WO2022011581A1

WO2022011581A1 - Plasma treatment with isolated cooling paths

Info

Publication number: WO2022011581A1
Application number: PCT/CN2020/102029
Authority: WO
Inventors: HuaYong HE; Milan SMART; John GUINN; Robert CONDRASHOFF; Chris WITMAN; Jack NEWLIN
Original assignee: Nordson Corporation
Priority date: 2020-07-15
Filing date: 2020-07-15
Publication date: 2022-01-20
Also published as: TW202217057A

Abstract

A plasma treatment system (100) has a chamber (200) defining a cavity (202) therein, and a plurality of electrodes (204) supported in the cavity (202). The plurality of electrodes (204) includes a first set of electrodes (204(1)) and a second set of electrodes (204(2)). The electrodes (204(1)) of the first set are alternatingly arranged with the electrodes (204(2)) of the second set. The system (100) has a cooling fluid system (300) that includes a first manifold (306(1)) that is in fluid communication with the electrodes (204(1)) of the first set so as to supply cooling fluid to the electrodes (204(1)) of the first set but not to the electrodes (204(2)) of the second set. The cooling fluid system (300) also has a second manifold (306(2)) that is in fluid communication with the electrodes (204(2)) of the second set so as to supply cooling fluid to the electrodes (204(2)) of the second set but not to the electrodes (204(1)) of the first set.

Description

PLASMA TREATMENT WITH ISOLATED COOLING PATHS

TECHNICAL FIELD

The present disclosure relates generally to plasma processing and, in particular, to plasma treatment systems and methods for treating substrates.

BACKGROUND

Plasma treatment is frequently used to modify the surface properties of substrates used in a diversity of applications including, but not limited to, integrated circuits, electronic packages, and printed circuit boards. In particular, plasma treatment may be used in electronics packaging, for example, to etch resin, to remove drill smear, to increase surface activation and/or surface cleanliness for eliminating delamination and bond failures, to improve wire bond strength, to ensure void free underfilling of chips attached to printed circuit boards, to remove oxides from surfaces, to enhance die attach, and to improve adhesion for chip encapsulation.

In a conventional plasma processing system, multiple substrates are placed inside a vacuum chamber, the vacuum chamber is evacuated and filled with a partial pressure of a source gas, a plasma consisting of a partially ionized source gas is generated inside the vacuum chamber, and a surface of each substrate is exposed to the plasma species. The outermost surface layer (s) of atoms are removed from each substrate by physical sputtering, chemically-assisted sputtering, and chemical reactions promoted by the plasma. The physical or chemical action may be used to condition the surface to improve properties such as adhesion, to selectively remove an extraneous surface layer, or to clean undesired contaminants from the substrate's surface.

In conventional plasma processing systems, a rack holds a plurality of panels such that each panel is in a vertical orientation and the panels are spaced from one another along a horizontal direction. The rack is inserted into a plasma treatment chamber having a plurality of vertical planar electrodes such that each panel is received between a pair of the vertical planar electrodes. The electrodes are energized with a suitable atmosphere present in the treatment chamber of the treatment system to generate the plasma. The environment between each planar vertical electrode and the adjacent surface of the panel supplies a local process chamber in which the partially ionized source gas is present.

Plasma processing may be used during the manufacture of semiconductor substrates. Process uniformity across the entire surface area of each substrate achieved by conventional processing systems, while adequate for their intended purpose, may be insufficient as technological advances are made.

SUMMARY

In an example, a plasma treatment system, comprises a plasma treatment chamber defining a cavity therein, and a plurality of electrodes supported in the cavity. The plurality of electrodes comprises a first set of electrodes and a second set of electrodes. The electrodes of the first set of electrodes are alternatingly arranged with the electrodes of the second set of electrodes. The plasma treatment system comprises a cooling fluid system having one or more first manifolds and one or more second manifolds. The one or more first manifolds are each in fluid communication with the electrodes of the first set. A manifold of the one or more first manifolds is configured to supply cooling fluid to the electrodes of the first set but not to the electrodes of the second set. The one or more second manifolds are each in fluid communication with the electrodes of the second set. A manifold of the one or more first manifolds is configured to supply cooling fluid to the electrodes of the second set but not to the electrodes of the first set.

Another example is a method of operating a plasma treating system that comprises a plasma treatment chamber defining a cavity therein, and first and second sets of electrodes disposed in the cavity, the electrodes of the first set being alternatingly arranged with the electrodes of the second set. The method comprises a step of supplying a cooling fluid to a manifold of one or more first manifolds of the plasma treatment system and to a manifold of one or more second manifolds of the plasma treatment system. The method comprises a step of supplying the cooling fluid from the manifold of the one or more first manifolds to the electrodes of the first set but not to the electrodes of the second set. The method comprises a step of supplying the cooling fluid from the manifold of the one or more second manifolds to the electrodes of the second set but not to the electrodes of the first set.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description of the illustrative examples may be better understood when read in conjunction with the appended drawings. It is understood that potential examples of the disclosed systems and methods are not limited to those depicted.

Fig. 1 shows a simplified schematic diagram of a plasma treatment system according to one example;

Fig. 2 shows a front perspective view of the plasma treatment system of Fig. 1 according to one example, having a chamber with a door of the chamber being removed;

Fig. 3 shows a rear perspective view of the plasma treatment system of Fig. 2;

Fig. 4 shows a cross-sectional view of an electrode of the plasma treatment system of Fig. 2;

Fig. 5 shows a perspective view of a top of the plasma treatment system of Fig. 2;

Fig. 6 shows an enlarged perspective view of a portion of the top of the plasma treatment system of Fig. 2;

Fig. 7 shows a top plan view of the plasma treatment system of Fig. 2;

Fig. 8 shows a side view of the plasma treatment system of Fig. 2 with a sidewall hidden to illustrate an interior of the chamber; and

Fig. 9 shows a bottom plan view of a source gas delivery system of the plasma treatment system of Fig. 2.

