GB2590511A - Hybrid CMP conditioning head - Google Patents

Abstract

A conditioning head or disk 24 comprises a substrate comprising a substrate surface 26 and a plurality of protrusions 28, 120 extending between 5 and 250 microns from the substrate surface 26 and forming one or more sinusoidal wave patterns 130, 160 on the substrate surface 26. The plurality of protrusions may form an array (fig. 3) of repeating unit cells 110 which may be squares or rectangles. Each wave pattern may comprise at least 6 protrusions 120. There may be at least two sinusoidal wave patterns with a phase offset between 30° and 270° and which may have different amplitudes and/or frequencies. The substrate 26 may be a ceramic or a carbide and may have an evenly distributed layer of natural or synthetic diamond grit 28 and a continuous film 30 of CVD polycrystalline diamond encasing the protrusion layer 28 and bonding it to the substrate 26. Abrasive regions (200 fig. 4) of the pad may be separated by non-abrasive channels (210 fig. 4) and a central non-abrasive region (220 fig. 4).

Description

HYBRID CMP CONDITIONING HEAD

FIELD OF THE INVENTION

The present invention relates generally to a conditioning head comprising a geometric array of protrusions designed to condition a pad for polishing semiconductor wafers. More specifically, the present invention relates to conditioning heads comprising a substrate of various non-planar configurations and methods for manufacturing thereof.

BACKGROUND TO THE INVENTION

The products of the present invention have utility in a wide variety of applications, including heads or disks for the conditioning of polishing pads, including pads used in Chemical-Mechanical-Planarization (CMP), CMP is an important process in the fabrication of integrated circuits, disk drive heads, nano-fabricated components, and the like. For example, in patterning semiconductor waters, advanced small dimension palterninc.) techniques require an absolutely flat surface. After the wafer has been sawed from a crystal ingot, and irregularities and saw damage has been removed by rough polishing, CMP is used as a final polishing step to remove high points on the wafer surface and provide an absolutely flat surface. During the CMP process, the wafer will be mounted in a rotating holder or chuck, and lowered onto a pad surface rotating in the same direction. When a slurry abrasive process is used, the pad is generally a cast and sliced polyurethane material, or a urethane-coated felt. A slurry of abrasive particles suspended in a mild etc,hant is placed on the polishing pad. The process removes material from high points, both by mechanical abrasion and by chemical conversion of material to, e.g., an oxide, which is then removed by mechanical abrasion. The result is an extremely flat surface.

In addition, CMP can be used later in the processing of semiconductor wafers, when deposition of additional layers has resulted in an uneven surface. MP is desirable in that it provides global planarization across the entire wafer, is applicable to all materials on the wafer surface, can be used with multi-material surfaces, and avoids use of hazardous gases. As an example, GNP can be used to remove metal overfill in damascene inlay processes.

CMP represents a major portion of the production cost for semiconductor wafers. These CMP costs include those associated with polishing pads, polishing slurries, pad conditioning disks and a variety of CMP parts that become worn during the planarizing and polishing operations. The total cost for the polishing pad, the downtime to replace the pad and the cost of the test wafers to recalibrate:he pad for a single wafer polishing run can be quite high. In many complex integrated circuit devices, up to thirty or more CMF' runs are required for each finished wafer, which further increases the total manufacturing costs for such waters.

With polishing pads desk.med for use with abrasive slurries, the greatest amount of wear on the polishing pads is the result of polishing pad conditioning that is necessary to place the pad into a suitable condition for these wafer planarization and polishing operations. A typical polishing pad comprises closed-cell polyurethane foam approximately /16 inch thick.

Pad conditioning determines the asperity structure (peaks and valleys) of the pad and acts to maintain the surface stability. During pad conditioning; the pads are subjected to mechanical abrasion to physically cut through the cellular layers of the surface of the pad.

