Fig. 3 shows the bending profile of Cu films deposited at different parameters and theresidual stress calculated with Stoney's equation. Due to the mismatch in the coefficientsof thermal expansion, the Cu films mainly exhibit tensile stress on the Si substrate. Ingeneral, the stress of films prepared by HPPMS is higher than that of the films preparedby deMS. This can be explained by the fact that grain growth generally makes the filmmore tensile due to coalescence of the boundaries [22-24]. Meanwhile, when theionization degree increased at a higher peak power, more ion bombardment on films canalso result in an increase in tempcrature, thercby increasing the thermal stress, whichcontributes to the tensile stress.