Patent ID: 12211728

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one implementation may be beneficially used in other implementations without specific recitation.

DETAILED DESCRIPTION

Disclosed herein is an improved electrostatic chuck (ESC) design. The ESC described herein facilitates arcing free deposition of conductive films with center to edge thickness uniformity. The ESC aspects described herein facilitate deposition of conductive films at high operating temperatures with reduced or eliminated arcing and uniformity better than other substrate supports. The arc-resistant ESC enables high voltage deposition processes that provide an advantage for next node applications by reducing or eliminating DC discharge phenomenon during deposition. Such discharge can lead to substrate damage and particle contamination issues. Additionally, overall film uniformity (thickness, k) is improved, including reduced edge thickness drop, which sometimes cannot be resolvable by process alterations or other hardware tuning adjustments. The ESC also reduces or eliminates the probability of substrate sliding with high density dimples. The ESC enables high RF power substrate processing for improved processing throughput. The improvements have an additional benefit of low cost ESC design.

Challenges faced during conductive film deposition include arcing (i.e., DC discharge) due to the conductive nature of the film, and poor uniformity of the deposited film, specifically at the edge of the substrate. As the film uniformity increases, the charge build-up on the heater increases. The discharge of this build-up may result in chamber arcing events. The edge uniformity issues can result from the non-uniform plasma density distribution and shadowing effects from the pocket used to keep the substrate in position.

ESC's can increase uniformity at the expense of high arcing frequency for thick conductive films or vice versa. The aspects of the ESC disclosed herein address these issues. Aspects of the ESC disclosed herein facilitate increased deposition uniformity while facilitating reduced or eliminated arcing, with respect to the occurrences and/or magnitude of arcing.

The ESC disclosed herein utilizes easily machineable design aspects to facilitate “correction” of the plasma density distribution over the substrate area to improve deposition uniformity. The ESC is configured to expand the plasma from the substrate edge in a direction from a center of the substrate and radially outwards and away from the substrate edge, facilitating deposition uniformity and reduced arcing. The expansion, or pushing, of the plasma radially outward from the substrate edge enables the use of a pocket design which facilitates reduced or eliminated arcing during thick film deposition. Thus, aspects of the ESC described herein are able to combine a high arcing margin with low profile on-substrate uniformity into a single pedestal heater for the first time.

Aspects of the present disclosure include benefits such as significant arcing margin which facilitates qualifying product to the next node development, increased deposition uniformity, decreased edge thickness loss, high RF power substrate processing, ease of manufacturing involving reduced costs, reduced substrate defects, and increased yield and throughput.

FIG.1is a cross-sectional schematic view of a plasma processing chamber100, according to one implementation. The plasma processing chamber100is shown configured as a deposition chamber. A substrate support assembly126is disposed in the plasma processing chamber100and is configured to support a substrate during processing. The substrate support assembly126may be utilized in various processing chambers, for example plasma treatment chambers, annealing chambers, physical vapor deposition chambers, chemical vapor deposition chambers, etch chambers, and/or ion implantation chambers, among others. The substrate support assembly126may be used in other systems to control processing uniformity for a surface or workpiece, such as a substrate. Aspects of the present disclosure facilitate control of dielectric properties tan (δ) (i.e., dielectric loss) or ρ (i.e., the volume resistivity) at elevated temperature ranges for the substrate support assembly126. Control of the dielectric properties facilitates azimuthal processing control, (i.e., processing uniformity) for a substrate124disposed on the substrate support assembly126.

The plasma processing chamber100includes a chamber body102having one or more sidewalls104, a bottom106and a lid108that enclose an interior processing region110. An injection apparatus112is coupled to the sidewalls104and/or lid108of the chamber body102. A gas panel114is coupled to the injection apparatus112to allow processing gases to be provided into the interior processing region110. The injection apparatus112may be a showerhead, such as a diffuser and a backing plate. Processing gas, along with any processing by-products, are removed from the interior processing region110through an exhaust port128formed in the sidewalls104and/or the bottom106of the chamber body102. The exhaust port128is coupled to a pumping system132, which includes throttle valves and pumps utilized to control the vacuum levels within the interior processing region110and exhaust materials from the interior processing region110.

The processing gas is energized to form a plasma within the interior processing region110. The processing gas may be energized by capacitively or inductively coupling RF power provided to the processing gases. In the example illustrated inFIG.1, the injection apparatus112is disposed below the lid108of the plasma processing chamber100and coupled through a matching circuit118to an RF power source120.

