Quantum dot devices with multiple layers of gate metal

A method of manufacturing a quantum dot device, the method comprising:

• forming a quantum well stack;
• forming an insulating material above the quantum well stack, wherein the insulating material includes a trench;
• and
• forming a gate, wherein the gate includes a first gate metal in the trench and a second gate metal above the first gate metal,
• wherein at least one of:
• the first gate metal and the second gate metal have different material compositions,
• the first gate metal and the second gate metal have different microstructures, or
• a seam is present between the first gate metal and the second gate metal.

A quantum computing device, comprising:

• a quantum processing device, wherein the quantum processing device includes an insulating material having a trench that extends toward a quantum well layer, and a plurality of gates, wherein a gate of the plurality of gates includes a first layer of gate metal and a second layer of gate metal, wherein the first layer of gate metal is between the second layer of gate metal and the quantum well layer, the first layer of gate metal is in the trench, and the first layer of gate metal has a different microstructure than the second layer of gate metal;
• a non-quantum processing device, coupled to the quantum processing device, to control voltages applied to the plurality of gates of the quantum processing device;
• and
• a memory device to store data generated by quantum dots formed in the quantum well layer during operation of the quantum processing device.