular 2D grid in order to trigger a laser pulse and acquire data at each point [3,4,5], we introduce complementary or alternative scanning methods that provide more options and flexibility when preparing the design of experiment (DoE) of a laser testing campaign. The benefits of each method in terms of scan duration, area coverage and accuracy of SEE localization are presented and discussed as a function of the test constraints, priority objectives, and practical considerations. Understanding the strengths and limitations of each method enables optimizing the efficiency of a DoE. We illustrate the discussion with experimental results obtained on the AMD Xilinx Zynq-7000 system-on-chip (SoC) using the different scanning methods with backside single-photon absorption laser testing.
