CA1077437A

CA1077437A - Sputtering apparatus

Info

Publication number: CA1077437A
Application number: CA263,664A
Authority: CA
Inventors: Manfred R. Kuehnle
Original assignee: Coulter Systems Corp
Current assignee: Coulter Systems Corp
Priority date: 1975-12-17
Filing date: 1976-10-19
Publication date: 1980-05-13
Also published as: DK149926B; DK469976A; JPS5275669A; IL50722A; FR2335615B1; DD127637A5; JPS6035429B2; IL50722A0; BE847413A; FR2335615A1; IT1066543B; AU511961B2; LU76026A1; SE7611581L; DE2647149A1; AT344501B; SE429108B; MX145314A; ATA776076A; NL7611563A

Abstract

ABSTRACT

A sputtering machine which has a rotary anode that is insulated from its supporting structure and maintained at a voltage differing from that of the supporting structure.
The temperature of the surface of the anode is controlled through circulating heat exchange liquid.

Description

The field of the invention is sputtering and the apparatus which is used in sputtering techniques. Spe-cifically the invention is concerned with sputtering machines in which the anode is rotary and a flexible substrate is led over the anode and required to receive materials that are deposited thereon.
Apparatus which comprises the environment of the invention includes a pressure vessel having at least one -~
cathodic target mounted therein, a rotary anode mounted for rotation within the vessel, a supply of flexible substrate such as polyester film mounted in the vessel and a ta~e-up mechanism for coated substrate mounted also in the vessel. Suitable controls are provided for operating the apparatus. The substrate is arranged to be led over the anode and a sputtering plasma established in the vessel. The material from which the target is made is sputtered onto the anode, but since the substrate is carried on the surface of the anode, the material is coated onto the substrate.
Auxilliary apparatus, supply means and controls are provided for furnishing the ionizing gas and its mixed com-ponents and for monitoring and controlling the feed to the chamber; for furnishing electrical energy to the apparatus and monitoring and controlling the same and its effects~ for controlling and monitoring speed, ` ~

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temperature, thickness of deposit, and many other param-eters; ~or driving the substrate in its path and moni-toring and controlling its tension; etc.
It has been found that for the deposit of certain materials, particularly photoconductors upon thin, fle~-ible, transparent substrates, the conaitions of deposition include, among others, the following:
(a) The anode is requlred to rotate, (b) The power which is supplied is coupled to the cathode, anode and shielding in the vessel in an electrical circuit or network in which the cathode is at maximum negative voltage, the shielding is at ground potential and the anode :~ -is at a potential that is also negativla with respect to ground, but to a much lesser degree than the cathode, (c) The anode surface is required to be temperature controlled to prevent excessive loss of heat during sputtering, Certain other re~uirements of the apparatus render the achievement of the above conditions very difficult to effect and these include:
(d) Maintaining all of the supporting structure of the apparatus including the chamber walls, at ground potential for practicality and safety, (e) Maintaining the ends of the drum shielded to prevent excessive deposit thereon, (f) Moving the substrate-carrying portion or trans- ~ -port of the apparatus into and out of the chamber when the sputtering is completed.
The last-mentioned requirement is for the most part understood to be necessary in the case of a sputtering apparatus which is to produce quantities of sputtered substrate and which of necessity is large and cumbersome.
One proposed solution to such problem is to mount the substrate-carrying portion on the apparatus on a car- ~-riage along with much of the control and measuring equip-ment, and to fix the chamber and all of its auxilliary apparatus to a support which is stationary. ~n such case the targets are secured within the chamber and the high voltage connections are associated with the chamber, along with the controls and instrumentation therefor;
however, this arrangement does not take into considera-tion that the anode must be maintained at a voltage different from ground. - ~ccordingly, the invention provides a sputtering apparatus wherein a sputtering plasma condition is established and maintained between target means and a rotary anode mounted within a pressure chamber defined ~5 within an electrically earthed metal vessel and a clo-sure therefor, flexible strip substrate being transported . . ~

