Method of fabricating a high dielectric constant transistor gate using a low energy plasma apparatus
The present invention generally provides methods and apparatuses that are adapted to form a high quality dielectric gate layer on a substrate. Embodiments contemplate a method wherein a metal plasma treatment process is used in lieu of a standard nitridization process to form a high dielectric constant layer on a substrate. Embodiments further contemplate an apparatus adapted to “implant” metal ions of relatively low energy in order to reduce ion bombardment damage to the gate dielectric layer, such as a silicon dioxide layer and to avoid incorporation of the metal atoms into the underlying silicon. In general, the process includes the steps of forming a high-k dielectric and then terminating the surface of the deposited high-k material to form a good interface between the gate electrode and the high-k dielectric material. Embodiments of the invention also provide a cluster tool that is adapted to form a high-k dielectric material, terminate the surface of the high-k dielectric material, perform any desirable post treatment steps, and form the polysilicon and/or metal gate layers.
1. A method of forming a high-k dielectric layer using a sputtering process, wherein the sputtering process comprises:
positioning a substrate having a dielectric layer formed thereon in a processing region of a plasma processing chamber;
disposing a first material in the dielectric layer using a sputtering process, wherein the sputtering process comprises:
delivering a plurality of RF energy pulses from a first RF generator to a target comprising the first material, wherein the RF energy of each pulse is delivered at a first RF frequency; and
delivering a plurality of DC energy pulses to the target from a DC source assembly, wherein the plurality of RF energy pulses and the plurality of DC pulses are synchronized.
2. The method of claim 1 , wherein the RF energy pulses and the DC energy pulses do not overlap in time.
3. The method of claim 1 , wherein the first RF frequency is between about 1 MHz and about 200 MHz.
4. The method of claim 1 , wherein the thickness of the dielectric layer is less than about 30 Angstroms.
5. The method of claim 1 , wherein the dielectric layer contains a material selected from a group consisting of silicon dioxide, zirconium oxide, hafnium silicate oxides, lanthanum oxides, and aluminum oxide.
6. The method of claim 1 , wherein the first material comprises a material selected from a group consisting of aluminum, titanium, zirconium, hafnium, lanthanum, strontium, lead, yttrium, and barium.
7. The method of claim 1 , wherein the plurality of RF energy pulses and the plurality of DC energy pulses are delivered at a pulsing frequency between about 1 Hz and about 50 kHz.
8. A method of forming a high-k dielectric layer using a sputtering process, wherein the sputtering process comprises:
positioning a substrate having a dielectric layer formed thereon in a processing region of a plasma processing chamber;
disposing a first material in the dielectric layer using a low energy sputtering process, wherein the sputtering process comprises:
delivering a first amount of RF energy to a target comprising the first material for a first period of time, wherein the first amount of RF energy is delivered at a first RF frequency; and
delivering a second amount of RF energy to the target for a second period of time, wherein the second amount of RF energy is delivered at a second RF frequency, wherein the second frequency is greater than the first frequency.
9. The method of claim 8 , wherein the first RF frequency and the second RF frequency are between about 1 MHz and about 200 MHz.
10. The method of claim 8 , wherein the thickness of the dielectric layer is less than about 30 Angstroms.
11. The method of claim 8 , wherein the dielectric layer contains a material selected from a group consisting silicon dioxide, zirconium oxide, hafnium silicate oxides, lanthanum oxides, and aluminum oxide.
12. The method of claim 8 , wherein the first material comprises a material selected from a group consisting of aluminum, titanium, zirconium, hafnium, lanthanum, strontium, lead, yttrium, and barium.
13. A method of forming a high-k dielectric layer using a sputtering process, wherein the sputtering process comprises:
positioning a substrate having a dielectric layer formed thereon in a processing region of a plasma processing chamber;
disposing a first material in the dielectric layer using a sputtering process, wherein the sputtering process comprises:
delivering a first plurality of RF energy pulses from a first RF generator to a coil that is in electrical communication with the processing region, wherein the RF energy is delivered at a first RF frequency and a first power; and
delivering a plurality of DC pulses to a target comprising the first material from a DC source assembly, wherein the plurality of RF energy pulses and the plurality of DC pulses are synchronized.
14. The method of claim 13 , wherein the first plurality of RF energy pulses and the plurality of DC pulses do not overlap in time.
15. The method of claim 13 , wherein the first RF frequency is between about 40 kHz and about 20 MHz.
16. The method of claim 13 , wherein the thickness of the dielectric layer is less than about 30 Angstroms.
17. The method of claim 13 , wherein the dielectric layer contains a material selected from a group consisting silicon dioxide, zirconium oxide, hafnium silicate oxides, lanthanum oxides, and aluminum oxide.
18. The method of claim 13 , wherein the first material comprises a material selected from a group consisting of aluminum, titanium, zirconium, hafnium, lanthanum, strontium, lead, yttrium, and barium.
19. The method of claim 13 , further comprising delivering a second plurality of RF energy pulses from a second RF generator to the target, wherein the second plurality of RF energy pulses and the plurality of DC pulses are synchronized.
20. The method of claim 13 , further comprising delivering the first plurality of RF energy pulses from the first RF generator to the target.
21. The method of claim 19 , wherein the first plurality of RF energy pulses and the second plurality of RF energy pulses are delivered at a pulsing frequency between about 1 Hz and about 50 kHz.
22. A method of forming a high-k dielectric layer using a sputtering process, wherein the sputtering process comprises:
positioning a substrate having a dielectric layer formed thereon in a processing region of a plasma processing chamber;
disposing a first material in the dielectric layer using a sputtering process, wherein the sputtering process comprises:
delivering a first plurality of RF energy pulses from a first RF generator at a first RF frequency to a coil that is in electrical communication with the processing region; and
delivering a second plurality of RF energy pulses from a first RF generator at a second RF frequency to a target that is in electrical communication with the processing region.
23. The method of claim 22 , wherein the first RF frequency is between about 40 kHz and about 20 MHz and the second RF frequency is between about 1 MHz and about 200 MHz.
24. The method of claim 22 , wherein the thickness of the dielectric layer is less than about 30 Angstroms.
25. The method of claim 22 , wherein the dielectric layer contains a material selected from a group consisting silicon dioxide, zirconium oxide, hafnium silicate oxides, lanthanum oxides, and aluminum oxide.
26. The method of claim 22 , wherein the first material comprises a material selected from a group consisting of aluminum, titanium, zirconium, hafnium, lanthanum, strontium, lead, yttrium, and barium.
27. The method of claim 22 , wherein the first plurality of RF energy pulses and the second plurality of RF energy pulses are delivered at a pulsing frequency between about 1 Hz and about 50 kHz.