WO1997042648A1 - Bobinage a evidement servant a generer un plasma - Google Patents

Bobinage a evidement servant a generer un plasma Download PDF

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Publication number
WO1997042648A1
WO1997042648A1 PCT/US1997/008008 US9708008W WO9742648A1 WO 1997042648 A1 WO1997042648 A1 WO 1997042648A1 US 9708008 W US9708008 W US 9708008W WO 9742648 A1 WO9742648 A1 WO 9742648A1
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WO
WIPO (PCT)
Prior art keywords
wall
standoff
ofthe
cover member
coil
Prior art date
Application number
PCT/US1997/008008
Other languages
English (en)
Inventor
Anantha Subramani
John Forster
Bradley O. Stimson
Sergio Edelstein
Howard Grunes
Avi Tepman
Zheng Xu
Original Assignee
Applied Materials, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Applied Materials, Inc. filed Critical Applied Materials, Inc.
Priority to JP54025297A priority Critical patent/JP3175835B2/ja
Priority to EP97925528A priority patent/EP0845151A1/fr
Publication of WO1997042648A1 publication Critical patent/WO1997042648A1/fr

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32082—Radio frequency generated discharge
    • H01J37/321—Radio frequency generated discharge the radio frequency energy being inductively coupled to the plasma
    • H01J37/3211—Antennas, e.g. particular shapes of coils
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32458—Vessel
    • H01J37/32477—Vessel characterised by the means for protecting vessels or internal parts, e.g. coatings
    • H01J37/32504—Means for preventing sputtering of the vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32082—Radio frequency generated discharge
    • H01J37/321—Radio frequency generated discharge the radio frequency energy being inductively coupled to the plasma
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32623—Mechanical discharge control means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32623—Mechanical discharge control means
    • H01J37/32651—Shields, e.g. dark space shields, Faraday shields
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32082—Radio frequency generated discharge
    • H01J37/32137—Radio frequency generated discharge controlling of the discharge by modulation of energy

