Stress characteristics in EUV mask Mo/Si multilayers deposited by ion beam sputtering
Résumé
The stress evolution of IBS-deposited Mo and Si 100-nm-thick films has been investigated. Mo films’ compressive stress decreases from −2550 MPa to −1000 MPa as the sputtering gas changes from Ar to Xe, whereas Si films’ stress remains constant around −850 MPa whatever the sputtering gas. Then the stress behaviour of Mo/Si multilayers sputtered either with Ar or Xe has been observed. In both cases, the multilayer stress first becomes less compressive and then increases, as Mo thickness in the multilayer increases. However, like in the single layer case, the level of stress strongly depends on the sputtering gas. The multilayers sputtered with Xe even become tensile. Moreover, the analysis of the contraction of the multilayers led us to the conclusion that a Mo/Si interface grows, but in a different way, depending on the sputtering gas. Possible stress-generating mechanisms during growth of these multilayers as well as single layer films of Mo and Si are discussed.
Domaines
Sciences de l'ingénieur [physics]
Origine : Fichiers produits par l'(les) auteur(s)