DETAILED DESCRIPTION

In plasma treatment systems, the electrodes are commonly divided into first and second sets, where an electrical charge applied to the electrodes of the first set is different from that of the electrodes of the second set. Further, plasma treatment systems commonly employ cooling fluid systems in which cooling fluid is flowed to the electrodes. However, the cooling fluid is often conductive and can form a conductive path between the electrodes of the first and second sets and ground that results in power loss, electrolysis of the cooling fluid, and corrosion in the cooling fluid path. To limit the effect of these issues, plasma treatment systems can be implemented such that the cooling fluid is provided to first and second sets of electrodes via separate cooling paths that are isolated from one another as will be discussed below.

Referring to Fig. 1, a simplified schematic of a plasma treatment system 100 is shown according to one example. The plasma treatment system 100 comprises a plasma treatment chamber 200 that defines a cavity 202 therein. The cavity 202 can be configured to support a plurality of electrodes 204 (shown in Fig. 2) therein that are used to treat workpieces as will be described below.

The plasma treatment system 100 comprises a cooling fluid system 300 that is configured to deliver a cooling fluid, such as water, to the electrodes 204 during plasma treatment operations. The cooling fluid system 300 can comprise at least one fluid conduit 304 that is configured to communicate fluid between a fluid source 302 and the electrodes 204. The fluid source 302 can be, for example, a tank, building water supply, or other suitable fluid source. In some examples, the cooling fluid system 300 can comprise the fluid source 302, although it will be understood that the fluid source 302 can be separate from, and connectable to, the plasma treatment system 100. In some examples, the cooling fluid system 300 can define a closed system in which the fluid source 302 is configured to reuse cooling fluid received from the electrodes 204 and return the cooling fluid back to the electrodes 204. In other examples, the cooling fluid system 300 can define an open loop in which the fluid source 302 is configured to supply fresh cooling fluid to the electrodes 204, and the fluid source 302 has a fluid sink configured to discard the cooling fluid returned from the electrodes 204.

The plasma treatment system 100 comprises a source gas delivery system 400 that is configured to deliver a source gas to the cavity 202 during plasma treatment operations. The source gas delivery system 400 can comprise gas conduits 404 that are configured to deliver the source gas from a gas source 402, such as a gas tank or other suitable gas source, to the cavity 202. In some examples, the source gas delivery system 400 can comprise the gas source 402, although it will be understood that the gas source 402 can be separate from, and connectable to, the plasma treatment system 100.

The plasma treatment system 100 comprises an electrical energy supply system 500 that is configured to supply electrical energy to the electrodes 204 in the cavity 202. The energy supply system 500 can comprise electrical conductors 504 that are configured to communicate energy from an energy source 502, such as a radio-frequency (RF) generator, to the electrodes 204. In some examples, the energy supply system 500 can comprise the energy source 502, although it will be understood that the energy source 502 can be separate from, and connectable to, the plasma treatment system 100.

The plasma treatment system 100 comprises a vacuum pumping system 600 that is configured to at least partially evacuate the atmosphere within the cavity 202 during plasma treatment operations. The vacuum pumping system 600 can comprise fittings and/or conduits 604 that are configured to place a pump 602 in fluid communication with the cavity 202. In some examples, the vacuum pumping system 600 can comprise the pump 602, although it will be understood that the pump 602 can be separate from, and connectable to, the plasma treatment system 100. The vacuum pumping system 600 can be configured to draw at least a partial vacuum within the cavity 202.

The plasma treatment system 100 comprises a controller 700 that is configured to control operations of one or more, up to all, of the cooling fluid system 300, the source gas delivery system 400, the energy supply system 500, and the vacuum pumping system 600 to perform plasma treatment operations. The controller can be a server, a personal computer, a laptop, a tablet, or any other suitable computing device.

It will be understood that the various systems and/or components described above can be distributed separately. Thus, the term “plasma treatment system” does not necessarily imply a complete system comprising all of the systems and/or components described above. In some examples, plasma treatment systems of this disclosure can comprise fewer than all of the systems and/or components described above, which can be later combined with the remaining components to form complete systems. For example, plasma treatment systems of the disclosure can comprise one or more of the cooling fluid system 300, the source gas delivery system 400, the electrical energy supply system 500, the vacuum pumping system 600, and the controller 700. Plasma treatment systems of the disclosure can also comprise portions of the systems described above.

