Semiconductor device and method for manufacturing
View Patent ↗A semiconductor device and a method for manufacturing the semiconductor device is disclosed. The semiconductor device includes a bit line formed to extend into a semiconductor substrate, a charge storage layer formed on the semiconductor substrate, a word line formed above the charge storage layer to extend across the bit line, a gate electrode formed on the charge storage layer under the word line and between bit lines, a first insulating film formed over the bit line and to extend in the direction of the bit line and a second insulating film that includes a different material than that of the first insulating film and formed to adjoin a side surface of the first insulating film. In addition, the semiconductor device includes an interlayer insulating film that includes a different material from that of the second insulating film that is formed on the first insulating film and the second insulating film and a contact plug coupled to the bit line and formed to penetrate through the first insulating film and the interlayer insulating film and to be sandwiched by the second insulating film.
1. A semiconductor device comprising:
a bit line formed to extend into a semiconductor substrate;
a charge storage layer formed on the semiconductor substrate;
a word line formed above the charge storage layer and to extend across the bit line;
a gate electrode formed on the charge storage layer under the word line and between bit lines;
a first insulating film formed over the bit line to extend in the direction of the bit line;
a second insulating film comprising a different material than that of the first insulating film and formed to adjoin a side surface of the first insulating film;
an interlayer insulating film comprising a different material from that of the second insulating film and formed on the first insulating film and the second insulating film; and
a contact plug coupled to the bit line and formed to penetrate through the first insulating film and the interlayer insulating film and to be sandwiched by the second insulating film.
2. The semiconductor device according to claim 1 , wherein
the second insulating film has a U-shaped cross-sectional shape and is provided over the bit line to extend in a direction of the bit line,
the first insulating film is provided so as to be embedded in the second insulating film of the U-shaped cross-sectional shape, and
the contact plug is provided so as to penetrate through a bottom surface of the second insulating film of the U-shaped cross-sectional shape.
3. The semiconductor device according to claim 1 , wherein the second insulating film is provided on the charge storage layer in between the word lines and in between the first insulating films.
4. The semiconductor device according to claim 1 , wherein
the second insulating film comprises:
a third insulating film provided on the charge storage layer in between the word lines and in between the first insulating films; and
a fourth insulating film provided over the bit line to extend in a direction of the bit line, having a U-shaped cross-sectional shape and adjoining a side surface of the third insulating film, and wherein
the first insulating film is embedded in the fourth insulating film of the U-shaped cross-sectional shape, and
the contact plug penetrates a bottom surface of the fourth insulating film of the U-shaped cross-sectional shape.
5. The semiconductor device according to claim 1 wherein the second insulating film comprises a material harder to etch than those of the first insulating film and the interlayer insulating film.
6. The semiconductor device according to claim 1 wherein the second insulating film is formed on a side surface of the first conductive layer prior to the forming of the first insulating film.
7. The semiconductor device according to claim 1 wherein the second insulating film is formed over the bit line to extend in a direction of the bit line and to adjoin the side surface of the first insulating film.
8. The semiconductor device according to claim 1 wherein the second insulating film is formed between the first conductive layers and comprises a contact hole formed to penetrate the second insulating film.
9. A flash memory device, comprising:
a data input component;
a data output component; and
a plurality of charge storage components, comprising:
a bit line provided to extend into a semiconductor substrate;
a charge storage layer provided on the semiconductor substrate;
a word line provided above the charge storage layer to extend across the bit line;
a gate electrode provided on the charge storage layer under the word line and in between the bit lines;
a first insulating film provided over the bit line to extend in a direction of the bit line;
a second insulating film composed of a different material from that of the first insulating film and provided to adjoin a side surface of the first insulating film;
an interlayer insulating film composed of a different material from that of the second insulating film and provided on the first insulating film and the second insulating film; and
a contact plug coupled with the bit line and provided to penetrate the first insulating film and the interlayer insulating film and to be sandwiched by the second insulating film.
10. The flash memory device according to claim 9 , wherein
the second insulating film has a U-shaped cross-sectional shape and is provided over the bit line to extend in a direction of the bit line,
the first insulating film is embedded in the second insulating film of the U-shaped cross-sectional shape, and
the contact plug penetrates a bottom surface of the second insulating film of the U-shaped cross-sectional shape.
11. The flash memory device according to claim 9 , wherein the second insulating film is provided on the charge storage layer in between the word lines and in between the first insulating films.
12. The flash memory device according to claim 9 , wherein
the second insulating film comprises:
a third insulating film provided on the charge storage layer in between the word lines and in between the first insulating films; and
a fourth insulating film provided over the bit line to extend in a direction of the bit line, having a U-shaped cross-sectional shape and adjoining a side surface of the third insulating film, and wherein
the first insulating film is embedded in the fourth insulating film of the U-shaped cross-sectional shape, and
the contact plug is provided to penetrate a bottom surface of the fourth insulating film of the U-shaped cross-sectional shape.
13. The flash memory device according to claim 9 wherein the second insulating film comprises a material harder to etch than those of the first insulating film and the interlayer insulating film.
14. The flash memory device according to claim 9 wherein the second insulating film is formed on a side surface of the first conductive layer prior to the forming of the first insulating film.
15. A method for manufacturing a semiconductor device, the method comprising:
forming a charge storage layer on a semiconductor substrate;
forming a first conductive layer on the charge storage layer;
forming a bit line in the semiconductor substrate using the first conductive layer as a mask;
forming a first insulating film that is embedded in between the first conductive layers;
forming a second conductive layer on the first conductive layer and the first insulating film;
forming a word line by etching the second conductive layer with a mask layer to extend across the bit line on the second conductive layer as a mask;
forming a gate electrode by etching the first conductive layer with the mask layer as a mask;
forming a second insulating film composed of a different material from that of the first insulating film to adjoin a side surface of the first insulating film;
forming an interlayer insulating film composed of a different material from that of the second insulating film on the first insulating film and the second insulating film;
forming a contact hole that penetrates the interlayer insulating film and the first insulating film and is sandwiched by the second insulating film; and
forming a contact plug that is coupled with the bit line so as to be embedded in the contact hole.
16. The method for manufacturing a semiconductor device according to claim 15 , wherein the second insulating film is composed of a material that is harder to etch than those of the first insulating film and the interlayer insulating film in the forming of the contact hole.
17. The method for manufacturing a semiconductor device according to claim 15 , wherein
the forming of the second insulating film comprises forming the second insulating film between the first conductive layers prior to the forming of the first insulating film, and the forming of the contact hole comprises forming the contact hole to penetrate the second insulating film.
18. The method for manufacturing a semiconductor device according to claim 17 , wherein the forming of the bit line is carried out after the forming of the second insulating film.
19. The method for manufacturing a semiconductor device according to claim 15 , wherein the forming of the second insulating film comprises forming the second insulating film on the charge storage layer in between the word lines and in between the first insulating films after etching the first conductive layer and the second conductive layer.
20. The method for manufacturing a semiconductor device according to claim 15 , wherein
the forming of the second insulating film comprises:
forming a fourth insulating film between the first conductive layers prior to the forming of the first insulating film, and
forming a third insulating film on the charge storage layer between the word lines between the first insulating films to adjoin a side surface of the fourth insulating film after etching the first conductive layer and the second conductive layer; and
the forming of the contact hole comprises forming the contact hole to penetrate the fourth insulating film.