Method for forming semiconductor device and resulting device
A method for forming a semiconductor device includes steps of: forming at least one gate structure comprising a gate electrode over a substrate, and forming a first dielectric layer of a first dielectric material along a side wall of the at least one gate structure. The first dielectric layer of the first dielectric material includes fluorine doped silicon oxycarbonitride with a doping concentration of fluorine. The dielectric constant of the first dielectric layer is adjusted through the doping concentration of fluorine.
1. A method for forming a semiconductor device, comprising:
forming at least one gate structure including a gate electrode over a substrate, the gate electrode including a first conductive material; and
forming a first dielectric layer of a first dielectric material along a side wall of the at least one gate structure, the first dielectric layer of the first dielectric material comprising a fluorine doped silicon oxycarbonitride or silicon oxycarbide with a doping concentration of fluorine,
wherein the forming the first dielectric layer comprises:
forming a base layer comprising silicon ocycarbonitride or silicon oxycarbide along the side wall of the at least one gate structure; and
doping the base layer through molecular ion implantation using a precursor composition comprising a fluorine-containing precursor, wherein the fluorine-containing precursor comprises hydrogen fluoride (HF).
2. The method of claim 1 , wherein the first conductive material in the gate electrode comprises polysilicon.
3. The method of claim 1 , wherein the doping concentration of fluorine in the first dielectric layer is in a range of from about 1×10 3 to about 1×10 6 atoms/cm 3 .
4. The method of claim 1 , wherein the first dielectric layer has a dielectric constant, and the dielectric constant of the first dielectric layer is adjusted through the doping concentration of fluorine.
5. The method of claim 4 , wherein the dielectric constant of the first dielectric layer is in a range of from about 2 to about 3.
6. The method of claim 1 , further comprising:
forming a second dielectric layer of a second dielectric material laterally over and in contact with the first dielectric layer.
7. The method of claim 6 , further comprising:
forming an interlayer dielectric (ILD) layer laterally over and in contact with the second dielectric layer.
8. The method of claim 6 , wherein the second dielectric material comprises silicon nitride, and the ILD layer comprises silicon oxycarbonitride.
9. The method of claim 1 , further comprising:
replacing the first conductive material in the gate electrode with a second conductive material comprising at least one metal.
10. The method of claim 1 , wherein carbon and oxygen are implanted together with fluorine when the first dielectric layer is formed.
11. The method of claim 1 , wherein the at least one gate structure having the second conductive material comprising at least one metal is a dummy gate providing a resistor-capacitor (RC) structure.
12. The method of claim 1 , wherein the fluorine-containing precursor is a mixture of HF and carbon monoxide (CO) having a molar ratio of HF:CO in a range from about 1:5 to 5:1.
13. The method of claim 12 , wherein the mixture of HF and CO is energized to form a mixture of molecular ions including HF+ and CO+.
14. The method of claim 12 , wherein the first dielectric layer is in contact with the gate electrode.
15. A method for forming a semiconductor device, comprising:
forming at least one gate structure comprising a gate electrode over a substrate, the gate electrode comprising a first conductive material;
forming a first dielectric layer along a side wall of the at least one gate structure, the first dielectric layer comprising fluorine doped silicon oxycarbonitride with a doping concentration of fluorine; and
forming a second dielectric layer comprising silicon nitride laterally over and in contact with the first dielectric layer,
wherein the forming the first dielectric layer of a first dielectric material comprises:
forming a base layer comprising silicon oxycarbonitride along the side wall of the at least one gate structure; and
doping the base layer through molecular ion implantation using a precursor composition comprising hydrogen fluoride (HF).
16. The method of claim 15 , wherein the precursor composition further comprises carbon monoxide (CO).
17. The method of claim 15 , further comprising:
forming an interlayer dielectric (ILD) layer laterally over and in contact with the second dielectric layer, the ILD layer comprising silicon oxycarbonitride; and
replacing the first conductive material in the gate electrode with a second conductive material comprising at least one metal.
18. A method for forming a semiconductor device, comprising:
forming at least one gate structure comprising a gate electrode over a substrate, the gate electrode comprising a first conductive material;
forming a first dielectric layer along a side wall of the at least one gate structure, the first dielectric layer comprising fluorine doped silicon oxycarbonitride with a doping concentration of fluorine; and
forming a second dielectric layer comprising silicon nitride laterally over and in contact with the first dielectric layer,
wherein the forming the first dielectric layer of a first dielectric material comprises:
forming a base layer comprising silicon oxycarbonitride along the side wall of the at least one gate structure; and
doping the base layer through molecular ion implantation using a precursor composition comprising a mixture containing molecular ions of HF+ and CO+.
19. The method of claim 18 , wherein the mixture has a ratio of HF+ and CO+ in a range of 1:1.