1(:)77437 over said rotary anode interior of the chamber through the sputtering condition, earthed shielding means surrounding at least the target means and leaving a sputtering opening facing the anode and a high voltage S source coupled to said anode and target means and means maintaining the anode at a voltage which differs from that at the shielding means and the target means.
Referring now to the accompanying drawings:
Figure 1 is a side elevational view of the sput-tering apparatus of the invention in a closed condition, certain of the connections to exterior apparatus being illustrated fragmentarily, indicating that such exte-rior apparatus is associated with the sputtering appa-ratus;
Figure 2 is a view similar to that of Figure 1 but in which the sputtering apparatus is in an open condi-tion;
Figure 3 is a diagrammatic view taken generally from the plane 3-3 of Figure 2 and looking in the direc-tion indicated to illustrate the path of movement of the substrate on the transport arrangement;
Figure 4 is a more or less diagrammatic perspec-tive view of the transport arrangement;
Figure 5 is a fragmentary sectional view taken gen-erally through the chamber of the apparatus along the line 5-5 of Figure 2 and in the indicated direction;

` 1077437 Figure 6 is a fragmentary perspective view of gen-erally the same portion of the chamber as illustrated in Figure 5;
Figure 7 is a detailed sectional view taken through the lower part of the drum anode of the apparatus of Figure 1 to illustrate the manner in which contact is made with the same;
Figure 8 is a block diagram illustrating the electrical circuitry of the sputtering apparatus of Figure l; and Figure 9 is a sectional view, more or less diagram-matic, of a modified apparatus.
Two desired practical embodiments of the invention herein are described. One is suitable for commercially sputtering coatings on relatively wide strips of poly-ester film. The other is suitable for low production or experimental wor~ and sputters coatings on narrow strips. The sizes of the two sputtering apparatuses are considerably different and the lengths of material capable of being coated without opening the apparatus also differ. In the one instance the strip is of the order of about 50 centimeters wide and in the other it is of the order of 10 centimeters wide~
The apparatus which shall be detailed initially is the larger of the two and the more complex, but operat-ing and constructed in accordance with principles common to those governing the construction and operation of the - smaller apparatus.
-6- ~-The sputtering apparatus illustrated in Figures 1 through 8 is designated generally by the reference char-acter 10 and comprises a stationary base or supporting framework 12 which includes tracks 14 along an upper edge thereof; a component cabinet 16 mounted on rollers or wheels 18 engaged on the tracks 14; a pressure vessel or chamber 20 supported from the framework 12 by fixed standards 22; and various other parts and structure to be described~ The cabinet 16 has a transport arrange-ment 24 mounted to its left hand end supported on a suitable cantilever subframe 26 which is secured to the forwardly facing wall 28 of the cabinet 16.
The wall 28 mounts a circular sealing seat 30 and the transport arrangement 24 and the subframe 26 therefor are dimensioned and arranged to be encompassed within the cylinder defined by a projection of the sealing seat 30. The pressure chamber or vessel 20 is closed on all sides but its right hand end where a flange 32 is pro-vided adapted to be sealingly engaged against the seat 30.
In Figure 1 the apparatus is shown in its closed condi-tion, the cabinet 16 having been rolled forward ~to the left) and thereby having inserted the transport arrange-ment 24 into the chamber or vessel 20, the joint repre-sented by the flange 32 and the sealing seat 30 being ren-dered hermetic by suitable gasket and locking arrangement, ~077437 In Figure 2 the apparatus is shown in its open condition, the cabinet 16 and the chamber or vessel 20 being sepa-rated, giving access to the transport arrangement 24 and any substrate which is carried thereon and to the inte-rior of the chamber 20, The tran~port arrangement 24 as illustrated does not show driving and controlling mechanisms which are con- -tained in the cabinet 16, these mechanisms for a great part being mounted on the rear of the wall 28. The exact nature thereof is subject to wide variation and such details are not germane to the invention although presumed to be re~uired for the operation of the appa-ratus. The cabinet also contains considerable apparatus and structure needed for the total operation of the lS apparatus, including speed controls, driving mechanism pumps and conduits for handling heat exchange liquid, a large number of measuring instruments for temperatures, pressures, currents, voltages, etc. The outer wall of the cabinet 16 is illustrated as having many push-buttons, meters, lights, and the like but only by way of representa-tion.
The chamber or vessel 20 is shown having gas connec-tions at 34 and 36, an electrical panel at 38, pipes and conduits at 40, electrical lines at 42, push-buttons, meters, etc. Viewing windows are shown at 44. All of these are also representative. The apparatus 10 reguires considerable control and monitoring well-known to those skilled in this art and the nature of measurement, opera-tion and control apparatus will vary with the requirements of the apparatus.
Basically, there are needs to operate a sputtering machine which must be furnished, controlled, measured and often recorded. There are phenomena which must be measured and observed. The parameters are manifold.
High frequency energy must be furnished to the targets, requiring matching and control circuits, conduits, and often cooling devices. In the latter respect, since the targets are in the chamber or vessel 20, the coolant for the targets must be provided in the chamber, and the coolant must be carried and circulated. The chamber has to be pumped down, requiring vacuum pumps with accompanying regulation, controls and measurement;
gases for ionization and background have to be intro-duced requiring regulation, control, measurement and proportioning.
It is assumed that those structures necessary for accomplishing the functions for a sputtering machine as described will be provided, hence there is no need to illustrate them in more detail and describe them further.
The cantilever subframe 26 is illustrated only in Figure 2 but should be understood to provide the support for the transport arrangement 24 although not illustrated 1~77437 in other figures. There is an outer plate 46 and posts 48 connected therewith and in turn connected to the wall 28 but within the confines of the seat 30. All of the rollers and the drum to be described are journalled for roation, either driven or idling, between the plate 4~ and the wall 28. - -In Figures 3 and 4 the transport arrangement 24 is illustrated, but without showing the journals and mount-ings and also without showing the drive, clutch and brake mechanisms which can be used therewith, all of the latter being contained within the cabinet 16 as explained. ~he substrate which is to be coated is designated 50 and is shown to be transparent. In the preferred use of the apparatus, the substrate 50 forms the base for an electro-photographic fllm which has inorganic coatings sputtered thereon. In such instance the substrate 50 is synthetic resin sheeting such as polyester of about .005 to .010 inch thick. Several hundred meters of this material can be readily mounted on a spool or reel and contained within the apparatus 10 while being sputtered along its entire length. Such a spool or reel is shown at 52 and comprises the supply within the apparatus. It is mounted on a shaft 54 which is preferably driven by a suitable drive motor but controlled by a tension clutch that receives feedback information from speed measurement and control apparatus, all of which is contained in the cabinet 16.