Referring now more specifically to Figs. 2 and 3, the plasma treatment chamber 200 can comprise an upper end 200a and a lower end 200b that are opposite one another along a vertical direction V. The upper end 200a can define a ceiling of the plasma treatment chamber 200. The lower end 200b can define a floor of the plasma treatment chamber 200. The plasma treatment chamber 200 can include at least one sidewall 200c that extends between the upper end 200a and the lower 200b. For example, the at least one sidewall 200c can extend from the upper end 200a to the lower end 200b. The at least one sidewall 200c can define the cavity 202 between the upper end 200a and the lower end 200b. For example, the at least one sidewall 200c can extend at least partially around the cavity 202. The at least one sidewall 200c can comprise a first lateral sidewall 200d and a second lateral sidewall 200e that are spaced from one another along a lateral direction A, perpendicular to the vertical direction V. The at least one sidewall 200c can comprise a rear sidewall 200f. The plasma treatment chamber 200 can comprise a chamber door (not shown) that can be opened to provide access to the cavity 202 inside the plasma treatment chamber 200, and closed to provide a fluid-tight seal that isolates the cavity 202 from the surrounding ambient environment. The chamber door can be disposed at a front of the chamber 200 and can be spaced from the rear sidewall 200f along a longitudinal direction L, perpendicular to the lateral direction A and the vertical direction V. The chamber door can be positioned so as to provide access to the cavity 202 between the upper end 200a and the lower end 200b, such as through the at least one sidewall 200c. In Figs. 2 and 3, the chamber 200 has a cubic shape. However, it will be understood that the chamber 200 can have any other suitable shape. Further, it will be understood that the chamber door can alternatively be disposed at a location other than the front of the chamber 200.

The plasma treatment system 100 can comprise at least one electrode 204, such as a plurality of electrodes 204. The electrodes 204 can be spaced from one another so as to define air gaps therebetween. The air gaps can be sized so as to receive workpieces therebetween that are to be plasma treated. For example, a plurality of workpieces can be supported by a rack (not shown) , and the rack can be received within the cavity 202 of the chamber 200 such that individual ones of the workpieces are received between adjacent pairs of the electrodes 204. The workpieces can be product such as (without limitation) , integrated circuits, electronic packages, printed circuit boards, leadframes, or any other suitable product to be plasma treated.

Turning briefly to Fig. 4, a cross-section of an electrode 204 of the plasma treatment system 100 is shown according to one example. One or more, up to all, of the electrodes 204 of Fig. 2 can be implemented as shown in Fig. 4. The electrode 204 can be constructed from an electrically conductive material, such as a metal. The electrode 204 can have a substantially planar shape. For example, the electrode 204 can extend in a plane that extends in the longitudinal direction L and the vertical direction V. In alternative examples, the electrode 204 can be planar in a plane that extends along the lateral direction A and the vertical direction V, or in a plane that extends in the longitudinal direction L and lateral direction A. The electrode 204 can have first and

second faces

204c and 204d (labeled in Fig. 2) that are opposite from one another.

The electrode 204 can have an inlet 204a that is configured to receive the cooling fluid into the electrode 204 from the cooling fluid system 300. The electrode 204 can have an outlet 204b that is configured to discharge the cooling fluid from the electrode 204 to the cooling fluid system 300. The electrode 204 can define at least one fluid channel 204e disposed therein that is configured to carry cooling fluid from the inlet 204a to the outlet 204b. The at least one fluid channel 204e can disposed between the first and

second faces

204c and 204d of the electrode 204. The at least one fluid channel 204e can define a winding path through the electrode 204. The winding path can be configured in any suitable manner, such as in the manner shown. The winding path can be configured such that cooling fluid is distributed throughout a substantial portion of the electrode 204. The electrode 204 can define at least one opening 206, such as a plurality of openings 206, therethrough. Each opening 206 can permit the source gas to pass therethrough. Each opening 206 can extend through the electrode along a direction that extends through the plane defined by the electrode 204.

The plasma treatment system 100 can comprise a stem 208 for each electrode 204 that is configured to fluidly connect the inlet 204a of the electrode 204 to the cooling fluid system 300. Stem 208 may be referred to as an inlet stem. Similarly, the plasma treatment system 100 can comprise a stem 210 for each electrode 204 that is configured to fluidly connect the outlet 204b of the electrode 204 to the cooling fluid system 300. Stem 210 may be referred to as an outlet stem. Each

stem

208, 210 can have a length that is sized to extend from the electrode 204 through a wall of the chamber 200. In one example, each

stem

208, 210 can extend through the ceiling defined by the upper end 200a of the chamber 200, although each

stem

208, 210 could extend through another wall in alternative examples. Each

stem

208, 210 can be formed from a conductive material, such as a metal. Each

stem

208, 210 can be configured to be electrically coupled to the energy supply system 500, such as to the energy source 502, via at least one electrical conductor 504 (labeled in Fig. 1) . When electrically connected to the energy source 502, the stems 208 and 210 can be at the same electrical potential.

Referring back to Figs. 2 and 3, the plurality of electrodes 204 can comprise a first set of one or more electrodes 204 (1) and a second set of one or more electrodes 204 (2) . The electrodes of the first and second sets can be arranged in alternating fashion. Thus, the electrodes 204 can be arranged in the following order: electrode 204 (1) , electrode 204 (2) , electrode 204 (1) , electrode 204 (2) , and so on. Individual ones of the electrodes 204 (1) of the first set are disposed between a pair of adjacent electrodes 204 (2) of the second set. Similarly, individual ones of the electrodes 204 (2) of the second set are disposed between a pair of adjacent electrodes 204 (1) of the first set.

The plasma treatment system 100 is configured such that, during a plasma treatment operation, the energy supply system 500 applies an electrical charge to the electrodes 204 (1) of the first set that is different from an electrical charge of the electrodes 204 (2) of the second set. For example, the plasma treatment system 100 can apply electrical energy to the electrodes 204 (1) of the first set at a first power, and the electrodes 204 (2) of the second set can be grounded. Thus, the electrodes 204 (1) of the first set can be said to be powered electrodes and the electrodes 204 (2) of the second set can be said to be grounded electrodes. In another example, the plasma treatment system 100 can apply electrical energy to the electrodes 204 (1) of the first set at a first power, and electrical energy to the electrodes 204 (2) of the second set at a second power, different from the first power. Thus, the electrodes of the first and second sets can each be said to be powered electrodes.

