From its first commercial development in the late 1870s, on through some slight tweaks to size and shape, the bulb has been a glass-and-filament mainstay for more than 130 years.

Based on the analysis of the structure, size, and actual work efficiency of an ion source filament insulator in ion implantation system, an optimization design of the filament insulator is presented.

In addition, with the increasing distance between the filament and the substrate, the crystalline volume fraction and the grain size of poly-Si films notablely decrease.