Definitions

  • the present invention relates to plasma generators, and more particularly, to a method and apparatus for generating a plasma in the fabrication of semiconductor devices.
  • Radio frequency (RF) generated plasmas have become convenient sources of energetic ions and activated atoms which can be employed in a variety of semiconductor device fabrication processes including surface treatments, depositions, and etching processes.
  • RF radio frequency
  • Sputtered material has a tendency to travel in straight line paths from the target to the substrate being deposited at angles which are oblique to the surface ofthe substrate.
  • materials deposited in etched trenches and holes of semiconductor devices having trenches or holes with a high depth to width aspect ratio can bridge over causing undesirable cavities in the deposition layer.
  • the sputtered material can be "collimated" into substantially vertical paths between the target and the substrate by negatively charging the substrate or substrate support and positioning appropriate vertically oriented collimating electric fields adjacent the substrate if the sputtered material is sufficiently ionized by the plasma.
  • material sputtered by a low density plasma often has an ionization degree of less than 1% which is usually insufficient to avoid the formation of an excessive number of cavities. Accordingly, it is desirable to increase the density of the plasma to increase the ionization rate ofthe sputtered material in order to decrease the formation degree of unwanted cavities in the deposition layer.
  • the term "dense plasma” is intended to refer to one that has a high electron and ion density.
  • sputtering chambers have a generally annular-shaped shield enclosing the plasma generation area between the target and the pedestal supporting the wafer.
  • the shield provides a smooth gently curved surface which is relatively easy to clean and protects the interior ofthe chamber from being deposited with the sputtering material.
  • a coil and any supporting structure for the coil would of necessity tend to have relatively sha ⁇ ly curved surfaces which would be more difficult to clean away deposited materials from the coil and its supporting structures.
  • the smooth gently curved surface ofthe shield would tend to shed fewer particles than the sharply curved surfaces ofthe coil and its supporting structure.
  • a plasma generating apparatus which inductively couples electromagnetic energy from a coil which is recessed with respect to the sputtering surface of a target so as to minimize the deposition of target material onto the coil.
  • the coil is recessed with respect to the perimeter ofthe pedestal (support member) and the deposition surface ofthe workpiece supported on the pedestal such that any target material deposited upon, and subsequently shed by, the coil onto the workpiece is minimized. As a consequence, contamination ofthe workpiece by particulate matter shed by the coil is reduced.
  • the coil is partially shielded from deposition material by a dark space shield which is positioned above the coil to prevent a substantial portion of the target material from being deposited onto the coil.
  • the coil is carried by a separate adapter ring which has a coil chamber to protect the coil from deposition material.
  • the coil chamber has a floor positioned below the coil to catch particulate matter shed by the coil to reduce contamination of the workpiece.
  • the adapter ring coil chamber is separate from the shield. As a consequence, the shield may be separately cleaned or discarded thereby substantially facilitating the cleaning ofthe shield and chamber and reducing the cost of the shield itself.
  • the coil is carried on the shield or in the adapter ring chamber by a plurality of novel coil standoffs and RF feedthrough standoffs which have an internal labyrinth structure.
  • the labyrinth structure permits repeated depositions of conductive materials from the target onto the coil standoffs while preventing the formation of a complete conducting path of deposited material from the coil to the shield which could short the coil to the shield which is typically at ground.
  • the labyrinth structure permits the standoff to have a low height which can reduce the overall size ofthe chamber.
  • Fig. 1 is a perspective, partial cross-sectional view of a plasma generating chamber in accordance with one embodiment ofthe present invention.
  • Fig. 2 is a partial cross-sectional view ofthe plasma generating chamber of Fig. 1 shown installed in a vacuum chamber.
  • Fig. 3 is a partial cross-sectional view of a plasma generating chamber in accordance with another embodiment ofthe present invention.
  • Fig. 4 is a cross-sectional view of a coil standoff of the plasma generating chamber of Fig. 2.
  • Fig. 5 is a cross-sectional view of a coil feedthrough standoff of the plasma generating chamber of Fig. 2.
  • Fig. 6 is a schematic diagram ofthe electrical interconnections to the plasma generating chamber of Fig. 1.
  • Fig. 7 is a cross-sectional view of a coil standoff in accordance with an alternative embodiment.
  • Fig. 8 is a cross-sectional view of a coil feedthrough standoff in accordance with an alternative embodiment.
  • a plasma generator in accordance with a first embodiment ofthe present invention comprises a substantially cylindrical plasma chamber 100 which is maintainable at vacuum and in this embodiment has a single helical coil 104 which is carried internally ofthe chamber walls 108 by a shield 106.
  • the shield 106 protects the interior walls 108 (Fig. 2) ofthe vacuum chamber 102 from the material being deposited within the interior ofthe plasma chamber 100.
  • Radio frequency (RF) energy from an RF generator is radiated from the coil
  • the coil 104 is recessed with respect to the perimeter ofthe target 1 10 so as to minimize the deposition of target material onto the coil 104.
  • the coil 104 is recessed with respect to the perimeter ofthe chuck or pedestal 1 14 and the workpiece 112 supported on the pedestal such that any target material subsequently shed by the coil 104 onto the workpiece 112 is minimized. As a consequence, contamination of the workpiece 112 by particulate matter shed by the coil 104 is reduced.
  • the coil 104 is carried on the shield 106 by a plurality of novel coil standoffs 120 which electrically insulate the coil 104 from the supporting shield 106.
  • the insulating coil support standoffs 120 have an internal labyrinth structure which permits repeated deposition of conductive materials from the target 110 onto the coil standoffs 120 while preventing the formation of a complete conducting path of deposited material from the coil 104 to the shield 106 which could short the coil 104 to the shield 106 (which is typically at ground).
  • RF power must be passed through the chamber walls and through the shield 106 to opposite ends ofthe coil 104.
  • Vacuum feedthroughs (not shown) extend through the chamber wall to provide RF current from a generator preferably located outside the chamber.
  • Feedthroughs 124, 124a which pass RF current through the shield 106 need not be vacuum feedthroughs, as both sides of shield 106 should be at the same pressure. However, they do need to be protected from the chamber environment, so as to prevent formation of a deposition layer thereon which would create an electrical path from the coil 104 to the shield 106.
  • RF power is applied to the coil 104 by feedthroughs 122 which are supported by insulating feedthrough standoffs 124.