~077437 The substrate strip 50 passes over an idler roller 56 which guides the reach to the drum 58 which comprises the anode of the sputtering apparatus 10. Looking for the moment at Figure 8, it can be seen that the substrate 50 passes around the drum 58 which is also rotating, nor-mally idling, in close proximity to the targets 60 and 62 which are located in the bottom of the chamber or vessel 20 as will be described and then passes upward to another idler roller 64 from which it is led around a take-up roller 66 that is driven by suitable drive motors from the interior of the cabinet 16. Since the diameters of the rolls of substrate on the supply reel 52 and the take-up roller 66 vary inversel~ to one another during sputtering and it is essential that the speed of movement of the substrate 50 relative to the targets be uniform and carefully controlled and a suitable variable drive to effect this must be provided.
The targets 60 and 62 are shown in Figures 5, 6 and 8.
The chamber or vessel 20 is in the form of a cylindrical shell 68 with an end bell 70 that couples with the con-duit 36. All of the parts of the chamber or vessel 20 are formed of stainless steel and maintained at ground potential for safety. Fabrication of the vessel from this material is relatively simple compared to making it from glass or other insulatin~ materials. The tar-gets 60 and 62 are mounted in target assemblies 72 and 74 1~77437 respectively that comprise shields 76 of metal that are mechanically mounted to the bottom of the shell 68 by the brackets 78 and cooled by coolant circulated through the walls of the shields 76. The conduits for the cool-ant are passed through the shell 68 by way of housings 80 that also provide for passage of electrical coupling elements for connecting the targets to the power supply.
The positions of the targets relative to the drum 58 are adjustable as the targets are consumed. Adjustable structure whereby such adjustments can be effected may be contained in the housings 80 or can be effected by adjust-ments on the brackets 78.
Each target 62 is formed of a plurality of plates or plaques such as best shown in Figure 6 at 82 which are cemented on a suitable metal backing plate, usually stainless steel. The target plates 82 can have their surfaces facing the drum 58 flat planar or arcuately planar. They are arranged generally to define a cylin-drical surface that is coaxial with the drum 58 when the drum is in position adjacent the targets and the appa-ratus 10 is closed. Each target 60 and 62 is spaced from its shield 76 leaving a space framing itself.
Background gas is introduced into the hollow behind each target by way of the pipes 84 that pass through the wall of the shell 68 and emerge from the spaces around the targets to bathe the surfaces of the targets. `

