Methods of fabricating a poly-crystalline silcon ingot from a nucleation promotion layer comprised of chips and chunks of silicon-containing particles

Abstract

A method of fabricating a poly-crystalline silicon ingot includes: (a) loading a nucleation promotion layer onto a bottom of a mold; (b) providing a silicon source on the nucleation promotion layer in the mold; (c) heating the mold until the silicon source is melted into a silicon melt completely; (d) controlling at least one thermal control parameter regarding the silicon melt continually to enable the silicon melt to nucleate on the nucleation promotion layer such that a plurality of silicon grains grow in the vertical direction; (e) controlling the at least one thermal control parameter to enable the plurality of the silicon grains to continuously grow with an average grain size increasing progressively in the vertical direction until entirety of the silicon melt is solidified to obtain the poly-crystalline silicon ingot, wherein the nucleation promotion layer is loaded by spreading a plurality of mono-Si particles over the bottom of the mold.