01.ppt-AdvancedSiliconDeviceandProcessLab.pptVIP

NOVEL WAFER BONDING TECHNOLOGY SURVEY Po-Wen Chen Department of Electrical Engineering and Graduate Institute of Electronics Engineering National Taiwan University, Taipei, Taiwan, R.O.C. Outline Introduction Wafer bonding Wafer bonding application TEM inspection of our bonding achievement Introduction Clean(hydrophilic) Alignment Pre-bonding Anneal Wafer Bonding Anodic Bonding Silicon Direct Bonding/Fusion Bonding Intermediate-Layer Bonding Anodic Bonding Anodic Bonding Silicon Direct Bonding/Fusion Bonding Join silicon wafer by Create and contact hydrophobic or hydrophilic surfaces Anneal at high temperature Hydrophobic case HF dip before contact More challenging than hydrophilic wafer ,but ultimately better? Hydrophilic case SC1(standard cleaning) before bonding Silicon Direct Bonding/Fusion Bonding AfterSC1 ,the mirror polished silicon wafer filled with hydroxyl radicals(OH- ) OH- on polished silicon face permit a good initial contact bond Silicon Direct Bonding/Fusion Bonding Subsequent heating dehydrates OH- cause oxidation of the bonding surface resulting in a Si-O-Si bond As annealing temperature are increased beyond 1000℃ ,the strength of the bond approaches that of silicon itself Viscosity and pressure of ambient gas ,wafer contact energy influence speed Silicon Direct Bonding/Fusion Bonding Press in the middle of wafer to create a preliminary point of contact While mechanical spacer maintain wafer physically separated Retract spacer to form a single bonding wave from center to wafer Spacer integrity is important Multiple bonding waves promote warpage and voids Gas trapped in pocket form by multiple waves Silicon Direct Bonding/Fusion Bonding From room temperature 110?C Slow fracture effect and interface water rearrangement From 110 ?C to 150 ?C Polymerization of silanol groups across the interface From 150 ?C to 800 ?C Bonding energy limited by contacted area From 800 ?C and above Complete bonding via oxide flow I