The recently introduced constant-resistance deep-level transient spectrosco
py (CR-DLTS) was successfully applied to study virgin and radiation-damaged
junction field-effect transistors (JFET's). We have studied three groups o
f devices: commercially available discrete silicon JFET's; virgin and expos
ed to high-level neutron radiation silicon JFET's, custom-made by using a m
onolithic technology; and commercially available discrete germanium p-chann
el JPET's. CR-DLTS is similar to both the conductance DLTS and to the const
ant-capacitance variation (CC-DLTS). Unlike the conductance and current DLT
S, it is independent of the transistor size and does not require simultaneo
us measurement of the transconductance or the free-carrier mobility for cal
culation of the trap concentration. Compared to the CC-DLTS, it measures on
ly the traps inside the gate-controlled part of the space charge region. Co
mparisons have also been made with the CC-DLTS and standard capacitance DLT
S. In addition, possibilities for defect profiling in the channel have been
demonstrated. CR-DLTS was found to be a simple, very sensitive, and device
area-independent technique which is well suited for measurement of a wide
range of deep level concentrations in transistors.