CN100561182C - Use the polishing endpoint detection system of friction sensor - Google Patents

Abstract

Systems approach and the equipment of monitoring the friction factor of the substrate that is just experiencing polishing have been described.Polishing pad component comprises polishing layer with polished surface and the flexible couplings substrate contact member to polishing layer, and the substrate contact member has the top surface of the exposed surface of contact substrate.The basic coplane of at least a portion of top surface and polished surface.Sensor is set easily measures the transversal displacement of substrate contact member.Some embodiment can provide accurate endpoint detection to indicate the exposure of lower floor during chemically mechanical polishing.

Description

Use the polishing endpoint detection system of friction sensor

Technical field

The present invention relates to the chemically mechanical polishing of substrate.

Background technology

Integrated circuit is formed on the substrate by the deposition in succession at silicon wafer upper conductor, semiconductor or insulator layer usually.A manufacturing step relates to packing layer is deposited on the non-planar surfaces, and the complanation packing layer exposes up to non-planar surfaces.For example, in (STI) handled, the oxide filler layer can be deposited on the nitride layer of patterning to fill groove or the hole in the nitride layer (with following silicon) at shallow trench isolation.Packing layer is followed polished projection pattern up to nitride layer and is exposed.After complanation, the part of remaining oxide skin(coating) provides the isolation between the circuit on the substrate.In addition, need complanation so that substrate surface planeization is used for photoetching.

Chemically mechanical polishing (CMP) is a kind of received method of planarizing.This method of planarizing need be installed in substrate on carrier head or the rubbing head usually.The exposed surface of substrate is placed as against the polished surface such as rotation polishing plate mat or band pad.Polished surface can be " standard " pad or fixed abrasive pad.Standard pad has durable rough surface, and fixed abrasive pad has and remains on the abrasive grains that holds in the medium.Carrier head is provided on the substrate controlled load with its backup polishing pad.If the abrasive grains when comprising the polishing slurries of at least a chemical reactor and using standard pad is supplied to polished surface.

A problem in CMP is to judge whether polishing is finished, that is, whether substrate layer has been planarized to desired flatness or thickness, when has removed desired quantity of material, perhaps when has exposed following layer.The variation of load can cause the variation on the material removal rate on relative velocity between the original depth of substrate layer, slurry content, polishing pad condition, polishing pad and the substrate and the substrate.These variations have caused arriving the variation of polishing end point required time.In this, polishing end point only can not be judged as the function of polishing time.

A kind of mode of judging polishing end point is to remove substrate and check substrate from polished surface.For example, substrate can be transferred to metrology station, utilizes profilograph for example or resistivity measurement to measure the thickness of substrate at the metrology station place.If do not satisfy desired specification, then substrate is downloaded in the CMP equipment with further processing by refitting.This is a time consuming process, and it has reduced the production capacity of CMP equipment.Alternatively, inspection may show the material that has removed the mistake volume, makes substrate unavailable.

Recently, in order to detect polishing end point, utilized optics for example or capacitive transducer to carry out the original place monitoring of substrate.The endpoint Detection of other proposals has related to the measurement of friction, current of electric, slurries chemistry, acoustics, electric conductivity and the vortex flow of inducting.But, depend on that the technology to the detection that is deposited on electric conductivity between two substrate layers on the substrate or reflexive change is invalid when two layers have similar electric conductivity or reflectivity.

Summary of the invention

Generally, in one aspect, the present invention is directed to the equipment of friction factor that the substrate of polishing is just being experienced in a kind of monitoring.This equipment comprises movable member and sensor, and movable member has the top surface of the exposed surface of contact substrate, and described sensor produces signal based on the transversal displacement of movable member.Described member is in response to from the friction force of substrate and transversal displacement, and comprises the top surface with surface area littler than the surface area of the exposed surface of substrate.

The embodiment of this equipment comprises one or more in the following feature.Answer material such as sheet spring or a plurality of spring can be coupled to movable member.Movable member can comprise the polishing pad segment.The polishing pad segment can comprise two-layer.Movable member can comprise the support chip that is coupling between answer material and the polishing pad segment.The sensor that produces signal based on the transversal displacement of movable member can be a strainometer.A plurality of strainometers can be attached to described spring at maximum strain point place.The sensor that produces signal based on the transversal displacement of movable member can be optical sensor or the piezoelectric sensor such as laser interferometer.The top surface of movable member can with the basic coplane of the polished surface of polishing pad.Movable member can be connected to pressing plate, for example rotatable pressing plate.Movable member can separate gapped with pressing plate.Soft sealing film can be coupled to movable member, is used to prevent slurries transmission passing through gap.Soft sealing film can be inserted in replys between material and the movable member.

Generally, in yet another aspect, the present invention is directed to the equipment of friction factor that the substrate of polishing is just being experienced in a kind of monitoring.This equipment comprises member, replys material and sensor, and described member has the top surface of the exposed surface of contact substrate, and described answer material is connected to structure with member, and described sensor produces signal based on replying material strain.Described top surface has the surface area littler than the surface area of the exposed surface of substrate.

Generally, in yet another aspect, the present invention is directed to a kind of chemical-mechanical polisher.This equipment comprises supporter, carrier, motor and sensor, described supporter is used for polishing article, described carrier is held against substrate the polished surface of polishing article, described motor be coupled in polishing article and the carrier at least one be used for producing betwixt relative motion, described sensor is used to measure strain.Described sensor comprises movable member, described member has the top surface of the exposed surface of contact substrate, described member is in response to from the friction force of substrate and transversal displacement, described top surface has the surface area littler than the surface area of the exposed surface of substrate, and described sensor comprises the sensor that produces signal based on the transversal displacement of described movable member.

Embodiments of the present invention can comprise one or more in the following feature.When keeping polishing article by supporter, top surface can with the basic coplane of polished surface.

Generally, in yet another aspect, provide a kind of pressing plate that is used for chemical-mechanical polisher.This pressing plate comprises substrate, and described have the recess that is used to hold strain transducer substantially, and described recess has the cross-sectional area bigger than the cross-sectional area of strain transducer, to allow the displacement of strain transducer.Also comprise the strain transducer that is placed in the recess, described strain transducer comprises replys material and at least one device, described answer material has the cross-sectional area littler than the cross-sectional area of polished surface, described answer material directly contacts substrate sometimes, or by being coupled to the other materials contact substrate of replying material, described other materials has the cross-sectional area littler than the cross-sectional area of polished surface, and described at least one device is used to measure on the direction of relative movement between substrate and the sensor replys material strain.

In yet another aspect, the present invention is directed to a kind of object that is used for polishing system.This object comprises film and polishing pad flexible, fluid impermeable, and described polishing pad is fixed to the first surface of film.The edge of film extends beyond the edge of polishing pad.

Embodiments of the present invention can comprise one or more in the following feature.Bonding agent can be positioned at film with the first surface opposing second surface on and/or on the first surface of the film of polishing pad.Removable liner can cover bonding agent.Polishing pad can comprise overlayer and backing layer, and the backing layer can be than the easier compression of overlayer.Film can be silicone or latex.

In one aspect, the invention describes the system of friction factor that the substrate of polishing is just being experienced in a kind of monitoring.Polishing pad component comprises polishing layer and substrate contact member, and described polishing layer comprises polished surface, and described substrate contact member is coupled to polishing layer flexibly, and described polishing layer has the top surface of the exposed surface of contact substrate.At least a portion of top surface and the basic coplane of described polished surface.Be provided with sensor and measure the transversal displacement of substrate contact member.

