Si wafer Edge grinding / Downsizing

In order to provide the maximum of services and push the boundaries to succed within your topics, Sil'tronix ST offers the possibility to downsize your substrates (silicon, SOI, etc...) following a strict process.

With the aim to be a partner of your success, we provide a complete solution to supply not only a smaller wafer but a substrate answering to the SEMI standard (edge rounding) in order to provide you a wafer comparable to a new production.

Silicon wafer downsizing

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We achieve the downsizig process from large wafers (150-300 mm), simply polished, SOI wafer (Silicon On Insulator) or with devices. This process is only available to provide a finish product from 1" to 6".

Sil'tronix Silicon Technologies supplies downsizing solution according the following operations:

  • Spin coating of a classical photoresist resin on one or both sides as protection of the sensible surfaces already performed
  • Laser cutting of the wafer with potential one, two or more wafers designed with standard flats following the orientation of the initial wafer.
  • Edge rounding at the precise final diameter +/- 0.02 mm if needed.
  • Removing of the protected resin (Tape)
  • Cleaning and packaging the wafers in compatible boxes under vacuum in cleanroom.

The residual rings (after laser cutting) could be diced in squares for additional test pieces.

Silicon wafer edge rounding

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Silicon is very hard, but brittle material. The sharp edge of sawn wafers fractures readily, producing unacceptable edge chips and particles. This edge is ground with a diamond disk to remove the damage and to eliminate periferical stress. By edge grinding, the final diameter of the wafer is fitted. During this process, we adjust also the flat (major and minor) according the SEMI standard.

Specific profile

On customer’s request, we can also provide non standard wafers. We adjust the diameter of the wafer to a specific value (e.g ; 60mm diameter). We can also modify the length or the position of the flat (e.g. JEIDA flat, for a 6 inches wafer, the lenght of the flat is 45.7mm). For silicon parts with a thickness above 1mm, we can also make a beveled edge (e.g., edge with 45° angle).

 

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