Fault Isolation of Resistive/Open 3D Wafer Bonding Interconnects by Thermal Laser Stimulation and Light-Induced Capacitance Alteration

Monday, December 7, 2020: 1:30 PM
Dr. Kristof J.P. Jacobs , Imec, Leuven, Belgium
Dr. Soon-Wook Kim , IMEC, Leuven, Belgium
Prof. Ingrid De Wolf , imec, Leuven, Belgium
Dr. Eric Beyne , Imec, Leuven, Belgium

Summary:

A resistive defect (~ kΩ range) and hard open defect (> 100 GΩ range) were successfully localized in high density W2W interconnect structures (2.2 µm pitch) by applying thermal laser stimulation (TLS) and light-induced capacitance alteration (LICA), respectively. Removing the Si substrate of the top wafer (5 µm in thickness) by an etch back process in combination with visible light laser excitation at 405 nm enabled us to achieve excellent defect localization for both techniques.