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

A transition from triode-like to pentode-like
I_{d}-V_{d}
characteristics is observed in diffusion-type vertical JFET's by varying the channel impurity concentration from 5 × 10
¹⁴
to 5 × 10
¹⁵
cm
^-3
. In calculated
I_{d}-V_{d}
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, drain currents show two distinct drain-voltage-dependent regions. It has an exponential dependency when the drain current is less than 0.2 mA . cm
^-1
. It has an
n
th power depndency on the drain voltage when the drain current is larger than 5 mA . cm
^-1
. Other important electrical properties are also calculated and compared with experimental data.