CN1841671A

CN1841671A - Fabrication process of semiconductor device and polishing method and polishing device

Info

Publication number: CN1841671A
Application number: CN 200510091424
Authority: CN
Inventors: 白数哲哉
Original assignee: Fujitsu Ltd
Current assignee: Fujitsu Semiconductor Ltd
Priority date: 2005-03-30
Filing date: 2005-08-11
Publication date: 2006-10-04
Also published as: JP2006278977A

Abstract

This invention provides a method of fabricating a semiconductor device includes a polishing process of a substrate, wherein the polishing process includes the steps of applying a chemical mechanical polishing process to the substrate on a polishing pad while using slurry, and conditions a surface of the polishing pad, the conditioning step including the step of grinding the surface of said polishing pad by at least first and second conditioning disks of respective, different surface states.

Description

The manufacture method of semiconductor device, finishing method and burnishing device

Technical field

The application is based on respectively on March 30th, 2005 and the Japanese patent application No.2005-099890 of application on May 11st, 2005 and the priority of 2005-138705, and its full content is contained in this for your guidance.

Background technology

The present invention relates generally to CMP (chemico-mechanical polishing) technology, relate in particular to the production process of semiconductor device that comprises by the glossing of CMP technical finesse.

In the production of semiconductor device, CMP (chemico-mechanical polishing) technology is widely used in the complanation substrate or removes dielectric film or conducting film.

Especially, form to use low resistive metal for example in the technology of copper as the multiple level interconnect architecture of interconnection layer, CMP technology is important.And, CMP technology not only for the surface treatment of silicon wafer and disk and also for the polishing of optical element for example lens all be important.

Figure 1A-1E illustrates the manufacturing process of the conventional semiconductor devices that comprises copper enchasing technology.

With reference to Figure 1A, SiO ₂, SiOC, SiON, analogs such as SiN, BPSG dielectric film 21 on the Semiconductor substrate (not shown), form so that cover for example unshowned transistor of active device.Dielectric film 21 can directly form on Semiconductor substrate, perhaps forms on the dielectric film that is formed on the Semiconductor substrate.

Then, in the step of Figure 1B, be formed in the dielectric film 21 by etching with the interconnected corresponding interconnected groove 21G that expects.Under the situation of dual-damascene technics, through hole is formed among the interconnected groove 21G, so that expose the conductive layer be positioned at below the dielectric film 21.

And in the step of Fig. 1 C, the surface of dielectric film 21 comprises side surface and the lower surface of interconnected groove 21G, and (TaN, barrier metal film 22 TiN) covers by tantalum (Ta), titanium (Ti) or its nitride.

Then, in the step of Fig. 1 D, copper film 23 forms on barrier metal film 22, makes the interconnected groove 21G of copper film 23 fillings, and wherein this formation of copper film 23 is finished by sputtering technology or electroplating technology or the combination of the two.

And, in the step of Fig. 1 E, use the CMP device that copper film 23 and barrier metal film 23 are removed from the surface of dielectric film 21, be embedded to interconnect architecture among the interconnected groove 21G thereby obtain copper pattern 23G via barrier metal film 22.

List of references

Patent references 1 Japanese Laid-Open Patent Application 2003-165048

Patent references 2 Japanese Laid-Open Patent Application 2001-127017

Patent references 3 Japanese Laid-Open Patent Application 2000-248263

Patent references 4 Japanese Laid-Open Patent Application 2000-252242

Patent references 5 Japanese Laid-Open Patent Application 2000-252243

Patent references 6 Japanese Laid-Open Patent Application 2001-28437

Summary of the invention

Fig. 2 illustrates the structure of the typical C MP device 10 of the technology that is used for Fig. 1 E.

With reference to figure 2, CMP device 10 comprises the platen 11 that rotates by unshowned actuating force, and polishing pad (polishing pad) 12 is fixed on the platen 11.And Semiconductor substrate 14 is held by the carrier (carrier) 13 that rotates by another actuating force, and is pushed to the polishing pad 12 on the platen 11 under predetermined polish pressure effect.And, slurries 16 are dropped on the polishing pad 12, and use the slurries that keep on the polishing pad 12 to carry out the surface that chemico-mechanical polishing comes the polishing semiconductor substrate.Use this chemico-mechanical polishing, dielectric film on the substrate and conducting film are polished individually or simultaneously.

Use this CMP device 10, by use conditioner discs 15 (be fixed with on it abrasive grains for example diamond or pottery and rotate by the actuating force different with the actuating force of rotating platen 11), the surface of polishing pad 12 stands to grind, in other words be exactly to stand " finishing ", be used for evenly and polishing effectively.Usually,, carry out this finishing of polishing pad, be also referred to as polishing (dressing) during the glossing of semiconductor wafer or after finishing polishing.Use this finishing, wipe the surface of polishing pad off and expose the pad surface that makes new advances.

