Electronic devices comprising overlay marks

An electronic device comprising:

• a multideck structure comprising a base stack of materials and one or more stacks of materials on the base stack of materials;
• at least one high aspect ratio feature in an array region in the base stack of materials and in the one or more stack of materials;
• overlay marks comprising an optical contrast material in or on only an upper portion of the base stack of materials in an overlay mark region of the electronic device, the overlay mark region laterally adjacent to the array region;
• and
• at least one medium aspect ratio feature in the base stack of materials and extending through the overlay marks.

An electronic device comprising:

• a multideck structure comprising a base stack of materials and one or more stacks of materials on the base stack of materials;
• at least one high aspect ratio feature in an array region in the base stack of materials and in the one or more stack of materials;
• overlay marks comprising an optical contrast material in or on only an upper portion of the base stack of materials in an overlay mark region of the electronic device, the overlay mark region laterally adjacent to the array region;
• and
• at least one medium aspect ratio feature in the base stack of materials and extending through the overlay marks, wherein the at least one medium aspect ratio feature is optically transparent.