Material electronic quality specification factors for polycrystalline silicon wafers

We present a scheme to monitor quality (diffusion length) improvement, or upgrading, for inhomogeneous polycrystalline silicon wafers. Statistically-based parameters and scaling factors are defined to represent individual regions of varying diffusion length, and are used to follow material electronic property changes from crystal growth through upgrading steps, including phosphorus diffusion, hydrogen passivation and aluminum firing. Measurements of diffusion length using two different methods, SPV and IRPC are used.