Turning now to Figs. 5 to 7, as discussed above, the energy supply system 500 can comprise electrical conductors 504 that are configured to communicate energy from an energy source 502 to the electrodes 204. The electrical conductors 504 can comprise electrical conductors 506 that are electrically coupled to the

stems

208, 210 of the electrodes. The conductors 506 can comprise a first set of conductors 506 (1) and a second set of conductors 506 (2) . Each conductor 506 (1) of the first set can be configured to electrically and mechanically couple to the stems 208 (1) , 210 (1) of an electrode 204 (1) of the first set of electrodes. Similarly, each conductor 506 (2) of the second set can be configured to electrically and mechanically couple to the stems 208 (2) , 210 (2) of an electrode 204 (2) of the second set of electrodes.

Each conductor 506 can have a first end 506a and a second end 506b that are offset from one another. The first end 506a can be configured to electrically and mechanically couple to an inlet stem 208 of an electrode 204. In one example, the first end 506a can define an opening in the conductor 506 that is configured to receive the stem 208, although the first end 506a can be coupled to the stem 208 in any other suitable manner. The second end 506b can be configured to electrically and mechanically couple to an outlet stem 210 of the same electrode 204. In one example, the second end 506b can define an opening in the conductor 506 that is configured to receive the stem 210, although the second end 506b can be coupled to the stem 210 in any other suitable manner. Each conductor 506 can have a third end 506c that is configured to electrically couple the first and

second ends

506a and 506b to the energy source 502 (shown in Fig. 1) .

In one example, each conductor 506 can have a body that defines the first, second, and

third ends

506a, 506b, and 506c. The body can include a first arm 506d having the first end 506a and the second end 506b. The body can include a second arm 506e having the third end 506c. The second arm 506e can be coupled to the first arm 506d at a location between the first and

second ends

506a and 506b. The body have define a plate, although other shapes and configurations are contemplated than that shown.

The electrical conductors 504 of the energy supply system 500 can comprise at least one electric bus, such as first and second electric busses 508 (1) and 508 (2) . In one example, each electric bus 508 (1) , 508 (2) can be define an elongate bar, although other shapes are contemplated. The electric busses 508 (1) , 508 (2) can be elongate along a select direction, such as the lateral direction A, although other directions are contemplated. The electric busses 508 (1) , 508 (2) can be spaced from one another along a perpendicular direction that is perpendicular to the select direction. In some examples, the stems 208 (1) , 208 (2) , 210 (1) , 210 (2) can be between the first and second electric busses 508 (1) and 508 (2) .

The first electric bus 508 (1) can be electrically coupled to the electrical conductors 506 (1) of the first set of electrical conductors, and hence to the electrodes 204 (1) of the first set of electrodes. The second electric bus 508 (2) can be electrically coupled to the electrical conductors 506 (2) of the second set of electrical conductors, and hence to the electrodes 204 (2) of the second set of electrodes. The first electric bus 508 (1) can be configured apply an electrical charge to the electrodes 204 (1) of the first set via the electrical conductors 506 (1) of the first set that is different from an electrical charge applied by the second electrical bus 508 (2) to the electrodes 204 (2) of the second set via the electrical conductors 506 (2) of the second set. For example, electric bus 508 (1) can apply electrical energy to the electrodes 204 (1) of the first set at a first power, and the electric bus 508 (2) can be grounded. In another example, the electric bus 508 (1) can apply electrical energy to the electrodes 204 (1) of the first set at a first power, and the electric bus 508 (2) can apply electrical energy to the electrodes 204 (2) of the second set at a second power, different from the first power.

Referring now to Figs. 5 and 7, as discussed above, the cooling fluid system 300 comprises at least one fluid conduit 304 that is configured to communicate fluid between a fluid source 302 and the electrodes 204. The at least one fluid conduit 304 comprises one or more first manifolds 306 (1) , 308 (1) , each being in fluid communication with the electrodes 204 (1) of the first set. A manifold 306 (1) of the one or more first manifolds is configured to supply cooling fluid to the electrodes 204 (1) of the first set but not to the electrodes of the second set 204 (2) . A manifold 308 (1) of the one or more first manifolds can also be configured to receive the cooling fluid from the electrodes 204 (1) of the first set but not from the electrodes 204 (2) of the second set. Thus, it can be said that the one or more first manifolds are isolated from the second set of electrodes 204 (2) . In one example, the one or more first manifolds can comprise a first supply manifold 306 (1) and a first return manifold 308 (1) . The first supply manifold 306 (1) can be implemented as a first manifold block, and the first return manifold 308 (1) can be implemented as a second manifold block, separate from the first manifold block.

The first supply manifold 306 (1) can be configured to supply cooling fluid from the fluid source 302 to the electrodes 204 (1) of the first set. The at least one fluid conduit 304 can comprise a plurality of first fluid supply conduits 310 (1) , each in fluid communication with the first supply manifold 306 (1) and an input stem 208 (1) of a respective one of the electrodes 204 (1) of the first set of electrodes. Each first fluid supply conduit 310 (1) can be configured to carry fluid from the first supply manifold 306 (1) to the respective electrode 204 (1) of the first set. Each first fluid supply conduit 310 (1) can be, for example, a pipe or tube. Each first fluid supply conduit 310 (1) can be formed of a non-conductive, electrically isolating material.