The exposed surface of the pad contains open cells, which trap abrasive slurry consisting of the spent polishing slurry and material removed from the wafer. In each subsequent pad-conditioning step; the ideal conditioning head removes only the outer layer of cells containing the embedded materials without removing any of the layers below the outer layer.

Conditioning also addressing the loss of polish rates caused by glazing of the pads surface.

Glazing is known to be caused by plastic deformation which flattens the asperity peaks.

Conditioning is used to break up the glazed area and restore the asperity structure to the pad.

An ideal conditioning head would: a achieve a rapid and complete removal of the top most layer of cells of the polishing pad with the least possible removal of underlying cell layers of the polishing pad that do not contain embedded materials to maximize the useful life of the pad; rejuvenate the asperity structure of the pad to maintain the polishing rate and performance of the pad; and * remove the spent slurry and debris from the conditioning pad's pores without c out the pores; resulting in less aggressive conditioning and a longer pad life.

Over-texturing of the pad results in a shortening of the pad life, whilst under-texturing results in insufficient material removal rate during the CMP step and lack of wafer uniformity.

Over-texturing of the pads is often a result of abrasion being concentrated to US6,368,198 attempted to address the problem oi uneven conditioning of the polishing pad through bonding abrasive particles to a substrate such that they are uniformly spaced apart.

While this increased the life of the polish pad compared to using CMP using randomly spaced abrasive particles, there is still scope for improvement.

US2006/0010780 addresses the problem of uneven texturing through using a tool containing abrasive grains orientated in an array according to a non-uniform pattern having an exclusionary zone around each abrasive grain to avoid areas of high texturing. Whilst this was seen as an improvement over uniform spaced and randomly spaced abrasive particles, there is still a need for further improvement; particularly in respect to the ability to tune the decree of texturing, whilst avoiding portions of the polishing pad to become prematurely over-textured.

SUMMARY OF THE INVENTION

in a first aspect of the present disclosure, there is provided a cond ning head comp g: a. a substrate comprising a substrate surface; b. a plurality of protrusions extending between 5 and 250 microns from the substrate surface, wherein the plurality of protrusions form one or more sinusoidal wave patterns on the substrate surface.

The use of a protrusions in a sinusoidal wave pattern has been found to produce a combination of low cut rates of the pads being conditions, while providing sufficient rejuvenation of the asperity structure of the pad to maintain the polishing rate and performance of the pad. This has been achieved with a protrusion pattern which is based upon the relative rotational movement of the conditioning head and the pad to avoid the tendency of the conditioning pad to unevenly remove layers of the pad during conditioning.

The sinusoidal wavelength (A) may comprise at least 6 protrusions or at least 8 protrusion or at least 10 protrusions or at least 12 protrusion or at least 14 protrusions or at least 16 protrusion or at least 18 protrusions or at least 20 protrusions per wavelength (i.e. 2tr, angular rotation). The upper limit of protrusions per wave period is likely to be determined by practical considerations relating to the size of the conditioning head; required density of protrusions; and the rotational movement between the conditioning head and the pad.

However; it would be expected that no more than 30 protrusions or no more than 20 protrusions per wavelength would be required in most circumstances.

In one embodiment, the plurality of protrusions are within 5 mm or within 1 mm or within 500 pm or within 100 pm or within 50 pm or within 20 pm or within 10 um distance of a virtual pathway of the one of more sinusoidal wave patterns. In another embodiment, 95% of the protrusions are no more than 5 mm or no more than 1 mm or no more than 500 um or no more than 100 pm or no more than 50 um or no more than 20 pm or no more than 10 pm distance from a virtual pathway of the one of more sinusoidal wave patterns. The degree of allowable variance between the protrusions and the theoretical virtual pathway will depend upon the dimensions of the sinusoidal wave pattern. Preferably, the variation of the protrusions from he virtual pathway is no more than 2.0% or no more than 10% or no more than 5% or no more than 3% or ic more than 2% or no more than 1% of the amplitude of the sinusoidal wave pattern. Preferably, 90% or 95% of protrusions fail within these limits, While some scatter of protrusions around the sinusoidal wave pattern vvill still provide a beneficial result, it is preferred that protrusions are located close to or on the virtual sinusoid pathway. A virtual sinusoidal pathway is the virtual line formed by the sinusoidal equation, from which protrusions are location (on or near to) to produce the sinusoidal wave pattern.

