Direct silicon wafer bonding outside cleanroom conditions

We present a method for direct bonding of silicon wafers that does not require a cleanroom environment, freeing up space and reducing operating costs.The required cleanliness of the environment is maintained by performing the bonding process under high purity MilliQ water, while simultaneously reducing the use of chemicals and annealing the bonded samples at low temperatures.We verify the atomic bonds with non-destructive time-domain spectroscopy and destructive methods.