  • Fig. 2 shows the plasma chamber 100 installed in the vacuum chamber 102 of a PVD (physical vapor deposition) system.
  • PVD physical vapor deposition
  • the plasma generator ofthe present invention is described in connection with a PVD system for illustration purposes, it should be appreciated that a plasma generator in accordance with the present invention is suitable for use with all other semiconductor fabrication processes utilizing a plasma including plasma etch, chemical vapor deposition (CVD) and various surface treatment processes.
  • the plasma chamber 100 has a dark space shield ring
  • the dark space shield 130 which provides a ground plane with respect to the target 110 above which is negatively biased.
  • the shield ring 130 shields the outer edges ofthe target from the plasma to reduce sputtering ofthe target outer edges.
  • the dark space shield 130 performs yet another function in that it is positioned to shield the coil 104 (and the coil support standoffs 120 and feedthrough standoffs 124) from the material being sputtered from the target 110.
  • the dark space shield 130 does not completely shield the coil 104 and its associated supporting structure from all ofthe material being sputtered since some of the sputtered material travels at an oblique angle with respect to the vertical axis of the plasma chamber 100.
  • the dark space shield 130 which is positioned in an overlapping fashion above the coil 104, prevents a substantial amount of sputtered material from being deposited on the coil 104.
  • the generation of particles by the material which is deposited on the coil 104 (and its supporting structures) can be substantially reduced.
  • the lifetimes of these structures may be increased as well.
  • the dark space shield 130 is a closed continuous ring of titanium or stainless steel having a generally inverted frusto-conical shape. It is recognized, of course, that the dark space shield may be made from a variety of other conductive materials and have other shapes which shield the coil 104 and its associated supporting structures from at least some ofthe material being deposited from the target. In the illustrated embodiment, the dark space shield extends inward toward the center of plasma chamber 100 so as to overlap the coil 104 by a distance d of 1/4 inch. It is recognized, of course, that the amount of overlap can be varied depending upon the relative size and placement ofthe coil and other factors. For example, the overlap may be increased to increase the shielding ofthe coil 104 from the sputtered material but increasing the overlap could also further shield the target from the plasma which may undesirable in some applications.
  • the chamber shield 106 is generally bowl-shaped and includes a generally cylindrically shaped, vertically oriented wall 140 to which the standoffs 120 and 124 are attached to insulatively support the coil 104.
  • the shield further has a generally annular-shaped floor wall 142 which surrounds the chuck or pedestal 1 14 which supports the workpiece 112.
  • a clamp ring 154 clamps the wafer to the chuck 114 and covers the gap between the floor wall 142 ofthe shield 106 and the chuck 114.
  • the chamber shield 106 together with the clamp ring 154 protects the interior ofthe vacuum chamber 102 from the deposition materials being deposited on the workpiece 112 in the plasma chamber 100.
  • the vacuum chamber wall 108 has an upper annular flange 150.
  • the plasma chamber 100 is supported by an adapter ring assembly 152 which engages the vacuum chamber wall flange 150.
  • the chamber shield 106 has a horizontally extending outer flange member 160 which is fastened by a plurality of fastener screws (not shown) to a horizontally extending flange member 162 ofthe adapter ring assembly 152.
  • the chamber shield 106 is grounded to the system ground through the adapter ring assembly 152.
  • the dark space shield 130 also has an upper flange 170 which is fastened to the horizontal flange 162 ofthe adapter ring assembly 152.
  • the dark space shield 130 like the chamber shield 106, is grounded through the adapter ring assembly 152.
  • the target 1 10 is generally disk-shaped and is also supported by the adapter ring assembly 152.
  • the target 110 is negatively biased and therefore should be insulated from the adapter ring assembly 152 which is at ground.
  • a ceramic insulation ring assembly 172 which is also seated in a corresponding channel 174 in the upper side ofthe target 152.
  • the insulator ring assembly 174 which may be made of a variety of insulative materials including ceramics spaces the target 110 from the adapter ring assembly 152 so that the target 110 may be adequately negatively biased.
  • the target, adapter and ceramic ring assembly are provided with O-ring sealing surfaces (not shown) to provide a vacuum tight assembly from the vacuum chamber flange 150 to the target 110.
  • Fig. 3 shows a recessed coil in accordance with an alternative embodiment of the present invention in which the generation of particulate matter by the coil is reduced by a different structure to reduce contamination ofthe workpiece.
  • an adapter ring assembly 200 has been modified to form a recessed coil chamber 202 which encloses a helical coil 206 on three sides but exposes the coil 206 to the plasma at an open fourth side ofthe recessed coil chamber 202.
  • the recessed coil chamber 202 is generally annular shaped and is defined by a generally cylindrical vertical wall 210 which carries the coil 206 on insulative standoffs (not shown) similar to the standoffs 120 and 124 ofthe embodiment of Figs. 1 and 2.
  • the recessed coil chamber 202 further has an upper ceiling wall 214 which performs a similar function to that ofthe dark space shield 130 ofthe embodiment of Figs. 1 and 2. More specifically, the coil chamber ceiling wall 214 provides a ground plane with respect to the negatively biased target 110 and also shields the periphery ofthe target 110 from the plasma. Still further, the coil chamber ceiling wall 214 shields the coil 206 to a limited extent from deposition material being ejected from the target 110.
  • the adapter ring assembly 200 is insulatively spaced from the target 110 by an insulator ring assembly 216 between the target 110 and the top surface of the chamber sealing wall 214 of the adapter ring assembly 200.
  • the coil chamber 202 ofthe adapter ring assembly 200 further has a floor wall 220 which is positioned below the coil 206. Because the coil 206 within the coil chamber 202 is recessed with respect to the target 110, it is believed that the quantity of target material which will be deposited upon the coil 206 (and its supporting structures) will be reduced. However, to the extent target materials are deposited on the coil 206, the coil chamber floor wall 220 is positioned to catch much of any particulate matter shed by the coil 206 such that the particulate matter accumulates on the coil chamber floor wall 220 rather than on the wafer or other workpiece. As a consequence, it is believed that contamination ofthe workpiece will be further reduced.
  • the shield 230 is removably attached to a lower flange 232 ofthe adapter ring assembly 200 by screws or other suitable fasteners. Such an arrangement permits the shield 230 to be removed from the adapter ring assembly 220 and separately cleaned and reattached to the adapter ring assembly 200. Once the shield 230 has reached the end of its useful life, it may be discarded and a new shield 230 attached to the adapter ring assembly 200.
