Post-irradiation Gate Stress – PiGS

At present, space actors are highly concerned with heavy ion-induced power MOSFETs hard failures and in particular by oxide rupture after heavy ion irradiation. In order to guarantee the reliability of space systems, contractors have to follow qualification procedures. The American military standard for heavy ion testing, MIL-STD-750E method 1080, recommends performing a Post-irradiation Gate Stress (PiGS) in order to reveal latent defects sites that might have been created during irradiation. Unfortunately, this type of test can only be considered as a pass or fail test. With a too much restrictive approach, rare are the devices to be qualified.
Even if the American test method is accurate on most of the points, the main issue is related to the Post-irradiation Gate Stress. What is lacking is that this specific part of the American Test Standard has neither been dedicated to real space missions nor adapted to space environment. The PiGS test has even no physical basis justifying performing it for space applications. Working from fundamental to applicative, we aim at drawing up test standards dedicated to the engineer in charge of space applications.
Moreover, the PiGS test and all the results obtained during the project will be validated through a dedicated in flight experiment embedded in ICARE/ARSAT geostationary satellite.
The qualification of power MOSFETs for space applications is one of the major challenges for European space actors. The independence of European end-users and manufacturers is clearly at stake. Consequences in practice are at a geopolitical level and related to the ITAR legislation.