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i~
Preferably, the target plaques are formed as sintered members of the material which is to be sputtered.
Between the target assemblies there is a standard 86 which mounts one or an assembly of brushes or wiper contacts at 88. These connect to a part of the power sup-ply electrical circuit by electrical lines passing through the shell 68 as will be explained. Preferably these con-tacts are mounted with resilient supports spring pressing them to the right as viewed in Figures 2 and 7. They must be insulated from the shell 68 as are the targets 60 and 62.
The details of construction of the drum 58 are being passed for the present to explain the operation of the circuit of the power supply that is used in the apparatus 10. Reference now is made to Figure 8 for an explanation of the circuit of the power supply. The construction of the drum 58 is better appreciated when one understand~
the power circuit.
In Figure 8, the power or energy supply for the apparatus 10 is shown in most basic diagrammatic form.
There is a high voltage power source shown at the left as the block 90~ The source 90 is coupled to the appa-ratus 10 by way of a matching network 92 that is shown having two lines at 94 and 96 for its output. The high~
est voltage, say of the order of 3000 volts at a fre-quency of 13.56 megahertz appears at the line 9~ and '' , .

is applied to the targets 60 and 62, appearing as a voltage to ground. The line 96 is at ground potential.
All of the shielding in the apparatus 10 (represented here only by the drum 58, shields 76 and the drum shields) is at ground potential, but the drum itself is not.
Thus, the output from the matching network 92 is applied ~ -to a voltage divider which comprises in this simple ex-ample two impedances Zl and Z2 connected across the lines 94 and 96. In the practical example these are capacitors and a part of the voltage divider can take into account ~-parasitic capacitance paths which could have some sig-nificance at this frequency. The lines can be high fre-quency plumbing, coaxial cable, shielded leads, etc.
The voltage is divided in accordance with the re-spective reactance of the two impedances Zl and Z2. ~he drum 58 is connected by way of a line 98 to the terminal 100 between the impedances Zl and z2. In order to enable the drum 58 to rotate, the contacts 88 previously de-scribed are provided to enable the drum to remain at a voltage which is not ground. The electronic effect in sputtering in apparatus 10 is that of a diode, such that there is an effective rectifying action. The cathodes are the targets 60 and 62 and these are maintained at a very high negative voltage, which for the example given is -3000 volts. This is below ground which assumes the maximum positive voltage for the system, being zero volts.

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iO77437 Conventionally, the anode is at ground potential and the substrate is laid upon it. Herein, only the shield-ing is at ground potential. The anode is the drum 58 and it is maintained at a voltage which is also below ground, but not to the same extent as the targets 60 and 62. In the practical example, the voltage of the drum was maintained at some value about 50 volts or less below ground, that is -50 volts. This was achieved by proper design of the voltage divider string Zl and z2 and other parts of the circuit. Those skilled in designing power supplies for r.f. energized sputtering apparatus will understand this type of circuit and the nature thereof~
The drum 58 is required to be rotary, it is required to be made out of metal so that it can be easily fabri-cated and will have the necessary strength to stand up to the requirements of the sputtering apparatus, it is required to be journalled using mechanically durable bear-ings, shafts and supports, and yet at least its outer skin is required to be at a voltage that differs from its sur-roundings. Another requirement for the drum is that its outer skin must be subjected to temperature control by means of heat exchange liquids. Thus, in the practical example of the invention, it was deemed necessary to heat the outer skin of the drum by means of oil to main-tain the same at a temperature of about 150 C.

