Method for increasing photoresist etch selectivity to enable high energy hot implant in sic devices

A method for performing an ion implantation process, comprising:

• providing a substrate to be implanted, the substrate including an n-drift layer and a silicon nitride layer disposed atop the n-drift layer;
• providing a hardmask layer disposed atop the substrate, the hardmask layer having a thickness in a range of 0.5 um to 3 um;
• providing a photoresist layer disposed atop the hardmask layer, the photoresist layer defining a trench exposing a portion of the hardmask layer, the photoresist layer having a thickness in a range of 1 um to 3 um;
• performing a first ion implantation process wherein an ion beam formed of an ionized first dopant species is directed onto the photoresist layer and the exposed portion of the hardmask layer, the first dopant species selected to make the exposed portion of the hardmask layer more susceptible to etching;
• performing at least one of an ion etching process and a wet etching process wherein the exposed portion of the hardmask layer is etched away to expose an underlying portion of the substrate;
• and
• performing a high energy, hot, second ion implantation process wherein the photoresist layer is removed, and wherein an ion beam formed of a ionized second dopant species is directed onto the hardmask layer and the exposed portion of the substrate to implant the exposed portion of the substrate with the second dopant species.