Embodiment can comprise one or more in the following feature.Polishing pad component can have the hole by it.The substrate contact member can be positioned in the described hole.Sensor can comprise strainometer or pressure gauge.Alignment device can be coupling between substrate contact member and the sensor.Polishing pad can center on but not contact the substrate contact member.Seal can extend between substrate contact member and polishing pad.Seal comprises flexible, fluid impermeable material.Seal can be made by silicone, latex or polyurethane.Seal can be the O ring, and the O ring can utilize adhesives to be fixed to substrate contact member and polishing pad.Seal can extend through the substrate contact member.The substrate contact member can be by being connected the substrate contact member with polishing layer with the curved pleat of polishing pad decoupling zero.Curved pleat can form by the recess in the apparent surface of polishing pad.

In yet another aspect, the invention describes a kind of polishing system.This system comprises displacable platen.Polishing pad is connected to displacable platen, and polishing pad has polished surface and has therein hole.The substrate contact member is included in the hole, and has the top surface of the exposed surface of contact substrate.The basic coplane of the top surface of substrate contact member and polished surface.The transversal displacement of sensor measurement substrate contact member also produces signal based on the transversal displacement of substrate.Controller is from the sensor received signal.

Embodiment can comprise one or more in the following feature.Sensor can be strainometer or pressure gauge.Alignment device can be coupling between substrate contact member and the sensor.Polishing pad has the top surface of the exposed surface of contact substrate.Polishing pad can center on but not contact the substrate contact member.Diaphragm seal can extend between substrate contact member and polishing pad.Diaphragm seal can be made by material flexibility, fluid impermeable.Diaphragm seal can be made by silicone, latex or polyurethane.Diaphragm seal can be the O ring.The O ring can utilize adhesives to be fixed to substrate contact member and polishing pad.Seal can extend through the substrate contact member.Polishing pad can have the top surface of the exposed surface of contact substrate, and polishing pad can be by making with substrate contact member identical materials sheet.Curved pleat can mechanically be isolated substrate contact member and polishing pad.

In yet another aspect, the invention describes a kind of object that is used for polishing system.Polishing pad has polished surface.The substrate contact member has the top surface of the expose portion of contact substrate.The basic coplane of top surface and polished surface.Seal is formed by flexibility and material fluid impermeable, the substrate contact member is fixed to polishing pad and allows the substrate contact member laterally to move with respect to polishing pad.

Embodiment can comprise one or more in the following feature.Polishing pad can have two-layer or more multi-layered.Seal can be fixed between polishing pad two-layer.Seal can extend through whole polishing pad, perhaps can only partly extend in the polishing pad.The first surface of alignment device can be attached to the substrate contact member.Containment member can also contact with alignment device.Alignment rods can be extended from the second surface of alignment device.The top surface of substrate contact member can be by forming with the polishing pad identical materials.The top surface of substrate contact member can comprise groove, and described groove leaves the substrate contact member with the liquid guiding.Seal can be the O ring.Seal can comprise silicone, latex or polyurethane.Polishing pad can be become by a continuous material piece system with the substrate contact member.

In yet another aspect, the invention describes the equipment of friction factor that the substrate of polishing is just being experienced in a kind of monitoring.Movable member has the top surface of the exposed surface of contact substrate.Top surface has the surface area littler than the surface area of the exposed surface of substrate.Connecting elements is coupled to movable member.Connecting elements can be along the channel laterally displacement in response to the friction force from substrate.Sensor is based on the transversal displacement generation signal of connecting elements along raceway groove.

Embodiment can comprise following one or more.Movable member can comprise the polishing pad segment.The sensor that produces signal based on the transversal displacement of connecting elements can be a strainometer.The top surface of movable member can with the basic coplane of the polished surface of polishing pad.Stationary installation can be coupling between polishing pad segment and the connecting elements.Stationary installation can be coupled to connecting elements by alignment rods.Film flexible, fluid impermeable can make polishing slurries not enter raceway groove or sensor between stationary installation and connecting elements.Film can be silicone, latex or polyurethane.

In yet another aspect, the invention describes a kind of method of assembling polishing pad.The substrate contact member is aligned in the mould.Mould has the lug edge, makes the substrate contact member aim at the inside surface on lug edge.The polishing pad that will have opening is aimed at the outside surface on lug edge, makes opening aim at the outside surface on lug edge.Encapsulant is placed on by substrate contact member, polishing pad and lug along in the recess that forms.

Embodiment can comprise one or more in the following feature.Alignment device can be aimed at the substrate contact member, be made the first surface of alignment device be attached to the substrate contact member, and also contact float device of encapsulant.Alignment rods can be extended from the second surface of alignment device.The top surface of substrate contact member can be by forming with the polishing pad identical materials.The top surface of substrate contact member can comprise groove, and described groove leaves the substrate contact member with the liquid guiding.Encapsulant can be the O ring.Encapsulant can be latex, silicone or polyurethane.

In yet another aspect, the present invention is directed to a kind of equipment of monitoring the friction factor of substrate during polishing operation.This equipment has member, and described member cooperates with the zone of the substrate surface that just experiences polishing.Described zone has the surface area littler than the surface area of substrate, and described member is laterally removable with respect to polished surface.

Embodiment can comprise one or more in the following feature.This equipment can comprise the device that is used to produce signal, and described signal has been indicated the side-friction of substrate to member.Member can comprise the part of polishing pad, perhaps comprises the main body that is connected to pressing plate movably.Member can be laterally removable on single substantially direction, perhaps can be laterally removable on two vertical directions.

In yet another aspect, the present invention is directed to a kind of method of monitoring the friction factor of substrate during polishing operation.This method may further comprise the steps: with the surface alignment of substrate for contact with polished surface and contact with the top surface of member simultaneously, described member with respect to polished surface laterally removable and generation indicate the signal of substrate to the friction force of member.

These basic and concrete aspects can using systems, method or equipment, and perhaps any combination of system, method and apparatus is implemented.And any one of above-described various features can be used in combination with other features or other aspects of the present invention.

The present invention can implement with realize in the following advantage some, all or do not have.Can during chemically mechanical polishing, provide the exposure of accurate endpoint detection in conjunction with chemical-mechanical polishing system of the present invention or equipment with indication lower floor.Provide end point determination during the polishing of in addition, the present invention can be just polished therein layer is nonconductor.In addition, the present invention can be just polished therein layer and layer to be exposed provides terminal point to control during having the polishing of similar optical properties (for example reflectivity and refraction coefficient).Particularly, silicon dioxide layer is polished to provide end point determination during shallow-trench isolation (STI) polishing that exposes silicon nitride layer therein in the present invention.The present invention can also be just polished therein layer and to be exposed layer of polishing with similar electric conductivity in end point determination is provided.

One or more embodiments of the detail of the present invention will be illustrated in accompanying drawing and following explanation.From instructions and accompanying drawing, and in the accessory rights requirement, other features of the present invention, purpose and advantage will become clear.

Description of drawings

Fig. 1 is the schematic, exploded, isometric illustration of chemical-mechanical polisher.

Fig. 2 is the schematic side elevation that comprises that the part of the chemical-mechanical polisher of the sensor-based system that rubs is analysed and observe.

Fig. 3 is the schematic plan that comprises the chemical-mechanical polisher of strain transducer.

Fig. 4 A-4B is the schematic side elevation that the part of strain transducer is analysed and observe.

Fig. 4 C-4E is the schematic side elevation with polishing pad of strain transducer.

Fig. 5 is the schematic circuit of strain gauge means.

Fig. 6 A, 6B, 6D and 6M are the schematic cross sectional views of strain transducer.

Fig. 6 C is the schematic cross sectional views that is mounted in the object in the polissoir.

Fig. 6 E schematically illustrates the method with polishing pad and the assembling of sticking patch dig pass sensor.

Fig. 6 F-6J is the schematic cross sectional views that is mounted in the object in the polissoir.