  • the surface ofthe shield 230 is more easily cleaned because the shield surfaces are not interrupted by standoffs for supporting the coil. Consequently, the usable life of the shield 230 may be extended. In addition, the shield may be more rapidly cleaned which can decrease downtime in which the processing chamber is idled. Still further, because the shield 230 does not have any coils or coils standoffs attached to it, the shield 230 may be more economically manufactured and therefore also more economically discarded at the end of its useful life.
  • coil chamber 202 ofthe adapter ring assembly 200 by protecting the coil from target deposition material, can reduce the amount of cleaning necessary to remove deposited material from the coil. This can also contribute to decreasing downtime and increasing the lifetime ofthe coil, Furthermore, because the coil chamber 202 ofthe adapter ring is more readily separable from the shield 230, the coil 206 and coil chamber 202 need not be replaced when the shield 230 needs to be replaced. Because shields tend to require replacement more frequently than the coils, the cost of operation can be reduced by replacing the coils 206 less frequently than the shields 230.
  • the coil standoff 120 includes a generally disk-shaped base member 250 which is preferably made of an insulative dielectric material such as a ceramic. Covering and shielding the base member 250 is a generally cylindrically shaped cover member 252 which is preferably made ofthe same material which is being deposited. Hence, if the material being deposited is made of titanium, the cover member 252 is preferably made of titanium as well. To facilitate adherence ofthe deposited material (here for example, titanium), it is preferable to treat the surface ofthe metal by bead blasting which will reduce shedding of particles from the deposited material.
  • affixed to the front ofthe cover member 252 is a generally hook shaped bracket 254 of bead blasted titanium which receives and supports a turn ofthe coil 104.
  • the base member 250 is shown attached to the wall 140 ofthe shield 106 by a bolt 251 or other suitable fastener. (The base member 250 is attached to the wall 210 ofthe coil chamber 202 ofthe embodiment of Fig. 3 in a similar manner.)
  • the base member 250 and the cover member 252 together define a labyrinth structure which inhibits the formation of a conducting path across the standoff which could short the coil to the shield (or the adapter ring ofthe embodiment of Fig. 3).
  • the base member 250 has an upstanding inner circular wall 260 of sufficient height to space a top surface 262 ofthe base member 250 from the inner surface 264 ofthe cover member 252 to define a gap GO.
  • the outer diameter D 1 of the base member 250 is smaller than the inner diameter ofthe cover member 252 to define a gap Gl between the outer peripheral face 270 ofthe base member 250 and the inner peripheral face 272 ofthe cover member 252.
  • the cover member 252 is sufficiently thin so that the rear face 280 ofthe cover member 250 is spaced from the wall 140 ofthe shield 106 so as to define another gap G2. It is seen that the gaps G2, Gl, GO define a plurality of passageways as represented by the arrow 290 between the cover member 252 and the shield wall 140 and also between the cover member 252 and the insulative base member 250.
  • the arrow 290 represents the multi-angled path that deposition material would have to take in order to coat the interior ofthe standoff 120.
  • the deposition material To short the coil 104 to the shield wall 140, it would be necessary for the deposition material to coat the interior ofthe standoff 120 to an extent such that a complete conductive path is provided by the deposition material from the cover member 252 to the insulative base member 250. To make such a complete conductive path, the deposition material would have to bridge either the gap G2 at the entrance to the interior ofthe standoff 120 or the gap Gl or gap GO ofthe internal passageways 290 unless the conductive deposition material reached all the way to the innermost wall 260 ofthe insulative base member 250.
  • the front face 262 of the base member 250 has a plurality of concentric channels 300a, 300b, 300c which are positioned to accumulate conductive deposition material from the target to prevent the deposition material from reaching the inner wall 260 and causing a short.
  • the concentric channels may have varying widths with the outer channels preferably having the greater width so as to accumulate deposited material to prevent sufficient material from accumulating adjacent the gap GO which could bridge the gap GO. It has been found that this labyrinth structure permits the plasma chamber to be used for a relatively large number of depositions of conductive metal without causing a short between the coil and the shield.
  • the overall thickness ofthe standoff 120 is relatively thin. As a consequence, the overall diameter ofthe plasma chamber can be made smaller because ofthe reduced thickness ofthe standoffs.
  • the insulative base member 250 has a diameter Dl of 1.50 inches and the gap Gl between the outer periphery 270 ofthe base member 250 and the inner periphery 272 ofthe cover member 252 is 0.10 inches. It has been found that the ratio ofthe diameter Dl ofthe insulative base member 252 to the gap Gl between the outer periphery 270 ofthe base member 250 and the inner periphery 272 ofthe cover member 252 is preferably a ratio of 14 or greater.
  • the diameter to gap ratio ofthe illustrated embodiment of Fig. 4 is 15.
  • Another ratio which has been found important in preventing shorts through the standoffs is the ratio between the length LI ofthe passageway between the rear face 280 ofthe cover member 252 and the front face 262 ofthe insulative base member 250, to the width of that passageway which is the gap Gl .
  • the length ofthe passageway LI is 0.19 inches and the gap Gl is 0.10 inches which provide an aspect ratio of 1.9 or approximately 2. It has been found that an aspect ratio substantially below 2 is not as effective in preventing shorts through the standoff.
  • the gap GO should not be made so narrow as to facilitate the formation of a bridge of deposition material across the gap GO which could short the two sides ofthe gap together.
  • a gap GO of .05 inches has been found satisfactory as noted above.
  • the length of travel L2 from the periphery 270 to the inner wall 260 ofthe insulative base member 250 is .50 inches in the illustrated embodiment.
  • the aspect ratio of this portion ofthe passageway is .5/.05 or 10. It is believed that a lower aspect ratio could undesirably increase the chances of a short occurring.
  • the base member 250 has a plurality of concentric channels 300a, 300b and 300c to accumulate deposition material to prevent it from reaching the inner wall 260.
  • the channels 300a, 300b and 300c have widths of .10, .05 and .05, respectively. Increasing the number and widths of these channels can further reduce the chance of a short but such is likely to result in increasing the overall width ofthe standoff which may not be acceptable for some applications.
  • the number of channels can be reduced to as few as one but such a simplified design may increase the chance of a short.
  • the gaps GO, Gl and G2 should be chosen as discussed above to reduce the chances of a short.
  • Fig. 5 illustrates the coil feedthrough standoff 124 in greater detail.
