Patent ID: 7549225

Claim:
A method of bonding two semiconductor substrates to form a printhead comprising: providing a first substrate and a second substrate separate from the first substrate; aligning a top surface of the first substrate with a bottom surface of the second substrate, wherein the first substrate has a fluid channel in the top surface; heating the first and second substrates to a first temperature in a vacuum pressure; and placing the top surface of the first substrate in contact with the bottom surface of the second substrate while heating the first and second substrates to the first temperature in the vacuum pressure to form a fusion bond between the top surface of the first substrate and the bottom surface of the second substrate, wherein a patterned etch mask layer is formed on at least one of the top surface of the first substrate and the bottom surface of the second substrate, wherein the patterned etch mask layer is formed on the top surface of the first substrate and has at least one opening defined therein, wherein the at least one opening is aligned with the fluid channel in the top surface of the first substrate.