Integrated multichannel and single channel device structure and method of making the same

An integrated circuit comprising:

• a single channel device comprising a first portion of a single shared heterostructure overlying a substrate structure in a single channel device area, and a gate contact that is in contact with the first portion of the single shared heterostructure;
• a multichannel device comprising a second portion of the single shared heterostructure overlying the substrate structure in a multichannel device area, the multichannel device further comprising a superlattice structure overlying the single shared heterostructure, the superlattice structure comprising a plurality of heterostructures, wherein trenches are formed in portions of the multichannel structure to create castellated gate contacts;
• an isolation region in the single shared heterostructure that electrically isolates the single channel device from the multichannel device;
• and
• source and drain contact regions formed on opposite sides of the gate contacts in each of the single channel device and the multichannel device regions to create transistors in each region.