Abstract-The High-Luminosity Large Hadron Collider (HL-LHC) is a novel machine configuration which will rely on a number of key innovative technologies to enhance the performance of the present LHC machine as of 2025. The upgrade will also involve increased radiation levels which need to be predicted by combining scaled measurements and calculations in order to define the qualification requirements for electronic systems. In this work we describe such levels first of all by introducing the monitoring and calculation approaches used for the present LHC machine, and secondly by applying scaling factors and dedicated simulations for the future HL-LHC accelerators. We present the levels according to the different areas relevant for the operation of electronics-based equipment, and discuss the associated Radiation Hardness Assurance implications.

Accelerated terrestrial neutron irradiations were performed on different commercial SiC power MOSFETs with planar, trench and double-trench architectures. The results were used to calculate the failure cross-sections and the failure in time (FIT) rates at sea level. Enhanced gate and drain leakage were observed in some devices which did not exhibit a destructive failure during the exposure. In particular, a different mechanism was observed for planar and trench gate MOSFETs, the first showing a partial gate rupture with a leakage path mostly between drain and gate, similar to what was previously observed with heavy-ions, while the second exhibiting a complete gate rupture. The observed failure mechanisms and the post irradiation gate stress (PIGS) tests are discussed for the different technologies.

High sensitivity of SiC power MOSFETs has been observed under heavy ion irradiation, leading to permanent increase of drain and gate leakage currents. Electrical postirradiation analysis confirmed the degradation of the gate oxide and the blocking capability of the devices. At low drain bias, the leakage path forms between drain and gate, while at higher bias the heavy ion induced leakage path is mostly from drain to source. An electrical model is proposed to explain the current transport mechanism for heavy-ion degraded SiC power MOSFETs.