  • the coil feedthrough standoff 124 like the coil standoff 120 has a generally disk-shaped insulative base member 350 and a generally cylindrical cover member 352 of bead blasted titanium which covers the insulative base member 350.
  • the feedthrough standoff 124 has a central aperture through which extends a threaded conductive feedthrough bolt 356 through which RF power is applied to the coil 104.
  • the feedthrough bolt 356 is received by a titanium sleeve 358 which has a termination sleeve 359 of bead blasted titanium which receives the coil 104.
  • RF current propagates along the surfaces ofthe sleeves 358 and 359 to the coil 104.
  • the feedthrough standoff 124 is secured to the wall 140 ofthe shield by the insulative base member on the interior side ofthe wall 140 and a nut 366 threaded onto the feedthrough bolt 356 on the other side ofthe wall 140.
  • the nut 366 is spaced from the wall 140 by a connector 368 and an insulative spacer 374.
  • the electrical connector 368 connects the feedthrough to an RF generator (not shown) through a matching network (also not shown).
  • the feedthrough standoff 124 also has an internal labyrinth structure somewhat similar to that ofthe coil standoff 120 to prevent the formation of a short between the coil 104 and the wall 140 ofthe shield.
  • the insulative base member 350 has a diameter of D2 of 0.84 inches and a gap G3 of 0.06 inches between the outer periphery 370 ofthe base member 350 and the inner periphery 372 ofthe cover member 352.
  • the ratio ofthe diameter D2 to the gap G3 is 14, similar to the diameter to gap ratio of 15 ofthe coil standoff 120 of Fig. 4.
  • the aspect ratio ofthe feedthrough standoff 124 of Fig. 5 is larger than the aspect ratio ofthe coil standoff 120 of Fig. 4.
  • the length L3 ofthe passageway between the outer periphery 370 ofthe insulative base member 350 and the inner periphery 372 ofthe cover member 352 is 0.27 inches.
  • the aspect ratio ofthe length L3 to the gap G3 is 4.5. Consequently, the larger aspect ratio ofthe embodiment of Fig. 5 may be more effective in preventing undesirable shorts.
  • a gap G4 of .04 inches between the front face 362 of the base member 350 and the rear face 364 ofthe cover member 352 has been found satisfactory.
  • the length of travel L4 from the periphery 370 to the inner wall 360 ofthe insulative base member 350 is .24 inches in the illustrated embodiment.
  • the aspect ratio of this portion of the passageway 390 is .24/.04 or 6. It is believed that a lower aspect ratio could undesirably increase the chances of a short occurring.
  • the base member 350 like the base member 250 has a plurality of concentric channels 400a, and 400b to accumulate deposition material to prevent it from reaching the inner wall 360.
  • the channels 400a and 400 have widths of .06 and .04 inches, respectively.
  • the gap G5 between the rear face 380 of the cover member 350 and the shield is .12 inches.
  • each ofthe embodiments discussed above utilized a single helical coil in the plasma chamber. It should be recognized that the present invention is applicable to plasma chambers having more than one coil. For example, the present invention may be applied to multiple coil chambers for launching helicon waves ofthe type described in copending application serial No.08/559,345 referenced above.
  • the coil 104 ofthe illustrated embodiment is made of 1/2 by 1/8 inch heavy duty bead blasted titanium or copper ribbon formed into a three turn helical coil.
  • the thickness ofthe coil may be reduced to 1/16 inch and the width increased to 2 inches.
  • hollow copper tubing may be utilized, particularly if water cooling is desired.
  • the appropriate RF generators and matching circuits are components well known to those skilled in the art.
  • an RF generator such as the ENI Genesis series which has the capability to "frequency hunt" for the best frequency match with the matching circuit and antenna is suitable.
  • the frequency ofthe generator for generating the RF power to the coil is preferably 2 MHz but it is anticipated that the range can vary at other a.c. frequencies such as, for example, 1 MHz to 100 MHz and non-RF frequencies.
  • the shield 106 has an inside diameter of 16" but it is anticipated that good results can be obtained with a width in the range of 6"-25".
  • the shields may be fabricated from a variety of materials including insulative materials such as ceramics or quartz.
  • the shield and all metal surfaces likely to be coated with the target material are preferably made of a material such as stainless steel or copper unless made ofthe same material as the sputtered target material.
  • the material ofthe structure which will be coated should have a coefficient of thermal expansion which closely matches that ofthe material being sputtered to reduce flaking of sputtered material from the shield or other structure onto the wafer.
  • the material to be cooled should exhibit good adhesion to the sputtered material.
  • the preferred metal ofthe shields, coils, brackets and other structures likely to be coated is bead blasted titanium.
  • the material to be deposited is a material other than titanium
  • the preferred metal is the deposited material, stainless steel or copper.
  • Adherence can also be improved by coating the structures with molybdenum prior to sputtering the target.
  • the wafer to target space is preferably about 140 mm but can range from about 1.5" to 8".
  • a variety of precursor gases may be utilized to generate the plasma including Ar, H 2 , O 2 or reactive gases such as NF 3 , CF 4 and many others.
  • Various precursor gas pressures are suitable including pressures of 0.1 - 50 mTorr. For ionized PVD, a pressure between 10 and 100 mTorr is preferred for best ionization of sputtered material.
  • Fig. 6 is a schematic representation ofthe electrical connections ofthe plasma generating apparatus ofthe illustrated embodiment.
  • the target 110 is preferably negatively biased by a variable DC power source 400 at a DC power of 3 kW.
  • the pedestal 1 14 may be negatively biased by a source 401 at -30 v DC to negatively biased the substrate 112 to attract the ionized deposition material to the substrate.
  • One end ofthe coil 104 is coupled to an RF source such as the output of an amplifier and matching network 402, the input of which is coupled to an RF generator 404 which provides RF power at approximately 4.5 kW.
  • the other end ofthe coil 104 is coupled to ground, preferably through a capacitor 406 which may be a variable capacitor.
  • the coil 104 may also be positioned in such a manner that the coil may sputter as well as the target.
  • the deposited material may be contributed by both the target and the coil.
  • the coil may have as few turns as a single turn to reduce complexity and costs and facilitate cleaning.
  • Fig. 7 is a cross-sectional view of a support standoff 500 in accordance with an alternative embodiment.
  • the standoff 500 includes a cylindrical insulative base member 502 and a cup-shaped metal cover member 504 having a cylindrically shaped side wall 506 spaced from the lateral side 508 ofthe base member 502 to form a labyrinthine passageway 510 oriented substantially transverse to the wall 140 of the shield.
  • the base member 502 ofthe standoff 500 does not have the concentric channels 300 that the base member 250 ofthe standoff of Fig. 4 has. It is believed that for many applications, the passage way 510 ofthe standoff 500 of Fig.