The first return manifold 308 (1) can be configured to return cooling fluid from the electrodes 204 (1) of the first set to the fluid source 302. The at least one fluid conduit 304 can comprise a plurality of first fluid return conduits 312 (1) , each in fluid communication with the first return manifold 308 (1) and an outlet stem 210 (1) of a respective one of the electrodes 204 (1) of the first set of electrodes. Each first return conduit 312 (1) can be configured to carry fluid from a respective electrode 204 (1) of the first set to the first return manifold 308 (1) . Each first fluid return conduit 312 (1) can be, for example, a pipe or tube. Each first return conduit 312 (1) can be formed of a non-conductive, electrically isolating material.

The at least one fluid conduit 304 comprises one or more second manifolds 306 (2) , 308 (2) that are in fluid communication with the electrodes 204 (2) . A manifold 308 (2) of the second set is configured to supply cooling fluid to the electrodes 204 (2) of the second set but not to the electrodes of the first set 204 (1) . A manifold 308 (2) of the one or more second manifolds can also be configured to receive the cooling fluid from the electrodes 204 (2) of the second set but not from the electrodes 204 (1) of the second first. Thus, it can be said that the one second or more second manifold are isolated from the first set of electrodes 204 (1) . In one example, the one or more second manifold can comprise a second supply manifold 306 (2) and a second return manifold 308 (2) . The second supply manifold 306 (2) can be implemented as a first manifold block, and the second return manifold 308 (2) can be implemented as a second manifold block, separate from the first manifold block.

The second supply manifold 306 (2) can be configured to supply cooling fluid from the fluid source 302 to the electrodes 204 (2) of the second set. The at least one fluid conduit 304 can comprise a plurality of second fluid supply conduits 310 (2) , each in fluid communication with the second supply manifold 306 (2) and an input stem 208 (2) of a respective one of the electrodes 204 (2) of the second set of electrodes. Each second fluid supply conduit 310 (2) can be configured to carry fluid from the second supply manifold 306 (2) to the respective electrode 204 (2) of the second set. Each second fluid supply conduit 310 (2) can be, for example, a pipe or tube. Each second fluid supply conduit 310 (2) can be formed of a non-conductive, electrically isolating material.

The second return manifold 308 (2) can be configured to return cooling fluid from the electrodes 204 (2) of the second set to the fluid source 302. The at least one fluid conduit 304 can comprise a plurality of second fluid return conduits 312 (2) , each in fluid communication with the second return manifold 308 (2) and an outlet stem 210 (2) of a respective one of the electrodes 204 (2) of the second set of electrodes. Each second return conduit 312 (2) can be configured to carry fluid from a respective electrode 204 (2) of the second set to the second return manifold 308 (2) . Each second fluid return conduit 312 (2) can be, for example, a pipe or tube. Each second return conduit 312 (2) can be formed of a non-conductive, electrically isolating material. In some examples, each fluid path from the first supply manifold 306 (1) to the first return manifold 308 (1) can be substantially equal in length to each fluid path from the second supply manifold 306 (2) to the second return manifold 308 (2) .

Each fluid supply manifold 306 (1) , 306 (2) comprises a supply inlet 306a and a plurality of supply outlets 306b. The supply inlet 306a is in fluid communication with the fluid source 302. The supply outlets 306b are each connected to a respective fluid supply conduit 310 (1) or 310 (2) . Each fluid supply manifold 306 (1) , 306 (2) is configured to divide an inlet stream of fluid received from the fluid supply 302 at the supply inlet 306a into a plurality of outlet streams at the supply outlets 306b. Each fluid return manifold 308 (1) , 308 (2) comprises a plurality of return inlets 308a and a return outlet 308b. The return inlets 308a are each connected to a respective fluid return conduit 312 (1) or 312 (2) . The return outlet 308b is in fluid communication with the fluid source 302. Each fluid return manifold 308 (1) , 308 (2) is configured to combine a plurality of inlet streams of fluid received from the respective electrodes 204 (1) , 204 (2) at the return inlet 308a into an outlet stream at the return outlet 308b.

The manifolds 306 (1) , 306 (2) , 308 (1) , 308 (2) can be supported by the chamber 200. The manifolds 306 (1) , 306 (2) , 308 (1) , 308 (2) can be supported by outside of the cavity 202 of the chamber 200. In one example, the manifolds 306 (1) , 306 (2) , 308 (1) , 308 (2) can be supported by the upper end 200a of the chamber 200. However, in alternative examples, one or more, up to all, of the manifolds 306 (1) , 306 (2) , 308 (1) , 308 (2) can be supported by a wall other than the upper end 200a of the chamber 200. Each manifold 306 (1) , 306 (2) , 308 (1) , 308 (2) can extend along a select direction, such as the lateral direction A, although other directions are contemplated. For example, each manifold 306 (1) , 306 (2) , 308 (1) , 308 (2) can be elongate along the select direction. The manifolds 306 (1) , 306 (2) , 308 (1) , 308 (2) can be spaced from one another along a perpendicular direction, that is perpendicular to the select direction. The outlets of each manifold can be spaced from one another along the select direction. In some examples, the stems 208 (1) , 208 (2) , 210 (1) , and 210 (2) can be between (i) the first and second supply manifolds 308 (1) , 308 (2) and (ii) the first and second return manifolds 308 (1) , 308 (2) . Importantly, the first manifolds 306 (1) and 308 (1) can be electrical isolated from the second manifolds 306 (2) , 308 (2) . Further, one or more of the manifolds 306 (1) , 306 (2) , 308 (1) , 308 (2) can be electrically isolated from ground.

