Measuring Holding Voltage Related to Homogeneous Current Flow in Wide ESD Protection Structures Using Multilevel TLP

Due to the negative-differential-resistance-related instability, the current-density distribution in sufficiently wide devices exhibiting S-shaped I-V characteristics becomes inherently inhomogeneous along the device width. High-current-density on-state (i.e., a current filament) and low-current-density off-state regions are spontaneously formed, leading to the formation of a vertical branch in the I-V curve at a so-called coexistence voltage uCO. In electrostatic discharge (ESD) protection devices (PDs), this vertical I- branch usually determines the lowest voltage point that can be accessed by a conventional transmission line pulser (TLP). However, the real holding point of device VH, which is related to an I-V part with a homogeneous current distribution, lies below uCO, i.e., VH