RF SUBSTRATE BIAS WITH HIGH POWER IMPULSE MAGNETRON SPUTTERING (HIPIMS)

• US 20080135401A1
• Filed: 12/12/2007
• Published: 06/12/2008
• Est. Priority Date: 12/12/2006
• Status: Active Grant

• Current Assignee: Evatec AG
• Original Assignee: OC Oerlikon Balzers AG (OC Oerlikon Corporation AG)
• Inventors: Kadlec, Stanislav, Weichart, Jurgen
• Granted Patent: US 8,435,389 B2
• Time in Patent Office: Days
• US Class Current: 204/192.13
• 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: H01J 37/32045 Circuits specially adapted for controlling the glow discharge
• CPC Class Codes: H01J 37/32064 Circuits specially adapted for controlling the arc discharge for plasma torches H01H1/36
• CPC Class Codes: H01J 37/32944 Arc detection
• CPC Class Codes: H01J 37/3408 Planar magnetron sputtering
• CPC Class Codes: H01J 37/3444 Associated circuits
• CPC Class Codes: H01J 37/3467 Pulsed operation, e.g. HIPIMS

Abstract

An apparatus for generating sputtering of a target to produce a coating on a substrate with a current density on a cathode of a magnetron between 0.1 and 10 A/cm² is provided. The apparatus comprises a power supply that is operably connected to the magnetron and at least one capacitor is operably connected to the power supply. A first switch is also provided. The first switch operably connects the power supply to the magnetron to charge the magnetron and the first switch is configured to charge the magnetron according to a first pulse. An electrical bias device is operably connected to the substrate and configured to apply a substrate bias.

Claims

1. An apparatus for generating sputtering of a target to produce a coating on a substrate with a current density on a cathode of a magnetron between 0.1 and 10 A/cm² comprising:

a power supply operably connected to the magnetron;

at least one capacitor operably connected to the power supply;

a first switch operably connecting the power supply to the magnetron to charge the magnetron and configured for administering a first pulse to the magnetron; and

an electrical bias device operably connected to the substrate and configured to apply a substrate bias.

2. An apparatus according to claim 1 further comprising a chuck operably connected to the electrical bias device wherein the substrate is located on the chuck.

3. An apparatus according to claim 2 wherein a distance between the magnetron and the chuck is between 20 mm to 100 mm.

4. An apparatus according to claim 2, further comprising a matching unit placed between the electrical bias device and the chuck;

wherein the matching unit is configured to match an impedance of a plasma at the substrate and/or the chuck with an impedance of the substrate.

5. An apparatus according to claim 2 further comprising a RF self-bias monitoring device operably connected to the chuck;

wherein the RF self-bias monitoring device is configured to monitor a self-bias of the electrical bias device;

wherein the electrical bias device is an RF generator.

6. An apparatus according to claim 1 wherein the electrical bias device applies a load of greater than 50 W with an argon gas flow rate of less than 20 sccm into a chamber housing the target and the substrate.

7. An apparatus according to claim 1 wherein the electrical bias device applies a load of greater than 50 W with gas pressure in the range of 2×

10<sup>−

4</sup> to 5×

10<sup>−

3</sup> mbar into a chamber housing the target and the substrate.

8. An apparatus according to claim 1 further comprising:

a coil operably connected to the at least one capacitor; and

a second switch operably connected to discharge the magnetron and configured to discharge the magnetron according to a second pulse.

9. An apparatus according to claim 1 further comprising:

at least one detector operably connected to the magnetron wherein the at least one detector is configured for detecting an arc that is forming; and

a second switch operably connected to discharge the magnetron and configured to discharge the magnetron and inhibit a formation of the arc upon a detection of the arc forming by the at least one detector.

10. An apparatus according to claim 9 wherein the first switch is controlled in response to the detection of the arc by the at least one detector.

11. An apparatus according to claim 9 further comprising:

a coil operably connected to the at least one capacitor; and

wherein the second switch is operably connected at a point along the coil and the second switch is configured to administer a second pulse.

