Method of fabricating a high dielectric constant transistor gate using a low energy plasma apparatus

• US 7,837,838 B2
• Filed: 12/20/2006
• Issued: 11/23/2010
• Est. Priority Date: 03/09/2006
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Hung, Steven, Paterson, Alex M., Todorow, Valentin, Liu, Patricia M., Sato, Tatsuya, Chua, Thai Cheng, Holland, John P.
• Primary Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US11/614,027
• Publication Number:
  US 20070218623A1
• Time in Patent Office: 1,434 Days
• Field of Search: 204/192.12, 204/192.15, 204/192.22, 204/192.23, 204/298.08, 204/298.06
• US Class Current: 204/192.22
• CPC Class Codes: C23C 14/10 Glass or silica
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: C23C 14/3471 Introduction of auxiliary energy into the plasma
• CPC Class Codes: H01L 21/02148 the material containing hafnium, e.g. HfSiOx or HfSiON
• CPC Class Codes: H01L 21/02156 the material containing at least one rare earth element, e.g. silicate of lanthanides, scandium or yttrium
• CPC Class Codes: H01L 21/02161 the material containing more than one metal element
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02238 silicon in uncombined form, i.e. pure silicon
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/02266 deposition by physical ablation of a target, e.g. sputtering, reactive sputtering, physical vapour deposition or pulsed laser deposition
• CPC Class Codes: H01L 21/02321 introduction of substances into an already existing insulating layer H01L21/02227 and subgroups take precedence
• CPC Class Codes: H01L 21/02323 introduction of oxygen
• CPC Class Codes: H01L 21/02329 introduction of nitrogen
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/28167 on single crystalline silicon, e.g. using a liquid, i.e. chemical oxidation
• CPC Class Codes: H01L 21/28185 with a treatment, e.g. annealing, after the formation of the gate insulator and before the formation of the definitive gate conductor
• CPC Class Codes: H01L 21/28202 in a nitrogen-containing ambient, e.g. nitride deposition, growth, oxynitridation, NH3 nitridation, N2O oxidation, thermal nitridation, RTN, plasma nitridation, RPN
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/3144 : on silicon
• CPC Class Codes: H01L 21/31612 : on a silicon body
• CPC Class Codes: H01L 21/3162 : on a silicon body
• CPC Class Codes: H01L 21/31641 : Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 21/31645 : Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 29/40114 : the electrodes comprising a conductor-insulator-conductor-insulator-semiconductor structure
• CPC Class Codes: H01L 29/40117 : the electrodes comprising a charge-trapping insulator
• CPC Class Codes: H01L 29/51 : Insulating materials associated therewith for MIS structures on thin film semiconductor H01L29/4908

Abstract

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.

Claims

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.