Magnetron sputtering apparatus with an integral cooling and pressure relieving cathode

• US 6,494,999 B1
• Filed: 11/09/2000
• Issued: 12/17/2002
• Est. Priority Date: 11/09/2000
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Herrera, Manuel J., Pitcher, Philip G.
• Primary Examiner(s): VerSteeg, Steven H.
• Application Number:
  US09/708,735
• Time in Patent Office: 768 Days
• Field of Search: 204/192.12, 204/298.09, 204/298.12, 204/298.17, 204/298.2, 204/298.37
• US Class Current: 204/192.12
• CPC Class Codes: C23C 14/3407 Cathode assembly for sputtering apparatus, e.g. Target
• CPC Class Codes: H01J 37/3408 Planar magnetron sputtering

Abstract

A sputtering apparatus includes a sputtering process chamber, a sputtering target assembly, and an adjustable magnetron assembly. The sputtering target assembly includes heating/cooling passages within the sputtering target assembly. A first side of a heat exchanger/pressure relieving plate is attached to a target backing. A second or opposing side of the heat exchanger/pressure relieving plate is attached to an insulation cover to form, within the sputtering target assembly, pressure relieving vacuum passages. The target assembly completely covers and seals against a high-vacuum-compatible insulator resting over and sealed to a top flange of the process chamber. A magnetron assembly resting over the target assembly, is independent from vacuum, or vacuum components, and provides means to move or scan a magnetron or magnet array over the target assembly. The distance between the magnetron and target assembly is adjustable throughout the useful life of the target independent from vacuum, or vacuum components.

Claims

1. A magnetron sputtering apparatus comprising:

a housing,

at least one magnetron within the housing;

a substrate;

a sputtering processing chamber having a top flange, the flange having a shape and perimeter according to a predetermined form, the substrate being within the sputtering process chamber;

a sputtering target assembly sealed to and insulated from the flange, such that a vacuum is capable of being maintained in the sputtering process chamber;

wherein the sputtering target assembly comprises;

a sputtering target and target backing plate assembly having opposed first and second sides, the first side providing material for sputtering,

a pressure relief plate having opposed first and second sides, the target and target backing plate assembly second side being in contact with the first side of the pressure relief plate,

heat exchange passages selected from at least one member of the group consisting of;

heat exchange passages defined between the opposed sides of the sputtering target and backing plate assembly,

heat exchange passages defined between the opposed sides of the pressure relief plate, and

heat exchange passages defined by heat exchange cavities formed in at least one member of the group consisting of the first side of the pressure relief plate and the second side of the target and target backing plate assembly, wherein the heat exchange passages are formed between the first side of the pressure relief plate and the second side of the target and target backing plate assembly which enclose the heat exchange cavities,

the heat exchange passages having one or more inlet and outlet openings,

an insulation cover unit having opposed first and second sides, wherein the insulation cover unit is electrically isolated from the sputtering target;

wherein the second side of the pressure relief plate is in contact with the first side of the cover unit to form at least one vacuum pressure space therebetween capable of maintaining a vacuum therein and the at least one vacuum pressure space having at least one vacuum port;

wherein the pressure in the sputtering processing chamber is vacuum pressure which is the same or different from the pressure in the at least one vacuum pressure space;

wherein every magnetron of the magnetron sputtering apparatus is outside the at least one vacuum pressure space of the sputtering target assembly.

2. The magnetron sputtering apparatus of claim 1, wherein the heat exchange passages are selected from at least one member of the group consisting of(a)

(a) heat exchange passages defined within the sputtering target and backing plate assembly,

(b) heat exchange passages defined by having heat exchange cavities formed in the first side of the pressure relief plate such that, when the first side of the pressure relief plate is contacted to the second side of the target and target backing plate assembly, the heat exchange passages are formed between the heat exchange cavities in the pressure relief plate and the target and target backing plate assembly enclosing those heat exchange cavities, and

(c) heat exchange passages defined by having heat exchange cavities formed in the second side of the target and target backing plate assembly such that, when the first side of the pressure relief plate is contacted to the second side of the target and target backing plate assembly, the heat exchange passages are formed between the heat exchange cavities in the target and target backing plate assembly and the pressure relief plate enclosing those heat exchange cavities.

