Manufacturing method of semiconductor device with dual slit and contact plug structure
A semiconductor device includes a line; a source structure on the line; a stack structure on the source structure; a first slit structure penetrating the stack structure; a second slit structure penetrating the stack structure; and a contact plug adjacent to the first slit structure in a first direction. The first slit structure and the second slit structure may be spaced apart from each other by a first distance in a second direction that is perpendicular to the first direction. The contact plug penetrates the source structure, the contact plug being electrically connected to the lower line. The first slit structure and the contact plug may be spaced apart from each other by a second distance in the first direction, and the second distance may be longer than the first distance.
1 . A method of manufacturing a semiconductor device, the method comprising:
forming a line;
forming a source structure over the line, wherein the source structure includes a sacrificial layer and a first source layer;
forming a contact plug that penetrates the source structure, the contact plug being electrically connected to the line;
forming a stack structure over the source structure and the contact plug;
forming a first slit that penetrates the stack structure, extends in a first direction, and is adjacent to the contact plug in the first direction;
forming a second slit that penetrates the stack structure and is adjacent to the first slit in a second direction intersecting the first direction; and
replacing the sacrificial layer of the source structure with a second source layer through the first slit,
wherein the first slit and the second slit are spaced apart from each other by a first distance, the first slit and the contact plug are spaced apart from each other by a second distance, and
wherein the second distance is longer than the first distance.
2 . The method of claim 1 , wherein, when the sacrificial layer is replaced with the second source layer through the first slit, a cavity is formed in the source structure, and
wherein the contact plug is spaced apart from the cavity.
3 . The method of claim 1 , wherein the replacing of the sacrificial layer with the second source layer comprises:
forming an opening by removing the sacrificial layer;
forming a conductive layer in the opening and the first slit; and
forming the second source layer by etching the conductive layer formed in the first slit.
4 . The method of claim 3 , wherein the conductive layer includes a first cavity that is located in the opening, and
wherein a second cavity is formed in the source structure by etching the conductive layer at the periphery of the first cavity when the conductive layer is etched.
5 . The method of claim 4 , wherein the contact plug is spaced apart from the second cavity.
6 . The method of claim 1 , wherein the second distance is twice as long as or more than twice as long as the first distance.
7 . The method of claim 1 , further comprising forming a slit structure that penetrates the stack structure before the first slit is formed,
wherein the first slit intersects the slit structure.
8 . The method of claim 1 , further comprising:
forming an isolation layer that penetrates the source structure before the stack structure is formed; and
replacing the sacrificial layer with the second source layer through the second slit,
wherein the isolation layer is located between the second slit and the contact plug.
9 . The method of claim 8 , wherein the isolation layer includes an insulating material.
10 . The method of claim 8 , wherein, when the sacrificial layer is replaced with the second source layer through the second slit, a cavity is formed in the source structure, and
wherein the contact plug is spaced apart from the cavity.
11 . The method of claim 8 , wherein the isolation layer includes an edge adjacent to the first slit and the edge of the isolation layer and the contact plug are spaced apart from each other by a third distance, and
wherein the third distance is longer than the first distance.
12 . The method of claim 11 , wherein the third distance is twice as long as or more than twice as long as the first distance.
13 . The method of claim 1 , wherein the contact plug is a discharge contact plug.