Capacitive coupled plasma source for sputtering and resputtering

• US 10,480,063 B2
• Filed: 09/09/2016
• Issued: 11/19/2019
• Est. Priority Date: 12/21/2015
• Status: Active Grant

• Current Assignee: Ionquest Corp.
• Original Assignee: Ionquest Corp.
• Inventors: Chistyakov, Roman, Abraham, Bassam Hanna
• Primary Examiner(s): Berman, Jason
• Application Number:
  US15/260,841
• Publication Number:
  US 20170178912A1
• Time in Patent Office: 1,166 Days
• CPC Class Codes: C23C 14/0057 using reactive gases other than O2, H2O, N2, NH3 or CH4
• CPC Class Codes: C23C 14/0605 Carbon
• CPC Class Codes: C23C 14/14 Metallic material, boron or silicon
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: C23C 14/3485 using pulsed power to the target
• CPC Class Codes: C23C 14/35 by application of a magnetic field, e.g. magnetron sputtering C23C14/3457 takes precedence
• CPC Class Codes: C23C 14/354 Introduction of auxiliary energy into the plasma
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32825 Working under atmospheric pressure or higher
• CPC Class Codes: H01J 37/3405 Magnetron sputtering
• CPC Class Codes: H01J 37/3417 Arrangements
• CPC Class Codes: H01J 37/3426 Material
• CPC Class Codes: H01J 37/3435 Target holders (includes backing plates and endblocks)
• CPC Class Codes: H01J 37/345 Magnet arrangements in particular for cathodic sputtering apparatus material of magnets or magnets in general H01F1/00, H01F7/00
• CPC Class Codes: H01J 37/3452 Magnet distribution
• CPC Class Codes: H01J 37/3455 Movable magnets
• CPC Class Codes: H01J 37/3464 Operating strategies
• CPC Class Codes: H01J 37/3467 Pulsed operation, e.g. HIPIMS
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/76843 : formed in openings in a dielectric
• CPC Class Codes: H01L 21/76871 : Layers specifically deposited to enhance or enable the nucleation of further layers, i.e. seed layers
• CPC Class Codes: H01L 21/76879 : by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 21/76882 : Reflowing or applying of pressure to better fill the contact hole
• CPC Class Codes: H01L 23/5226 : Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/53238 : Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers

Abstract

An ionized physical vapor deposition (I-PVD) source includes an electrically and magnetically enhanced radio frequency (RF) diode, which has magnetic field lines directed substantially perpendicular to a cathode that terminate on an electrode positioned between an anode around the cathode. The anode forms a gap and the electrode is positioned behind the gap. An RF power supply connected to the cathode generates RF discharge. The cathode is inductively grounded to prevent forming a constant voltage bias during RF discharge. The electrons drift between the cathode and the gap, thereby producing ionization and forming high density plasma. The electrons drift and energy are controlled by applying different voltage potentials to the electrode. The I-PVD source is positioned in a vacuum chamber to form an I-PVD apparatus that generates ions from sputtered target material atoms and deposition. During sputtering, the substrate is biased. The I-PVD source performs chemically enhanced ionized physical vapor deposition (CE-IPVD).

Claims

1. A method of ionized physical vapor deposition (I-PVD) sputtering of a layer on a substrate, the method comprising:

positioning a cathode, an anode, and a cathode magnet assembly in a vacuum chamber;

providing a gap inside the anode around the cathode, a cusp magnetic field being provided in the gap, at least a portion of magnetic field lines associated with the cusp magnetic field passing through the gap and terminating on the cathode magnet assembly;

positioning an electrode in the gap;

providing a noble gas selected to sputter target material;

applying radio frequency (RF) power to the cathode, thereby generating plasma discharge that ionizes sputtered target material;

applying voltage to the electrode; and

applying a negative bias voltage to the substrate, thereby attracting positively charged sputtered material ions to the substrate.

2. The method, as defined by claim 1, wherein a value of the negative bias voltage on the substrate is in a range of about 10 to 100 V.

3. The method, as defined by claim 1, wherein a value of the cusp magnetic field is in a range of about 300 to 10000 G.

4. The method, as defined by claim 1, wherein the feed gas is a mixture of the noble gas and a gas that comprises target material atoms.

5. The method, as defined by claim 1, wherein the feed gas comprises a mixture of the noble gas and a reactive gas.

6. The method, as defined by claim 1, wherein the cathode magnet assembly rotates at a speed in the range of 1 to 100 revolutions per minute.

7. The method, as defined by claim 1, wherein the substrate is a semiconductor wafer with a diameter in a range of 100 mm to 450 mm.

8. The method, as defined by claim 1, wherein a voltage on the electrode is a negative pulsed voltage.

9. An apparatus that ionized physical vapor deposition (I-PVD) sputters a layer on a substrate, the apparatus comprising:

a cathode, an anode, and a cathode magnet assembly positioned in a vacuum chamber;

a gap provided inside the anode around the cathode, a cusp magnetic field being provided in the gap, at least a portion of magnetic field lines associated with the cusp magnetic field passing through the gap and terminating on the cathode magnet assembly;

an electrode positioned in the gap, the electrode providing a voltage;

a noble feed gas selected to sputter target material;

a circuit connecting the cathode to radio frequency (RF) power, thereby generating plasma discharge that ionizes sputtered target material; and

a bias power supply providing negative bias voltage to the substrate, thereby attracting positively charged ions from the sputtered target material to the substrate surface.

10. The apparatus, as defined by claim 9, wherein the electrode comprises a floating electrical potential.

11. The apparatus, as defined by claim 9, wherein the electrode is connected to a power supply.

12. The apparatus, as defined by claim 9, wherein the cathode is connected to a direct current (DC) power supply.

13. The apparatus, as defined by claim 9, wherein a width of the gap is in a range of 1-10 mm.

14. A method of generating high density plasma, the method comprising:

positioning a cathode, an anode, and a cathode magnet assembly in a vacuum chamber;

providing a gap inside the anode around the cathode, a cusp magnetic field being provided in the gap, at least a portion of magnetic field lines associated with the cusp magnetic field passing through the gap and terminating on the cathode magnet assembly;

positioning an electrode in the gap;

providing a feed gas selected to generate high density plasma;

applying voltage to the electrode; and

applying radio frequency (RF) power to the cathode, thereby generating plasma discharge that generates high density plasma.

15. The method, as defined by claim 14, wherein a value of the cusp magnetic field in the gap is in a range of about 300 to 10000 G.

16. The method, as defined by claim 14, wherein the feed gas comprises a mixture of a noble gas and a reactive gas.

17. The method, as defined by claim 14, wherein the cathode magnet assembly rotates at a speed in a range of 1 to 100 revolutions per minute.

18. The method, as defined by claim 14, wherein the substrate is a semiconductor wafer with a diameter in a range of 100 to 450 mm.

19. The method, as defined by claim 14, wherein the voltage on the electrode is a negative pulsed voltage.

20. The method, as defined by claim 14, wherein the cathode is connected to a ground electrical potential through a circuit comprising an inductor.