Structures for bonding a group iii-v device to a substrate

A method for forming an integrated chip, the method comprising:

• forming a chip comprising an epitaxial stack and a first metal bump on the epitaxial stack, wherein the first metal bump is localized to a mesa area of the epitaxial stack;
• forming a second metal bump on a substrate;
• bonding the chip to the substrate at an interface at which the first and second metal bumps contact each other;
• and
• performing an etch into the chip to define a mesa structure at the mesa area of the epitaxial stack, wherein sidewalls of the mesa structure are laterally offset from sidewalls of the first metal bump.

A method for forming an integrated chip, the method comprising:

• forming a chip comprising an epitaxial stack, an etch stop layer, and a metal layer, wherein the etch stop layer is between the epitaxial stack and the metal layer;
• forming a first metal bump on a substrate;
• bonding the chip to the substrate, such that the metal layer is between the first metal bump and the epitaxial stack;
• performing an etch into the epitaxial stack to define a mesa structure, wherein the etch stops on the etch stop layer;
• patterning the etch stop layer to transfer a pattern of the mesa structure to the etch stop layer;
• and
• patterning the metal layer to form a second metal bump between the first metal bump and the mesa structure.