Near-infrared photoluminescent dynamics of thermally annealed Si-rich SiOx films grown by plasma enhanced chemical vapor deposition at different substrate temperatures and N2O/SiH4 fluence ratios are studied. The size of nanocrystallite Si (nc-Si) critically depends on the density of oxygen atoms in a Si-rich layer when the N2O/SiH 4 ratio is smaller than 4; that is, it significantly increases at low N2O/SiH4 ratios. Deposition at a high N 2O/SiH4 ratio strongly reduces the density of nc-Si and degrades the luminescence at 700-800 nm since the density of oxygen atoms is sufficient in the reaction of nc-Si with silicon atoms and formation of a stoichiometric SiO2 matrix. Under a high RF power condition, the increasing substrate temperature usually inhibits the precipitation of nc-Si since high-temperature growth facilitates stochiometric SiO2 deposition. The disappearance of visible PL reveals the complete regrowth of a stoichiometric SiO2 matrix around a nanocrystallite Si cluster after annealing. The results of the transient luminescent analysis of Si-rich SiO x samples corroborate well with the observed values and reveal a lifetime of 43 μs under an optimized nc-Si precipitation condition of 1100°C annealing for 3 h.
|Number of pages||4|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Issue number||2 A|
|State||Published - 8 Feb 2006|
- Plasma enhanced chemical vapor deposition
- Si-rich silicon dioxide
- Silicon nanocrystals