The sinusoidal wave pattern of the (X,Y) 2D plot may be represented by the formula: Y = A*Bin (B (X-C)) + D Where: A -amplitude of the wave; B = the frequency of the wave; C -the herizontai shift of the wave; and D = the vertical shift of the wave.

A unit cell may have a plurality of sinusoidal wave patterns which have the same or different amplitude, frequency, horizontal and/or vertical shifts.

In one embodiment, the wave extends in a horizontal direction and some sinusoidal waves are horizontally offset from adjacent vertically adjacent waves.

The period or wavelength (1/B or A) of the wave is the distance, in the direction of the wave progression, of a single oscillation (e.g. peak to peak).

A unit cell preferably has a frequency of a halt wavelength, such that the unit cell can be disposed against each other while maintaining the continuum of the sinusoidal wave pattern. Once the equations for each of the sinusoidal waves have been determined relative to each other, the unit cell may be scaled in the vertical (A) and the horizontal (1/B) directions.

The horizontal shift of the wave may be conveniently expressed in terms of the angular position in the wave cycle, expressed in degrees (>00 to 'c360°) or rad (>0 to <27). Alternatively, the horizontal shift may be expressed as a proportion of the wavelength (A).

In some embodiments, the relationship between adjacent or intersecting wave patterns may be governed by a requirement that a protrusion disposed on the wave pattern is set at a minimum distance to an adjacent protrusion on the same or adjacent wave pattern. Thus, the density of protrusions within the unit cell will influence the number of wave patterns and their relative position to each other. Mathematical modelling may be used to determine the most suitable wave pattern arrangement for a particular arrangement.

in one embodiment, the design of the conditioning head takes into account the relative rotational speeds of the conditioning head; and the pathway that the conditioning head progresses over the polishing pad. A mathematical model may be constructed to calculate the net result of the sinusoidal wave pattern of the protrusions of the conditioning head and the resultant sinusoidal wave pattern at each point on the polishing pad, such that an indentation pattern of the protrusions on the polishing pad may be calculated. An iterative process may be used to produce an arrangement of protrusions defining a sinusoid wave pattern which produces a uniform protrusion indentation pattern on the polishing pad. Alternatively, for a given protrusion pattern, mathematical modelling may determine the optimal rotational speeds of the polishing pad and the conditioning head; and relative pathway thereof to provide a uniform protrusion indentation pattern on the polishing pad.

The protrusions in a wave pattern are preferably spaced at equidistance along the wave pattern. The distance between protrusions on a first wave pattern may or may not be different to the distance between protrusions on a second wave pattern.

In one embodiment, the plurality of protrusions form at least two sinusoidal wave patterns, wherein the wave patterns have a phase offset of between 30" and 270". In some embodiments, the phase offset is about 1800 (half a wavelength), which enables sinusoidal waves of the same wave length to nest together, enabling the density of protrusions to be increased.

In some embodiments, the wave patterns have different amplitudes. In some embodiments, the wave patterns having different frequencies. The overall sinusoidal wave pattern may be dependent upon a number gl factors, including the characteristics of the pad being conditioned; the relatively rotational movement between the conditioning head and pad; and the degree of texturing required, In a preferred embodiment, the plurality of protrusions form an array comprising a plurality of repeating unit cells. Each of the unit cells may be in the shape of a polygon, such as a square or rectangle. The unit cells may be a full or part segment of a sinusoidal wave (e.g. a half wave segments). Neighbouring unit cells preferably have one or more common protrusions at the unit cell interfaces. In one embodiment, a protrusion defines a corner of a cell forming part of an adjacent unit cell. The unit cells may form a building block which enables the array (and sinusoidal pattern comprised therein) to extend across the surface of the conditioning head.

