Study of surface weak spots on SiC Schottky Diodes under specific operating regimes by Infrared Lock-in sensing

摘要

Several Silicon Carbide Schottky Barrier Diodes (SBDs) were inspected by Infrared Lock-In Thermography to study and determine the origin of structural weak spots resulting from their manufacturing and electro-thermal stressing tests. These spots are frequency modulated following three different approaches representative of their operating conditions and detected by their infrared emission, as they behave as hot spots. Such weak spots could have originated from barrier modification due to wire-bonding process, non-uniform active area resistance for bad metallization electrical contact, deep level traps creation due to high energy implantation in the edge termination, and internal crack propagation during thermal cycling.