  • the base member 502 may be more easily and less expensively manufactured than the base member 250, particularly when fabricated from materials such as ceramics which are not readily machined.
  • the standoff 500 of Fig. 7 comprises a second cup-shaped metal cover member 512 having a cylindrically shaped side wall 514 spaced from the side 506 ofthe first cover member 502 to form a second labyrinthine passageway 516 oriented generally parallel to the passageway 510 to further reduce the likelihood ofthe formation of a shorting conductive path.
  • the second cover member 512 performs another function.
  • the second cover member 512 has a back wall 518 positioned between a shoulder 520 ofthe base member 502 and the shield wall 140.
  • the base member shoulder 520 ensures that the second cover member 512 is tightly engaged against and in good electrical contact with the shield wall 104 which is maintained at electrical ground.
  • the second cover member 512 spaced from the first cover member 504, is likewise maintained at ground.
  • the first cover member 504 is tightly engaged against the coil 104. Consequently, the cover member 504 is at the same potential as the coil 104 and hence may sputter. Because the second cover member 512 is at ground potential and is positioned to cover most ofthe exposed surfaces of the first cover member 504, it is believed that the second cover member can substantially reduce sputtering ofthe first cover member 504 in those applications in which sputtering ofthe standoffs is undesirable.
  • sputtering ofthe standoffs may introduce nonuniformities since the standoffs are typically not arrayed in a continuous ring around the substrate. Hence, retarding sputtering ofthe standoffs may be useful in a number of applications.
  • the first insulative base member 502 has a collar 528 which extends through an opening in the shield wall 140.
  • the standoff 500 further includes a second insulative base member 530 positioned on the other side ofthe shield wall 140 from the first insulative base member 502. Seated in a metal sleeve 531 is a bolt 532 which passes through interior openings in the sleeve 531, second insulative base member 530, shield wall 140, second cover member 512, and first insulative base member 502.
  • a nut 534 having flanges 536 passes through openings in the coil 104, first cover member 504 and the first insulative base member 502 and threadably fastens to the bolt 532.
  • the nut flanges 536 engage the coil 104 and compress the assembly of the standoff 500 together to secure the standoff and coil 104 to the shield wall 140.
  • the collar 528 ofthe first insulative base member 502 insulates the metal sleeve 531 and the bolt 532 from the grounded shield wall 140.
  • a space 538 is provided between the collar 528 and the second insulative base member 530 so that the compressive force ofthe bolt 532 and the nut 534 does not damage the insulative members which may be made of breakable materials such as ceramics.
  • the end ofthe bolt 532 may be covered by a third insulative member 540 which, in the illustrated embodiment is button-shaped.
  • the second insulative base member has a flange 542 spaced from the shield wall 140 which receives a lip 544 ofthe insulative cover member 540 to retain the cover member 540 in place.
  • Fig. 8 is a cross-sectional view of a feedthrough standoff 600 in accordance with an alternative embodiment.
  • the feedthrough standoff 600 includes a cylindrical insulative base member 602 and a cup-shaped metal cover member 604 having a cylindrically shaped side wall 606 spaced from the lateral side 608 ofthe base member 602 to form a labyrinthine passageway 610 oriented substantially transverse to the wall 140 ofthe shield.
  • a second cup-shaped metal cover member 612 having a cylindrically shaped side wall 614 spaced from the side 606 ofthe first cover member 602 to form a second labyrinthine passageway 616 oriented generally parallel to the passageway 610 to further reduce the likelihood ofthe formation of a shorting conductive path.
  • the second cover member 612 is fastened to the shield wall 140 by screw fasteners 617 which ensure that the second cover member 612 is tightly engaged against and in good electrical contact with the shield wall 104 and therefore grounded to retard sputtering of the first cover member 604.
  • An annular shaped channel 618 in the second cover member is coupled to the threaded holes for the fasteners 617 to vent gases that might inadvertently be trapped in the fastener holes.
  • a base member shoulder 620 between the end ofthe first cover member 604 and the second cover member 612 has sufficient clearance so as to avoid stress on the insulative base member 602.
  • the first insulative base member 602 has a collar 628 which extends through an opening in the shield wall 140. Seated in the insulative base member 602 and the collar 628 is a conductive metal sleeve 630 which passes from one side ofthe shield wall 140 to the other.
  • the standoff 600 further includes a second insulative base member 632 positioned on the other side ofthe shield wall 140 from the first insulative base member 602. Seated in the second insulative base member 632 and engaging the end ofthe sleeve 630 is a conductive metal bar 633. Seated in the conductive metal bar 633 is a bolt 634 which passes through interior openings in the bar 633 and sleeve 630 to the coil side ofthe shield wall 140.
  • a nut 635 having flanges 636 passes through openings in the coil 104, first cover member 604 and the sleeve 630 and threadably fastens to the bolt 634.
  • the nut flanges 636 engage the coil 104 and compress the assembly of the standoff 600 together to secure the feedthrough standoff and coil 104 to the shield wall 140.
  • the collar 628 ofthe first insulative base member 602 insulates the metal sleeve 630 and the bolt 634 from the grounded shield wall 140.
  • the second insulative member 632 insulates the conductive bar 633 from the grounded shield wall 140.
  • RF current travels along the surface ofthe conductive bar 633 from an RF source exterior to the chamber, along the surfaces ofthe sleeve 630, the first cover member 604 engaging the end ofthe sleeve to the coil 104 engaging the first cover member 604.
  • the sleeve 630 has a shoulder 637 to retain the first insulative member 602 in place. However, a space 638 is provided between the shoulder 637 and the first iinsulative base member 604 so that the compressive force of the bolt 634 and the nut 635 does not damage the insulative members which may be made of breakable materials such as ceramics.
  • the conductive bar 633 carrying RF currents from the exterior generator to the feedthrough is seated in a second insulative member 632. Covering the other side ofthe conductive bar 633 and the end ofthe bolt 634 is a third insulative member 640.
  • the insulative members 632 and 640 conform around the RF conductive members to fill the available space to avoid leaving spaces larger than a darkspace to inhibit formation of a plasma and arcing from the conductive bar 633 and the bolt 634.
  • the coil may be positioned closer to the substrate such that the coil 104 is within line of sight ofthe target 1 10. However, such a position will likely increase deposition onto the standoffs. In addition, it is prefe ⁇ ed that the coil position not pass the line between the edge ofthe target 110 and the edge ofthe substrate 112 so that the coil does not "shadow" the substrate 1 12.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Power Engineering (AREA)
  • Plasma Technology (AREA)
  • Electron Sources, Ion Sources (AREA)