3. The magnetron sputtering apparatus of claim 1, wherein the at least one vacuum pressure space is defined by vacuum passages capable of maintaining a vacuum and having at least one vacuum port, the vacuum passages selected from at least one member of the group consisting of:

(a) vacuum passages defined by having vacuum cavities formed in the second side of the pressure relief plate such that, when the first side of the insulation cover unit is contacted to the second side of the pressure relief plate, the vacuum passages are formed between the vacuum cavities in the pressure relief plate and the insulation cover unit enclosing those vacuum cavities, and

(b) vacuum passages defined by having vacuum cavities formed in the first side of the insulation cover unit such that, when the second side of the pressure relief plate is contacted to the first side of the insulation cover unit, the vacuum passages are formed between the vacuum cavities in the insulation cover unit and the pressure relief plate enclosing those vacuum cavities.

4. The magnetron sputtering apparatus as in claim 1, wherein the heat exchange passages are defined within the sputtering target and target backing plate assembly to have channels having a perimeter, transverse to a direction for flow of heat exchange fluid, entirely defined by the sputtering target and target backing plate assembly.

5. The magnetron sputtering apparatus as in claim 1, wherein the heat exchange passages are defined by having heat exchange cavities formed in the first side of the pressure relief plate such that, when the first side of the pressure relief plate is contacted to the second side of the target and target backing plate assembly, the heat exchange passages are formed between the heat exchange cavities in the pressure relief plate and the target and target backing plate assembly enclosing those heat exchange cavities.

6. The magnetron sputtering apparatus as in claim 5, wherein the second side of the target and target backing plate assembly is generally flat.

7. The magnetron sputtering apparatus as in claim 1, wherein the heat exchange passages are defined by having heat exchange cavities formed in the second side of the target and target backing plate assembly such that, when the first side of the pressure relief plate is contacted to the second side of the target and target backing plate assembly, the heat exchange passages are formed between the heat exchange cavities in the target and target backing plate assembly and the pressure relief plate enclosing those heat exchange cavities.

8. The magnetron sputtering apparatus as in claim 7, wherein the first side of the pressure relief plate is generally flat.

9. The magnetron sputtering apparatus as in claim 1, wherein the at least one vacuum pressure space comprises vacuum passages defined by having vacuum cavities formed in the second side of the pressure relief plate such that, when the first side of the insulation cover unit is contacted to the second side of the pressure relief plate, the vacuum passages are formed between the vacuum cavities in the pressure relief plate and the insulation cover unit enclosing those vacuum cavities.

10. The magnetron sputtering apparatus as in claim 9, wherein the first side of the insulation cover unit is generally flat.

11. The magnetron sputtering apparatus as in claim 1, wherein the at least one vacuum pressure space comprises vacuum passages defined by having vacuum cavities formed in the first side of the insulation cover unit such that, when the second side of the pressure relief plate is contacted to the first side of the insulation cover unit, the vacuum passages are formed between the vacuum cavities in the insulation cover unit and the pressure relief plate enclosing those vacuum cavities.

12. The magnetron sputtering apparatus as in claim 11, wherein the second side of the pressure relief plate is generally flat.

13. The magnetron sputtering apparatus of claim 1, wherein the sputtering target and target backing plate assembly comprises a sputtering target having opposed first and second sides and a target backing plate assembly having opposed first and second sides;

the sputtering target second side is in contact with the first side of the target backing plate assembly; and

the target backing plate assembly second side is in contact with the first side of the pressure relief plate.

14. The magnetron sputtering apparatus as in claim 1, wherein the sputtering target and target backing plate assembly is a monolith of a material.

15. The magnetron sputtering apparatus as in claim 1, wherein the target backing plate assembly is configured to cover a top opening of the sputtering process chamber to seal the top opening, and wherein a magnet of the magnetron operates at ambient pressure while maintaining a vacuum pressure in the at least one vacuum pressure space.

16. The magnetron sputtering apparatus as in claim 1, wherein the housing comprises a top chamber in which the at least one magnetron is located, wherein the target backing plate assembly is configured to cover a bottom opening of the top chamber of the housing to seal the bottom, and such that a magnet of the at least one magnetron is capable of operating at ambient pressure while maintaining a vacuum pressure in the at least one vacuum pressure space.

17. The magnetron sputtering apparatus as in claim 1, wherein the heat exchange passages run parallel to one another and are configured to distribute a fluid flow approximately equally between them when they receive the flow from an inlet manifold area.

18. The magnetron sputtering apparatus as in claim 1, wherein the heat exchange passages run adjacent to one another and are configured to distribute a fluid flow to maintain a generally uniform temperature across a surface of the sputtering target and target backing plate assembly.

19. The sputtering apparatus as in claim 1, wherein the sputtering target assembly is configured to cover a bottom opening of a top chamber to seal the bottom opening such that a vacuum chamber beneath the bottom opening is capable of operating at a vacuum pressure while the top chamber operates at ambient pressure, and while a vacuum pressure is maintained in the at least one vacuum pressure space, wherein the pressure in the vacuum chamber is the same or different from the pressure in the at least one vacuum pressure space.

