Cascade
eVue Microscope
A revolutionary new microscopy tool
eVue Microscope Overview
The eVue™ digital imaging system is optimized for on-wafer test with Cascade probe stations. The revolutionary multi-optical path, multi-camera design of eVue offers the perfect balance of optical resolution, digital zoom and live-motion video. The eVue utilizes 3MP cameras to enhance optical visualization and increased color frame rate to ensure efficient wafer and in-die navigation. The eVue increases productivity with fast navigation, set-up and unattended thermal test functionality, with on-site probe-to-pad alignment (PTPA) technology – VueTrack™.
The VueTrack technology provides a novel method to track probe tips and correct for drift, allowing a customer to run a probe station unattended at multiple temperatures with no operator intervention. The VueTrack technology significantly increases test productivity and test cell efficiency by eliminating the idle time between temperature transitions and automatically generating parametric and reliability data.
eVue Microscope Key Features
Device Characterization and Modeling
Unattended Over-Temperature Wafer Test
Due to the demands of shrinking design rules and increased reliability, many wafer test plans call for collecting data at multiple temperatures, though introducing temperature into probes causes mechanical drift of both needles and pads. These misalignments need to be corrected manually at every temperature change. Soak times of 30-60 minutes are required to reach the thermal equilibrium before alignment error correction can be done.
Thermal imbalance is also introduced into the system when stepping a number of test sites with large distance, requiring soak times and alignment error corrections.
eVue PRO Solution:
The eVue utilizes a single downward-looking microscope to measure the probe tips and wafer locations with the chuck in the same position that the electrical measurement (or probe contact) will be made. On-site probe tip and wafer location measurements enable automatic PTPA error corrections, and the best possible alignment to be maintained throughout a wafer test plan. The VueTrack, automatic on-site PTPA correction approach, maximizes test productivity, by reducing idle time, transition and die soak times, as well alignment correction times. Test data quality is maintained with constant contact quality, even on small pads.
Failure Analysis
Internal Node Probing
Setup and navigation of sub-micron probe tips take a long time with the need to constantly change microscope objectives and switch between fields of view. Multiple probes tips can not be seen simultaneously – a non-viewed probe tip might lift off the node. Probe tips can be crashed when changing objectives, and moving microscope. Tips are often ‘lost’ using high magnification.
eVue PRO Solution:
The eVue simultaneously displays low, medium, and high magnification (FOV) video of the probe needle, allowing you to quickly “land” the sub-micron tip on a 1-5µm² pad. Multiple probe tips can be viewed and tracked simultaneously, to ensure all probe tips are contacting pads.
Process Development/Reliability
Probe Card Alignment – Process Monitoring
Using long or high pin count probe cards, it is difficult to easily align needle tips to pads, because both ends of the card cannot be simultaneously seen with adequate magnification. Card alignment wastes time switching between magnifications and locations. All needles may not have equal contact or spacing on the pads.
eVue PRO Solution:
eVue’s high resolution Multi-View capability displays both ends, intermediate sites and the full card layout – simultaneously. For quick alignment and planarization, eVue eliminates the need to move the microscope or change objectives.
Advanced Technology/Research
High-resolution/fidelity Color Image Capture
High-resolution microscope images are needed for management reports, product yield results, and research. Multiple FOV images need to be stitched together to show a “navigation story” (wafer, IC, device/test node). External software is needed for annotations and to convert images to JPEG for reports. Hours can be consumed switching to a high-resolution camera.
eVue Solution:
Image capture and live video modes are integrated in the eVue (megapixel image/video in PRO package). Annotate, resize, and output images in popular file formats, all from within eVue. Easily capture the navigation story using eVue PRO package Multiple FOV image capture.