Inkjet-printed electrical interconnects for high resolution integrated circuit diagnostics

Abstract

As semiconductors continue to shrink in size and become more three-dimensional in shape, the size of defects that can induce a failure also reduces, pushing the need for better fault isolation. The resolving capability of microscopes used in failure analysis (FA) is frequently limited by how close the microscope can be brought to the circuit under test. Accessibility is often restricted by the presence of probe needles or wire bonds that are needed to power up the device during the measurement. Here, I describe a robust, rapid and cost-effective method to overcome the contacting bottleneck by re-routing the probe pads with a low-profile redistribution layer, realized by conductive inkjet printing. I demonstrate that the method enables analytical FA with high spatial resolution on a backside power delivery network structure in combination with the optical beam induced resistance change (OBIRCH) technique. Electrical and structural characterization of the printing process are also reported.