20. The sputtering apparatus as in claim 1, wherein the sputtering target assembly sealed to and insulated from the flange defines a vacuum passage to a vacuum system from the vacuum pressure space.

21. A scanning magnetron sputtering apparatus comprising:

a magnetron assembly comprising a movable magnetron;

a magnetron housing comprising a top chamber for locating the magnetron therein and a sputtering process chamber for locating a substrate therein;

a sputtering target assembly between the top chamber and the sputtering process chamber, comprising a target surface for providing sputtering material;

the magnetron assembly comprising;

the movable magnetron,

a magnetron lift base plate mounted to the magnetron housing,

springs compressed between the magnetron lift base plate and the magnetron housing, wherein the magnetron lift base plate presses against the springs,

the magnetron being functionally attached to the magnetron lift base plate, and connected to a drive shaft to control motion of the magnetron;

rotatable cam shafts mounted within the housing, and a gear for controlling rotation of the cam shafts to control distance between the magnetron and the target surface for providing sputtering material, wherein the cam shafts contain cams pressing against the magnetron lift base plate such that rotation of the cams moves the magnetron lift base plate transverse to a longitudinal axis of the cam shaft and the magnetron functionally mounted to the magnetron lift base plate is also forced to move transverse along with the magnetron lift base plate to set the distance between the magnetron and the surface of the target.

22. A linear scanning magnetron sputtering apparatus comprising:

a magnetron assembly comprising a movable magnetron;

a magnetron housing comprising a top chamber for locating the magnetron therein and a process chamber for locating a substrate therein;

a sputtering target assembly between the top chamber and the process chamber, comprising a target surface for providing sputtering material;

the magnetron assembly comprising;

the movable magnetron, a magnetron base plate secured to the moveable magnetron, at least one slide mount fitted with bearings attached to the magnetron base plate, and slide shafts, wherein the slide mount is mounted to receive the slide shafts,

a magnetron lift base plate mounted to the magnetron housing, wherein the ends of the slide shafts are mounted to the magnetron lift base plate, wherein the magnetron slides freely on the slide shafts,

springs compressed between the magnetron lift base plate and the magnetron housing, wherein the magnetron lift base plate presses against the springs,

a leadscrew nut, a nut mount and a leadscrew having a longitudinal axis generally parallel to the slide shafts, the nut mount being attached to the leadscrew nut, and fitted with bearings so that shafts mounted about the base plate are capable of transmitting push/pull motion of the leadscrew;

the magnetron being connected to the nut mount such that the magnetron is pushed or pulled axially by motion of the leadscrew nut driven by the leadscrew, the magnetron is also capable of sliding transversally to the axis of the leadscrew;

rotatable cam shafts mounted within the housing, and a gear for controlling rotation of the cam shafts to control distance between the magnetron and the target surface for providing sputtering material, wherein the cam shafts contain cams pressing against magnetron lift base plate such that rotation of the cams forces the magnetron lift base plate to move transverse to a longitudinal axis of the cam shaft and the magnetron, sliding on slide shafts mounted to the magnetron lift base plate is also forced to move transverse along with the magnetron lift base plate to set the distance between the magnetron and the surface of the target.

23. The linear scanning magnetron sputtering apparatus of claim 22, further comprising a first driver pulley attached to the leadscrew, a motor having a shaft attached to a second driver pulley, and a timing belt, wherein a back and forth rotating motion of the motor shaft is transmitted to the leadscrew by the timing belt.

24. The linear scanning magnetron sputtering apparatus of claim 22, wherein the ends of the slide shafts are mounted to the magnetron lift base plate by being mounted to mounting supports mounted to the magnetron lift base plate, and the mounting supports are rotatable to cause the magnetron to travel rotated by an angle in the range of ±

45 degrees from perpendicular to the leadscrew longitudinal axis.

25. The linear scanning magnetron sputtering apparatus of claim 22, further comprising shims for controlling the parallelism of the magnetron with respect to the surface of the target, wherein ends of the cam are supported by cam shaft mounts, wherein the cam shaft mounts and shims are fastened to the magnetron housing.

26. The linear scanning magnetron sputtering apparatus of claim 22, wherein the gear for controlling rotation comprises a respective self-locking worm and worm gear set provided for each cam shaft.

