Electrical properties of a triode-like silicon vertical-channel JFET

A transition from triode-like to pentode-like Id-Vd characteristics is observed in diffusion-type vertical JFETs by varying the channel impurity concentration from 5 x 10 to the 14th to 5 x 10 to the 15th per cu cm. In calculated Id-Vd characteristics of a low concentration and short-channel JFET, Geurst's theory has been shown to agree qualitatively with the experimental curves. In a triode-like JFET, the drain current shows two distinct drain-voltage-dependent regions. It has an exponential dependency at values less than 0.2 mA/cm. It has an n-th power dependency on the drain voltage when the drain current is larger than 5 mA/cm. Other important electrical properties are also calculated and compared with experimental data.