An advantage of the unit cell is that the size of the unit cells can be proportionally adjusted to change the density of protrusions, enabling the same sinusoidal pattern to be convenienlly scaled depending upon the specific needs of the application.

Each unit cell may comprise at least 5 or at least 8 or at least 12 or at least 20 protrusions.

The size of the unit cell will be dependent on the specific application, but the average length of a size of the unit cells is typically between 100 pm and 10,000 pm. The surface area of the unit cell is typically in the range of 0.01mm2 to 100mm2.

The relative positioning of the sinusoidal pattern design is preferably such that neighbouring protrusions have a minimum separation distance. The minimum separate distance between protrusions (edge to edge) may be at least 50 pin or at least 100 pm or at least 150 pm or at least 200 pm or at least 250 pm. A minimum separate distance reduces the likelihood that localised protrusion density does not result in uneven conditioning of the resultant polishing pad.

In a second aspect of the present disclosure, there is provided a method a designing protrusion patlern on a conditioning head comprising the steps of: a. creating one or more sinusoidal wave patterns and b. placing a plurality of protrusions on the one of more sinusoidal wave patterns.

The method of design may produce conditioning head as described in the saspect of the present invention.

The plurality of protrusions preferably form a unit cells. The unit cell may be repeated to creale a. conditioning head protrusion pattern.

In one embodiment, the one of more inusoidal pattern is determined through taking into account the relative rotational movement of the conditioning head and a polishing pad. Other parameters, such as the larget pad cut rate; the polishing pad material; and the slurry characteristics may also be taken into account when designing the protrusion pattern.

Abrasive region The protrusions forming the abrasive region may be made from any suitable material, including refractory particles, including diamond grit, cubic boron carbide, boron suboxide, boron carbide, silicon carbide, tungsten carbide, titanium carbide and chromium boride; composite materials comprising said refractory particles disperse in a matrix of filler or bond material including ceramic or polymeric bond matrixes. The protrusions may be coated with a refractory coating, such as a CVD diamond layer.

Each protrusion preferably has a height above the mean height of the substrate surface in the range of 5 pm to 250 pm, more preferably in the range of 10 pm to 150 pm, even more preferably in the range of 15 pm to 100 pm, and yet even more preferably in the range of 20 pm to 60 pm. In embodiments requiring low polishing pad wear rates, each protrusion has a height above the mean height of preferably less than 55 pm or less than 50 pm or less than pm or less than 40 pm.

The abrasive region may comprise a plurality of spiral vanes. In one embodiment, the top of the vanes are raised above the substrate surface with the protrusion extending from the raised vane surface.

Each protrusion has a cross-sectional length preferably in the range of 10 pm to 250 pm, more preferably in the range of 10 um to 150 pm, even more preferably in the range of 15 pm to 100 pm, and yet even more preferably in the range of 20 pm to 60 pm.

Each protrusion is preferably rounded, convex, and/or has a flat top surface. In some embodiments, the protrusions are geometric in shape (e.g. polygon, square, circle, triangle, hexagon etc.). In other embodiments, the protrusions are non-geometric in shape (e.g. refractory particles, such as diamond grit). In embodiments where protrusions are formed from refractory particles, conditioner heads are monitored to screen out over-sized protrusions that may detrimentally impact upon the balance between pad wear rate, wafer material removal from the polishing pad, rejuvenation of asperity structure of the polishing pad, and slurry retention of the polishing pad.

Non-abrasive region In some embodiments, the conditioning head comprises a non-abrasive region. The nonabrasive region may function as a means to carry away debris and slurry particles from the conditioning head surface. The non-abrasive region may comprise channels which radiate from a central portion of the conditioning head to an outer portion of the conditioning head.

