Reactive sputtering with HIPIMS

Patent metadata

Field	Value
Publication number	US-11380530-B2
Application number	US-202017000846-A
Country	US
Kind code	B2
Filing date	Aug 24, 2020
Priority date	Dec 7, 2007
Publication date	Jul 5, 2022
Grant date	Jul 5, 2022

Abstract

A method and apparatus for sputter depositing an insulation layer onto a surface of a cavity formed in a substrate and having a high aspect ratio. A target formed from a material to be included in the insulation layer and the substrate are provided in a substantially enclosed chamber defined by a housing. A plasma is ignited within the substantially enclosed chamber and a magnetic field is provided adjacent to a surface of the target to contain the plasma adjacent to the surface of the target. A voltage is rapidly increased to repeatedly establish high-power electric pulses between a cathode and an anode. An average power of the electric pulses is at least 0.1 kW, and can be much greater. An operational parameter of the sputter deposition is controlled to promote sputter depositing of the insulation layer in a transition mode between a metallic mode and a reactive mode.

First claim

What is claimed is:

1. A sputtering apparatus for sputter depositing an insulation layer onto a surface of a cavity formed in a substrate and having a high aspect ratio, the apparatus comprising:
a housing defining a substantially enclosed chamber;
a pedestal to be exposed to an interior of said chamber for supporting the substrate at an appropriate position within said chamber during sputter depositing;
a magnet assembly for providing a magnetic field adjacent to a surface of a target formed at least in part from a material to be included in the insulation layer to be deposited onto the surfaces of the cavity;
a power supply for establishing high-power electric pulses with a rapid voltage increase in a plasma to be maintained within the magnetic field between a cathode and an anode, wherein an average power of the electric pulses is at least 0.1 kW; and
a controller for controlling an operational parameter of the sputtering apparatus to conduct the sputter depositing of the insulation layer substantially in a transition mode between a metallic mode and a reactive mode,
wherein the sputtering apparatus is configured to determine an average discharge current of the high-power electric pulses and to adjust an energy per pulse by adjusting a duration of the high-power electric pulses in dependency of said average discharge current.

2. The sputtering apparatus of claim 1 further comprising a variable-rate flow controller for governing a flow rate of a reactive sputter gas into the substantially enclosed chamber, wherein the operational parameter controlled by the controller to conduct the sputter depositing in the transition mode is the flow rate of the reactive sputter gas.

3. The sputtering apparatus of claim 2 , wherein the reactive sputter gas is selected from the group consisting of oxygen and nitrogen.

4. The sputtering apparatus of claim 1 , wherein the material of the target to be included in the insulation layer is selected from the group consisting of silicon and aluminum.

5. The sputtering apparatus of claim 1 , wherein a voltage of the electric pulses is maintained substantially constant during the sputter depositing of the insulation layer.

6. The sputtering apparatus of claim 1 , wherein the operational parameter controlled by the controller to conduct the sputter depositing of the insulation layer substantially in the transition mode is a duration of the electric pulses.

7. The sputtering apparatus of claim 1 , wherein the duration of the electric pulses is controlled by the controller and at least one of a voltage of the electric pulses and a flow rate of a reactive gas into the substantially enclosed chamber is maintained at a substantially constant value.

8. The sputtering apparatus of claim 1 , wherein the operational parameter controlled by the controller to conduct the sputter depositing of the insulation layer substantially in the transition mode is a frequency of the electric pulses.

9. The sputtering apparatus of claim 8 , wherein the frequency of the electric pulses is controlled by the controller and at least one of a voltage of the electric pulses and a flow rate of a reactive gas into the substantially enclosed chamber is maintained at a substantially constant value.

10. The sputtering apparatus of claim 1 further comprising a variable power source electrically connected to the pedestal for applying a high-frequency signal to the pedestal for supporting the substrate to generate a self-bias field adjacent to said substrate.

11. The sputtering apparatus of claim 10 further comprising an impedance matching network for matching an impedance of a load supplied with the high-frequency signal generated by the variable power source to sustain an increasing voltage as an impedance of the insulation layer increases.

12. The sputtering apparatus of claim 11 , wherein the impedance matching network establishes a maximum self-bias voltage approximately simultaneously with a maximum discharge current delivered by the power supply establishing the high-power electric pulses.

13. The sputtering apparatus of claim 1 , wherein a specific deposition rate of the insulation layer deposited in the transition mode is at least 2.5 Å/kWs.

14. The sputtering apparatus of claim 1 , wherein a specific deposition rate of the insulation layer deposited in the transition mode is within a range from about 2.5 Å/kWs to about 4.2 Å/kWs.

15. A method of sputter depositing an insulation layer onto a surface of a cavity formed in a substrate and having a high aspect ratio, the method comprising:
providing a target formed at least in part from a material to be included in the insulation layer and the substrate in a substantially enclosed chamber defined by a housing;
igniting a plasma within the substantially enclosed chamber;
providing a magnetic field adjacent to a surface of the target to at least partially contain the plasma adjacent to the surface of the target;
rapidly increasing a voltage to repeatedly establish high-power electric pulses between a cathode and an anode, wherein an average power of the electric pulses is at least 0.1 kW;
controlling an operational parameter to promote the sputter depositing of the insulation layer substantially in a transition mode between a metallic mode and a reactive mode; and
reacting the material from the target with a reactive gas within the substantially enclosed chamber to form an insulating material and depositing the insulating material onto the surface of the cavity,
determining an average discharge current of the high-power electric pulses, and
adjusting an energy per pulse by adjusting a duration of the high-power electric pulses in dependency of said average discharge current.

16. The method of claim 15 further comprising depositing a dielectric layer onto the surface of the cavity before sputter depositing the insulating material onto the surface of the cavity, wherein the dielectric layer separates the insulation layer from the surface of the cavity.

17. The method of claim 15 , wherein controlling the operational parameter to promote the sputter depositing of the insulation layer substantially in the transition mode comprises controlling a duration of the electric pulses to substantially minimize an average discharge current of the electric pulses.

18. The method of claim 15 further comprising maintaining at least one of a voltage of the electric pulses and a flow rate of a reactive gas into the substantially enclosed chamber is maintained at a substantially constant value.

19. The method of claim 15 , wherein controlling the operational parameter to promote the sputter depositing of the insulation layer substantially in the transition mode comprises controlling a frequency of the electric pulses.

20. The method of claim 15 further comprising maintaining at least one of a voltage of the electric pulses and a flow rate of a reactive gas into the substantially enclosed chamber is maintained at a substantially constant value.

21. The method of claim 15 further comprising applying a high-frequency signal to a support for supporting the substrate within the substantially enclosed chamber to generate a self-bias field adjacent to said substrate.

22. The method of claim 21 further comprising matching an impedance of a load supplied with the high-frequency signal generated by a variable power source to sustain an increasing voltage as an impedance of the insulation layer increases.

23. The method of claim 22 ,

Assignees

• Evatec Ag

Inventors

• Weichart Juergen
• Kadlec Stanislav
• Elghazzali Mohamed

Classifications

• H01J37/3405

  Magnetron sputtering · CPC title

• H01J37/3444

  Associated circuits · CPC title

• H01J37/3467

  Pulsed operation, e.g. HIPIMS · CPC title

• H01J37/3408 Primary

  Planar magnetron sputtering · CPC title

• C23C14/0036

  Reactive sputtering · CPC title