The substrate support assembly126is disposed in the interior processing region110below the injection apparatus112. The substrate support assembly126includes a substrate support174and a cooling base130. The cooling base130is supported by a base plate176. The base plate176is supported by one of the sidewalls104and/or the bottom106of the plasma processing chamber100. The substrate support174may be a vacuum chuck, a heater, an electrostatic chuck (ESC) or other suitable support for holding a substrate thereon while processing the substrate in the plasma processing chamber100. In one example, the substrate support174is an ESC. The substrate support assembly126may additionally include an embedded resistive heater assembly. The heater may be integral to the substrate support174. Additionally, the substrate support assembly126may include a facility plate145and/or an insulator plate disposed between the cooling base130and the base plate176to facilitate electrical, cooling, and/or gas connections within the substrate support assembly126.

The substrate support174includes one or more chucking electrodes (e.g., RF Mesh or other electrically conductive members)186disposed in a dielectric body175. The dielectric body175has a workpiece support surface137to support the substrate124and a bottom surface133opposite the workpiece support surface137. The dielectric body175of the substrate support174is fabricated from a ceramic material, such as alumina (Al2O3), aluminum nitride (AlN), or other suitable material. The dielectric body175may be fabricated from a polymer, such as polyimide, polyetheretherketone, polyaryletherketone, and the like.

The dielectric body175optionally includes one or more resistive heaters (heating elements)188embedded therein. The resistive heaters188are utilized to elevate the temperature of the substrate support assembly126to a temperature suitable for processing the substrate124disposed on the workpiece support surface137of the substrate support assembly126. The resistive heaters188may be used to maintain the temperature of the substrate support assembly126between processing substrates. The resistive heaters188are coupled through the facility plate145to a heater power source189. The heater power source189may provide 900 watts or more AC power to the resistive heaters188. A controller is utilized control the operation of the heater power source189, which is set to heat the substrate124and/or the substrate support assembly126to a predefined temperature. In one example, the resistive heaters188include a plurality of laterally separated heating zones. The controller enables at least one zone of the plurality of laterally separated heating zones to be preferentially heated relative to one or more resistive heaters188located in one or more of the other zones. For example, the resistive heaters188may be arranged concentrically in a plurality of separated heating zones. The one or more resistive heaters188maintain the substrate124at a temperature for processing, such as between about 180 degrees Celsius to about 700 degrees Celsius. In one example, the temperature for processing is greater than about 550 degrees Celsius, such as between about 350 degrees Celsius and about 700 degrees Celsius.

The chucking electrode186may be configured as a mono polar or bipolar electrode, or other suitable arrangement. The chucking electrode186is coupled through an RF filter to a chucking power source187, which provides a DC power to electrostatically secure (e.g., chuck) the substrate124to the workpiece support surface137of the substrate support174. The RF filter prevents RF power utilized to form a plasma within the plasma processing chamber100from damaging electrical equipment or presenting an electrical hazard outside the plasma processing chamber100.

The workpiece support surface137of the substrate support174may include gas passages for providing backside heat transfer gas to the interstitial space defined between the substrate124and the workpiece support surface137of the substrate support174. The substrate support174also includes lift pin holes for accommodating lift pins for elevating the substrate124above the workpiece support surface137of the substrate support174to facilitate robotic transfer into and out of the plasma processing chamber100. An edge ring may optionally be disposed along a periphery of the workpiece support surface137of the substrate support174. For example, the edge ring may be disposed about an outer edge of the substrate124.

FIG.2Ais a top schematic view of a substrate support200, according to one implementation. The substrate support200is suitable for use as the substrate support174illustrated in the plasma processing chamber100ofFIG.1.FIG.2Bis a cross sectional schematic view of the substrate support200ofFIG.2A, according to one implementation.FIGS.2A and2Bwill be discussed together. The substrate support200includes an integrated edge ring such that the substrate support200and the integrated edge ring form a single mass of material (e.g., monobody) that does not utilize a separate edge ring.

The substrate support200has a body202. The body202has a circular top profile with a center232and an outer periphery234. The body202has a plurality of surfaces extending along a top face230of the body202. The body202has a lower ledge212which extends from the center232of the substrate support200. The lower ledge212extends to a first lip214. The first lip214is configured to support the substrate124thereon. A troth216extends from the first lip214to a second lip218configured to support the substrate124thereon. The first lip214and the second lip218are substantially coplanar with the troth216below both the first lip214and the second lip218. The first lip214and the second lip218are configured to support the substrate105thereon. The substrate124is supported in a pocket270of the substrate support200. The substrate124is at least partially supported on one or more support surfaces of the first lip214and/or the second lip218.

