Methods for forming alignment marks

A method for forming alignment marks, comprising:

• forming a first alignment mark on a first substrate, wherein the first alignment mark has a first width within 5% of a first critical dimension (CD) of copper pads on the first substrate;
• forming a first dummy pattern of first dummy copper pads on the first substrate around the first alignment mark, wherein the first dummy pattern has a first dummy pattern density within 5% of a first copper pad density of the first substrate and the first dummy copper pads have a first dummy copper pad CD within 5% of the first CD of copper pads on the first substrate;
• forming a second alignment mark on a second substrate, wherein the second alignment mark has a second width within 5% of a second critical dimension (CD) of copper pads on the second substrate;
• and
• forming a second dummy pattern of second dummy copper pads on the second substrate around the second alignment mark, wherein the second dummy pattern has a second dummy pattern density within 5% of a second copper pad density of the second substrate and the second dummy copper pads have a second dummy copper pad CD within 5% of the second CD of copper pads on the second substrate,
• wherein the first CD of copper pads on the first substrate is different than the second CD of copper pads on the second substrate,
• wherein the second alignment mark nests within the first alignment mark from a top-down view point without any boundary overlay when the second substrate overlays or underlays the first substrate resulting in a predetermined alignment of the first substrate and the second substrate, and
• wherein the second alignment mark when positioned within the first alignment mark from a top-down viewpoint is spaced away from the first alignment mark by approximately 5 microns to approximately 10 microns to allow for alignment shift.

A non-transitory, computer readable medium having instructions stored thereon that, when executed, cause a method for forming alignment marks to be performed, the method comprising:

• forming a first alignment mark on a first substrate, wherein the first alignment mark has a first width within 5% of a first critical dimension (CD) of copper pads on the first substrate;
• forming a first dummy pattern of first dummy copper pads on the first substrate around the first alignment mark, wherein the first dummy pattern has a first dummy pattern density within 5% of a first copper pad density of the first substrate and the first dummy copper pads have a first dummy copper pad CD within 5% of the first CD of copper pads on the first substrate;
• forming a second alignment mark on a second substrate, wherein the second alignment mark has a second width within 5% of a second critical dimension (CD) of copper pads on the second substrate;
• and
• forming a second dummy pattern of second dummy copper pads on the second substrate around the second alignment mark, wherein the second dummy pattern has a second dummy pattern density within 5% of a second copper pad density of the second substrate and the second dummy copper pads have a second dummy copper pad CD within 5% of the second CD of copper pads on the second substrate,
• wherein the second alignment mark nests within the first alignment mark from a top-down viewpoint without any boundary overlay when the second substrate overlays or underlays the first substrate resulting in a predetermined alignment of the first substrate and the second substrate.