Automated optical inspection
The Confovis WAFERinspect AOI system is suitable for various inspection jobs involving structured as well as unstructured wafers and offers individual solutions in the field of defect inspection and classification. Depending on the structure sizes to be inspected, defects can be detected by using the golden sample method or, in the case of very small structures, by way of artificial intelligence (AI). The defects will be classified either through rule-based neural networks or by way of Deep Learning AI.
Defect inspection & classification
Defects of any kind will be detected with Confovis by an image comparison with a golden sample or by way of Deep Learning AI. In a first step, all deviations (defects) will be detected. Following that, the defects will be classified or filtered by freely configurable parameters. Critical defects not corresponding to a defined class will be marked as such, unlike in other AOI systems, and not ignored, so that no defects go undetected, even without training the classifier. Cross-image defects are stitched and classified in their entirety.
The Confovis wafer inspection system identifies deviations in wafer production processes and allows for an analysis of the reasons. It is a process control instrument that detects and classifies defects and can measure defects thus detected in 2D as well as 3D. Moreover, standard metrology applications are also made possible (e.g. line/space, overlay, critical dimensions, step heights).
The patented imaging measurement method SIM (Structured Illumination Microscopy) combines high-resolution 3D measurement data and the Cognex 2D image analysis tool in an all-in-one solution for the MEMS industry. Numerous inspection and measurement tasks can be performed with the Confovis method:
- measurement of different materials
- highly demanding topographies
- transparent layers
- contour measurements in nanometer precision
- roughness measurements
A large number of handling configurations are available to support the various wafer sizes and types.
The Confovis WAFERinspect AOI allows for the control of III-V compound semiconductors (such as GaN, GaAs, InP). Likewise, sensitive layer structures as produced on the basis of the epitaxy method can be controlled with a high degree of sensitivity to identify critical defects. The WAFERinspect AOI detects and classifies sub-micrometer defects with rule-based neural networks or also by way of Deep Learning. Thanks to the imaging technique defects can be classified and visually assessed directly after the scan.
5G applications are the basis of the Internet of Things (IoT) and of the automation of every-day life. The requirements as regards the reliability of safety-relevant systems in the field autonomous driving demand a zero defect strategy that has not existed so far in the consumer electronics sector.
With their numerous inspection options in 2D and 3D, the measurement systems from Confovis offer the required process stability, so that resonators, MEMS etc. can be subjected to a detailed optical inspection.
Power semiconductors are a central part of energy-efficient motor drives and of industrial automation systems.
In its function as process control instrument, the WAFERinspect measuring system from Confovis measures the layer thicknesses of different materials applied (e.g. Pd, Al, Ag) precisely, reproducible and stable in the long term in 3D. Similarly, roughness, structure width and many other features can also be measured. The wafer’s total thickness variation (TTV) can also be established by integrating further sensors, to name just one example.
Confovis offers inspection and measurement options for the dicing process of wafers. The individual reticles or dies will remain aligned after the dicing on the basis of alignment marks defined prior to it in the measurement coordinate system. Position and rotation variations will be fully automatically determined and corrected, thus ensuring the data consistency from the unsingulated wafer right through to the last process step. The landmark detection afforded by the software renders time-consuming mechanical alignment processes unnecessary.
The wafer inspection and measuring system WAFERinspect AOI from Confovis provides data for advanced wafer level packaging that are required by semiconductor fabs, in order to increase the process stability. This can be done by measuring geometric deviations for each rewiring layer separately.
Smaller structure sizes, new integration schemes and heterogeneous integration of several components into individual housings result in stricter requirements as regards the process control. Our systems will make it possible to detect deviations speedily as well as to eliminate and monitor them, so as to facilitate a better quality control and to ensure an improved equipment performance.