Fig. 3 illustrates the sectional view of the polishing pad of the closed cellular foam structure (closedcellular foam structure) that is usually used in traditional CMP technology.

With reference to figure 3, polishing pad with closed cellular foam structure on its pad surface and its inside comprise that separate diameter is at several microns to tens microns the fine foam body 12P that is called hole (pore), in have, and slurries are contained in by in the pad formed depressions of lip-deep these pores (depression) 12U.Because these pores are separate, therefore the slurries on pad interface can not be penetrated into its inside, and for this reason, compare with the polishing pad with open type stephanoporate shape structure, can reduce the loss of slurries, and slurry infiltration can take place to the interior infiltration of polishing pad in the latter.

For slurries, use usually to add the pure water that pH adjusts agent, wherein also sneak into abrasive grains (abrasive particles) usually toward the there, be used for increasing polishing speed.

In recent semiconductor device, use copper as the low resistance interconnection material, and CMP technology become independently treatment process now, be used for using mosaic technology to form copper interconnect pattern therefore.

On the other hand, use the polishing pad with closed cellular foam structure therefore, this problem takes place easily, that is, as the result of polishing or product, dust can be trapped in the foam structure of this pad, causes the obstruction of pad interface.When the obstruction that takes place therefore, polishing speed can reduce and polish the instability that becomes.Therefore, the uniformity of polishing worsens.

Therefore, in tradition, put into practice this mode, that is, each when having used polishing pad during the scheduled time, use the trimming polished pads of conditioner discs shown in Figure 2 15 surface, so that the processing dust that pad interface is represented by Reference numeral 12X is wiped off in Fig. 4.

Traditionally, polishing pad with closed cellular foam structure shown in Figure 4 uses in the production of micro semiconductor device usually, and therefore such polishing pad, can not be avoided because some variations take place the pad characteristic that the manufacturing process of pad causes based on foams 12P.In present ultra-fine semiconductor device was made, these variations of polishing pad can cause variety of issue, for example, and the variation of polishing speed, the deterioration of polishing uniformity, increase of polishing time or the like.

And when attempting to use the ledge structure of CMP (Chemical Mechanical Polishing) process planar surface, the foams 12P of the softness in the polishing pad is easily along with the warpage of step that will be flattened, thereby can not obtain satisfied complanation.As in the situation of present semiconductor device, this problem is especially serious in the situation of polishing microminiature structure.And, under the situation of surface polishing structure, also there is the possibility of the pit (dishing) that causes at polished surface owing to the flexibility of polishing pad.

Therefore, in view of above-mentioned variety of issue, the someone proposes to use the polishing pad of non-foam body structure shown in Figure 5 at present.

With reference to figure 5, similar to traditional polishing pad with open type stephanoporate shape foam structure is that the polishing pad of non-foam body structure is formed by the material of analogs such as for example polyurethane, except this polishing pad inside does not comprise foams.

Because this non-foam body structure, the present invention might produce polishing pad and suppress variation between the product simultaneously, and such polishing pad has the uniformity characteristic.And, owing to when polishing, do not have foams as mechanical damping device part, therefore the hardness ratio of the polishing pad of non-foam body has the polishing pad of foams big, therefore, when using polishing pad to polish to have ledge structure surperficial, the ledge structure on the polished surface of complanation effectively.And, also can suppress the pit of polished surface, and use the polishing pad of this non-foam body structure might be convenient to the complanation substrate surface.

On the other hand, the polishing pad of non-foam body does not have foam segment 12P shown in Figure 2, therefore, with respect to the polishing pad that foam structure is arranged, has the more weak problem of slurries confining force in this pad.Therefore, the polishing speed that can not obtain to expect.

Polishing speed when Fig. 6 illustrates the polishing pad that uses the non-foam body structure in the CMP device among Fig. 2 polishes the plasma oxide film that forms on silicon wafer situation, the situation when being used for the polishing pad that uses open poroid foam structure is compared.In the experiment of Fig. 6, when polish pressure is set at 4psi, the velocity of rotation of polishing carrier 13 and polishing platen 11 is set at 90rpm and 80rpm respectively, and when providing flow rate to be the slurries of 200ml/min, polishes.

As from what Fig. 6 saw, compare with the polishing pad that uses foams, polishing speed has descended about 16% when the situation of the polishing pad that uses the non-foam body structure.In the experiment of Fig. 6, to be that high relatively concentration is about 15% for the concentration of abrasive grains in slurries, and can believe, for this reason, for the situation of the polishing pad that uses the non-foam body structure, the polishing speed decline scope has been suppressed in about 16% the scope.Otherwise polishing speed should be able to descend manyly.