Abstract

Bobinage à évidement pour une chambre à plasma dans un système de fabrication de semi-conducteurs. L'évidement ménagé dans le bobinage réduit le dépôt de matière sur le bobinage, ce qui entraîne une réduction de la matière particulaire répandue par le bobinage sur la pièce.
PCT/US1997/008008 1996-05-09 1997-05-08 Bobinage a evidement servant a generer un plasma WO1997042648A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP54025297A JP3175835B2 (ja) 1996-05-09 1997-05-08 プラズマ発生用埋込み形コイル
EP97925528A EP0845151A1 (fr) 1996-05-09 1997-05-08 Bobinage a evidement servant a generer un plasma

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US64718296A 1996-05-09 1996-05-09
US08/647,182 1996-05-09

Publications (1)

Publication Number Publication Date
WO1997042648A1 true WO1997042648A1 (fr) 1997-11-13

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PCT/US1997/008008 WO1997042648A1 (fr) 1996-05-09 1997-05-08 Bobinage a evidement servant a generer un plasma

Country Status (5)

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EP (1) EP0845151A1 (fr)
JP (1) JP3175835B2 (fr)
KR (1) KR100489917B1 (fr)
TW (1) TW324831B (fr)
WO (1) WO1997042648A1 (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0908922A1 (fr) * 1997-10-10 1999-04-14 European Community Chambre de traitement par plasma et dispositif utilisant cette chambre de traitement
WO2000022646A1 (fr) * 1998-10-15 2000-04-20 Applied Materials, Inc. Bobine refroidie par eau pour chambre a plasma
WO2000022647A1 (fr) * 1998-10-15 2000-04-20 Applied Materials, Inc. Bobine et traversee de bobine
WO2000030149A1 (fr) * 1998-11-16 2000-05-25 Applied Materials, Inc. Appareil de commande de trajet de courant de retour rf dans un systeme de traitement de plaquette en semiconducteur
WO2000062329A1 (fr) * 1999-04-14 2000-10-19 Tokyo Electron Limited Procede et appareil permettant d'isoler une radio frequence de lignes d'alimentation et de decharge de milieu liquide de transfert thermique
US6139696A (en) * 1999-10-25 2000-10-31 Motorola, Inc. Method and apparatus for forming a layer on a substrate
US6146508A (en) * 1998-04-22 2000-11-14 Applied Materials, Inc. Sputtering method and apparatus with small diameter RF coil
US6277253B1 (en) 1999-10-06 2001-08-21 Applied Materials, Inc. External coating of tungsten or tantalum or other refractory metal on IMP coils
WO2001078105A1 (fr) * 2000-04-12 2001-10-18 Aixtron Ag Chambre de reaction dotee d'au moins une ouverture pour ligne h.f.
US6652713B2 (en) 2001-08-09 2003-11-25 Applied Materials, Inc. Pedestal with integral shield
CN102437003A (zh) * 2011-12-07 2012-05-02 宁波江丰电子材料有限公司 聚焦环组合、imp溅射设备
US8980045B2 (en) 2007-05-30 2015-03-17 Applied Materials, Inc. Substrate cleaning chamber and components
US9481608B2 (en) 2005-07-13 2016-11-01 Applied Materials, Inc. Surface annealing of components for substrate processing chambers

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6192829B1 (en) * 1999-05-05 2001-02-27 Applied Materials, Inc. Antenna coil assemblies for substrate processing chambers
US10342114B2 (en) * 2017-09-15 2019-07-02 Axcelis Technologies, Inc. RF resonator for ion beam acceleration
KR102378722B1 (ko) * 2020-08-06 2022-03-28 (주)아이작리서치 플라즈마 처리 장치 및 이의 rf 전원 공급 장치

