Wafer cleaning is essential through the fabrication process. Although a clean room is not necessary for our fabrication processes, it is important to ensure that the chips are free or organic contaminants and particles during various phases of the process. Etching is an integral part of the wafer patterning process and is most commonly done to remove oxide or open “windows” in to create a mask that determines the areas of the chip that become doped during diffusion.
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1. After the wafers are diced to appropriate dimensions, they are thoroughly cleaned to remove particulates, organic contaminants and (often) native oxide. |
| 2. During etching with HF, the chips are held in inert teflon chip carriers that allow easy handling of the chips and will not react with the HF. |  |
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3. Cleaning and etching is carried out in the fume hood to minimize exposure to toxic or caustic agents and to contain any spills. |