Self-aligned Schottky-source source-gated transistors (SGTs) have been made in polysilicon. The structures enable a direct comparison to be made between a SGT and a standard thin-film field-effect transistor (FET) on the same device. SGTs having excellent characteristics have been fabricated, with intrinsic gains approaching 10,000. The effects of bulk doping in the polysilicon and of the source barrier modification implant are considered in the context of the electrical output characteristics. It is shown that the choice of source length is a tradeoff between device speed and variations in current output due to variability during fabrication. (C) 2011 Elsevier Ltd. All rights reserved.