It will be understood that in alternative examples, the cooling fluid system 300 can comprise a single first manifold block (not shown) and a single second manifold block (not shown) . The single first manifold block can include both the first fluid supply manifold 306 (1) and first fluid return manifold 308 (1) . In other words, the first manifold block can have separate supply and return passages therein that are fluidly coupled to the first set of electrodes. Similarly, the single second manifold block can include both the second fluid supply manifold 306 (2) and second fluid return manifold 308 (2) . In other words, the second manifold block can have separate supply and return passages therein that are fluidly coupled to the second set of electrodes. In such alternative examples, the first and second manifold blocks can be electrically isolated from one another.

In operation, a method of operating the plasma treatment system 100 comprises a step of supplying a cooling fluid to a manifold 306 (1) of one or more first manifolds and a manifold 306 (2) of one or more second manifolds. The method comprises a step of supplying the cooling fluid from the manifold 306 (1) of the one or more first manifolds to the electrodes 204 (1) of the first set but not to the electrodes 204 (2) of the second set. The method comprises a step of supplying the cooling fluid from the manifold 306 (2) of the one or more second manifolds to the electrodes of the second set but not to the electrodes of the first set. The method can comprise a step of flowing the fluid through the electrodes 204 (1) and 204 (2) of the first and second sets. The method can comprise a step of supplying the cooling fluid from the electrodes 204 (1) of the first set to a manifold of the one or more first manifolds but not to a manifold of the one or more second manifolds. The method can comprise a step of supplying the cooling fluid from the electrodes 204 (2) of the second set to a manifold of the one or more second manifolds but not to the manifold of the one or more first manifolds.

Turning to Figs. 5, 8, and 9, as discussed above, the source gas delivery system 400 can comprise gas conduits 404 that are configured to deliver the source gas from a gas source 402 to the cavity 202 of the plasma treatment chamber 200. The gas conduits 404 comprise a gas main 406 and a plurality of gas supply branches 408 (1) , 408 (2) , 408 (3) , and 408 (4) that are in fluid communication with the gas main 406 so as to receive the source gas from the gas main 406. Each gas supply branch 408 (1) , 408 (2) , 408 (3) , and 408 (4) is configured to carry the source gas to the cavity 202 of the chamber 200. The source gas delivery system 400 defines, for each supply branch, a fluid path that extends from the gas main 406 to an end of the supply branch. The fluid paths of the supply branches can be equal in length so as to more uniformly distribute the source gas to the cavity 202 of the chamber 200. The plurality of supply branches can include two, three, four, five, six, or more supply branches. A higher number of branches can result in more uniform gas distribution within the cavity 202 than a lower number of branches. Distributing the source gas more uniformly throughout the cavity 202 can result in less variability in product treatment, a higher number of reactive species available for plasma processing, higher etch rates, and thus, higher throughput.

Each gas supply branch 408 (1) , 408 (2) , 408 (3) , and 408 (4) can comprise a gas manifold 410 (1) , 410 (2) , 410 (3) , 410 (4) that is configured to distribute the source gas within the cavity 202. Each gas manifold can be disposed in the cavity 202 of the chamber 200. In some examples, at least a portion of each gas supply branch 408 (1) , 408 (2) , 408 (3) , and 408 (4) can be routed outside of the cavity 202 and can pass through a wall of the chamber 200 to a respective one of the gas manifolds 410 (1) , 410 (2) , 410 (3) , 410 (4) . For example, each gas supply branch 408 (1) , 408 (2) , 408 (3) , and 408 (4) can comprise, for example, a pipe or tube disposed outside of the chamber 200 that is in fluid connection with a respective gas manifold 410 (1) , 410 (2) , 410 (3) , 410 (4) . Each gas manifold 410 (1) , 410 (2) , 410 (3) , 410 (4) can have a gas inlet 410a and a plurality of gas outlets 410b. Each gas manifold 410 (1) , 410 (2) , 410 (3) , 410 (4) can be configured to receive a stream of the source gas at its gas inlet 410a and divide the source gas into a plurality of streams that are discharged out its gas outlets 410b into the cavity 202.

Each gas manifold 410 (1) , 410 (2) , 410 (3) , 410 (4) can extend along a select direction, such as the lateral direction A, although other directions are contemplated. For example, each gas manifold can be elongate along the select direction. The gas manifolds 410 (1) , 410 (2) , 410 (3) , 410 (4) can be spaced from one another along a perpendicular direction, that is perpendicular to the select direction. In some examples, the stems 208 (1) , 208 (2) , 210 (1) , and 210 (2) can be between (i) the first and second gas manifolds 410 (1) , 410 (2) and (ii) the third and fourth gas manifolds 410 (3) , 410 (4) . Each gas manifold can have a first end 410c and a second end 410d that are spaced from one another along the select direction. The gas inlet 410a can be disposed between the first end 410c and the second end 410d, such as midway between the first and second ends 410c and 410d. The gas outlets 410b of each gas manifold can be spaced from one another along the select direction. Each gas manifold can have a length from its first end 410c to its second end 410d. The lengths of the gas manifolds can be equal to one another. It will be understood that, in alternative examples, each gas manifold can have another suitable shape and configuration than that shown.