The channels may be in the form of a single spiral or a plurality of spirals. The channels are preferably defined between abrasive regions comprising the plurality of protrusions according to the first aspect of the present disclosure. The width of the channel is typically between 100 pm and 20 mm and in some embodiments may between 200 pm and 5 mm.

The spirals can be discreet or continuous, separate or joined. Separate spirals can emanate from different central points (i.e., each spiral has its own central point), can emanate from a common central point (i.e., each spiral shares a central point), or combinations thereof. Spiral patterns can include: an Archimedean spiral; a Euler spiral, Cornu spiral, or clothoid; a Fermat's spiral; a hyperbolic spiral; a lituus; a logarithmic spiral; a Fibonacci spiral; a golden spiral; or combinations thereof.

The non-abrasive region may also include a central zone position at or near the centre of the conditioning head. By leaving a central non-abrasive zone around the axis of rotation of the conditioning head, an otherwise high concentration of wear near the axis of rotation can be avoided. The non-abrasive region may comprise at least 2% or at least 5% or at least 10% or at least 20% of the radial length from the central axis to the peripheral edge of the conditioning head.

As used herein, the meaning of the term "conditioning" encompasses the removal of the outer layers of the polishing pad and the embedded wafer material embedded therein and/or the rejuvenation of the polishing pad's asperity structure. As used herein, the term "conditioning head" and the term "conditioner head' are terms which may be used interchangeably.

As used herein, the term "wear rate" (unless context dictates otherwise) means the rate of removal of the outer layers of the polishing pad, which is a measure of the durability of the polishing pad.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a schematic diagram of a conditioning head conditioning a polishing pad.

Figure 2 is a 2D plot of a unit cell illustrating the location of protrusions along a virtual sinusoidal pathway.

Figure 3 is a 20 plot of a plurality of unit cells of Figure 2.

Figure 4 is an illustration of a spiral arrangement defining an abrasive region of a conditioning head.

Figure 5 is a magnified image of Figure 4, illustrating the sinusoidal protrusion pattern forming the abrasive region.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE PRESENT INVENTION

CMP apparatus 10 illustrated in Figure 1 contains platen 12 with a polishing pad 14 securely fastened thereto. The polishing pad 14 is shown rotating, for example, in a clockwise direction. The semiconductor wafer holder 16 with a wafer 18 is, positioned as shown to urge and maintain the wafer 18 against the exposed surface of the pad 14. The holder 16 is shown rotating, for example, in a counter clockwise direction. The water 18 is secured to the holder 16 by means of a vacuum or other means well known in the art. The polishing slurry is dispensed within the center region of the pad 14 through the nozzle of a conduit 22. The slurry 20 lypically consists of silicon dioxide dispersed within a suitable liquid, typically an acidic or alkaline etchant solution such as potassium hydroxide diluted with water. The exact composition of the slurry is closely calculated to provide the desired pianarization of the exposed surface of the wafer. Although the apparatus 10 shows only one wafer holder, CMP equipment is commerciatly available that includes multiple holders.

The polishing pad conditioning head or disk 24 comprises a substrate 26 comprising a plurality of protrusions which are aligned along one or more sinusoidal virtual pathways (otherwise known as sinusoidal wave patterns). In one embodiment, the substrate 26 (inclusive of protrusions) comprises natural or synthetic diamond grit 28 (shown schematically) evenly distributed over the surface of substrate 26 and a continuous thin film 30 of CVD polycrystalline diamond (hereinafter referred to as ''CVD diamond") grown onto protrusion 28 and substrate 26 so that the protrusion 28 is encased in CVD diamond 30 and bonded to the surface of substrate 26. The protrusion pattern (not shown) is configured such that the relatively movement of the protrusions over the polishing pad 14 surface results in a relatively even distribution of protrusion impact tracks on the polishing pad surface.

