Role of ammonia in depositing silicon nanoparticles by remote plasma enhanced chemical vapor deposition

The optimal development of silicon photonics could improve the current state of microelectronics technology. However due to the multiple parameters involved in the elaboration processes, it is not a simple task to fabricate and reproduce silicon emitting structures. In this paper we discuss the role played by ammonia in depositing silicon nanoparticles (Si-NPs) embedded in silicon nitride matrix by remote plasma enhanced chemical vapor deposition (RPECVD). We found that by varying the ammonia flow, the deposition rate changes. It was observed by high resolution transmission electron microscopy (HRTEM) that higher density and a lower average size of Si-NPs is achieved by increasing the ammonia flow. We recognized a linear behavior between the ammonia flow used to deposit a sample and its maximum photoluminescence (PL) emission peak. Finally we propose a model that allows to predict the maximum PL peak for a given ammonia flow within the range of 403–540 nm.