A new FA method used for OTP disturbance failure

In this paper, a new FA method was proposed and successfully used in the OTP (one time programmable) memory disturbance failure. The traditional FA method PVC (positive voltage contrast) is employed to detect the failed location, but it failed to find it. The more sensitive method, AFP biased current image was also failed to locate the failed location. The new method uses the light to stimulus the sample, and use AFP to scan and measure the induced current. The abnormal contrast was observed. The EFA was performed to probe the failed location to breakdown. The result show the breakdown voltage is lower than good unit. Further PFA was performed to find the Silicon-related defects, which also confirm the success of this method.