12. An apparatus for generating sputtering of a target to produce a coating on a substrate with a current density on a cathode of a magnetron between 0.1 and 10 A/cm² comprising:

a power supply operably connected to the magnetron;

at least one capacitor operably connected to the power supply;

a first switch operably connecting the power supply to the magnetron to charge the magnetron and configured for administering a first pulse to the magnetron;

an electrical bias device operably connected to the substrate and configured to apply a substrate bias;

a chuck operably connected to the electrical bias device wherein the substrate is located on the chuck;

a coil operably connected to the at least one capacitor;

a second switch operably connected to discharge the magnetron and connected at a point along the coil wherein the second switch is configured to discharge the magnetron according to a second pulse;

at least one detector operably connected to the magnetron wherein the at least one detector is configured for detecting an arc that is forming; and

wherein the first switch and the second switch are controlled in response to a detection of the arc by the at least one detector to inhibit a formation of the arc.

13. An apparatus for generating sputtering of a target to produce a coating on a substrate with a current density on a cathode of a magnetron between 0.1 and 10 A/cm² comprising:

a power supply operably connected to the magnetron to charge the magnetron and configured for administering a first pulse to the magnetron;

a RF electrical bias device operably connected to the substrate and configured to discharge the magnetron according to a bias pulse; and

a synchronization device operably connected to the power supply and to the RF electrical bias device;

wherein the synchronization device is configured to synchronize a frequency and a time delay of the first pulse with the bias pulse.

14. An apparatus according to claim 13, wherein the power supply is configured for administering the first pulse to the magnetron with a duty cycle for the first pulse between 0.01% and 20%, and the frequency in the range of 1 Hz to 20 kHz.

15. An apparatus according to claim 13, wherein the power supply is configured for administering the first pulse to the magnetron with a duty cycle for the first pulse between 2% and 50%.

16. An apparatus according to claim 13, wherein the synchronization device is configured to administer the bias pulse before the first pulse with the time delay between 0.1 μ

s to 500 μ

s.

17. A method of applying a substrate bias in an apparatus for generating sputtering where pulses are applied to produce a coating on a substrate with a current density on a cathode of a magnetron between 0.1 and 10 A/cm² comprising the steps of:

applying a first pulse to a first switch to charge the magnetron from a power supply; and

applying the substrate bias from an electrical bias device operably connected to the substrate.

18. A method according to claim 17 further comprising the step of:

using the electrical bias device during the first pulse as a pre-ionization for the discharge of the magnetron.

19. A method according to claim 17 further comprising the step of:

using the electrical bias device to etch and pre-clean the substrate prior to deposition.

20. A method according to claim 17 further comprising the step of:

adjusting a voltage of the substrate bias to regulate the energy of ions bombarding the substrate to provide a desired coating for the substrate.

21. A method according to claim 17 further comprising the steps of:

applying a second pulse to a second switch to discharge the magnetron.

22. A method according to claim 21 wherein:

the first pulse includes a relatively long off-time for the first switch during which at least one capacitor is charged; and

a relatively short time elapses when the first switch is activated to store energy in a coil before the second pulse activates the second switch wherein activation of the second switch causes a discharging of the magnetron.

23. A method according to claim 21 wherein:

the first pulse and the second pulse periodically change between a first mode and a second mode;

the first mode comprises the first pulse including a relatively long off-time time for the first switch during which a capacitor is charged; and

a relatively short time elapses when the first switch is activated to store energy in a coil before the second pulse activates the second switch wherein activation of the second switch causes a discharging of the magnetron; and

the second mode comprises the first pulse including a relatively long pulse to administer a voltage to the magnetron; and

the second pulse is a series of short pulses.

24. A method according to claim 21 wherein:

the first pulse is a relatively long pulse to administer a voltage to the apparatus; and

the second pulse is a series of short pulses.

25. A method according to claim 21 further comprising the steps of:

detecting that an arc is forming through a use of at least one detector; and

activating the second switch to discharge the magnetron in response to a detection of the arc to inhibit a formation of the arc.