Method for manufacturing a bonding structure
AssigneeWuhan Xinxin Semiconductor Manufacturing Co., Ltd.
InventorTian Zeng
Life of this patent
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Abstract
A bonding structure and a method for manufacturing the same. First edge trimming is performed from the bonding surface of an n-th wafer in bonding the n-th wafer and an (n−1)th wafer, and a width of the first edge trimming is Wn. As n increases, the width of the first edge trimming is gradually increased. In the trimming, a portion that is not even at the edge of the n-th wafer can be removed. The bonding surface of the n-th wafer faces the bonding surface of the (n−1)-th wafer, so as to bond the n-th wafer and the (n−1)-th wafer. Afterwards the substrate of the n-th wafer is thinned, so as to form the (n−1)-th wafer stack. There is a reduced possibility that a gap exists between the bonding interfaces of the wafers, a bonding strength between the wafers is improved, and a risk of cracking is reduced.
Claims6
A method for manufacturing a bonding structure, comprising:
- bonding N wafers sequentially,
- wherein for each integer n ranging from 2 to N, bonding an n-th wafer and an (n−1)-th wafer comprises:
- performing first edge trimming from a bonding surface of the n-th wafer, wherein a width of the first edge trimming is Wn, and the first edge trimming extends into a substrate of the n-th wafer in depth;
- bonding the n-th wafer and the (n−1)-th wafer, wherein the bonding surface of the n-th wafer faces the (n−1)-th wafer;
- and
- thinning the substrate of the n-th wafer, to form an (n−1)-th wafer stack;
- wherein N is a natural number greater than 1;
- wherein Wn is greater than Wn−1 when n≥3;
- and
- wherein after thinning the substrate of the n-th wafer, bonding the n-th wafer and the (n−1)-th wafer further comprises:
- performing second edge trimming on the (n−1)-th wafer stack;
- wherein a width of the second edge trimming is Dn−1, and the second edge trimming extends into the substrate of a first wafer in depth;
- and
- wherein Dn−1 is greater than Wn and small than Wn+1 when 2≤n<N.
Dependencies are inferred from the claim text.