Ultra thin polysilicon layer formation: Statistical process optimization by Taguchi´s technique

Taguchi method was performed on a series of ultra thin Polysilicon films in order to study the parameter affecting the Polysilicon growth. The samples of ultra thin Polysilicon were prepared through pyrolizing silane SiH₄ for Low pressure chemical deposition method. There are three level of temperature used, that are 575, 600 and 6500°C. The samples were grown in 0.333 litre/min, 0.667liter/min and 1liter/min nitrogen flow rate and with variation in time that is 1, 2 and 3 minutes. The thickness characterization was done by elipsometer. The thickness of the nitride was obtained and is ranging from 1 to 5 nm. All the data were interpreted using Taguchi´s method to analyze the most affecting factors in producing an ultra thin polysilicon using a high temperature furnace.