Reverse masking profile improvements in high aspect ratio etch

A method of fabricating a memory device, the method comprising:

• depositing a layer of amorphous carbon over a substrate, wherein the substrate comprises an array portion and a periphery portion;
• depositing a first hard mask over the layer of amorphous carbon;
• removing a portion of the first hard mask located over the periphery portion of the substrate;
• removing the first hard mask resulting in a thicker layer of amorphous carbon over the array than the periphery;
• and
• depositing a second hard mask over the layer of amorphous carbon;
• performing photolithography;
• and
• high aspect ratio etching.

A method of improving high aspect ratio etching by reverse masking profiling to provide a more uniform mask height between the array and periphery of a memory device, the method comprising:

• depositing a layer of amorphous carbon over a substrate, wherein the substrate comprises an array portion and a periphery portion;
• depositing a hard mask over the layer of amorphous carbon;
• removing the portion of the hard mask located over the periphery portion of the substrate;
• removing the hard mask resulting in a thicker layer of amorphous carbon over the array than the periphery;
• depositing a second hard mask over the layer of amorphous carbon;
• performing photolithography on the memory device;
• high aspect ratio plasma oxide etching;
• and
• adjusting the portion of amorphous carbon removed depending on consumption of the amorphous carbon during high aspect ratio plasma oxide etching.