Intrinsic Gain in Self-Aligned Polysilicon Source-Gated Transistors

Thin-film self-aligned source-gated transistors (SGTs) have been made in polysilicon. The very high output impedance of this type of transistor makes it suited to analog circuits. Intrinsic voltage gains of greater than 1000 have been measured at particular drain voltages. The drain voltage dependence of the gain is explained based on the device physics of the SGT and the fact that a pinchoff occurs at both the source and the drain. The results obtained from these devices, which are far from optimal, suggest that, with a proper design, the SGT is well suited to a wide range of analog applications.