Fig. 6 K-6L is the schematic cross sectional views with biplate polishing pad of shield gasket layer.

Fig. 7 A-7C indicative icon use strain transducer to detect the method for polishing end point.

Fig. 8 A-8B illustrates for the friction of the polishing figure to the illustrative trace of time.

Fig. 9 illustrates the process flow diagram of the method for the chemically mechanical polishing that is used to realize to use strain transducer.

Figure 10 is the schematic circuit of the embodiment of strainometer bridge joint and amplifying circuit.

Figure 11 is the schematic side elevation that the part of the optional embodiment of strain transducer is analysed and observe.

Figure 12 is the schematic side elevation that the part of the optional embodiment of friction sensor is analysed and observe.

Figure 13 A is the schematic plan with polishing block of a plurality of sensors.

Figure 13 B has the schematic plan of a plurality of sensors with the polishing block of the friction on the measurement orthogonal directions.

Figure 14 is the schematic plan with strain transducer of support column.

Similar label is represented similar components in each figure.

Embodiment

With reference to Fig. 1 and 2, can be by the one or more substrates 10 of CMP equipment 20 polishings.Similarly the explanation of polissoir 20 can be in U.S. Patent No. 5,738, finds in 574, and it is all open to be incorporated into this by reference.Polissoir 20 comprises mechanical base 21, and mechanical base 21 supports a series of polishing blocks 22 and band to band transfer module 23.Band to band transfer module 23 transmits substrate between carrier head and charging appliance.

Each polishing block comprises the rotary pressure plate 24 of placing the polishing article such as polishing pad 30 on it.Polishing pad 30 can be double-deck polishing pad, the individual layer hard pad with the durable outside surface of hard, fixed abrasive pad or the soft relatively pad with embedding abrasive grains.Each polishing block can also comprise that pad conditioning equipment 28 makes it incite somebody to action polished substrate 10 effectively with the condition of keeping polishing pad 30.

Double-deck polishing pad 30 has the backing layer 32 and the overlayer 34 with polished surface 31 in abutting connection with the surface of pressing plate 24 usually, and polished surface 31 is used for polished substrate 10.Overlayer 34 is stiffer than backing layer 32 usually.Overlayer 34 can be made up of foam or molded polyurethane, and it can have for example filler and/or the grooved surface of hollow microspheres if possible.Backing layer 32 can be by fibrous with the compression felt of urethanes leaching.The double-deck polishing pad of the backing layer that has the overlayer be made up of IC-1000 and be made up of SUBA-4 can obtain (ProductName that IC-1000 and SUBA-4 are Rodel company limited) from the Rodel company limited in the Niu Huake city of the Delaware State.

Rotatable bull transfer station 60 supports four carrier head 70.By transfer station electric machine assembly (not shown), transfer station by newel 62 around transfer station axis 64 rotation so that carrier head systems and be attached to its substrate orbital motion between polishing block 22 and band to band transfer module 23.Three in the carrier head systems receive and the maintenance substrate, and by substrate being pressed polishing pad 30 with its polishing.Simultaneously, in the carrier head systems receives substrate 10 and substrate 10 is delivered to band to band transfer module 23 from band to band transfer module 23.

Each carrier head 70 is connected to carrier head electric rotating machine 76 (illustrating by removing 1/4th lids 68) by carrier drive shaft 74, makes that each carrier head can be independently around himself axis rotation.In addition, each carrier head 70 transverse vibration in the radial slot in being formed at transfer station back up pad 66 72 independently.The explanation of suitable carrier head 70 can be the Application No. No.10/810 that on March 26th, 2004 submitted, and finds in 784, and it is whole openly to be incorporated into this by reference.When operation, pressing plate 24 is around its central axis 25 rotations, and carrier head is also laterally transmitted the surface of crossing polishing pad around its central axis 71 rotations.

Slurries 38 can be fed to polishing pad 30 by slurries/cleaning arm 39 that slurries are supplied port or combination.If polishing pad 30 is standard pad, then slurries 38 can comprise abrasive grains (silicon dioxide that for example, is used for oxide cmp).

With reference now to Fig. 2 and 3,, recess 26 is formed in the pressing plate 24, and hole 33 is formed in the polishing pad 30.Recess 26 and hole 33 are positioned in the below of some the effluxion substrate 10 during the relative motion between polishing pad 30 and the substrate 10.For example, suppose pressing plate 24 rotation, recess 26 will be along the path 96 be crossed substrate 10, so substrate 10 is crossed in scanning.

The friction sensor-based system of the change on the friction factor of the local zone of dispersion of monitoring and detection substrate partly is placed in the recess 26.The friction sensor-based system comprises that strain sensing mechanism (strain transducer) 46 and being used to such as computing machine 90 handle the treating apparatus from the data of strain transducer 46.

Strain transducer 46 comprises substrate contact member 58, replys material and sensor, substrate contact member 58 can move when being subjected to from substrate friction force, reply material the substrate contact member is oppressed backward to the neutral position, sensor produces signal based on the displacement of substrate contact member.

Strain transducer 46 is placed in the recess 26 and extends through hole 33 in the polishing pad 30, make the top surface 45 of substrate contact member 58 shelve into polished surface 31 coplanes of polishing pad 30, wherein the cross-sectional area of substrate contact member 58 is less than substrate 10.Suppose pressing plate 24 rotation, strain transducer 46 and substrate contact member 58 will be along the path 96 be crossed substrate 10.Like this, the surface 45 of substrate contact member 58 is at least at some times when the each rotation at pressing plate 24 (for example, periodically) contact substrate 10.

Suppose pressing plate 24 rotations once more, strain transducer 46 can be constructed so that substrate contact member 58 by removable the circular path of substrate contact member 58 processes tangential, and usually with other directions vertical by the circular path of substrate contact member 58 processes on not removable.

An embodiment of strain transducer has been shown among Fig. 4.In this embodiment, the answer material is mounted in the sheet spring 48 on the pedestal 42.Sheet spring 48 can be formed by the metal material such as stainless steel.Sheet spring 48 can be the rectangular solid with narrow side 47.The composition of the thickness of narrow side 47 and sheet spring 48 can be selected based on desired friction force, makes sheet spring 48 be subjected to elastic bending (and not experiencing inelastic deformation) owing to contacting the friction force that causes with substrate 10 at strain transducer 46.Sheet spring 48 is oriented in recess 26 and makes that the direction of relative motion is vertical between surface and the substrate 10 and the strain transducer 46 of wide side 49 of sheet spring 48.Pedestal 42 provides rigid support, is used for that sheet spring 48 is fixed on recess 26 interior also limit lateral and moves.The frictional resistance that is caused by relative motion makes sheet spring 48 experience strain with the form of bending.

Particularly, can be with sheet spring 48 orientations under wide side 49 and the state substantially parallel through the radius of the rotation 25 of pressing plate.Like this, sheet spring 48 can be along as the transverse curvature by the tangential direction of the circular path of substrate contact member 58 processes, but along other laterally (for example, being parallel to radius) inflexibility relatively.

Gap 43 between substrate contact member 58 and pressing plate 24 provide be used for substrate contact member 58 along with the bending of sheet spring 48 mobile space.The size of gap 43 on tangential is based on the spring constant of sheet spring 48 and be applied to the expection magnitude of the friction force on the substrate contact member 58 by substrate 10.Gap 43 should provide enough spaces, and substrate contact member 58 state with the sidewall that do not contact recess 26 under the polishing condition (for example, carrier head downforce, pressing plate rotating speed and slurry content) of expection is moved.

