Test structures to verify ESD robustness of on-glass devices in LTPS technology

Different test structures, used to investigate the electrostatic discharge (ESD) robustness of on-glass devices in a low temperature poly-Si (LTPS) process, are proposed in this paper. A transmission line pulse generator (TLPG) is used to monitor the I-V behavior of on-glass devices in the high-current region, and to evaluate the robustness of those LTPS devices during ESD stress conditions. Finally, a successful ESD protection design with P⁺-i-N⁺ diodes and a VDD-to-VSS ESD clamp circuit integrated on an LCD panel has been demonstrated with a machine-model (MM) ESD level of up to 275 V, whereas the traditional one can only sustain 100 V MM ESD stress.