Micro-fluid ejection device and method for assembling a micro-fluid ejection device by a wafer-to-wafer bonding

A method for assembling a micro-fluid ejection device, comprising:

• positioning separate first and second wafers together, the first wafer comprising a first silicon substrate, a first silicon oxide layer disposed on the first silicon substrate and flow features patterned in the first silicon oxide layer, the second wafer comprising a second silicon substrate, a second silicon oxide layer disposed on the second silicon substrate and a nozzle plate defined by the second silicon oxide layer, such that the wafers meet at an interface between the first and second silicon oxide layers;
• and
• after the positioning step, wafer-to-wafer bonding the first and second wafers together at the interface at a temperature between 90° C. and 150° C. such that the flow features patterned in the first silicon oxide layer of the first wafer are bonded to the nozzle plate defined by the second silicon oxide layer of the second wafer.