In examples in which the gas conduits 404 comprise three or more gas supply branches 408 (1) , 408 (2) , 408 (3) , and 408 (4) , the gas conduits 404 can comprise a plurality of intermediate branches. For example, the system 100 can comprise a first intermediate branch 412 (1) that fluidly couples the gas main 406 to first and second supply branches 408 (1) and 408 (2) . The first and second gas supply branches 408 (1) and 408 (2) can be coupled to the first intermediate branch 412 (1) by a first fitting 414 (1) such as a tee-fitting or y-fitting. The first fitting 414 (1) can be midway between the first and second gas manifolds 410 (1) and 410 (2) . The first gas supply branch 408 (1) can define a fluid path from the first intermediate branch 412 (1) to the gas inlet 410a of the first gas manifold 410 (1) that has a first length. The second gas supply branch 408 (2) can define a fluid path from the first intermediate branch 412 (1) to the gas inlet 410a of the second gas manifold 410 (2) that has a second length. The first and second lengths can be equal to one another.

The system 100 can comprise a second intermediate branch 412 (2) that fluidly couples the gas main 406 to third and fourth gas supply branches 408 (3) and 408 (4) . The third and fourth gas supply branches 408 (3) and 408 (4) can be coupled to the second intermediate branch 412 (2) by a second fitting 414 (2) such as a tee-fitting or y-fitting. The second fitting 414 (2) can be midway between the third and fourth gas manifolds 410 (3) and 410 (4) . The first and second intermediate branches 412 (1) and 412 (2) can be coupled to the gas main 406 by a third fitting 416 such as a tee-fitting or y-fitting. The third fitting 416 can be midway between the first and second fittings 414 (1) and 414 (2) . The second intermediate branch 412 (2) can define a fluid path that has a length that is equal to a length of a fluid path defined by the first intermediate branch 412 (1) . The third gas supply branch 408 (3) can define a fluid path from the second intermediate branch 412 (2) to the gas inlet 410a of the third gas manifold 410 (3) that has a third length. The fourth gas supply branch 408 (4) can have define a fluid path from the second intermediate branch 412 (2) to the gas inlet 410a of the fourth gas manifold 410 (4) that has a fourth length. The third and fourth lengths can be equal to one another and can be equal to the first and second lengths.

In operation, a method of operating the plasma treatment system 100 comprises a step of supplying a source gas to a first gas manifold 410 (1) along a first fluid path that has a first length. The method comprises a step of supplying the source gas from the first gas manifold 410 (1) to the cavity 202 of the plasma treatment chamber 200. The method comprises a step of supplying the source gas to a second gas manifold 410 (2) along a second fluid path that has a second length, equal to the first length. The method comprises a step of supplying the source gas from the second gas manifold 410 (2) to the cavity 202 of the plasma treatment chamber 200.

In some examples, the method can further comprise a step of supplying the source gas to a third gas manifold 410 (3) along a third fluid path that has a third length, equal to the first and second lengths, and a step of supplying the source gas from the third gas manifold 410 (3) to the cavity 202 of the plasma treatment chamber 200. In some examples, the method can yet further comprise a step of supplying the source gas to a fourth gas manifold 410 (4) along a fourth fluid path that has a fourth length, equal to the first, second, and third lengths, and a step of supplying the source gas from the fourth gas manifold 410 (4) to the cavity 202 of the plasma treatment chamber 200.

It should be noted that the illustrations and descriptions of the examples shown in the figures are for exemplary purposes only, and should not be construed limiting the disclosure. One skilled in the art will appreciate that the present disclosure contemplates various examples. Additionally, it should be understood that the concepts described above with the above-described examples may be employed alone or in combination with any of the other examples described above. It should further be appreciated that the various alternative examples described above with respect to one illustrated example can apply to all examples as described herein, unless otherwise indicated.

Conditional language used herein, such as, among others, "can, " "could, " "might, " "may, " “e.g., ” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more examples or that one or more examples necessarily include these features, elements and/or steps. The terms “comprising, ” “including, ” “having, ” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth.

While certain examples have been described, these examples have been presented by way of example only and are not intended to limit the scope of the inventions disclosed herein. Thus, nothing in the foregoing description is intended to imply that any particular feature, characteristic, step, module, or block is necessary or indispensable. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions disclosed herein. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of certain of the inventions disclosed herein.

It should be understood that the steps of the exemplary methods set forth herein are not necessarily required to be performed in the order described, and the order of the steps of such methods should be understood to be merely exemplary. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments of the present invention.

Although the elements in the following method claims, if any, are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.

It will be understood that reference herein to “a” or “one” to describe a feature such as a component or step does not foreclose additional features or multiples of the feature. For instance, reference to a device having or defining “one” of a feature does not preclude the device from having or defining more than one of the feature, as long as the device has or defines at least one of the feature. Similarly, reference herein to “one of” a plurality of features does not foreclose the invention from including two or more, up to all, of the features. For instance, reference to a device having or defining “one of a X and Y” does not foreclose the device from having both the X and Y.

