Direct bonding method with reduction in overlay misalignment
AssigneeSoitec
InventorsMarcel Broekaart, Gweltaz Gaudin, Arnaud Castex
Life of this patent
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Abstract
A method for the direct bonding of a first wafer having an intrinsic curvature before bonding to a second wafer having an intrinsic curvature before bonding, at least one of the two wafers including at least one series of microcomponents. The method includes bringing the two wafers into contact with each other so as to initiate the propagation of a bonding wave therebetween while imposing a predefined bonding curvature in the form of a paraboloid of revolution on one of the two wafers depending at least upon the intrinsic curvature before bonding of the wafer that includes the microcomponents, with the other wafer being free to conform to the predefined bonding curvature.
Claims18
A method for reducing overlay misalignment during the direct bonding of a first wafer having a first intrinsic curvature to a second wafer having a second intrinsic curvature, with at least the first wafer comprising at least one series of microcomponents thereon, which method comprises:
- contacting the wafers with each other so as to initiate the propagation of a bonding wave between the wafers, and
- imposing a predefined bonding curvature in the form of a paraboloid of revolution on one of the first or second wafers during the contacting, with the predefined bonding curvature depending at least upon the first intrinsic curvature of the first wafer comprising the at least one series of microcomponents thereon, with the other of the first or second wafers being free to conform to the predefined bonding curvature.
A method for reducing overlay misalignment during the direct bonding of a first wafer having a first intrinsic curvature to a second wafer having a second intrinsic curvature, with at least the first wafer comprising at least one series of microcomponents thereon, which method comprises:
- contacting the wafers with each other so as to initiate the propagation of a bonding wave between the wafers, and
- imposing a predefined bonding curvature in the form of a paraboloid of revolution on one of the first or second wafers during the contacting, with the predefined bonding curvature depending at least upon the first intrinsic curvature of the first wafer comprising the at least one series of microcomponents thereon, with the other of the first or second wafers being free to conform to the predefined bonding curvature, and before the wafers are bonded together:
- measuring the curvature of each wafer;
- and
- calculating the predefined bonding curvature from the measured curvature of each wafer.
Dependencies are inferred from the claim text.