Method for fabricating semiconductor device including etching an edge portion of a bonding layer by using an etching mask

A method for fabricating a semiconductor device comprising:

• forming a first bonding layer on a first wafer and an etching mask on the first bonding layer, wherein the first bonding layer comprises a first dielectric layer and a first conductive feature extending through the first dielectric layer;
• etching an edge portion of the first bonding layer by using the etching mask, such that a portion of the first wafer is exposed;
• removing the etching mask;
• and
• bonding a second wafer to the first bonding layer, wherein bonding the second wafer to the first bonding layer comprises:
• enabling the first dielectric layer to be in physical contact with a second dielectric layer of a second bonding layer over the second wafer;
• and
• enabling the first conductive feature to be in physical contact with a second conductive feature of the second bonding layer, the second conductive feature extending through the second dielectric layer.