The second lip218extends from the troth216to a first angled wall222. The first angled wall222begins at a first distance282from the center232and angles upward and outward at a first angle292away from the center232(e.g., radially outward) and from an upper plane of the second lip218. The upper plane corresponds to the support surface of the second lip218. The first angled wall222defines a sidewall272for the pocket270. The first distance282is between about 5.5 inches to about 6.15 inches from the center232. In one example, the first distance282is between about 5.5 inches to about 6.0 inches from the center232. In one example, the first distance282is between about 5.91 inches to about 6.15 inches from the center232. The first distance282defines a gap262between the substrate105and the sidewall272of the pocket270. In the example illustrated, the sidewall272of the pocket270is defined by the first angled wall222. The first angle292is between about 30 degrees and 90 degrees, as shown. The first angled wall222extends to a first upper surface224. The first upper surface224extends from the first angled wall222to a second angled wall226. The second angled wall226begins at a second distance284from the center232and angles upward and outward at a second angle294away from the center232and from a plane of the first upper surface224. The second distance284is between about 6.000 inches to about 7.000 inches from the center232. The second angle294of the second angled wall226extends between about 5 degrees and 60 degrees as shown. The second angle294is smaller than the first angle292. The second angled wall226extends to a second upper surface228. The second upper surface228extends from the second angled wall226to the outer periphery234. The first upper surface224and the second upper surface228are parallel to the support surface of the second lip218.

A difference between the second distance284and the first distance282defines a first step width296of the first angled wall222and the first upper surface224. The first step width296is within a range of 0 inches to 1.5 inches. A first ratio is defined by the first distance282relative to a radius of the substrate124. In one example, the first ratio is within a range of 1.0 to 1.1, such as 1.0 to 1.05. A second ratio is defined by the first step width296relative to the first distance282. In one example, the second ratio is 0.3 or less, such as within a range of 0.1 to 0.3.

The first upper surface224is higher than the upper plane of the second lip218. The first upper surface224is a third distance286above the second lip218to promote process uniformity by extending the plasma sheath upwards beyond the edge of the substrate105during plasma processing. The third distance286defines a height of the pocket270. In one embodiment, which can be combined with other embodiments, the third distance286is between about 0.005 inches and about 0.050 inches.

The second upper surface228is higher than both the first upper surface224and the second lip218. The second upper surface228is a fourth distance288above the second lip218to promote process uniformity by extending the plasma sheath upwards beyond the edge of the substrate105during plasma processing. In one embodiment, which can be combined with other embodiments, the fourth distance288is between about 0.050 inches and about 0.500 inches. In one example, the fourth distance288is between about 0.050 inches and about 0.100 inches.

The first distance282and the second distance284are taken along a horizontal plane. The third distance286and the fourth distance288are taken along a vertical plane that is substantially perpendicular to the horizontal plane of the first distance282and the second distance284.

The first angled wall222, first upper surface224, second angled wall226, and second upper surface228at least partially form a protrusion of the body202that protrudes upward from the second lip218. The protrusion is integrally formed with the body202.

Based on plasma simulations, the edge thickness variation is driven by plasma density variations from edge effects. Thus, to improve the edge uniformity, two stepped surfaces (e.g., the first upper surface224and the second upper surface228) facilitate preventing sliding of the substrate124. The two stepped surfaces also facilitate arcing performance, and promotes a smoother plasma sheath profile over the substrate124, such as near the outer edge of the substrate125. That is, the plasma sheath is flat extending beyond the outer edge of the substrate124for better processing uniformity at the outer edge of the substrate124.

FIG.3Ais a top schematic view of a substrate support300, according to one implementation. The substrate support300is suitable for use as the substrate support174in the plasma processing chamber100ofFIG.1.FIG.3Bis a cross sectional schematic view of the substrate support300ofFIG.3A, according to one implementation.FIGS.3A and3Bwill be discussed together. The substrate support300includes an integrated edge ring such that the substrate support300and the integrated edge ring form a single mass of material that does not utilize a separate edge ring.

The substrate support300has a body302. The body302has a circular top profile with a center332and an outer periphery334. The body302has a plurality of surfaces extending along a top face330of the body302. The body has a lower ledge312which extends from the center332of the substrate support. The lower ledge312extends to a support surface314. The support surface314is configured to support the substrate124thereon in a pocket370. In one example, the lower ledge312is below the support surface314and the substrate124supported on the support surface314does not contact the lower ledge312unless bowed or chucked. In such an example, a gap316is disposed between the substrate124and the lower ledge312unless the substrate124is bowed or checked. In one example, the lower ledge312is substantially planar and parallel with the support surface314.

