End-to-end gap fill using dielectric film
View Patent ↗A method for fabricating a semiconductor device includes forming a plurality of gate structures on a semiconductor substrate. The plurality of gate structures are arranged in a plurality of lines, wherein an end-to-end spacing between the lines is smaller than a line-to-line spacing between the lines. The method further includes forming an etch stop layer over the gate structures, forming an interlayer dielectric over the gate structures, and forming a dielectric film over the gate structures before the interlayer dielectric is formed. The dielectric film merges in end-to-end gaps formed in the end-to-end spacing between the gate structures.
1. A semiconductor device comprising:
a semiconductor substrate;
a plurality of gates formed on the semiconductor substrate, the plurality of gates including lines with a line-to-line spacing between parallel ones of the lines and an end-to-end spacing between co-linear ones of the gates;
an interlayer dielectric formed over the gates; and
a dielectric film formed between the gates and the interlayer dielectric, the dielectric film completely filling end-to-end gaps of the gates.
2. The semiconductor device of claim 1 in which the dielectric film is not merged in line-to-line gaps of the gates.
3. The semiconductor device of claim 1 in which the gates include sidewall spacers and wherein the dielectric film is a same film as in the sidewall spacers.
4. The semiconductor device of claim 1 in which the dielectric film is formed at a thickness according to the following relationship:
L2L_space/2>thickness>E2E_space/2; where L2L_space is the line-to-line spacing, and where E2E_space is the end-to-end spacing.
5. The semiconductor device of claim 4 in which the plurality of gates are formed according to the following relationship:
L2L_space>E2E_space+C; where L2L_space is the line-to-line spacing, and where E2E_space is the end-to-end spacing, further in which C is a distance in nanometers.
6. The semiconductor device of claim 1 in which the dielectric film is formed before the interlayer dielectric is formed.
7. The semiconductor device of claim 1 in which the end-to-end gaps do not include metal.
8. The semiconductor device of claim 1 in which the interlayer dielectric is formed over the dielectric film and does not merge in the end-to-end gaps.
9. The semiconductor device of claim 1 in which the dielectric film is selected from the list consisting of:
SiO2, SiN, SiCN, SiBN, SiOCN, SiON, SiOC, and SiC.
10. A semiconductor device comprising:
a plurality of gates formed upon a substrate, the gates formed in a plurality of lines, wherein gates in a line are separated by an end-to-end spacing, and wherein each of the lines are separated from adjacent lines by a line-to-line spacing; and
sidewall structures formed for each of the gates, the sidewall structures including a dielectric film that completely fills in gaps in the end-to-end spacing and not merged in gaps in the line-to-line spacing.
11. The semiconductor device of claim 10 in which the dielectric film is formed at a thickness according to the following relationship:
L2L_space/2>thickness>E2E_space/2; where L2L_space is the line-to-line spacing, and where E2E_space is the end-to-end spacing.
12. The semiconductor device of claim 11 in which the plurality of gates are formed according to the following relationship:
L2L_space>E2E_space+C; in which C is a distance in nanometers.
13. The semiconductor device of claim 10 further comprising:
an interlayer dielectric layer formed over the dielectric film, wherein the interlayer dielectric layer does not merge in the gaps in the end-to-end spacing.
14. The semiconductor device of claim 10 in which the dielectric film is selected from the list consisting of:
SiO2, SiN, SiCN, SiBN, SiOCN, SiON, SiOC, and SiC.
15. The semiconductor device of claim 10 in which the gaps in the end-to-end spacing do not include metal.
16. A semiconductor device comprising:
a semiconductor substrate;
a first line including a first plurality of gates arranged end-to-end upon the semiconductor substrate;
a second line including a second plurality of gates arranged end-to-end upon the semiconductor substrate, wherein the first and second lines are arranged parallel to each other and have a line-to-line gap therebetween; and
a plurality of sidewall structures formed in the line-to-line gap and in end-to-end gaps between ones of the gate structures, wherein the sidewall structures are formed of a film that completely fills the end-to-end gaps and not merged within the line-to-line gap.
17. The semiconductor device of claim 16 in which the film is formed at a thickness according to the following relationship:
L2L_space/2>thickness>E2E_space/2; where L2L_space is a spacing of the line-to-line gap, and where E2E_space is a spacing of the end-to-end gaps.
18. The semiconductor device of claim 17 in which gates are formed according to the following relationship:
L2L_space>E2E_space+C; where C is a distance in nanometers.
19. The semiconductor device of claim 16 further comprising:
an interlayer dielectric layer formed over the film, wherein the interlayer dielectric layer does not merge in the end-to-end gaps.
20. The semiconductor device of claim 16 in which the film is selected from the list consisting of:
SiO2, SiN, SiCN, SiBN, SiOCN, SiON, SiOC, and SiC.