27. A method of sputtering comprising:

providing a sputtering target assembly comprising;

a sputtering target and target backing plate assembly having opposed first and second sides, the first side providing material for sputtering,

a pressure relief plate having opposed first and second sides, the target and target backing plate assembly second side being in contact with the first side of the pressure relief plate;

heat exchange passages selected from at least one member of the group consisting of;

heat exchange passages defined between the opposed sides of the sputtering target and backing plate assembly,

heat exchange passages defined between the opposed sides of the pressure relief plate, and

beat exchange passages defined by heat exchange cavities formed in at least one member of the group consisting of the first side of the pressure relief plate and the second side of the target and target backing plate assembly, wherein the heat exchange passages are formed between the first side of the pressure relief plate and the second side of the target and target backing plate assembly which enclose the heat exchange cavities,

the heat exchange passages having one or more inlet and outlet openings;

an insulation cover unit having opposed first and second sides;

wherein the second side of the pressure relief plate is in contact with the first side of the insulation cover unit to form a vacuum pressure space therebetween and the vacuum pressure space has one or more vacuum ports,

sputtering material from the target first surface;

passing cooling medium through the heat exchange passages; and

maintaining a vacuum in the vacuum pressure space.

28. The method of claim 27, wherein the heat exchange passages are selected from at least one member of the group consisting of:

(a) heat exchange passages defined within the sputtering target and backing plate assembly,

(b) heat exchange passages defined by having heat exchange cavities formed in the first side of the pressure relief plate such that, when the first side of the pressure relief plate is contacted to the second side of the target and target backing plate assembly, the heat exchange passages are formed between the heat exchange cavities in the pressure relief plate and the target and target backing plate assembly enclosing those heat exchange cavities, and

(c) heat exchange passages defined by having heat exchange cavities formed in the second side of the target and target backing plate assembly such that, when the first side of the pressure relief plate is contacted to the second side of the target and target backing plate assembly, the heat exchange passages are formed between the heat exchange cavities in the target and target backing plate assembly and the pressure relief plate enclosing those heat exchange cavities.

29. The method of claim 27, wherein the vacuum pressure space is defined by vacuum passages in which a vacuum is maintained, and the vacuum passages have one or more vacuum ports, the vacuum passages selected from at least one member of the group consisting of:

(a) vacuum passages defined by having vacuum cavities formed in the second side of the pressure relief plate such that, when the first side of the insulation cover unit is contacted to the second side of the pressure relief plate, the vacuum passages are formed between the vacuum cavities in the pressure relief plate and the insulation cover unit enclosing those vacuum cavities, and

(b) vacuum passages defined by having vacuum cavities formed in the first side of the insulation cover unit such that, when the second side of the pressure relief plate is contacted to the first side of the insulation cover unit, the vacuum passages are formed between the vacuum cavities in the insulation cover unit and the pressure relief plate enclosing those vacuum cavities.

30. A sputtering apparatus configuration comprising:

a sputtering process chamber, a target assembly, and a magnetron housing and a magnetron drive mechanism;

the sputtering process chamber having a top flange, the flange having a shape and perimeter according to a predetermined form;

the target assembly sealed to and insulated from the flange;

wherein the target assembly comprises a sputtering target having opposed first and second sides, a target backing plate having opposed first and second sides, a heat exchanger/pressure relieving plate having opposed first and second sides, and an insulation cover unit having opposed first and second sides;

wherein the first side of a sputtering target is for being consumed by sputtering action in the sputtering process chamber;

wherein the second side of the sputtering target is in intimate contact to the first side of the target backing plate;

wherein a set of cooling cavities and fins are disposed in the first side of the heat exchanger/pressure relieving plate;

wherein the first side of the heat exchanger/pressure relieving plate is in intimate contact to the second side of the target backing plate;

wherein another set of cavities and fins are disposed in the second side of the heat exchanger/pressure relieving plate;

wherein the second side of the heat exchanger/pressure relieving plate is in intimate contact to the first side of the insulation cover unit to form a pressure relieving space.

31. A sputtering apparatus assembly comprising:

a sputtering process chamber, a target assembly, a magnetron, and a magnetron housing and a magnetron drive mechanism;

the sputtering process chamber comprising a top flange, the flange having a shape and perimeter according to a predetermined form;

the target assembly sealed to and insulated from the flange;

the magnetron generally enclosed by the magnetron housing, and movable or scanable over the target assembly by the magnetron drive mechanism;

wherein the target assembly comprises a sputtering target having first and second opposed sides, a target backing plate having first and second opposed sides, a heat exchanger/pressure relieving plate having first and second opposed sides, and an insulation cover unit having first and second opposed sides;

wherein the magnetron is movable or scanable in close proximity to the second side of insulation cover, on the target assembly, using the magnetron drive mechanism;

wherein the distance between the magnetron and the second side of insulation cover unit is adjustable throughout the useful life of the target without adversely affecting vacuum integrity in the sputtering process chamber.