A conditioning head typically comprises a backing plate, such as a stainless steel plate, bonded on a substrate, which may comprise a variety of material including ceramic material, such as Si or Si3N4, or from at least one ceramic material selected from the group consisting of A1203, AIN, TO,, ZrOA, 802, SiC, SiO,N, WI\la WC\ DLC (diamond like coating), BN, and 0r203. Preferably, the substrate is a carbide.

The substrate can be made from a cemented carbide material such as tungsten carbides (WC) selected from the group consisting of tungsten cart onite-cobalt (WC-Co), tungsten carbcmite-carbon titanium-cobalt (WC--I iC-Co), and tungsten carbonite-carbon titanium-carbon tantalum-cobalt (WC-TiC-TaC-Co). The substrate can also be made from other cemented carbide materials such as "HON, 840, or TiB2. In a preferred embodiment, the substrate comprises Reaction-Bonded Silicon Carbide (RBSiC) comprising silica carbide and unrea.cted silica carbide forming material, e.g. Si. Further details on RBSiC are disclosed in U87,367,875, which is incorporated into the current specification to the extent allowable under national law.

The substrate is usually in the form of a disk ranging in diameter from about two (2) to four (4) inches (about 50 to 100mm). However, other geometries have been used as the substrate for conditioning heads. The thickness of base substrate ranges from about 0.5mm to about 6.5mm, preferably 1.0mm to 2.0mm for a silicon substrate. Thicknesses for other substrates may vary from these ranges. For instance, the silicon carbide-silicon composite substrate may have a thickness ranging from about 1.0mm to about 7.5mm, although thickness outside this range are also feasible. Larger * lameter substrates will be correspondingly thicker.

In some embodiments, the substrate comprises an abrasive region in the form of a spiral vane. in some embodiments, the top of the spiral vane is raised approximately between 0.5mm to 2rnm from the natural plane of the conditioning head.

Details of the variations in configuration and methods of producing the abrasive region is further detailed in US20090224370 in the name of the applicant. US20090224370 is incorporated into the current specification to the extent allowable under national law.

A polycrystalline CVD diamond layer typically covers the whole of the conditioning head, although in some embodiments, the vanes, when present, may be separately attached to backing plate.

The diamond layer may cover the majority (e.g. > 80%) of the conditioning head. The abrasive region of the substrate is preferably uniformly distributed with about 100 to 5000 grains per mrn2 of diamond grit having an average particle diameter preferably less than 10 pm and even more preferably between 0.5 to 2 um. However, seedless formation of the CVD diamond layer is also possible. The concentration and size of the grain as well as the CVD diamond processing conditions may be adjusted to achieve the required surface roughness. Further details of the CVD diamond process is provided in paragraphs 73 to 76 of LIS20090224370 which are incorporated by reference, Other seeding methods are disclosed in US6054183.

Figure 2 illustrates a two dimension graphic plot 110 used in making a conditioning head of the present disclosure. The 1 mrn2 plot 110 may be used to determine the location of each protrusion 120 along a virtual sinusoidal pathway 130. The plot 110 preferably comprises of a unit cell. The unit cell 110 represents a repeatable sinusoidal pattern, which includes two sine waves 130, 160 and two cosine waves 140, 150. The unit cell has an array of 18 protrusions, with each corner protrusion shared with 4 adjacent unit cells, resulting in a protrusion density of 18 protrusions/mm2.

Sine wave 130 is defined by the formula: Y = A1Sin (8,(X + r.)) + Sine wave 140 is defined by the formula: '1= A2Cos (B2(X + rr)) + 02 Sine wave 150 is defined by the formula: '/= A2Cos (E2X) + 02 Sine wave 160 is defined by the formula: Y = A1Sin (E31X) = A2 1/SUP: B1=B2-1; (1\1-1)*U0; D2= (N-1⁄2)U; Ur = Unit cell; and N = row number of a Multiple unit cells may be conveniently used to generate an abrasive area, such as the 6 x 4. unit cells provKled in Figure 3.

