Implant hard mask for substrates

A method for forming an implant hard mask on a substrate, comprising:

• depositing a screen layer on the substrate, wherein the screen layer is an oxide layer with a first thickness of approximately 20 nm to approximately 100 nm;
• depositing a first layer of the implant hard mask on the screen layer, wherein the first layer is an amorphous carbon (a-C) layer with a second thickness of approximately 100 nm to approximately 3000 nm;
• depositing a second layer of the implant hard mask on the first layer of the implant hard mask, wherein the second layer of the implant hard mask is an oxide layer with a third thickness of approximately 100 nm to approximately 3000 nm;
• depositing a photoresist layer on the second layer of the implant hard mask;
• patterning the photoresist layer to expose portions of the second layer of the implant hard mask;
• and
• etching the second layer of the implant hard mask and then the first layer of the implant hard mask using a hard mask etch process to expose portions of the screen layer, wherein a vertical etch profile of the hard mask etch process has sidewalls within +/−5 degrees of vertical relative to a horizontal surface of the substrate.

A non-transitory, computer readable medium having instructions stored thereon that, when executed, cause a method for forming an implant hard mask on a silicon carbide (SiC) substrate to be performed, the method comprising:

• depositing a first layer of the implant hard mask on a screen layer on the SiC substrate, wherein the first layer is an amorphous carbon (a-C) layer with a second thickness of approximately 100 nm to approximately 3000 nm;
• depositing a second layer of the implant hard mask on the first layer of the implant hard mask, wherein the second layer of the implant hard mask is an oxide layer with a third thickness of approximately 100 nm to approximately 3000 nm;
• depositing a photoresist layer on the second layer of the implant hard mask;
• patterning the photoresist layer to expose portions of the second layer of the implant hard mask;
• and
• etching the second layer of the implant hard mask and then the first layer of the implant hard mask using a hard mask etch process to expose portions of the screen layer, wherein a vertical etch profile of the hard mask etch process has sidewalls within +/−5 degrees of vertical relative to a horizontal surface of the SiC substrate.