Substrate contact member 58 can be attached to the surface of sheet spring 48, makes substrate contact member 58 and polishing pad 30 coplanes.Substrate contact member 58 can be monolithic maybe can comprise miscellaneous part such as support chip 57 and polishing pad segment 59 thereby the top surface 45 and polishing pad coplane of resulting strain transducer 46.

Usually, the top surface 45 of substrate contact member 58 is not by can forming the material that polishing has a negative impact, and for example, this material should be chemically compatible with the polishing environment, and enough soft to avoid scraping or damage substrate.For example, the segment 59 of polishing pad (the two partially polished pad that comprises backing layer 32 and overlayer 34 for example discussed above) can be installed on the support chip 57 and be placed on the top of sheet spring 48, and wherein segment 59 has the cross-sectional area littler than substrate 10.So, be installed to the polishing pad segment 59 and polishing pad 30 coplanes that are installed on the pressing plate 24 of substrate contact member 58.

Usually, the top surface 45 of polishing pad segment 59 is by forming with polished surface 31 identical materials that are used for polishing pad 30.In one embodiment, top surface 45 can be designed as the performance that strengthens strain transducer 46.For example, shown in Fig. 4 C, top surface 45 can have groove pattern 287 or squeegee formula structure, and it is designed to the slurries guiding away from polishing pad segment 59.Alternatively, shown in Fig. 4 D, top surface 45 can have the brush shape structure of bristle 288, and it is designed to keep in touch with substrate.

With reference now to Fig. 4 E,, be offset outside the plane when moving away from the equilibrium position for fear of sheet spring 48 when strain transducer 46, top surface 45 can also be with certain angle moulding.When the sheet spring left the equilibrium position, certain part of top surface 45 kept contacting with substrate.No matter this allow whether away from equilibrium location of sheet spring, can not produce on the front surface of substrate under the situation that differential pressure distributes, and strain transducer is measured owing to contact the friction force that causes with substrate.

As noted above, top surface 45 has the cross-sectional area less than substrate 10 (and less than polished surface 31).For example, top surface can be less than 5% of substrate surface area, or less than 1%.Top surface 45 can have about 0.20cm ²To 10cm ²Surface area, for example, top surface 45 can be that the length of side is 0.5 to 3cm square or has the circle of similar diameter.

Substrate 10 makes the substrate contact member 58 of strain transducer 46 carry out physics with substrate 10 off and on relative motion between the polishing pad 30 and contacts.This contact produces friction force on strain transducer 46, this friction force depends on the friction factor between strain transducer 46 and the substrate 10.Substrate contact member 58 horizontal (that is, being parallel to the surface of substrate 10 and polishing pad 30) under the effect of friction force is movable, and this transversal displacement causes the strain on the sheet spring 48.The dependent variable of sheet spring 48 experience depends on by substrate 10 and is applied to friction force on the strain transducer 46.Friction force partly depends on the character of backing material and also depends on the complanation degree of substrate.The degree that has reflected strain from the number percent distortion of the original shape of sheet spring 48.Can be out of shape the strain of measuring sheet spring 48 by monitoring this.In one embodiment, sheet spring 48 can be designed as and makes the relation of distortion and the friction force that applies at least for will the scope of desired power being linear in polishing operation.

Be used to measure the strain of sheet spring 48 or the device of displacement can be included in the recess 26.For example, strain or displacement measuring device can be based on to the optical monitoring of the position of sheet spring 48, measure strain to the detection of the variation of physical attribute such as electric conductivity of sheet spring 48 or by the attaching strainometer.In one embodiment, strain transducer 46 comprises a plurality of strainometers 50 that adhere to sheet spring 48.Strainometer 50 can be by 56 other strainometers 50 that are interconnected on the opposite side of sheet spring 48 that go between, and are coupled to the output system (not shown).

When the friction force between substrate contact chip 58 and the substrate 10 made that sheet spring 48 is crooked, strainometer 50 was also with bending, in the identical strain of attachment point place experience and sheet spring 48.A lip-deep strainometer 50 at sheet spring 48 will extend, and the strainometer 50 on the apparent surface of sheet spring 48 will be compressed.As a result, strainometer will produce with sheet spring 48 on the proportional signal of strain.

Exemplary strainometer 50 comprises the lead of certain-length, and is fixed directly to the object of its strain to be measured by bonding agent, and in the case, object is a sheet spring 48.By lead is arranged in the strainometer 50 with serpentine path, the length of lead can be longer than strainometer self.The extension of conductor length or compression will change the conductive properties of lead in each strainometer 50.Along with the length extension of guiding, resistance increases.On the contrary, when the compresses in length of lead, resistance reduces.

In an embodiment of strain transducer 46, used four stress gauges 50.Two strainometers 50 are placed on the surface of sheet spring 48, and two other strainometer 50 is placed on the apparent surface of sheet spring 48.When 48 bendings of sheet spring, two strainometers 50 will present increased resistance, and two other strainometer 50 on the opposite side of sheet spring 48 presents the resistance that reduces.

With reference now to Fig. 5,, strainometer bridgt circuit 52 can be used to schematically show the interconnection between the strainometer 50.In strainometer bridgt circuit 52, strainometer 50 can be expressed as four resistance with same basic resistance value R.Shown in the common bridgt circuit among Fig. 5, the strainometer 50 of experience increased resistance is represented by R+dR, and the strainometer 50 of the resistance that experience reduces is represented by R-dR, and its dR is that the resistance that the distortion by strainometer 50 causes changes.As the result who changes resistance, the change of current/voltage is less usually, and can be amplified so that stronger output signal as a result to be provided by amplifier 54 in some embodiments.The adaptability to changes that acts on the sheet spring 48 has been indicated in output.

With reference to figure 2 and 5, the amplification of strainometer bridgt circuit 52 output is sent to computing machine 90 and is used for handling again.Processing can comprise the calculating of friction factor between polishing pad segment 59 and the substrate 10, has the measurement of correlation of the strain transducer 46 of radial position on substrate 10, come the process of analytical chemistry mechanical buffing processing and strain measurement is converted to graphical information based on strain measurement.Output can show by the device such as monitor 92.

With reference to figure 2, as discussed above, be formed on gap 43 between strain transducer 46 and the pressing plate 24 and allowed to be used for the space that strain transducer 46 laterally moves under from the friction force of substrate 10.Potentially, slurries can flow in the recess 26 by this gap.Exhaust stack 44 can extend through pressing plate 24 to remove the slurries that are accumulated in the recess 26 during polishing.Exhaust stack 44 can be individually or is combined with elasticity of discussing below with reference to Fig. 6 A-6M or flexible fluid impermeable film and to work.

With reference now to Fig. 6 A-6M,, elasticity such as silicone or latex film or flexible fluid impermeable film (for example, diaphragm seal) can be used to seal the gap between strain transducer 46 and the pressing plate 24.Diaphragm seal prevents that slurries are through the gap and enter recess 26.Some exemplary sealing embodiments have been shown in Fig. 6 A-6M.

As shown in Figure 6A, containment member 84 forms the part of the support chip 57 of substrate contact member 58, and is connected to pressing plate 24 by one or more securing members 94.Diaphragm seal 84 strides across the gap between support chip 57 and the pressing plate 24.Diaphragm seal 84 can form the ring that surrounds support chip 57, and perhaps diaphragm seal 84 can be to be integrated in the support chip 57 or to be placed on solid piece on the top of support chip 57.Securing member 94 can be the securing member such as threaded screw, perhaps can provide fastening by adhesives.Polishing pad segment 59 can be attached to support chip 57.It is identical with the polishing pad 30 that bonds to pressing plate 24 that polishing pad segment 59 does not need.But for the uniform polish of substrate 10, it is favourable using the polished surface with similar characteristic on the part of pressing plate 24 and strain transducer 46.In one embodiment, polishing pad 30 can flush with the edge of recess 26.Alternatively, as shown in Figure 6A, polishing pad 30 can be recessed into from the edge.

