Use of High Voltage OBIRCH Fault Isolation Technique in Failure Analysis of High Voltage IC's

Abstract

In this paper, we present an extension of Optical Beam Induced Resistance CHange (OBIRCH, <=40V) to the failure analysis and fault isolation of high voltage (HV) MOSFET failures up to 3KV. Current available OBIRCH amplifiers can only source up to 40V, while HV MOSFETs have shown anomalous breakdown voltages ranging from 350 ∼ 630V. These HV failures need new sourcing and amplification capabilities for debugging, fault isolation and failure analysis. We will show one intentional overstressed MOSFET at HV and two real HV MOSFET failure cases. All three cases were successfully analyzed using the new HV OBIRCH method.