Fault isolation and TEM study in the state-of-art Thin-Film Transistor

In this work, we discussed the fault isolation method for Thin-Film Transistor (TFT). Many defects in TFT can be directly observed by optical microscope; however, for some defects, they are not visible in either optical microscope or SEM, which makes the fault isolation very challenging. We demonstrated that OBIRCH can be used to find the defect location in the leakage/short type TFT failure. The TFT is so fragile that the laser power and biasing voltage have to be very carefully controlled to avoid damaging the TFT. After identifying the defect location by OBIRCH hot spot, the following TEM analysis has successfully captured the defect.