1077~37 All of these requirements are achieved using the drum as shown in Figure 7. The body of the drum 58 is formed of an inner metal cylinder 102 with end flanges or rings 104 welded thereto. The metal end caps or discs 106 are secured to the-cylinder 102 by the circumferentially spaced screws 108. An outer coaxial metal cylinder llO
forms the circumferential skin of the drum 58 and it is welded to a telescopically arranged coaxial metal cylinder 112 of smaller diameter to form a chamber 114 between them. The cylinders 110 and 112 are connected by metal end rings 116 welded in place at each and the left hand metal end is exposed as shown.
The chamber 114 carries the heat exchange liquid 118 either in a bulk form which fills the entire chamber or by way of coils wrapped around the interior of the chamber (not shown), These are connected by way of suitable conduits such as shown at 120 to the hollow shaft 122 by way of which they are connected to a source of such liquid. Conduits are shown at 120'. Since the liquid will normally be oil or other insulating fluid there is no problem with providing an insulating coupling or couplings for the conduits 120 or 120' so that the skin 110 is electrically insulated from the remainder of the drum 58, the shaft 122, etc.
The rings 116 and the discs 106 are spaced radially apart to pro~ide an annular space at each end of the , ~077437 drum 58 as shown at 124. A cylinder 126 of polytetrafluoro ethylene or other stable insulating material is formed as for example by machining and is positioned between the cylinder 102 and the cylinder 112. It has its ends S machined to a lesser thickness than its body so'that the shoulders 128 and 130 are formed. The resulting axial ends 132 are made to have a thickness the same as the annular space 124 and the axial length of the cylinder 126 is made to be identical to the overall length of the drum 58 so that it is flush with the outer ends of the discs 106 and the rings 116. There is thus provided a compos-ite cylindrical member in which the outer skin 110 is insulated from the remainder of the drum 58. The drum is held in assembly by a plurality of screws 134 that engage through washers 136 of the same insulating mate- ' rial and are spaced circum~erentially around the ends ' of the drum. The washers 136 are,set into deep recesses 138 that are bored into the ends of the drum 58, each ~ -recess 138 having a portion thereof in each of a disc 106, a ring 116 and an axial end 132. In this way, in addition to the washers 136 and screws 134 clamping the parts together axially, the parts are locked against relative movement circumferentially.
The ring 116 on the left hand end of the drum 58 is ~ ' located in such a manner that when the apparatus 10 is in -, . . .
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closed condition, the contacts 88 will engage and wipe the same thereby establishing electrical contact there-with.
The ends of the drum 58 are shielded as shown at 140, 142, 144 to prevent material from being sputtered onto any other parts of the drum while the substrate 50 is passing around the bottom of the skin 110 and being coated thereat. The plasma representing the sputtering is indicated at 146. Such shielding is supported from the wall 28 and subframe 46 as for example by connecting brackets indicated at 147 in Figures 2, 3 and 4. It should be clear from Figure 7 that the shielding members 140, 142 and 144 close off the ends of the drum 58 except to allow passage of the substrate strip 50 and to provide an opening to admit contacts 88 to wipe the ring 116.
Also, these shielding members are at ground potential and nowhere touch the drum skin 110.
A modified form of the invention is illustrated in Figure 9 which is especially useful for small projects.
The sputtering apparatus 200 comprises a chamber 210 which has a cover member 212 adapted to be engaged onto the flange 214 of the chamber 210 and locked in place.
Sealing is provided by the gasket 216 engaged between . the flange 214 and the flange 218.
The cover member carries a supply reel 220 and a take-up reel 222 mounted on shafts 224 and 226 , il~77437 respectively. The shafts are driven by motors 228 and 230 respectively controlled from the exterior of the appa-ratus 200, The cover 212 mounts a coupling 232 from which the drum 236 is suspended. In this case the drum is metal and the entire drum is insulatea from the chamber 210 and the cover 212 by suitable insulation provided in the coupling 232. It is mounted on a shaft 238 which passes through the coupling 232 driven by the motor 240 mounted on the top of the cover 212. A sprocket chain and sprocket wheels such as 242 provides the coupling to the shaft 238 without short-circuiting the drum to ground.
Suitable insulation is provided for this. A ring 244 on the shaft 238 connects to the drum 236 electrically and is isolated from all other parts of the apparatus 200.
Electrical connection 246 with the contacts 248 corre-spond to the line 98 and the contacts 88 of Figure 8.
The drum is hollow and has a central hollow conduit 250 providing coaxial chambers 252 and 254 which connect with the pipe 256 that passes around the skin 258 o~ the drum 236 on the interior thereof. Heat exchange liquid enters and circulates by way of the chambérs 252 and 254.
At the top of the view one can see where suitable cou-plings are attached to enable rotation of the shaft 250 through the use of rotary fluid couplings. These need not be shown.

