Ultrafast welding of stacked gallium arsenide wafers

Direct laser welding has the capability to ignore the difficulties in bonding of wafer structures in non-linear materials. Rather than growing a series of individual layers to precise dimensions a single wafer of GaAs can be polished to an appropriate, thickness, diced and layered to form an appropriate structure. In this arrangement optical contact (i.e. Van der Waals) holds the layers together. This temporary bonding can then be re-enforced through ps laser welding [3]. Using this process there is little technical restriction on the size of devices which can be constructed.

However ps laser welding has not been demonstrated for a series of layers or for GaAs-GaAs welding, nor for bonding GaAs to thermal-expansion-matched heatsink materials, which could be a major advantage for the semi-conductor device industry. The purpose of this seedcorn project is to provide a proof-of-principle demonstration of the bonding of GaAs wafers with thicknesses appropriate for the current laser-bonding manufacture process.

Contact Details: 

For more information please contact Dr Richard Carter, r.m.carter@hw.ac.uk.