Abstract This paper discusses the Failure Analysis methodology used to characterize 3D bonded wafers during the different stages of optimization of the bonding process. A combination of different state-of-the-art techniques were employed to characterize the 3D patterned and unpatterned bonded wafers. These include Confocal Scanning Acoustic Microscopy (CSAM) to determine the existence of voids, Atomic Force Microscopy (AFM) to determine the roughness of the films on the wafers, and the Double Cantilever Beam Test to determine the interfacial strength. Focused Ion Beam (FIB) was used to determine the alignment offset in the patterns. The interface was characterized by Auger Spectroscopy and the precession electron nanobeam diffraction analysis to understand the Cu grain boundary formation.

Abstract Through inline processing of a prospective Spin on Hardmask (SOH) material, bubble defects were observed randomly across a wafer. Several complementary FA techniques were utilized to characterize the bubble defects including SEM, TEM, and chemical analysis techniques. The root cause of defect formation was identified as a raw material imperfection in SOH, which led to excessive outgassing. Imperfections within the substrate formed nucleation sites for outgassing of SOH material forming bubbles, which allowed voids to propagate. These findings led to implementation of greater quality control methods by the raw material manufacturer.

Abstract The State-of-the-Art FinFET technology has been widely adopted in the industry, typically at 14 nm and below technology nodes. As fin dimensions are pushed into the nanometer scale, process complexity is highly escalated, posing great challenges for physical failure analysis. Meanwhile, the accelerated cycles of learning for new technology nodes demand high accuracy and fast turnaround time to solve the material and interface issues pertaining to semiconductor processing or device failure. In this paper, we report a case study of fin related defect that caused device failure. Several analytical techniques, namely, Scanning Electron Microscopy (SEM), plan-view and cross-section Transmission Electron Microscopy (TEM) with Energy Dispersive X-ray spectroscopy (EDX), Electron Energy Loss Spectroscopy (EELS) and Z-contrast tomography were employed to characterize the defect and identify root-cause, leading to the resolution of this issue.