MODULATING THE STRESS OF POLY-CRYSTALINE SILICON FILMS AND SURROUNDING LAYERS THROUGH THE USE OF DOPANTS AND MULTI-LAYER SILICON FILMS WITH CONTROLLED CRYSTAL STRUCTURE

摘要

In certain embodiments a method of forming a multi-layer silicon film is provided. A substrate is placed in a process chamber. An amorphous silicon film is formed on the substrate by flowing into the process chamber a first process gas comprising a silicon source gas. A polysilicon film is formed on the amorphous silicon film by flowing into the deposition chamber a first process gas mix comprising a silicon source gas and a first dilution gas mix comprising H₂ and an inert gas at a first temperature. In certain embodiments, the polysilicon film has a crystal orientation which is dominated by the 220 direction. In certain embodiments, the polysilicon film has a crystal orientation dominated by the 111 orientation. Structures comprising a lower amorphous silicon film and an upper polysilicon film having a random grain structure or a columnar grain structure are provided as well.