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US5269881A (en) * 1991-09-03 1993-12-14 Mitsubishi Denki Kabushiki Kaisha Plasma processing apparatus and plasma cleaning method
EP0593924A1 (fr) * 1992-10-17 1994-04-27 Leybold Aktiengesellschaft Dispositif pour la production d'un plasma au moyen d'une pulvérisation cathodique
EP0618606A1 (fr) * 1993-04-02 1994-10-05 Applied Materials, Inc. Appareil pour dépôt en phase vapeur à plasma réactif d'un matériau électriquement isolant utilisant une anode secondaire protégée
EP0625792A1 (fr) * 1993-05-19 1994-11-23 Applied Materials, Inc. Dispositif et procédé pour augmenter l'uniformité des faux de pulvérisation dans un appareil de pulvérisation

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Publication number Priority date Publication date Assignee Title
GB1263582A (en) * 1969-09-19 1972-02-09 Barr & Stroud Ltd Improvements in or relating to thin film deposition
US5269881A (en) * 1991-09-03 1993-12-14 Mitsubishi Denki Kabushiki Kaisha Plasma processing apparatus and plasma cleaning method
EP0593924A1 (fr) * 1992-10-17 1994-04-27 Leybold Aktiengesellschaft Dispositif pour la production d'un plasma au moyen d'une pulvérisation cathodique
EP0618606A1 (fr) * 1993-04-02 1994-10-05 Applied Materials, Inc. Appareil pour dépôt en phase vapeur à plasma réactif d'un matériau électriquement isolant utilisant une anode secondaire protégée
EP0625792A1 (fr) * 1993-05-19 1994-11-23 Applied Materials, Inc. Dispositif et procédé pour augmenter l'uniformité des faux de pulvérisation dans un appareil de pulvérisation

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0908922A1 (fr) * 1997-10-10 1999-04-14 European Community Chambre de traitement par plasma et dispositif utilisant cette chambre de traitement
US6146508A (en) * 1998-04-22 2000-11-14 Applied Materials, Inc. Sputtering method and apparatus with small diameter RF coil
WO2000022646A1 (fr) * 1998-10-15 2000-04-20 Applied Materials, Inc. Bobine refroidie par eau pour chambre a plasma
WO2000022647A1 (fr) * 1998-10-15 2000-04-20 Applied Materials, Inc. Bobine et traversee de bobine
US6139679A (en) * 1998-10-15 2000-10-31 Applied Materials, Inc. Coil and coil feedthrough
WO2000030149A1 (fr) * 1998-11-16 2000-05-25 Applied Materials, Inc. Appareil de commande de trajet de courant de retour rf dans un systeme de traitement de plaquette en semiconducteur
US6221221B1 (en) 1998-11-16 2001-04-24 Applied Materials, Inc. Apparatus for providing RF return current path control in a semiconductor wafer processing system
KR100699635B1 (ko) * 1999-04-14 2007-03-23 도쿄 엘렉트론 리미티드 액체 열교환 매체 공급 및 배출 라인의 무선 주파수 격리 방법 및 장치
WO2000062329A1 (fr) * 1999-04-14 2000-10-19 Tokyo Electron Limited Procede et appareil permettant d'isoler une radio frequence de lignes d'alimentation et de decharge de milieu liquide de transfert thermique
US6284110B1 (en) 1999-04-14 2001-09-04 Tokyo Electron Limited Method and apparatus for radio frequency isolation of liquid heat transfer medium supply and discharge lines
US6277253B1 (en) 1999-10-06 2001-08-21 Applied Materials, Inc. External coating of tungsten or tantalum or other refractory metal on IMP coils
US6139696A (en) * 1999-10-25 2000-10-31 Motorola, Inc. Method and apparatus for forming a layer on a substrate
US6500315B1 (en) 1999-10-25 2002-12-31 Motorola, Inc. Method and apparatus for forming a layer on a substrate
US7056388B2 (en) 2000-04-12 2006-06-06 Aixtron Ag Reaction chamber with at least one HF feedthrough
WO2001078105A1 (fr) * 2000-04-12 2001-10-18 Aixtron Ag Chambre de reaction dotee d'au moins une ouverture pour ligne h.f.
KR100796830B1 (ko) * 2000-04-12 2008-01-22 아익스트론 아게 기판코팅방법 수행용 반응실
US6652713B2 (en) 2001-08-09 2003-11-25 Applied Materials, Inc. Pedestal with integral shield
US6837968B2 (en) 2001-08-09 2005-01-04 Applied Materials, Inc. Lower pedestal shield
US9481608B2 (en) 2005-07-13 2016-11-01 Applied Materials, Inc. Surface annealing of components for substrate processing chambers
US8980045B2 (en) 2007-05-30 2015-03-17 Applied Materials, Inc. Substrate cleaning chamber and components
CN102437003A (zh) * 2011-12-07 2012-05-02 宁波江丰电子材料有限公司 聚焦环组合、imp溅射设备

Also Published As

Publication number Publication date
KR100489917B1 (ko) 2005-08-05
KR19990028803A (ko) 1999-04-15
EP0845151A1 (fr) 1998-06-03
JPH10510676A (ja) 1998-10-13
TW324831B (en) 1998-01-11
JP3175835B2 (ja) 2001-06-11

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