The support surface314extends from the lower ledge312to a first arcuate surface defined by a first radius392. The first radius392transitions the support surface314to a first angled sidewall322. The first angled sidewall322extends upward and outward from the first radius392and away from the center332toward a second arcuate surface defined by a second radius394. The first angled sidewall322defines an outer wall372of the pocket370. A gap is formed between the substrate105and the outer wall372. The second radius394transitions the first angled sidewall322to a first upper surface324. The first upper surface324extends from the second radius394to a third radius396. The third radius396transitions the first upper surface324to a second angled sidewall326. The second angled sidewall326extends downward and outward from the third radius396to a fourth radius398. The fourth radius398transitions the second angled sidewall326downward and outward from the second angled sidewall326to a second upper surface328. The second upper surface328extends from the fourth radius398to the outer periphery334of the body302of the substrate support300. The second upper surface328is disposed below the first upper surface324.

The first radius392is between 0.010 inches and about 0.020 inches. The second radius394provides a large radius (rounding) to reduce plasma coupling. The second radius394is between 0.020 inches and about 0.030 inches. The third radius396is smaller than the second radius394to increase plasma density and avoid edge effects on the substrate. The third radius396is between 0.0001 inches and about 0.010 inches. The fourth radius398may be substantially similar or in the same range of the first radius392. The fourth radius398is between 0.010 inches and about 0.020 inches.

In one example, the second radius394is larger than the first radius392, the third radius396is smaller than first radius392, and the fourth radius398is the same as the first radius.

A first distance382is provided for the first radius392relative to the center332. The first distance382defines a gap362between the substrate124and the first angled sidewall322, such as a bottom end of the first angled sidewall322. In one example, the first distance382of the first radius392from the center332is between about 5.5 inches and about 6.15 inches. In one example, the first distance382is between about 5.5 inches to about 6.0 inches from the center332. In one example, the first distance382is between about 5.91 inches to about 6.15 inches from the center332.

The first upper surface324is higher than the support surface314. The first upper surface324is a second distance384above the support surface314to promote process uniformity by extending the plasma sheath beyond the edge of the substrate105. The second distance384defines a height of the pocket370. In one example, the second distance384of the first upper surface324above the support surface314is between about 0.015 inches and about 0.500 inches. In one example, the second distance384is between about 0.015 inches and about 0.100 inches.

The second upper surface328is lower that the first upper surface324and higher than the support surface314. The second upper surface328is a third distance386above the support surface314to prevent arcing. In one example, the third distance386of the second upper surface328above the support surface314is between about 0.005 inches to about 0.500 inches.

Advantageously, the pocket370is close to the substrate124to minimize the exposed area at the level of the substrate124to reduce the potential for arcing. The smooth rounding of the substrate side of the pocket370facilitates preventing increased local plasma density. The smooth rounding of the substrate side of the pocket370also facilitates preventing deposition thickness reduction, such as at locations near the substrate edge. The pocket height is chosen such that a highly tensile bow substrate can be prevented from sliding away, while reducing or minimizing shadowing effects. The pocket height is equal to the second distance384. In one example, the pocket height is between about 0.015 inches and about 0.500 inches. The lower radius disposed outside of the pocket (such as the third radius396and/or the fourth radius398) increases plasma density on the outside area, which reduces edge effects on substrate. Furthermore, a stepped surface (such as the second upper surface328) behind the pocket370minimizes exposed area at substrate level, and thus prevents arcing. Aspects of the substrate support300improve edge thickness uniformity to about ˜2% vs 5% for typical Tight Pocket Heater (TPH) films.

The first distance382is taken along a horizontal plane. The second distance384and the third distance386are taken along a vertical plane that is substantially perpendicular to the horizontal plane of the first distance382.

The first radius392, second radius394, third radius396, fourth radius398, first angled sidewall322, first upper surface324, second angled sidewall326, and second upper surface328at least partially form a protrusion of the body302that protrudes upward from the support surface314. The protrusion is integrally formed with the body302.

FIG.4Ais a top schematic view of a substrate support400, according to one implementation. The substrate support400is suitable for use as the substrate support174in the plasma processing chamber100ofFIG.1.FIG.4Bis a cross sectional schematic view of the substrate support400illustrated inFIG.4A, according to one implementation.FIGS.4A and4Bwill be discussed together. The substrate support400has an edge ring450that is separable from the substrate support400.

