Figure 2
Top-view SEM micrograph of the (a) nt-Cu bump array with an enlarged image of a (b) single microbump flatted by CMP. (c) EBSD image at the normal direction (ND) of the bonding surface showing ~ 50% 〈111〉 orientation. (d) AFM micrograph taken in an area of 5 × 5 μm. The root mean square roughness (Rq) of the bumps was ~ 4 nm. (e) Typical surface geometry of the microbumps scanned from the red dotted line in (d).