The unit size may be any appropriate size as determined by skilled artisans in the field of CMP conditioning head design. However, as a guide, unit size cells may have side dimensions of between 100 pm and 100,000 pm. ihe unit cell illustrated in Figures 2 & 3 has side dimensions of 1000 um by 1000 pm.

The sine wave pattern (half wavelength) 130, 160 of the unit cell is formed from 6 protrusions, including two protrusions which are shared with neichbouring unit cells as illustrated in Figure 3. The cosine wave pattern (half wavelength) 140, 150 comprises 5 protrusions, includino at shared protrusion at coordinate 500, 500. This nesting configuration enables a higher density of protrusions per unit area to be achieved. The total number of protrusion were unit cell is 18 (with four corner protrusions being shared with neighbouring unit cells, such that the four corner protrusions contribute to a single protrusion to the unit cell). As indicated in Table 1. there may be a variation in the calculated protrusion density of a sinusoidal wave pattern design and the actual generated. Variations in the density of positioning of the protrusions may be due to variations in the manufacturing process.

The sinusoidal wave pattern of protrusions may be used as a template to be overlaid onto the macro design of the conditioning head. Whilst, the entire conditioning head may be covered by the sinusoidal wave pattern of protrusions as provided in Figures 2 & 3, in a preferred embodiment the sinusoidal wave patterns form abrasive regions of the conditioning head which are separated by non-abrasive regions.

Figure 4 illustrates a conditioning pad having a diameter of 100 mm. The abrasive region of the conditioning pad 200 is separated by non-abrasive reoions in the form of channels 210 designed to enable particulates (slurry and pad debris) to be removed from the conditioning head surface. The channels provide a non-abrasive region between adjacent abrasion regions of 2.55mm. The central portion of the conditioning head may also comprise a non-abrasive region 220. The central non-abrasive region has a diameter of about 32 mm. Figure 5 illustrates a magnified image of Figure 4, with the sinusoidal pattern of the protrusions forming the abrasive region 200 more dearly distinguishable.

EXPERIMENTS 5 EXAMPLE 1 A conditioning head was produced with a macro design outlining the abrasive and nonabrasive recions illustrated in Figure 3. The abrasive region comprised protrusions (CVD coated SIC) having a sinusoidal pattern based on a unit cell as illustrated in Figures 1, 2. The unit cells and parts thereof form the basis spiral abrasive region illustrates in Figures 3 and 4.

The comparative conditioning head had a conventional square array pattern.

The conditioning heads were used to condition 8" diameter microporous polyurethane polishing pad sold under the tradename IC1010 available from DOW®.

The polishing pad were conditioned using a slurry consisting of deionized water at a flow rate of 10 ml/min using 4' (100mm) diameter conditioner heads as described in Table 1. A Bruker C4 machine was used at a platen speed of 160 rpm and a conditioner head speed of 160 rpm with a downforce of 8 lbs. The conditioner head sweep setting was 1 mm.

The polishing pads were conditioned for 30 minutes with the polishing pad thickness measured with a Onix® probe before and after the test to determine pad removal rate.

Example 1 has a lower cut rate provides similar pad texture.

Parameter Example 1 Comparative example 1 Array type Sinusoidal Square Unit cell size(LU 1000 225 o. 18 20 Density Cale (#1mm-) Density actual (#/. Ira) 20.7 19.2 Feature shape Square Square Feature size 44.4 44 Feature height (p) 32.0 37 Pad art rate (t/hr) 16.4±9.1 29.018.1 Pad texture, Sa (p) 4.18+0.55 4.271-0.64 *laroest cross sectional dimension

