Solid Phase Crystallization in Initial Growth Region of Polycrystalline Silicon Layer During Deposition at 180^°C by Plasma Chemical Vapor Deposition

Abstract

Microstructures of low-temperature-grown polycrystalline Si (poly-Si) have been studied by transmission electron microscope measurements. Two poly-Si layers with different thicknesses in the n-i-p structure were prepared by plasma chemical vapor deposition at 180°C. The ∼50-nm-thick amorphous-rich layer is observed at the bottom of the 0.5-µm-thick poly-Si layer. Meanwhile, in the first hundreds of nanometers in the 2.4-µm-thick poly-Si layer, an increase in the crystalline fraction due to crystalline columns grown onto the substrate n-layer is found. Solid phase crystallization during the deposition in the initial growth region down to the substrate is discussed.