And in the CMP technical field, the scratch characteristic that occurs in this technology is a big problem.Traditionally, it is known can reducing scratch effectively by the concentration of abrasive grains in the reduction slurries.Abrasive grains in being dispersed in slurries causes caking and scratch can occur owing to a variety of causes in the formation bulky grain situation that this scratch can cause the reduction of semiconductor device output, and the control scratch is important target in the CMP technology.

And when the concentration of the abrasive grains in reducing slurries reduced scratch, this also can bring the reduction of abrasive grains consumption, and also can reduce the production cost of semiconductor device.

Yet, when reducing the concentration of abrasive grains in the CMP technology of using non-foam body polishing pad, can cause the serious decline of polishing speed.

And the technology of using the copper glossing for example to be carried out in the step of Fig. 1 E, usually be appreciated that, form cupric oxide by the oxidant that in slurries, is comprised on the surface of copper layer, and the cupric oxide that therefore forms grinds by the abrasive grains that joins in slurries and the polishing pad.And known a kind of technology that increases the polishing speed of copper promptly, will join in the slurries with the organic acid that copper forms compound, and copper and organic acid compound are dissolved in the slurry water solution.

And, in the CMP technology, mainly in the bossing of the semiconductor substrate surface that contact with abrasive grains with polishing pad, polish,, do once being considered to desirable like this owing to can not polishing with the sunk part that polishing pad contacts with abrasive grains.Therefore, what once reckoned with is that when polishing by CMP technology, in case finish polishing, just successfully complanation has the surface of projection and depression, thereby should obtain to be suitable for the surface that semiconductor device is produced.

Yet, when having the organic acid of being convenient to form compound effect when joining in the slurries, also can be in the sunk part that abrasive grains or polishing pad can not contact dissolved copper or cupric oxide, and can cause etching.In this case, erosion also can occur in polished surface, thus polished surface complanation fully.Therefore, can form the sunk part of depression for example or pit.

Traditionally, attempt corrosion inhibitor is joined in the slurries, be used for suppressing this organic acid and render a service, but not success.This may be because the projection of structure that will be polished and depression, and polishing pad (being formed by the poly-amino ester material that foam structure is arranged) stands strain, and the result is owing to contacting with polishing pad, even also can polish in sunk part.Here it is why traditional C MP technology can not realize the reason of satisfied complanation.

And, in traditional C MP technology, known by with abrasive grains for example silica join in the slurries and can increase polishing speed, therefore, usually abrasive grains is joined in the slurries, and the abrasive grains that joins in the slurries trends towards self caking and formation coarse particles.Therefore, use this coarse particles on pending body surface, to form scratch easily.Particularly, be soft and collect scratch easily by the formed copper interconnect pattern of mosaic technology.

It should be noted that, this scratch can cause serious problems in the production of ultra-small semiconductor devices, for example output reduces, and in the production of ultra-fine and ultra-speed semiconductor device, need to cause extremely and watch out for that this device has the strict design rule and manages CMP technology so that the caking of abrasive grains can not occur during CMP technology.Yet this process management has increased the production cost of semiconductor device.

In first aspect, the invention provides a kind of method of making semiconductor device, it comprises that described CMP (Chemical Mechanical Polishing) process comprises the pre-shaping step by at least the first and second conditioner discs grinding and polishing pad surfaces that have the different surfaces state respectively by the step of the substrate of CMP (Chemical Mechanical Polishing) process polishing on polishing pad.

On the other hand, the invention provides a kind of cmp method, comprise step:

Use the object of CMP (Chemical Mechanical Polishing) process polishing on polishing pad; With

Use has the surface that at least the first and second conditioner discs of different surface state are repaired described polishing pad.

According to the present invention, as under polishing pad that uses the non-foam body structure or the concentration of abrasive grains is lower in slurries situation, when chemico-mechanical polishing, be difficult to guarantee under the situation of enough polishing speeds, have the surface of the trimming polished pad of at least the first and second conditioner discs of different surfaces state by use, the slurries of sufficient amount might be remained on the polishing pad.Thereby, guarantee enough polishing speeds.And, be applied to the surface of polishing pad off and on by first conditioner discs that will have big surface roughness, perhaps, avoid the additional wear of polishing pad, and might prolong its life-span by alternately using first conditioner discs and second conditioner discs.

According to the present invention, when guaranteeing effective polishing speed,, might realize fabulous complanation to substrate surface that will be processed by using the polishing pad of non-foam body structure.

