Formation of Self-Assembled Nanocrystalline Silicon Dots by SiCl₄/H₂ RF Plasma-Enhanced Chemical Vapor Deposition

Abstract

Self-assembled nanocrystalline silicon (nc-Si) dots have been directly fabricated on thermally grown SiO 2 /c-Si at low temperatures of 150–200°C by controlling the early stages of a conventional parallel plate RF (13.56 MHz) plasma-enhanced chemical vapor deposition (PE-CVD) process using tetrachlorosilane (SiCl 4 ) and H 2 . The number density of nc-Si dots, and their sizes and heights were controlled by adjusting deposition time, substrate temperature T s , pressure, RF power and pulse duty ratio of RF plasma. These specific features originate from the low sticking probability of deposition precursors and chemical stability of the chlorine-terminated surface under the hydrogen plasma, which results in the direct formation of nc-Si dots on SiO 2 at low temperatures.