Wu P.-CLai Y.-CLee P.-IChiang M.-TChou JChuang T.-H.TUNG-HAN CHUANG2021-08-052021-08-0520219574522https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101208997&doi=10.1007%2fs10854-021-05442-3&partnerID=40&md5=37227c00a2bafbcb0456b117c54372a6https://scholars.lib.ntu.edu.tw/handle/123456789/576945For improving the performance of backside metallization for power electronic devices, an innovative Ag film with ultra-high twin density is proposed in this study. Experimentally, nanotwinned Ag films with thicknesses ranging from 2 to 8??m and a strong (111) preferred orientation were sputtered on Si (100) wafers with and without a Ti thin film. The results indicated that the coincident Σ3 twin and Σ9 near-twin boundaries in proportion to the total grain boundaries in this Ag nanotwinned film on Ti pre-coated Si (100) wafer were 50.8 % and 13.5 %, respectively. These Ag nanotwins had spacing of 2 to 50?nm, with an average spacing of about 12?nm, and were contained in columnar Ag grains grown normal to the Si wafer. The employment of a Ti interlayer of 0.1??m thickness clearly improved the adhesion at the Ag/Si interface under peeling tests, resulting in a bonding strength of 1.7?MPa and a maximal indentation hardness of 2 GPa. ? 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.Grain boundaries; Metallizing; Silicon wafers; Thin films; Wafer bonding; Average spacing; Backside metallization; Bonding strength; Indentation hardness; Power electronic devices; Preferred orientations; Ti interlayers; Twin boundaries; Power semiconductor devicesjournal article10.1007/s10854-021-05442-32-s2.0-85101208997