Method of porosifying part of a semiconductor wafer

    公开(公告)号:US11810779B2

    公开(公告)日:2023-11-07

    申请号:US17841781

    申请日:2022-06-16

    CPC classification number: H01L21/0203 H01L21/02019 H01L21/465 H01L21/8258

    Abstract: A method includes: in a semiconductor wafer having a first semiconductor layer and a second semiconductor layer adjoining the first semiconductor layer, forming a porous region extending from a front surface into the first semiconductor layer; and removing the porous region by an etching process, wherein a doping concentration of the second semiconductor layer is less than 10−2 times a doping concentration of the first semiconductor layer and/or a doping type of the second semiconductor layer is complementary to a doping type of the first semiconductor layer, wherein forming the porous region comprises bringing in contact a porosifying agent with the front surface of the first semiconductor layer and applying a voltage between the first semiconductor layer and a first electrode that is in contact with the porosifying agent, wherein applying the voltage comprises applying the voltage between the first electrode and an edge region of the first semiconductor layer.

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