Table 1

Conventional conditioner heads possess a correlation between pad cut rate and texture, with a higher texture on the polishing pad correlating with a higher pad cut rate. Conditioner heads under the scope of the present invention have been able to decouple this correlation through achieving a similar polishing pad texture, but at a significantly lower pad cut rate, thereby producing a high performance polishing pad with a longer effective service life.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. For the avoidance of doubt, the terms "may", "and/or", "e.g.", "for example" and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Claims (2)

1. CLAIMSA conditioning head comprising: a. a substrate comprising a substrate surface; b. a plurality of protrusions extending between 5 and 250 microns from the substrate surface, wherein the plurality of protrusions form one or more sinusoidal wave patterns on the substrate surface.
2. 2. The conditioning head according to claim 1, wherein a wavelength of each wave pattern comprises at:east 6 protrusions. 10 3. The conditioning head according to claim 1, wherein a wavelength each wave pattern comprises at least 8 protrusions.4. The conditioning head according to any one of the preceding claims, wherein the plurality of protrusions form at least two sinusoidal wave patterns, wherein the wave patterns have a phase offset of between 30° and 2700.5. The conditioning head according to claim 4, wherein the wave patterns comprise different amplitudes. 20 6. The conditioning head according to claims 4 or 5, wherein the wave patterns comprise different frequencies.7. The conditioning head according to any one of the preceding claims, wherein the plurality of protrusions form an array comprising a plurality of repeating unit cells.8. The conditioning head according to claim 7, wherein each unit cell comprises at least 6 protrusions.9. The conditioning head according to any one of claims 7 ore, wherein the unit cell is in the shape of a square or rectangle.10. The conditioning head according to any one of claims 7 to 9, wherein one-or more protrusions define a corner of the cell, each protrusion defining a. corner of a cell forming part of an adjacent unit cell.The conditioning head according to any one of claims 7 to 10, wherein the unit cell has a surface area in the range of 0.01 rnm2 to 100 rnm2.12. The conditioning head according to any one of the preceding claims wherein the density of protrusions is between 1 protrusionsimm2 and 100 protrusionsimm2.The conditioning head according to any one of the preceding cialms wherein the minimum distance between adjacent protrusions is in the range of to 10.0 The conditioning head according to any one of the preceding claims, wherein the substrate surface comprises a plurality of raised surfaces stemming from a planar base.The conditioning head according any one of the preceding claims, wherein the protrusions are within 20% of the amplitude of a virtual pathway of the one of more sinusoidal wave patterns.16. The conditioning head according to claim 15, wherein t p t y is delined by the formula: A*Sin (3 (X-C)) + Where: A = amplitude of the wave; the frequency of the wave' 0 = the horizontal shift of the wave; and D = the vertical shift of the ave.17. The conditioning head according to any one of the preceding claims, wherein the plurality of protrusions cover the substrate surface, except tor exclusions zones.The conditioning head according to claim 8, where in the exclusion zone comprises an area surrounding the central axis of the conditioning head.The conditioning head according to claim 8 or 9, wherein ihe exclusion zone includes one or more pathways radiating from a central zone to a peripheral zone. 20. 21. 22. 23. 24. 25.A collection of conditioning heads, comprising two or more conditioning heads according to any one of claims 1 to 16, wherein the two or more conditions having have different densities of protrusions and/or different protrusion height or shape.A method a designing a protrusion pattern on a conditioning head according to any one of the preceding claims comprising the steps of: a. creating one or more sinusoidal wave patterns; and b. placing a plurality ol protrusions on the one of more sinusoidal wave patterns.The method according to claim 21, wherein the plurality of protrusions form a unit The method according to claim 22, wherein the Una cell is repeated to create a conditioning head protrusion pattern.The method according to any one of claims 21 to 23, wherein the protrusion pattern comprises a spiral abrasive region separated by a non--abrasive region.The method according to any one of claims 21 to 24, wherein the one of more sinusoidal pattern is determined through taking into account the relative rotational movement of the conditioning head and a polishing pad.