' The target 260 in this apparatus 200 is a simple disc of the photoconductive material mounted on a holder 262 which is connected by way of the member 264 through the wall of the chamber 210 to a source of high voltage radio fre~uency 266. There is no need to show the circuitry of Figure 8 since it is assumed to be used in connection with the apparatus 200.
Shielding at 268, 270 and 272 at ground potential is provided adjacent the drum 236, the drum mounting on the shaft 238 and the target 260. Sputtering plasma is pro-duced in the same manner as in the case of the apparatus 10 through the use of suitable high frequency energy and a suitable background gas admitted as for example by the conduit 274 in the gap 276 between the s~in 258 of the drum 236 and the face of the target 260.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A sputtering apparatus wherein a sputtering plasma condition is established and maintained between target means and a rotary anode mounted within a pres-sure chamber defined within an electrically grounded metal vessel and a closure therefor, flexible strip substrate being transported over said rotary anode interior of the chamber through the sputtering condi-tion, grounded shielding means surrounding at least the target means and leaving a sputtering opening facing the anode, a high voltage source coupled to said anode and target means and means maintaining the anode at a vol-tage which differs from that at the shielding means and the target means.

2. The apparatus as defined in claim 1 wherein the anode is maintained at a negative voltage which is a fraction of the voltage at the target means.

3. The apparatus as defined in claim 1 wherein the anode is maintained at a negative voltage which is a small fraction of the negative voltage at which the target means are maintained.

4. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode being formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metallically connected to the closure, contact means mounted in the closure and insulated therefrom and said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the vessel.

5. The apparatus as defined in any one of claims 1, 2 or 3 wherein the substrate is capable of traveling in engagement with the anode as the anode rotates.

6. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode being formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metallically connected to the closure, contact means mounted in the closure and insulated therefrom, said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the vessel, and said substrate being capable of traveling in engagement with the outer skin of the anode as the anode rotates.

7. The apparatus as defined in any one of claims 1, 2 or 3 wherein said anode is formed of at least three telescopically assembled cylinders including, an inner metallic cyclindrical drum providing the support for the anode and mounted on said closure, an outer metallic cylinder and an intervening cylinder of insulating material, all three cylinders being clamped together to form an integral assembly.

8. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode being formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metallically connected to the closure, contact means mounted in the closure and insulated therefrom, said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the vessel, and said substrate being capable of traveling in engagement with the outer skin of the anode as the anode rotates, said anode being formed of at least three telescopically assembled cylinders in-cluding, an inner metallic cyclindrical drum providing the support for the anode and mounted on said closure, an outer metallic cylinder and an intervening cylinder of insulating material, all three cylinders being clamped together to form an integral assembly.

9. The apparatus according to any one of claims 1, 2 or 3 and electrical circuit means including contact means mounted on the closure and effecting electrical engagement with said anode when the closure is seated, the anode having an electrically insulated metallic outer skin, said contact means including a spring-pressed member movable parallel to the axis of said anode, said outer skin having an axially facing ring and the ring being brought into engagement with said spring-pressed member when said closure is seated, whereby to supply a fractional negative voltage to the anode.

10. The apparatus according to any one of claims 1, 2 or 3 wherein the anode has an inner body and a metallic outer skin electrically insulated therefrom, a coaxially arranged contact ring carried by said anode electrically connected with said outer skin, and wiper contact means in sliding electrical contact with said ring at least when the closure is seated and connected to said energy source.

11. The apparatus according to any one of claims 1, 2 or 3 and electrical circuit means including contact means mounted on the closure and effecting electrical engagement with said anode when the closure is seated, the anode having an electrically insulated metallic outer skin, said contact means including a spring-pressed member movable parallel to the axis of said anode, said outer skin having an axially facing ring and the ring being brought into engagement with said spring-pressed member when said closure is seated, whereby to supply a fractional negative voltage to the anode, said contact means being located inside of the vessel, said ring being located at an axial end of the anode and the dimensions and location of said contact means relative to the ring being such that when the closure is fully seated, the ring and contact means are brought into electrical engagement.

12. The apparatus according to any one of claims 1, 2 or 3 wherein the anode has an inner body and a metallic outer skin electrically insulated therefrom, a coaxially arranged contact ring carried by said anode electrically connected with said outer skin, and wiper contact means in sliding electrical contact with said ring at least when the closure is seated and connected to said energy source, said contact means being located inside of the vessel, said ring being located at an axial end of the anode and the dimensions and location of said contact means relative to the ring being such that when the closure is fully seated, the ring and contact means are brought into electrical engagement.

