Ring Oscillator-Based Prebond TSV Test

Resistive open fault and leakage fault in TSV decrease the yield and reliability of 3D-ICs. To screen out these faults early in the manufacturing flow, a prebond TSV test method using ring oscillator is proposed. Firstly, according to different TSV receivers which can be normal inverter or Schmitt-Trigger inverter, we divide the ring oscillators into two types and compare their test resolution. Then, the Schmitt-Trigger inverter is used as TSV receiver in our test structure. In order to avoid the wrong test or diagnosis, TSV is tested in multiple low voltage levels. Experimental results with HSPICE simulations using 45 nm CMOS technology show that the proposed test scheme achieved a higher resolution compared to previous works. In addition, the test scheme can be used to test large capacitance TSV and the TSV which exists resistance open fault and leakage fault.