Fig. 6 B illustrates the example of the system that uses two diaphragm seals.First diaphragm seal 88 is the rings that are connected to pressing plate 24 and support chip 57 recess among both by securing member 98.Second diaphragm seal 86 is to be bonded on the top of pressing plate 24 and to cross over the gap and both solid piece of support chip 57.Particularly, the surface of pressing plate 24 comprises groove 90 with fitting tight film 86, makes diaphragm seal 86 shelve to the top surface with pressing plate 24 and flushes.Then polishing pad 30 is installed on the top of pressing plate and diaphragm seal combination.Under the situation of two partially polished pads, backing pad 34 bonds to the combination of pressing plate 24 and diaphragm seal 86.For example by the bonding agent such as pressure adhesive (PSA), diaphragm seal 86 also bonds to the top surface of support chip 57 and bonds to polishing pad segment 59.

With reference to figure 6C, the combination of the polishing pad segment 59 and second diaphragm seal 86 can be used as pre-assembled unit and sells.Particularly, polishing pad segment 59 can be attached to the center of soft sealing film 86 (it for example is silicone or latex film) with for example pressure adhesive, so the edge of diaphragm seal 86 extends beyond the outer edge of polishing pad segment.In addition, the outer rim and the lower surface 92 of the upper surface 93 of diaphragm seal can be coated with bond layer 94, and each bond layer can be covered by liner 95.

During installation, remove liner 95, and this unit is bonded to the top of support chip 57 and bonds to the groove 90 of pressing plate 24 from the lower surface 92 of film 86.The top surface of film 86 can with the basic coplane of the top surface of pressing plate 24.Can remove liner 95 from the top surface of film, and polishing pad 30 can be fixed to the top surface of pressing plate, make hole 33, and the edge adjacent with the hole of film is shelved on the edge of upper surface 93 of film 86 around 59 assemblings of polishing pad segment.

Fig. 6 D illustrates strain transducer 46 wherein and is installed in the system that inserts in the piece 100, inserts piece 100 and is located in the recess 26 of pressing plate 24.Diaphragm seal 102 can then be installed in and insert between piece 100 and the substrate contact member 58, rather than diaphragm seal 102 is connected to pressing plate 24.Diaphragm seal 102 can with bonding with the described identical mode of Fig. 6 A-6B or be fastened on the contact support chip with the insertion sheet 100 between.The use of inserting piece 100 can allow modular, and it can be seated in the pressing plate 24 and need not then diaphragm seal 102 be fixed to pressing plate 24.After insertion piece 100 had been placed in the recess, polishing pad 30 can then bond to pressing plate 24 and bond to and insert piece 100.

Alternatively, can use polishing article, wherein substrate contact member and seal are fixed to polishing pad, make pad, seal and substrate contact member can be used as single parts and remove from pressing plate.Fig. 6 E and 6F illustrate the method for making polishing pad, and wherein seal and substrate contact member are integrated in the polishing pad.This method comprises by encapsulant is spread in the mould 315 substrate contact member 58 is sealed to pad.Mould 315 is flat, and is made by suitable material, make encapsulant 310 can permanent adhesive to mould.In one embodiment, the part on the surface of mould 315 is characterised in that lug is along 319.Edge 319 has surrounded edge regions 318.There have edge regions 318 and substrate contact member to have to be identical shaped, and be made into certain size with assembling substrate contact member.

The substrate contact member is placed in the mould 315 to be shelved in the edge regions 318.Polishing pad 30 can then be arranged in hole 307 318 assemblings around the edge that make in the mould 315 in the polishing pad, and polishing pad 30 is around substrate contact member 58.In one embodiment, polishing pad can self be formed with the hole that is suitable for placing after a while contact member.In another embodiment, the hole can be cut in the polishing pad.There is edge regions 318 to form the bottom of recess between substrate contact member 58 and the polishing pad 30.

In one embodiment, the aligning jig 305 with outward extending projection 307 can be attached to substrate contact member 58.The end relative of aiming at jig with outward extending projection 307 be fixed to the substrate contact member with that the surperficial relative side that contacts substrate.Aim at jig 305 and for example be fixed to the substrate contact member by glue or pressure adhesive.In one embodiment, aim at jig and can have antelabium 311, it partially or even wholly surrounds the substrate contact member.Outward extending projection can be shaped to circle or elliptical rod, rectangle or square bar or cone.

Shown in Fig. 6 M, when pad was installed on the pressing plate 24, the projection 307 of aiming at jig 305 can be inserted in the reception recess of alignment socket 309.In this way, aim at jig 305 and substrate contact member 58 and mechanically be coupled to strain transducer 46, allow pad and contact member 58 to install and to remove simultaneously easily as the unit.Alignment socket 309 has also helped the installation of substrate contact member 58 and polishing pad 30, and this is can judge when the substrate contact member correctly is positioned on the pressing plate because the operator of pad is installed.

Then, encapsulant 310 is placed in the gap between substrate contact member 58 and the polishing pad 30.Enough encapsulants 310 are placed in the gap, make encapsulant produce sealing between polishing pad 30, substrate contact member 58 and alignment rods 305.Encapsulant is enough flexible, so substrate contact member 58 can move in response to the friction factor of substrate when polishing.Suitable encapsulant comprises silicone, latex or polyurethane.

Fig. 6 F shows the polishing pad that uses above method construct.Encapsulant 310 seals between substrate contact member 58, polishing pad 30 and aligning jig 305 fully.The top surface 45 of contact member 58 can with top surface 31 coplanes of polishing pad 30.As the result that edge regions is arranged of mould, encapsulant 310 slightly is recessed to top surface 45 and 31 belows.In embodiment, by for example solidified liquid cushion material, polishing pad can form around substrate contact member and seal.

Shown in Fig. 6 M, when pad was installed on the pressing plate 24, the projection 307 of aiming at jig 305 can be inserted in the reception recess of alignment socket 309.In this way, aim at jig 305 and substrate contact member 58 and mechanically be coupled to strain transducer 46, allow pad and contact member 58 to install and to remove simultaneously easily as the unit.Alignment socket 309 also is convenient to the installation of substrate contact member 58 and polishing pad 30, and this is can judge when the substrate contact member correctly is positioned on the pressing plate because the operator of pad is installed.

Fig. 6 G and 6H show the polishing pad that is combined with the sealing bed course.Each comprises at least two layers, top layer 259 and secondary pad 224 polishing pad 30 and substrate contact member 58.Between substrate contact member 58 and polishing pad 30, form the gap.This gap allows the sticking patch pad to move freely in response to friction force during polishing operation.Sealing bed course 284 between top layer 259 and secondary pad 224 prevents that liquid from passing through gap area.Fig. 6 G shows an embodiment, wherein seals the whole substantially polishing pad 30 of bed course 284 extend throughs.Fig. 6 H shows optional embodiment, wherein seals the only part of extend through polishing pad 30 of bed course, particularly, and pad and parts hole 307 next-door neighbour.In two embodiments, the sealing bed course only exposes in patch area.The sealing bed course is made by flexible and liquid-impermeable material, for example silicone, latex or polyurethane.

Fig. 6 L shows the biplate pad that uses the shield gasket layer, and wherein shielding is attached in the polishing pad.In this embodiment, polishing pad 30 itself forms the porose accommodating substrates contact member that comes.During the formation of polishing pad was handled, shielding 290 was inserted between top layer 259 and the secondary pad 224.Shielding can only extend through the part of polishing pad, for example shown in Fig. 6 L, perhaps extends through whole polishing pad (not shown).Shielding is as sealant, and by flexibility and the impermeable material of liquid made for example silicone, latex or polyurethane.Polishing pad is attached to pressing plate 24 in aforesaid mode.Use suitable manner then, for example pressure adhesive is fixed to shielding 290 with substrate contact member 58.