13. The apparatus as defined in any one of claims 1, 2 or 3 wherein the anode is formed of an outer metallic skin and an inner body, the inner body of the anode being mounted on and grounded with said closure and there is a coaxial insulating space between the interior body and outer skin.

14. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metalli-cally connected to the closure, contact means mounted in the closure and insulated therefrom and said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the ves-sel, said contact means and said ring being disposed within the vessel when the closure is seated.

15. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metalli-cally connected to the closure, contact means mounted in the closure and insulated therefrom and said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the vessel, said contact means and ring being disposed on the exterior of the vessel and in electrical contact with one another also when the closure is not seated.

16. The apparatus as defined in any one of claims 1, 2 or 3 wherein the anode is formed of at least three telescopically assembled cylinders including, an inner metallic cylinder providing the support for the anode and mounted on the closure, an outer metallic cylinder defining an outer skin and an intervening cylinder of insulating material, all three cylinders being clamped together to form an integral assembly, the outer cylinder having a chamber formed therein for carrying heat-exchange liquid and means for conveying the heat-exchange liquid from the said chamber to the exterior of said apparatus through said closure.

17. The apparatus as defined in any one of claims 1, 2 or 3 wherein the mounting for said rotary anode in-cludes a hollow shaft that passes through the closure, a dispenser for passing heat-exchange liquid in proxim-ity to the outer part of the anode while same rotates, and means passing through the hollow shaft and connected with said dispenser to enable circulating of heat-exchange liquid from a source exterior of the chamber through the conduits and into heat-exchange relationship with said outer part to affect the substrate during sputtering.

18. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode being formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metallically connected to the closure, contact means mounted in the closure and insulated therefrom and said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the vessel and said shielding means include a mask for the axial end of the anode, there being open-ings provided in the shielding means for the anode to permit the substrate to be laid upon and leave the anode.

19. The apparatus as defined in any one of claims 1, 2 or 3 wherein there is an insulating coupling be-tween said anode and the closure to permit the anode to rotate while remaining electrically insulated from said closure.

20. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode being formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metallically connected to the closure, contact means mounted in the closure and insulated therefrom and said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the vessel there being an insulating coupling between said anode and closure to permit the anode to rotate while remaining insulated from the closure.

21. The apparatus as defined in any one of claims 1, 2 or 3 and in combination therewith, target means comprising, at least one target having an arcuate planar surface, a substantial portion of the area of said sur-face being exposed by said sputtering opening and spaced radially from the anode, the sputtering plasma condition being formed in the resulting gap, the cur-vature of said surface being generally coaxial with the said anode, and the arcuate planar surface is made up of a plurality of plaques of the material to be sputtered mounted on a metal backing.

22. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode being formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metallically connected to the closure, contact means mounted in the closure and insulated therefrom and said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the vessel and, in combination therewith, tar-get means comprising, at least one target having an arcuate planar surface, a substantial portion of the area of said surface being exposed by said sputtering opening and spaced radially from the anode, the sput-tering plasma condition being formed in the resulting gap, the curvature of said surface being generally coaxial with the said anode, and the arcuate planar surface is made up of a plurality of plaques of the material to be sputtered mounted on a metal backing.

23. The apparatus as defined in any one of claims 1, 2 or 3 and in combination therewith, target means comprising, at least one target having an arcuate planar surface, a substantial portion of the area of said sur-face being exposed by said sputtering opening and spaced radially from the anode, the sputtering plasma condition being formed in the resulting gap, the cur-vature of said surface being generally coaxial with the said anode, and the arcuate planar surface is made up of a plurality of planar plaques of the mate-rial to be sputtered mounted on a metal backing.

24. The apparatus as defined in any one of claims 1, 2 or 3 wherein the closure and vessel are maintained at the same potential as the shielding means, said anode being formed as a drum having a body and a metallic outer skin, said body being insulated from said outer skin and metallically connected to the closure, contact means mounted in the closure and insulated therefrom and said contact means effecting electrical engagement with the outer skin of the anode when the closure is seated closing the vessel and, in combination therewith, tar-get means comprising, at least one target having an arcuate planar surface, a substantial portion of the area of said surface being exposed by said sputtering opening and spaced radially from the anode, the sput-tering plasma condition being formed in the resulting gap, the curvature of said surface being generally coaxial with the said anode, and the arcuate planar surface is made up of a plurality of planar plaques of the material to be sputtered mounted on a metal backing.