Anisotropic wet etching in patterning

A method of forming a semiconductor device having at least two different types of semiconductor structures, the method comprising:

• forming a metal layer over a first semiconductor structure and a second semiconductor structure;
• forming a patterned photolithographic layer over the metal layer over the first semiconductor structure by:
• forming a photolithographic layer over the metal layer;
• and
• removing the photolithographic layer that is over the metal layer that is the over the second semiconductor structure;
• removing the metal layer from the second semiconductor structure via wet etch operations using a chemical etchant that is selected based on molecular weight, steric effect, and polarity to resist penetration into the photolithographic layer, wherein the chemical etchant is a solution comprising an organic acid, an oxidant, and water;
• and
• achieving, after the wet etch operations using the chemical etchant, a remaining metal ratio of a distance X over a distance Y that is less than 179 and greater than 1, wherein X is a first distance from a first line extending from an edge of the remaining metal layer over the first semiconductor structure to a second line extending from an edge of a channel region in the second semiconductor structure, and Y is a second distance from the first line to a third line extending from an edge of the metal layer formed over the channel region in the first semiconductor structure.

A method of forming a semiconductor device having at least two different types of semiconductor structures, the method comprising:

• forming a metal layer over a first semiconductor structure and a second semiconductor structure;
• forming a patterned photolithographic layer over the metal layer over the first semiconductor structure by:
• forming a photolithographic layer over the metal layer;
• and
• removing the photolithographic layer that is over the metal layer that is the over the second semiconductor structure;
• removing the metal layer from the second semiconductor structure via wet etch operations using a chemical etchant that is selected based on molecular weight, steric effect, and polarity to resist penetration into the photolithographic layer, wherein the chemical etchant is a solution comprising an organic base, an oxidant, and water;
• and
• achieving, after the wet etch operations using the chemical etchant, a remaining metal ratio of a distance X over a distance Y that is less than 179 and greater than 1, wherein X is a first distance from a first line extending from an edge of the remaining metal layer over the first semiconductor structure to a second line extending from an edge of a channel region in the second semiconductor structure, and Y is a second distance from the first line to a third line extending from an edge of the metal layer formed over the channel region in the first semiconductor structure.