In one embodiment, substrate contact member 58 can have the alignment rods 292 that is attached to it, and alignment rods is inserted through the hole in the shielding 290 in this case, makes alignment rods extend through shielding, and can be as mentioned above that substrate contact member 58 is fixing.

Fig. 6 I shows the polishing pad that is combined with O ring 286, and O ring 286 replacement sealing bed courses seal the space between polishing pad 30 and the substrate contact member 58.The O ring can be secured to polishing pad 30 and substrate contact member 58 by adhesives or by the force of compression that is applied on the O ring by polishing pad 30 and substrate contact member 58.

Fig. 6 J shows the polishing pad that substrate contact member wherein forms the integral part of polishing layer.Polishing pad 30 can comprise two-layer, top layer 259 and secondary pad 224, but this design also can be applicable to single-layer pad.In one embodiment,, with at a series of notches 274,276 of the desired region generating of substrate contact member substrate contact member 58 is formed in the polishing pad by milling polishing pad 30.Notch 274,276 is orientated as and is made that the part of polishing pad in the notch zone is the substrate contact member.Notch forms curved pleat 273, and it is mechanically decoupled with substrate contact member 58 and polishing pad 30, allows the substrate contact member to move fully in response to friction force during polishing operation, thereby allows the detection of friction factor.Because secondary pad 224 is not impermeable to liquid, so notch 274 should not extend beyond top layer 259 in pair pad 224.In optional embodiment, the top layer with the curved pleat that has formed the substrate contact member is pre-formed in mould, makes to produce notch during mold treatment.In any embodiment, because polishing pad and substrate contact member are by the impermeable continuous material piece of liquid being made and not had any opening that makes the polishing slurries process, so do not need extra encapsulant.

Fig. 6 K shows the biplate pad that uses the shield gasket layer, and wherein shielding is attached to the substrate contact member.Shielding 290 is attached to substrate contact member 58.Shielding is as sealant, and by flexibility and the impermeable material of liquid made for example silicone, latex or polyurethane.In one embodiment, sticking patch is connected to alignment rods 292.Shielding 290 extends beyond the edge of substrate contact member 58, and is shelved on the pressing plate 24.By for example mechanical treatment, recess 355 can be formed on the distortion that does not cause polishing pad 30 in the pressing plate 24 to hold shielding 290.Have the hole and come the polishing pad 30 of accommodating substrates contact member then to be placed on the pressing plate 24, thus fixed mask 290.In optional embodiment, by for example it solidifies the liquid cushion material when contact with shielding, can be around substrate contact member 58 formation polishing pads 30.

With reference to figure 7A, substrate 10 can comprise silicon wafer 12 and one or more sedimentary deposit 14 and 16.Sedimentary deposit can be semiconductor, conductor or insulator layer.After layer deposits, can use for example photoetching technique etching pattern.Follow-up layer can be deposited on the layer of patterning.Shown in Fig. 7 A-7C, substrate 10 can be polished reducing the thickness of sedimentary deposit 16, be exposed and the top surface coplane of layer 14 and 16 up to patterned layer 14.

Different substrate layers has different friction factor between sedimentary deposit and strain transducer 46.The difference of this friction factor means that different sedimentary deposits will produce the friction force of different amounts, and therefore produces the strain of different amounts in sheet spring 48.If friction factor increases, then the distortion of sheet spring 48 will increase.Similarly, if friction factor reduces, then the distortion of sheet spring 48 will reduce.When sedimentary deposit 16 when polishing is with exposure pattern layer 14 downwards, strain will change different friction factor between the material that reflects sedimentary deposit 14 and polishing pad 30.Therefore, the calculation element such as computing machine 90 can be used for judging polishing end point by monitoring by the change of the strain of strain gauge means detection and the change of therefore friction.

With reference now to Fig. 8 A and 8B,, show two exemplary graph, it illustrates during polishing may change in the detection friction at difference place.Fig. 8 A be friction during imaginary chemical mechanical polish process to time plot, wherein for the friction factor of sedimentary deposit 14 less than friction factor for sedimentary deposit 16.Similarly, Fig. 8 B be friction during imaginary chemical mechanical polish process to time plot, wherein for the friction factor of sedimentary deposit 14 greater than friction factor for sedimentary deposit 16.

With reference to figure 7A, in the beginning of polishing, the surface of layer 16 may not be the plane, but can have the Feng Hegu that is caused by deposition processes.For same material, non-planar surfaces causes bigger friction than plane surface.So shown in Fig. 8 A, initial non-planar surfaces begins to locate bigger friction by curve map and represents.

Forward Fig. 7 B to, sedimentary deposit 16 is flattened, but layer 14 also is not exposed.In Fig. 8 A, this state is illustrated by the change of friction from the higher level to the reduced levels, and this change is as the result of this friction that reduces.

At last, in Fig. 7 C, polishing is reduced to exposure sedimentary deposit 14 with the thickness of sedimentary deposit 16.In this example, sedimentary deposit 14 has littler friction factor than sedimentary deposit 16.As a result, in Fig. 8 A, curve map shows friction and reduces once more.The level of friction is corresponding to the terminal point of polishing.As a result, in whole polishing, rub and reduce.

With reference now to Fig. 8 B,, initial non-planar surfaces begins to locate bigger friction by curve map to be represented, and the complanation of sedimentary deposit 16 illustrates by the change of friction from the higher level to the reduced levels of plane layer 16, and this change is as the result of this friction that reduces.

In this example, sedimentary deposit 14 has the friction factor bigger than sedimentary deposit 16.So when polishing has been reduced to the thickness of sedimentary deposit 16 when exposing sedimentary deposit 14, in Fig. 8 B, curve map shows friction and increases.The level of friction is corresponding to the terminal point of polishing.As a result, friction increases to end-condition from the complanation point.

As mentioned above, Fig. 8 A and 8B are exemplary graph, and the initial degree of roughness of employed material of sedimentary deposit and sedimentary deposit 16 is depended in the relative change of friction force.Concrete terminal point friction valve can come to determine by experiment.

With reference now to Fig. 2 and 9,, computing machine 90 can be used to control polishing block 22.Computing machine 90 can receive from strainometer 50 and import and the result is presented on the monitor 92.In addition, computer program can be designed as the startup and the end of control chemical mechanical polish process.As shown in Figure 9, the embodiment that is used for the computer program of chemically mechanical polishing starts from being enabled in the chemical mechanical polish process (step 910) on the substrate 10.During polishing, computing machine 90 receives input (step 920) from strainometer 50.Can be continuously, periodically or its both certain in conjunction with the input that receives from strainometer 50.Computing machine 90 receives the strain input signal and judges the strain of being experienced by strainometer 50 (step 930).Computing machine 90 is then monitored the signal (step 940) that changes for strain.When desired polishing end point had been indicated in the strain change, computing machine 90 finished polishings (step 950).In one embodiment, polishing end point is judged in the change of the slope of computing machine 90 detection strain datas.Computing machine 90 also can be monitored the strain signal smoothness and judge polishing end point.Alternatively, in order to judge the generation of terminal point, computing machine 90 is consulted the database that comprises pre-judgement terminal point strain value based on employed sedimentary deposit.

In addition, as U.S. Patent No. 6,159,073 describedly is used for optical measurement, and computing machine 90 can will be classified according to radius from the measured value of strain transducer 46.This measured value can be then used in the real-time closed-loop control by 70 applied pressures of carrier head.For example, change if computing machine 90 detects to rub in the radius region at edges of substrate place, this can indicate at first and just expose its lower floor at the edges of substrate place.In response, computing machine 90 can be so that carrier head 70 applies littler pressure in the edge of substrate than the center.