Claims

A plasma treatment system, comprising:

a plasma treatment chamber defining a cavity therein;

a plurality of electrodes supported in the cavity, the plurality of electrodes comprising a first set of electrodes and a second set of electrodes, the electrodes of the first set being alternatingly arranged with the electrodes of the second set; and

a cooling fluid system comprising:

one or more first manifolds, each being in fluid communication with the electrodes of the first set, wherein a manifold of the one or more first manifolds is configured to supply cooling fluid to the electrodes of the first set but not to the electrodes of the second set; and

one or more second manifolds, each being in fluid communication with the electrodes of the second set, wherein a manifold of the one or more first manifolds is configured to supply cooling fluid to the electrodes of the second set but not to the electrodes of the first set.
The plasma treatment system of claim 1, wherein:

a manifold of the one or more first manifolds is configured to receive the cooling fluid from the electrodes of the first set but not from the electrodes of the second set; and

a manifold the one or more second manifolds is configured to receive the cooling fluid from the electrodes of the second set but not from the electrodes of the first set.
The plasma treatment system of claim 2, wherein the one or more first manifolds comprises:

a first supply manifold that is configured to supply cooling fluid to the electrodes of the first set but not to the electrodes of the second set; and

a first return manifold that is configured to receive the cooling fluid from the electrodes of the first set but not from the electrodes of the second set.
The plasma treatment system of claim 3, wherein the one second or more second manifolds comprises:

a second supply manifold that is configured to supply cooling fluid to the electrodes of the second set but not to the electrodes of the first set; and

a second return manifold that is configured to receive the cooling fluid from the electrodes of the second set but not from the electrodes of the first set.
The plasma treatment system of claim 1, wherein the one or more first manifold and the one or more second manifold are electrically isolated from ground.
The plasma treatment system of claim 1, wherein each electrode of the first and second sets has an inlet stem and an outlet stem that extends through a wall of the plasma treatment chamber, the inlet stem configured to receive cooling fluid into the electrode and the outlet stem configured to output cooling fluid from the electrode.
The plasma treatment system of claim 6, comprising:

a plurality of first fluid supply conduits, each in fluid communication with a manifold of the one or more first manifold and the input stem of a respective one of the electrodes of the first set of electrodes; and

a plurality of second fluid supply conduits, each in fluid communication with a manifold of the one or more second manifold and the input stem of a respective one of the electrodes of the second set of electrodes.
The plasma treatment system of claim 7, wherein, each first fluid supply conduit and each second fluid supply conduit is formed from an electrically isolating material.
The plasma treatment system of claim 6, comprising:

a plurality of first fluid return conduits, each in fluid communication with a manifold of the one or more first manifold and the output stem of a respective one of the electrodes of the first set of electrodes; and

a plurality of second fluid return conduits, each in fluid communication with a manifold of the one or more second manifold and the output stem of a respective one of the electrodes of the second set of electrodes.
The plasma treatment system of claim 1, wherein the plasma treatment system comprises an energy supply system that is configured to apply an electrical charge to the electrodes of the first set that is different from that of the electrodes of the second set.
The plasma treatment system of claim 1, comprising:

a first electric bus that is electrically coupled to the electrodes of the first set but not to the electrodes of the second set; and

a second electric bus that is electrically coupled to the electrodes of the second set but not to the electrodes of the first set.
The plasma treatment system of claim 1, wherein:

each electrode of the first and second sets comprises an input stem that is configured to receive cooling fluid from a fluid source, and an outlet stem that is configured to return cooling fluid to the fluid source; and

the plasma treatment system comprises:

a first electric bus that is electrically coupled to input and output stems of the electrodes of the first set; and

a second electric bus that is electrically coupled to the input and output stems of the electrodes of the second set.
The plasma treatment system of claim 1, comprising a source gas delivery system that is configured to deliver a source gas to the cavity, the source gas delivery system comprising:

a gas main; and

a plurality of gas supply branches that are configured to receive the source gas from the gas main and deliver the source gas to the cavity, wherein the source gas delivery system defines, for each gas supply branch, a fluid path that extends from the gas main to the cavity, the fluid paths being equal in length.
The plasma treatment system of claim 13, wherein each gas supply branch comprises a gas manifold disposed within the cavity, each gas manifold defining a plurality of gas outlets configured to distribute the source gas to the cavity of the plasma treatment chamber.
The plasma treatment system of claim 13, wherein the plurality of gas supply branches comprise more than two gas supply branches.
The plasma treatment system of claim 13, wherein the source gas delivery system comprises a first intermediate branch that fluidly connects first and second gas supply branches of the plurality of gas supply branches to the gas main, and a second intermediate branch that fluidly connects third and fourth gas supply branches of the plurality of gas supply branches to the gas main, the first and second intermediate branches being equal in length.
A method of operating a plasma treatment system that comprises a plasma treatment chamber defining a cavity therein, and first and second sets of electrodes disposed in the cavity, the electrodes of the first set being alternatingly arranged with the electrodes of the second set, the method comprising:

supplying a cooling fluid to a manifold of one or more first manifolds of the plasma treatment system and to a manifold of one or more second manifolds of the plasma treatment system;

supplying the cooling fluid from the manifold of the one or more first manifolds to the electrodes of the first set but not to the electrodes of the second set; and

supplying the cooling fluid from the manifold of the one or more second manifolds to the electrodes of the second set but not to the electrodes of the first set.
The method of claim 17, comprising:

discharging the cooling fluid from the electrodes of the first set to a manifold of the one or more first manifolds but not to a manifold of the one or more second manifolds; and

discharging the cooling fluid from the electrodes of the second set to a manifold of the one or more second manifolds but not to a manifold of the one or more first manifolds.
The method of claim 17, comprising applying an electrical charge to the electrodes of the first set that is different from that of the electrodes of the second set.
The method of claim 17, comprising:

supplying a source gas from a gas main to a plurality of gas supply branches, each gas supply branch defining a fluid path that extends from the gas main into the cavity of the plasma treatment chamber, wherein the fluid paths are equal in length; and

distributing the source gas from a plurality of gas manifolds to the cavity of the plasma treatment chamber, each gas manifold corresponding to one of the gas supply branches.