Fabrication of microfluidic channels using Si-Si bonding

During this semester’s project, an alternative process for manufacturing microfluidic channels was tested. Silicon wafers were processed to determine whether silicon-tosilicon bonding could be used to reduce the number of steps in the production process. To achieve this, different combinations of surface treatment and bonding temperature were tested to observe their effect on the process. Some wafers underwent HF cleaning prior to bonding, while others did not. Bonding temperatures ranging from 300°C to 450°C were also tested. Different designs were also created to observe the limitations of the process and the tools required. In addition to that, we were capable of performing direct wafer bonding on small structures as thin as 1 µm, which was a great achievement for us.