InGaAs-OI Substrate Fabrication on a 300 mm Wafer
In this work, we demonstrate for the first time a 300-mm indium–gallium–arsenic (InGaAs) wafer on insulator (InGaAs-OI) substrates by splitting in an InP sacrificial layer. A 30-nm-thick InGaAs layer was successfully transferred using low temperature direct wafer bonding (DWB) and Smart CutTM technology. Three key process steps of the integration were therefore specifically developed and optimized. The first one was the epitaxial growing process, designed to reduce the surface roughness of the InGaAs film. Second, direct wafer bonding conditions were investigated and optimized to achieve non-defective bonding up to 600 °C. Finally, we adapted the splitting condition to detach the InGaAs layer according to epitaxial stack specifications. The paper presents the overall process flow that achieved InGaAs-OI, the required optimization, and the associated characterizations, namely atomic force microscopy (AFM), scanning acoustic microscopy (SAM), and HR-XRD, to insure the crystalline quality of the post transferred layer.
Metallization defect detection in 3D integrated components using scanning acoustic microscopy and acoustic simulations
Abstract In the context of More than Moore 3D integration concepts, the μm to nm sized failure detection and analysis represents a highly demanding task. In this work, micron sized artificially induced metallization defects in open TSVs are detected by scanning acoustic microscopy (SAM). Micro X-ray computed tomography (μXCT) and scanning electron microscopy (SEM) are used to validate the SAM results. Notably, the SAM results show that the failures for certain TSVs are located at a different position as illustrated by μXCT and SEM. In order to interpret these controversial results, 2D elastodynamic finite integration technique (EFIT) simulations are performed. We discuss the results by taking the excitation of surface acoustic waves (SAWs) or Rayleigh waves into account which are leading to characteristic interference patterns within the TSV. The simulation and understanding of such interference effects can be highly beneficial for the use of SAM with respect to modern failure detection and analyses.
Accumulation of Bone-Seeking Radionuclides in Liver Metastasis from Colon Carcinoma
Fifteen colon cancer patients with metastasis to the liver were examined by both liver and bone scans. Seven of these showed accumulation of bone seeking radionuclides in the liver at the site of a defect in the scan. Such accumulation was found in two diphosphonate, in one pyrophosphate and in six 18F scans. To our knowledge, this is the first series to report localization of 18F in intrahepatic metastasis from colon cancer. The precise mechanism for this non-skeletal accumulation is unknown.