The substrate support400has a body402. The body402has a circular top profile with a center432and an outer periphery434. The body402has a plurality of surfaces extending along a top face430of the body402. In one example, the edge ring450is separable from the body402. The body402has a lower ledge412which extends from the center432of the substrate support400. The lower ledge412extends to a first lip414. The first lip414is configured to support the substrate105thereon. A troth416extends from the first lip414to a second lip418. The first lip414and the second lip418are substantially coplanar and/or parallel with the troth416below both the first lip414and the second lip418. The first lip414and the second lip418are configured to support the substrate105thereon in a pocket470. One or more support surfaces of the first lip414and/or the second lip418are configured to support the substrate124.

The second lip418extends from the troth416to a first angled wall422. The first angled wall422defines an outer-wall472of the pocket470. The first angled wall422, such as a bottom end of the first angled wall422, begins at a first distance484from the center432. The first angled wall422angles upward and outward at a first angle492from a plane of the second lip418. The first distance484is between about 5.5 inches to about 6.15 inches from the center432. In one example, the first distance484is between about 5.5 inches to about 6.0 inches from the center432. In one example, the first distance484is between about 5.91 inches to about 6.15 inches from the center432. The first distance484defines a gap462between the substrate124and a protrusion404of the body402.

The protrusion404is at least partially defined by the first angled wall422and is integrally formed with the body402. The first angle492is between about 30 degrees and 90 degrees, as shown inFIG.4B. The first angled wall422extends to a first top surface424of the protrusion404. The first top surface424is a first distance482between about 0.010 inches and about 0.030 inches above the second lip418. The first distance482defines a height of the pocket470. The first top surface424extends to a rear wall426of the protrusion404. The rear wall426extends downward to an outer surface442that is no longer on the protrusion404. The rear wall426defines an outer boundary of the protrusion404.

The outer surface442extends to the outer periphery434of the body402. The outer surface442may be substantially coplanar and/or parallel with the second lip418. The edge ring450is disposed on the outer surface442outside of the protrusion404. The edge ring450has a front surface451. The front surface451is disposed at a second distance486from the center432of the body402, which corresponds to a center of the edge ring450. The second distance486is between about 6.00 inches and about 6.5 inches from the center432of the body402. The second distance486defines a second gap464disposed between the edge ring450and the rear wall426of the protrusion404of the body402.

A ratio is defined by the second distance486of the front surface451relative to the first distance484of the first angled wall422. In one example, the ratio of the second distance486to the first distance484is within a range of 1.00 to 1.2, such as 1.05 to 1.2 or 1.08 to 1.095.

The front surface451of the edge ring450extends upward a second distance483from the outer surface442. The second distance483is between about 0.10 inches and about 0.30 inches. The second distance483of the front surface451may be substantially similar to, such as the same as, the first distance482of the protrusion404. A first angled wall452extends from the front surface451and angles upward and outward at a second angle494from a plane498that is orthogonal to the front surface451. The second angle494of the first angled wall452is between about 5 degrees and 20 degrees as shown. The first angled wall452extends to a top surface453. The top surface453extends to an outer wall454. The top surface453is above the first top surface424. The top surface453is disposed at a third distance488above the outer surface442. The outer wall454may be aligned with the outer periphery434of the body402of the substrate support400. The outer wall454may extend beyond or short of the outer periphery434. The outer wall454extends down from the top surface453to a bottom surface455of the edge ring450. The bottom surface455extends inward from the outer wall454to the front surface451. The bottom surface455of the edge ring450is disposed on, and interfaces with, the outer surface442of the body402of substrate support400.

The first distance484and second distance486are taken along a horizontal plane. The first distance482, second distance483, and third distance488are taken along a vertical plane that is substantially perpendicular to the horizontal plane of the first distance484and the second distance486.

The first angled wall222, first upper surface224, second angled wall226, and second upper surface228at least partially form a protrusion of the body202that protrudes upward from the second lip218. The protrusion is integrally formed with the body202.

Benefits for aspects of the substrate supports disclosed herein provide significant arcing margin, better deposition uniformity, less edge thickness loss, less substrate sliding, ease of machinability, reduced cost such as reduced manufacturing cost, enabled high RF power substrate processing, reduced substrate defects, and improved substrate throughput and yield.

The present disclosure contemplates that one or more of the aspects, features, components, and/or properties of the substrate support200, the substrate support300, and/or the substrate support400may be combined or utilized independently. The present disclosure also contemplates that the combined or independent aspects, features, components, and/or properties may achieve one or more of the above benefits.

While the foregoing is directed to implementations of the present invention, other and further implementations of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.