Implant scheme to improve high electron mobility transistor contact resistance

A method of forming a high electron mobility transistor, comprising:

• applying a first patterned mask on top of layered stack, wherein the layered stack comprises:
• a substrate,
• a buffer layer disposed over the substrate;
• a channel layer disposed above the buffer layer;
• and
• a barrier layer disposed above the channel layer;
• forming, through openings of the patterned mask, a plurality of source/drain contacts in the barrier layer by delivering a first implant into the barrier layer and the channel layer;
• performing an etch process to form a contact opening in each of the plurality of the source/drain contacts;
• and
• performing a second implant to the plurality of source/drain contacts, wherein the second implant is directed into the contact openings.

A system, comprising:

• a processor;
• a memory storing instructions executable by the processor to:
• perform a first implant to a layered stack to form a plurality of source/drain contacts, wherein the first implant is performed through a patterned mask formed atop the layered stack, wherein the layered stack comprises a substrate, a buffer layer disposed over the substrate, a channel layer disposed above a buffer layer, and a barrier layer disposed above the channel layer;
• and
• perform a second implant to the plurality of source/drain contacts, wherein the second implant is directed into a contact opening etched into each of the plurality of source/drain contacts.