A die to wafer direct hybrid bonding method includes providing at least one die comprising a first copper pad and a first silicon oxide layer, providing a wafer comprising a second copper pad and a second silicon oxide layer, and handling the die so as to position the face of the die facing the zone for receiving the die on the wafer, by aligning the first and second pads. At least one water drop is deposited in the zone for receiving the die and/or on the face of the die. Pressure on the die is applied to form, from the water drop, a water film between the face and the zone for receiving the die.

A low-temperature hybrid bonding method includes a pre-treatment step of plasma-treating surfaces of first and second objects to be bonded, and a bonding step of aligning the first and second objects to be bonded and annealing them to form a bond between the first object to be bonded and the second object to be bonded through thermal expansion, wherein the first and second objects to be bonded comprise a hybrid bonding layer comprising copper and a dielectric, and the pre-treatment step is performed by treating with plasma using a hydrocarbon-based gas (C.sub.xH.sub.y, where x and y are natural numbers).