Minority Carrier Recombination Properties of Crystalline Defect on Silicon Surface Induced by Plasma Enhanced Chemical Vapor Deposition

This research investigates the carrier recombination properties of a crystalline defect layer introduced by the plasma enhanced chemical vapor deposition (PECVD) process of amorphous hydrogenated silicon nitride (SiN x ) passivation films. A direct PECVD technique was used for SiN x films deposition. A crystalline defect layer existed on the surface of the silicon substrate and is under the SiN x passivation film. The recombination lifetime in this defect layer was obtained by focusing on the thickness of the defect layer and the effective lifetime before and after the defect layer etching. After etching a few nanometer thickness, effective lifetime drastically increased. On the other hands, the carrier recombination center could be electrically inactivated by 600°C annealing after SiN x deposition. According to the depth profile of effective lifetime, it was clarified the high carrier recombination region were concentrated near the surface of silicon substrate.