Memory device and method of manufacturing the same

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

• forming an ion implantation region in a portion of an outer portion of a first underlying structure;
• performing a heat treatment process for changing the ion implantation region into an etch stop pattern;
• alternately stacking first material layers and second material layers on the first underlying structure including the etch stop pattern;
• and
• forming, in the first material layers and the second material layers, a first hole that exposes a first portion of the etch stop pattern, wherein the first hole has a first width, and a second hole that exposes a second portion of the etch stop pattern, wherein the second hole has a second width greater than the first width.

A memory device comprising:

• an underlying structure including a first etch stop pattern and a second etch stop pattern;
• and
• a target structure formed over the underlying structure, wherein a first hole having a first aspect ratio and a second hole having a second aspect ratio less than the first aspect ratio are formed in the target structure, wherein the first etch stop pattern is exposed by the first hole and the second etch stop pattern is exposed by the second hole;
• wherein the first etch stop pattern and the second etch stop pattern include etching stop ions for stopping an etching process;
• and
• wherein the second etch stop pattern includes a region having a high concentration of etching stop ions and a region having a low concentration of etching stop ions.

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

• forming a target structure over an underlying structure;
• forming a mask pattern over the target structure;
• implanting etching stop ions into the underlying structure through the target structure using the mask patterns to form a first etch stop pattern and a second etch stop pattern;
• and
• etching the target structure using the mask pattern until the first etch stop pattern is exposed to form a first hole with a first aspect ratio and etching the target structure until the second etch stop pattern is exposed to form a second hole with a second aspect ratio less than the first aspect ratio;
• wherein, when the etch stop ions are implanted, the second etch stop pattern includes a region having a high concentration of etching stop ions and a region having a low concentration of etching stop ions.