Hybrid wafer bonding method

A method for forming a semiconductor structure, comprising:

• providing a first via structure in a first dielectric layer;
• providing a second via structure in a second dielectric layer;
• bonding the second via structure with the first via structure on a first portion of a surface of the first via structure;
• forming a barrier structure across and in the second dielectric layer and the first via structure after the bonding, the barrier structure comprising a first self-barrier portion formed into a second portion of the surface of the first via structure, and a second self-barrier portion formed into the second dielectric layer, wherein:
• the first via structure comprises a first element and a first contact via contacting the first element,
• the second via structure comprises a second contact via contacting a first portion of a surface of the first contact via and a second element contacting the second contact via,
• a first contact via surface of the first contact via fully covers the barrier structure and a second contact via surface of the second contact via, and
• an orthogonal projection of the second contact via on a lateral plane with respect to the vertical direction is greater than an orthogonal projection of the first element on the lateral plane.