<Process Example>
If the blade incurs damage due to the surface film, wafer backside chipping will increase as shown in Photo 1. The size of the blade damage is different depending on the type of film.
In such a case, it is possible to improve backside processing quality with either step cut or bevel cut* processing. Figure 1 shows the backside chipping size comparison when processing a coated wafer with a single cut** and a step cut process. The backside chipping size is significantly smaller for the step cut processing.
| | | | |
Mirror wafer | Oxidized film(0.8 µm) | Silicon nitride film(1 µm) | Titanium nitride film(0.4µm) | Aluminum film
(0.6µm) |
Photo 1 Backside chipping comparison with different surface film
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Photo. 2 Single cut Backside chipping | Photo. 3 Step cut Backside chipping |