Schematic circuit with strainometer 50 and amplifier 54 combinations has been shown among Figure 10.In this example, strainometer 50 is expressed as resistance R 51-R54, and each resistance has the no strain resistor of 350ohm.Strainometer 50 links together, and makes R51 and R52 increase resistance when the strain of sheet spring experience and strainometer R53 and R54 reduce resistance during in the strain of sheet spring experience.The voltage that strides across strainometer will depend on dependent variable and change.Output voltage by as shown in figure 10 amplifying circuit use gain is provided to output voltage from strainometer 50.Amount of gain partly depends on the value of resistance R G.For example, for circuit shown in Figure 10, the resistance value between 500ohm and the 50ohm can produce the approximate gain between 100 and 1000.The output of amplifier can then be transferred to computing machine and be used for handling.

Strain transducer 46 can be integrated in the various polishing systems.During polishing, substrate 10 and polishing article relative to each other move.Suppose strain transducer 46 along with polishing article moves, then the relative motion that provides between strain transducer 46 and the substrate 10 can be provided for polishing article supporter (for example, pressing plate 24) or carrier head 70 or both.Alternatively, strain transducer need be along with polishing article moves.In the case, strain transducer can be maintained fixed, and carrier head 70 can move so that the relative motion between strain transducer 46 and the substrate to be provided.Polishing article can be circle (or other shapes) pad that is fixed to pressing plate, in feed rolls with collect the band that extends between the roller or be with (continuous belt) continuously.Polishing article can be fixed on the pressing plate, is incrementally advancing above pressing plate between the polishing operation, or is being driven continuously above pressing plate during polishing.Polishing article can be the coarse pad of standard (for example, having or do not have the polyurethane of filler), cushion or fixed abrasive pad.Suitable openings can be created in any one of above-mentioned polishing pad 30, and be positioned on the pressing plate 24 and make during chemical mechanical polish process, strain transducer 46 can physically contact substrate 10, and strain transducer 46 has the surface in contact 45 of cross-sectional area less than substrate 10.The slurries 38 that are fed to polishing article can comprise lapping compound or not contain lapping compound.

In one embodiment, polishing pad segment 59 is directly connected to sheet spring 48 under the situation that does not have support chip 57.In addition, in the embodiment that does not have support chip 57, diaphragm seal 84,86,88 and 102 can directly be attached to sheet spring 48.

In another optional embodiment, reply material self substrate contact member 58 is provided.For example, replying material can be the flexible sheet (having basic identical shape with the sheet spring) that the material (for example flexible polyurethane) by the substrate of can not swiping forms.This flexible sheet can be extended from recess 26 makes it have the top surface and polished surface 31 coplanes of the cross-sectional area littler than substrate 10.In addition, except the sheet spring, replying material can be square or the circular metal bar.

Reply material and can be any and the distortion that causes by external force to the material that instead applies power, for example elasticity or compressible member.Reply material and substrate contact member 58 (alternatively via middle jig, shown in Fig. 6 C) can be connected to the polishing article supporter.For example, as shown in figure 11, strain transducer 46 can comprise a plurality of springs, and it is as the answer material that substrate contact member 58 is connected to pressing plate 24, and it allows member laterally moving owing to contacting with substrate 10 under the friction force that causes.Can be for example monitor the displacement of substrate contact member 58 optically by laser interferometer 112 or by electric capacity or eddy current sensor or by other displacement measurement sensors, the strain of being experienced by the attaching spring has been indicated in this displacement.Alternatively, light beam 120 can leave the sidepiece of substrate contact member 58 with reflection and is directed on the position sensing photodetector 124 from light source 122 guiding.The displacement of substrate contact member 58 makes the position change of light beam incident detecting device 124, in the transversal displacement that has provided indicating member 58 and the signal of friction factor.Suppose that strain transducer 46 does not move with polishing article, then reply material and substrate contact member 58 can be connected to holding clamp, for example support the mechanical base 21 of pressing plate.

In another optional embodiment shown in Figure 12, the friction sensor-based system comprises and is configured to laterally slide but not crooked strain transducer under from the friction force of substrate.In this embodiment, transportable substrate contact member 58 when friction sensor 246 is included in the friction force that is subjected to from substrate 10, be connected to the sliding bar 248 of the substantially rigid of substrate contact member 58, with sliding bar 248 and substrate contact member 58 backward towards the spring 249 of neutral position compressing with produce the pressure transducer 250 of signal based on the displacement of substrate contact member 58 and sliding bar 248.

Bar 248 is attached to pedestal 254 slidably, and it maybe can be the part of pressing plate that pedestal 254 can be fixed to pressing plate.Sliding bar 248 is delivered to pressure transducer 250 with the displacement of substrate contact member 58.The motion of sliding bar 248 can be subjected to the restriction of raceway groove 252 in the pedestal 254, thus sliding bar 248 be restricted to along with substrate and friction sensor 246 between the parallel axis of the direction of relative motion move.

Friction force on substrate contact member 58 will cause both transversal displacements of substrate contact member 58 and sliding bar 248.This makes sliding bar 248 exert pressure to pressure transducer 250, will apply bigger pressure when substrate contact member 58 is subjected to bigger friction force.Pressure transducer can be coupled to the output system (not shown).

Spring 249 is installed to sliding bar 248.Spring 249 can be formed by the metal material such as stainless steel.The composition of spring 249 can be selected based on desired friction force, makes to be subjected to because when contact the friction force that causes with substrate, spring ground compresses and extension (under the situation that does not experience inelastic deformation) when friction sensor 246.Spring 249 is oriented the direction that makes restoring force be parallel to relative motion between substrate and the friction sensor 246.Like this, spring 249 will apply restoring force against the sense of displacement of sliding bar 248 and substrate contact member 58.

Substrate contact member 58 is attached to sliding bar 248, makes substrate contact member 58 and polishing pad 30 coplanes.Substrate contact member 58 can be monolithic or comprise miscellaneous part such as support chip and polishing pad segment, so the top surface of the friction sensor 246 of gained and polishing pad 30 coplanes.The advantage of this embodiment is that the substrate contact member always remains parallel to the surface and the substrate of polishing pad, and therefore the whole surface of substrate contact member keeps contacting with substrate.This allows to be added in by undercoat the more accurate judgement of the friction force on the substrate contact member.

The output of pressure transducer 250 is sent to computing machine 90 and is used for handling.Processing can comprise the calculating of friction factor between substrate contact member 58 and the substrate 10, from the relevant measurement of the radial position with on the substrate 10 of friction sensor 246, come process that analytical chemistry mechanical buffing handles, control polissoir and pressure measuring value is converted to graphical information based on the change of measured pressure based on pressure measuring value.Can show output by the device such as monitor 92.

Can with various embodiments combine as discussed above another embodiment in, the friction sensor-based system comprises a plurality of sensors.For example, as shown in FIG. 13A, this system can comprise a plurality of sensors, and it is arranged in apart from the essentially identical distance of the rotation of pressing plate, but arranges at interval with angle same with the rotation around pressing plate.As another example, shown in Figure 13 B, this system can comprise be arranged in closely near but have difference (for example vertical) the orientation sensor (for example, a sensor measuring its substrate contact member displacement is parallel to the radius by the rotation 25 of pressing plate, and another sensor of measuring its substrate contact member displacement is perpendicular to the radius of the rotation 25 by pressing plate).Construct with this, this system can produce the measured value of indication total frictional force, for example, and as square root sum square of the strain of on two vertical direction, measuring.

