Innovative megasonic cleaning technology evaluated through direct wafer bonding.

Since 1990s semiconductor wafer cleaning has been widely investigated to face front-end and back-end issues. One of the main issues is surface particle contamination. Many applications in microelectronics, MEMS, or 3D process requires very clean surfaces. Among them Direct Wafer Bonding (DWB) has very aggressive requirement in terms of particle cleanliness. Indeed, a particle with a diameter of 1 µm is known to generate a bonding defect with a diameter of ~1 cm. Here, in addition to classical surface characterization, DWB technique could be proposed as a useful way to test efficiency of megasonic technique for particle contamination removal. We have focused this work on particle cleaning surface using an innovative megasonic cleaning technology and its characterization using bot