The ZetaScan is a completely automated 300mm-capable defect inspection tool that can study a large number of substrates including polished, unpolished, transparent, opaque, rough ground substrates and touch panels.
The ZetaScan defect inspectors work on Zeta’s multi-mode approach to inspection and offer high defect sensitivity at high output.
The ZetaScan integrates the advantages of a tiny laser spot with high sensitivity and resolution with the line scan optics speed or a high throughput.
The sample stage moves at a very slow speed, allowing for sample shape, thin samples, very thin and other delicate samples such as bonded wafers or thin glass.
The different channels are listed below:
- ZSP –Specular Channel measures surface reflectivity
- ZTP –TopographyChannel measures surface topography
- ZTS –Top ScatterZeta Proprietary Channel measures scattering signal above the sample
- ZSS –Side Scatter Channel measures scattering signal to the side of the sample
Key Features and Benefits
The key features of ZetaScan are:
Thin and transparent substrates –new detection optics design does not degrade signal as the substrate becomes thinner
Multiple channel detection offers the required signals to separate pits from particles down to submicron in size
The multiple detection channels can be used for easy defect classification. In the example shown below, all the particles can be detected in the Side Scatter (ZSS) channel.
Only the very large particles are seen in the ZetaScatter channel. Pits are clearly visible in the Zeta Top Scatter (ZTS), but cannot be detected in the Scatter channel. Thus, the multi-mode optical design is leveraged to provide accurate defect classification
New light collector design capable of detecting defects on rough surfaces or films
The linear scanning motion of the incident beam is combined with the lateral motion of the wafer to quickly generate the full wafer defect map.
This type of scan is more rapid, more stable and less sensitive to vibration as compared to other ‘helical’ or ‘spiral’ scan based tools.