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Method for producing bonded wafer

  • US 7,718,509 B2
  • Filed: 05/27/2009
  • Issued: 05/18/2010
  • Est. Priority Date: 06/03/2008
  • Status: Active Grant
First Claim
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1. A method for producing a bonded wafer, comprising a step of implanting oxygen ions from a surface of a wafer for active layer to form an oxygen ion implanted layer at a given position inside the wafer for active layer;

  • a step of bonding the wafer of active layer to a wafer for support substrate directly or through an insulating film so as to form a bonded wasfer;

    a step of subjecting the resulting bonded wafer to a heat treatment for increasing a bonding strength;

    a step of removing a portion of the wafer for active layer in the bonded wafer to a given position not exposing the oxygen ion implanted layer by a given method;

    a step of exposing the entire surface of the oxygen ion implanted layer; and

    a step of removing the exposed oxygen ion implanted layer to obtain an active layer of a given thickness, wherein the step of exposing the entire surface of the oxygen ion implanted layer is carried out by a dry etching under given conditionswherein the oxygen ion implanted layer has an oxygen concentration peak of not less than 1×

    1022 atoms/cm3 and satisfies a relationship of Re>



    {(ts)/(to)}×

    {(De+Dt)/(100−

    De)} when a thickness and a variation in an in-plane thickness of a silicon layer in the wafer for active layer on the oxygen ion implanted layer before the dry etching are ts and ±

    Dt %, respectively, and a thickness of the oxygen ion implanted layer is to and an etching rate ratio of Si to silicon oxide film (Si/SiOx) is Re and a variation in an in-plane etching is ±

    De %.

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