Method for forming semiconductor device and resulting device

1. A semiconductor device, comprising:

at least one gate structure comprising a gate electrode over a substrate, the gate electrode comprising a conductive material;

a first dielectric layer disposed along one or more side walls of the at least one gate structure, the first dielectric layer comprising fluorine doped silicon oxycarbonitride or fluorine doped silicon oxycarbide, wherein the fluorine doped silicon oxycarbonitride or the fluorine doped silicon oxycarbide is doped through molecular ion implantation using a precursor comprising hydrogen fluoride (HF) and carbon monoxide (CO), wherein a doping concentration of fluorine in the first dielectric layer following the molecular ion implantation is in a range of from about 1×10 3 to about 1×10 6 atoms/cm 3 , and wherein a dielectric constant of the first dielectric layer is established based on the doping concentration of fluorine;

a second dielectric layer disposed laterally over and in contact with the first dielectric layer such that the first dielectric layer is disposed between the gate electrode and the second dielectric layer and the second dielectric layer does not contact the gate electrode;

a third dielectric layer disposed on a top surface of the gate electrode, wherein the third dielectric layer comprises silicon nitride (SiN); and

a fourth dielectric layer disposed on a top surface of the third dielectric layer, wherein the fourth dielectric layer comprises silicon oxide (SiO 2 ).

2. The semiconductor device of claim 1 , wherein the precursor is a mixture of HF and CO having a molar ratio of HF:CO in a range from about 1:5 to 5:1.

3. The semiconductor device of claim 2 , wherein the dielectric constant is in a range of from about 2.3 to about 2.8.

4. The semiconductor device of claim 2 , wherein the dielectric constant is in a range of from about 2.4 to about 2.6.

5. The semiconductor device of claim 1 , further comprising an interlayer dielectric (ILD) layer laterally over and in contact with the second dielectric layer.

6. The semiconductor device of claim 5 , wherein the second dielectric material comprises silicon nitride, and the ILD layer comprises silicon oxycarbonitride.

7. The semiconductor device of claim 1 , wherein the gate electrode comprises polysilicon or metal.

8. The semiconductor device of claim 1 , further comprising:

a source region formed over the substrate adjacent a first side of the gate electrode; and

a drain region formed over the substrate adjacent a second side of the gate electrode, the second side being opposite to the first side with respect to the gate electrode.

9. The semiconductor device of claim 8 , further comprising a fifth dielectric layer formed over the source and drain regions.

10. The semiconductor device of claim 9 , wherein the fifth dielectric layer comprises at least one of: silicon nitride and silicon oxide.

11. A semiconductor device, comprising:

a first gate structure comprising a first gate electrode over a substrate, the gate electrode comprising a conductive material;

a second gate structure comprising a second gate electrode over the substrate, the second gate electrode comprising a second conductive material;

an interlayer dielectric (ILD) layer disposed between the first and second gate electrodes;

a first spacer disposed between the ILD layer and the first gate electrode, wherein the first spacer comprises a first dielectric layer comprising at least one of: fluorine doped silicon oxycarbonitride and fluorine doped silicon oxycarbide, and the fluorine doped silicon oxycarbonitride or the fluorine doped silicon oxycarbide is doped-through molecular ion implantation using a precursor comprising hydrogen fluoride (HF) and carbon monoxide (CO), wherein a doping concentration of fluorine in the first dielectric layer following the molecular ion implantation is in a range of from about 1×10 3 to about 1×10 6 atoms/cm 3 , and wherein a dielectric constant of the first dielectric layer is established based on the doping concentration of fluorine;

a second spacer disposed between the ILD layer and the second gate electrode;

a third spacer disposed between the ILD layer and the first spacer;

a fourth spacer disposed between the ILD layer and the second spacer,

wherein the ILD layer is disposed laterally over and in contact with the third and fourth spacers, respectively;

a third dielectric layer disposed on top surfaces of each of the first and second gate electrodes, wherein the third dielectric layer comprises silicon nitride (SiN); and

a fourth dielectric layer disposed on top surfaces of the third dielectric layer above each of the first and second gate electrodes, wherein the fourth dielectric layer comprises silicon oxide (SiO 2 ).

12. The semiconductor device of claim 11 , wherein a reaction temperature of the molecular ion implementation is in a range of from about 0° C. to about 100° C., and energy for generating molecular ions in the molecular ion implantation is in a range of from 0.5 KeV to about 100 KeV.

13. The semiconductor device of claim 12 , wherein the precursor is a mixture of HF and CO having a molar ratio of HF:CO in a range from about 1:5 to 5:1.

14. The semiconductor device of claim 12 , wherein each of the third and fourth spacers is formed from a second dielectric layer formed adjacent to and in contact with the first dielectric layer.

15. The semiconductor device of claim 14 , wherein the second dielectric layer comprises silicon nitride, and the ILD layer comprises silicon oxycarbonitride.

16. A semiconductor device, comprising:

a gate structure comprising a gate electrode over a substrate, the gate electrode comprising a conductive material;

a first dielectric layer disposed along and in contact with first and second side walls of the gate electrode, the first and second side walls being opposite to each other, the first dielectric layer comprising fluorine doped silicon oxycarbonitride or fluorine doped silicon oxycarbide, wherein the fluorine doped silicon oxycarbonitride or the fluorine doped silicon oxycarbide is doped through molecular ion implantation using a precursor comprising hydrogen fluoride (HF) and carbon monoxide (CO), wherein a doping concentration of fluorine in the first dielectric layer following the molecular ion implantation is in a range of from about 1×10 3 to about 1×10 6 atoms/cm 3 , and wherein a dielectric constant of the first dielectric layer is established based on the doping concentration of fluorine;

a source region formed over the substrate adjacent to the first side wall of the gate electrode;

a drain region formed over the substrate adjacent to the second side wall of the gate electrode;

an interlayer dielectric (ILD) layer disposed over the source and drain regions, wherein the first dielectric layer is disposed between the ILD layer and each of the first and second side walls of the gate electrode;

a second dielectric layer disposed laterally over and in contact with the first dielectric layer such that the first dielectric layer is disposed between the gate electrode and the second dielectric layer and the second dielectric layer does not contact the gate electrode, and

wherein the ILD layer is disposed laterally over and in contact with the second dielectric layer;

a third dielectric layer disposed on a top surface of the gate electrode, wherein the third dielectric layer comprises silicon nitride (SiN); and

a fourth dielectric layer disposed on a top surface of the third dielectric layer, wherein the fourth dielectric layer comprises silicon oxide (SiO 2 ).

17. The semiconductor device of claim 16 , wherein a reaction temperature of the molecular ion implementation is in a range of from about 0° C. to about 100° C., and energy for generating molecular ions in the molecular ion implantation is in a range of from 0.5 KeV to about 100 KeV.

18. The semiconductor device of claim 17 , wherein the precursor is a mixture of HF and CO having a molar ratio of HF:CO in a range from about 1:5 to 5:1.

19. The semiconductor device of claim 16 , wherein the second dielectric layer is formed adjacent to and in contact with the first dielectric layer and disposed between the first dielectric layer and the ILD layer at both the first and second sides of the gate electrode.

20. The semiconductor device of claim 19 , wherein the second dielectric layer comprises silicon nitride, and the ILD layer comprises silicon oxycarbonitride.