TABLE OF CONTENTS Leakage currents in devices can occur either in the active regions of devices in the semiconductor lattice itself or through the thin insulators separating regions of different electric potential. One of the sources of leakage current in the active regions of devices is the presence of extended defects in such regions. In insulators leakage current is usually related to the presence of point defects rather than extended defects. We will first discuss the properties of extended defects that may lead to enhanced conductivity due to their presence in the active regions of semiconductor devices and then we will discuss how various point defects act to enhance the leakage current in insulators.
Extended defects in semiconductors have the potential to become paths having higher conductivity than exists along paths through the bulk material for several reasons. In germanium it has been found that quasi-metallic conduction occurs along large angle grain boundaries of the ?11-structure in n as well as p-type with a carrier density of from 5 to 6 10 12 cm -3. However, no excess conductivity was detected along a ?-25-type (<100> tilt axis, 16.3 tilt angle) grain boundary in n-type silicon having a dopant concentration of 10 13cm -3.59
One dimensional conduction along one type of dislocation (unidentified) has been found in Ge with the conductance given by 6.9 10 -11 exp(-0.022/kT) ? -1m, where kT is...
