SiC MOSFET structure at the die level with AFM sMIM Mode

For the enhancement of Silicon Carbide (SiC) processes and reliability assessments, precise and comprehensive characterization of the structural and local electrical properties of semiconductor layers at the die level is crucial. In this study, the die-level structure of a commercial SiC MOSFET is analyzed. Conventional Scanning Electron Microscopy is compared with a microwave-based mode using Atomic Force Microscopy. Two SEM detectors are utilized to demonstrate the complementary nature of the analyses. A systematic evaluation is presented using the Backscattered Electron Detector to assess the impact of SEM parameters on SiC analysis. The chemical composition of the detected layers is identified through elemental analysis via Energy Dispersive Xray Spectroscopy. At the front-end level, the pn junctions in the SiC MOSFET are revealed using SEM-induced Passive Voltage Contrast with the Lower Electron Detector. Additionally, AFM topography and Scanning Microwave Impedance Microscopy (sMIM) techniques are employed to probe the structural and electrical properties of the die-level MOSFETs. By comparing SEM and AFM techniques, the layer detection capabilities of each method are evaluated for SiC MOSFET devices. The results underscore the powerful capabilities of the Scanning Microwave Impedance Microscopy technique for investigating Silicon Carbide devices.