Photoluminescence investigation of III-V semiconductor surface damage induced by PECVD silicon nitride films

Photoluminescence depth profiling measurements were carried out on SiNx/InP, SiNx/In1-xGaxAs and SiNx/In1-xGaxAsyP1-y to identify the possible surface “damage” induced by plasma-enhanced chemical vapour deposition silicon nitride films. A PL intensity decrease is always seen after the semiconductor surface is coated with a silicon nitride. The initial PL intensity recovers in the case of InP and In1-xGaxAsyP1-y semiconductors. A definite PL intensity decrease is seen in the case of In1-xGaxAs whatever the silicon nitride deposition conditions. Several suggestions for the causes of the common decrease of PL intensity and of the In1-xGaxAs anomalous behaviour are given.