As another example, the substrate contact member can be parallel to and perpendicular to both direction through the radius of the rotation 25 of pressing plate on can laterally move, and the friction sensor-based system can comprise the sensor of measuring member displacement in two directions.For example, with reference to Figure 14, replace the sheet spring, strain transducer can comprise the flexible support post 170 with rectangular cross section.First group of strain transducer 50 can be positioned on a pair of opposite face of support column 170 measuring support column deflection in one direction, and second group of strain transducer 50b can the position another on the opposite face to measure support column deflection in vertical direction.Every group of strain transducer can be as with reference to the connection of figure 4A-5 institute with discussing, thereby is created in the measured value of friction force on two vertical direction.Construct with this, this system can produce the measured value of total frictional force on the indication substrate contact member, for example, and as square root sum square of the strain of on two vertical direction, measuring.

In any embodiment, computing machine 90 can be carried out treatment step to the original strain data that is received so that data are converted to friction valve.Computing machine 90 can utilize the strain of strainometer 50 and the relation that is applied between the friction force on the substrate contact member 58 is calculated friction factor.Then can carry out endpoint based on friction factor.

Polishing operation can be to remove conductor, insulator or the semiconductor layer polishing operation with another layer of exposure same type (that is, conductor, insulator or semiconductor).Alternatively, polishing operation can be to remove conductor, insulator or semiconductor layer to expose the polishing operation of another dissimilar layers.Under any situation, polishing operation can be to remove layer has another layer (for example, two insulator layers) of similar reflectivity with exposure polishing operation.For example, polished layer can be a nitride, and the layer that is exposed can be an oxide, or opposite, and perhaps two layers can all be oxides.Polishing operation can be the step of shallow trench isolation in (STI), interlayer dielectric (ILD), inter-metal dielectric (IMD) and preceding inter metal dielectric (PMD), polymerization silicon or silicon-on-insulator (SOI) are handled.

The present invention can utilize Fundamental Digital Circuit, or utilizes computer hardware, firmware, software or its to make up and implement.Equipment of the present invention can be embedded in mode in the machine readable memory, that be used for the computer program carried out by programmable processor and implements with tangible; And method step of the present invention can be realized to be realized the programmable processor of function of the present invention by operation input data and generation output by execution of programs of instructions.The present invention can advantageously implement in the mode of one or more computer programs, described one or more program can be carried out on programmable system, programmable system comprises at least one programmable processor, at least one input media and at least one output unit, and wherein said at least one programmable processor is coupled to data-storage system to receive data and instruction from it and data and instruction are transferred to it.Each computer program can be implemented in mode advanced proceduresization or object oriented programming languages, if perhaps expectation is implemented in the mode of compilation or machine language; Under any circumstance, this language can be compiling or interpretative code.As example, suitable processor comprises general and special microprocessor.Usually processor will receive instruction and data from ROM (read-only memory) and/or random access storage device.The core parts of computing machine are processor and the storeies that is used to execute instruction.Usually, computing machine will comprise that one or more mass storage devices are used for storing data files; Such memory storage comprises the disk such as built-in hard disk and removable dish; Magneto-optic disk; And CD.Be suitable for visibly the memory storage of computer program instructions and data embedding being comprised the nonvolatile memory of form of ownership, it for example comprises the semiconductor memory system such as EPROM, EEPROM and flash memory device; Disk such as built-in hard disk and removable dish; Magneto-optic disk; Coil with CD-ROM.Any aforementioned part can be implemented or be combined among the ASIC by ASIC (special IC).

The present invention has been described according to embodiment.Other embodiments fall within the scope of the appended claims.

The application requires the U.S. Provisional Application No.60/516 that submits on October 31st, 2003, and 349 and the U.S. Provisional Application No.60/590 that submits on July 22nd, 2004,471 right of priority.

Claims (21)

1. the equipment of friction factor of the substrate of polishing is just being experienced in a monitoring, comprising:

Movable member, described movable member has the top surface of the exposed surface of contact substrate, described movable member is in response to from the friction force of described substrate and transversal displacement, and described top surface has the surface area littler than the surface area of the described exposed surface of described substrate;

Be coupled to the answer material of described movable member; With

Sensor, described sensor produces signal based on the transversal displacement of described movable member.

2. equipment as claimed in claim 1, wherein said answer material comprises the sheet spring.

3. equipment as claimed in claim 1, wherein said answer material comprises a plurality of springs.

4. equipment as claimed in claim 1, wherein said movable member comprises the polishing pad segment.

5. equipment as claimed in claim 4, wherein said polishing pad segment comprises two-layer.

6. equipment as claimed in claim 1, wherein said movable member also comprise the support chip that is coupling between described answer material and the described polishing pad segment.

7. equipment as claimed in claim 1 is strainometer based on the described sensor that the transversal displacement of described movable member produces signal wherein.

8. equipment as claimed in claim 7, wherein a plurality of strainometers are attached to described spring at maximum strain point place.

9. equipment as claimed in claim 1 is optical sensor based on the described sensor that the transversal displacement of described movable member produces signal wherein.

10. equipment as claimed in claim 9, wherein said optical sensor is a laser interferometer.

11. equipment as claimed in claim 1 is piezoelectric sensor based on the described sensor that the transversal displacement of described movable member produces signal wherein.

12. equipment as claimed in claim 1, the basic coplane of the polished surface of wherein said top surface and polishing pad.

13. equipment as claimed in claim 1, wherein said movable member is connected to pressing plate.

14. equipment as claimed in claim 13, wherein said movable member separates gapped with described pressing plate.

15. equipment as claimed in claim 14 also comprises the soft sealing film that is coupled to described movable member, it is used to prevent that the slurries transmission is by described gap.

16. equipment as claimed in claim 15, wherein said soft sealing film are inserted between described answer material and the described movable member.

17. equipment as claimed in claim 13, wherein said pressing plate is rotatable.

18. the equipment of friction factor of the substrate of polishing is just being experienced in a monitoring, comprising:

Member, described member have the top surface of the exposed surface of the described substrate of contact, and described top surface has the surface area littler than the surface area of the described exposed surface of described substrate;

Reply material, described answer material is connected to structure with described member; With

Sensor, described sensor produces signal based on described answer material strain.

19. a chemical-mechanical polisher comprises:

Supporter, described supporter is used to support polishing article;

Carrier, described carrier are held against substrate the polished surface of described polishing article;

Motor, described motor are coupled at least one in described polishing article and the described carrier, are used for producing betwixt relative motion; With

Be used to measure the strain transducer of strain, described strain transducer comprises movable member, described member has the top surface and the answer material that is coupled to described movable member of the exposed surface of contact substrate, described member is in response to from the friction force of described substrate and transversal displacement, described top surface has the surface area littler than the surface area of the described exposed surface of described substrate, and described sensor comprises the sensor that produces signal based on the transversal displacement of described movable member.

20. equipment as claimed in claim 19, wherein when keeping described polishing article by described supporter, described top surface and the basic coplane of described polished surface.

21. a pressing plate that is used for chemical-mechanical polisher comprises:

Substrate, described substrate has the recess that is used to hold strain transducer, and described recess has the cross-sectional area bigger than the cross-sectional area of described strain transducer, to allow the displacement of described strain transducer; With

Be placed on the described strain transducer in the described recess, described strain transducer comprises replys material and at least one device, described answer material has the cross-sectional area littler than the cross-sectional area of polished surface, described answer material directly contacts substrate sometimes, or by being coupled to the other materials contact substrate of described answer material, described other materials has the cross-sectional area littler than the cross-sectional area of described polished surface, and described at least one device is used to measure the described answer material strain on the direction of relative movement between the described sensor of described substrate and measurement strain.

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