And, by reducing the concentration of abrasive grains, might reduce the appearance of the scratch of substrate surface that will be processed, guarantee polishing speed simultaneously.

According on the other hand,, and, can realize above-mentioned purpose of the present invention by using the slurries that can suppress to the polishing of sunk part by the polishing pad of use non-foam body structure.

Therefore, the invention provides a kind of method of making semiconductor device, it comprises the step of polished substrate, and the described glossing of described substrate comprises: come the projection on the described substrate surface of complanation and the step of depression carrying out CMP (Chemical Mechanical Polishing) process on the polishing pad when using slurries

The polishing pad that wherein uses the non-foam body structure as described polishing pad and

Wherein use and to eliminate the slurries of polishing as described slurries to sunk part.

On the other hand, the invention provides a kind of burnishing device, comprising:

One or more polishing platens, each platen rotate and have polishing pad thereon;

The substrate supporting device, corresponding with each described polishing platen, when rotating described substrate, described substrate supporting device keeps substrate that will be processed and pushes described substrate to described polishing pad; With

The slurries feed mechanism offers described polishing pad with slurries,

At least first second trimming device, with each described polishing pad cooperation, each described trimming device keeps conditioner discs to repair described polishing pad,

When rotating described conditioner discs, each described trimming device is pushed described conditioner discs to described polishing pad.

According to the present invention, by using the polishing pad of non-foam body structure, improved the coefficient of elasticity and the hardness of polishing pad, and in polished substrate, the surface of polishing pad is no longer according to the structure of substrate surface and distortion in fact.Therefore, can obtain effective complanation to substrate surface.

Particularly, control to 3wt% or still less by concentration rank with the abrasive grains in the slurries, might eliminate the problem of depression, this depression is to use to invade at the sunk part of substrate surface and the abrasive grains in the slit between the polishing pad and polishes, and obstruction obtains the satisfied complanation to substrate surface.

As mentioned above, use the polishing pad of non-foam body structure, be difficult to slurries are remained on wherein with planar structure.Therefore, for the present invention, the conditioner discs that has the different surfaces state by use, twice finishing carried out on surface to the polishing pad of non-foam body structure at least, so that in polished substrate, by using first conditioner discs to form shallow slot in pad interface, and by in each scheduled time, using second conditioner discs to form deep trouth in pad interface.Therefore, increased the life-span of polishing pad, and slurries might have been remained on the surface of polishing pad of non-foam body structure.Therefore, might realize stable and the effective chemical mechanical polishing process.

In order to reach this target, the invention provides the burnishing device that is equipped with at least two trimming devices that are used for a polishing platen.By using this burnishing device, manual conversion conditioner discs, and might realize above-mentioned first and second finishings effectively to the polishing pad of non-foam body structure.

In conjunction with the accompanying drawings, other target of the present invention and characteristic will be apparent in following detailed description.

Description of drawings

Figure 1A-1E is the schematic diagram that shows the example of the process for fabrication of semiconductor device that passes through mosaic technology;

Fig. 2 shows the schematic diagram that is used for CMP apparatus structure of the present invention;

Fig. 3 is the schematic diagram that shows the cross section structure of traditional polishing pad that foam structure is arranged;

Fig. 4 is presented at the schematic diagram of repairing in the polishing pad of foam structure;

Fig. 5 is the schematic diagram of cross section structure that shows the polishing pad of non-foam body structure;

The schematic diagram of the polishing characteristic that Fig. 6 is comparison between the polishing pad of the polishing pad of foam structure and non-foam body structure;

Fig. 7 is presented at the schematic diagram that concerns between the concentration of the abrasive grains in the slurries and the polishing speed;

The schematic diagram of the polishing characteristic that Fig. 8 is comparison between the polishing pad of the polishing pad of foam structure and non-foam body structure;

Fig. 9 A and 9B are the schematic diagrames that shows the state of the slurries in the polishing pad of the polishing pad that remains on the non-foam body structure respectively and foam structure;

Figure 10 is the sectional view that shows the structure of common conditioner discs;

Figure 11 A and 11B are the schematic diagrames that shows the substrate on the polishing pad that polishes the different surfaces state;

Figure 12 A-12D is the schematic diagram that shows various conditioner discs;

Figure 13 A and 13B are the schematic diagrames that shows the surface state of the polishing pad that uses the conditioner discs grinding with different surfaces state;

Figure 14 is the schematic diagram that shows the polishing characteristic of the polishing pad that uses different conditioner discs grindings;

Figure 15 A and 15B are the schematic diagrames that shows with Figure 13 A and corresponding two the different conditioner discs of 13B;

Figure 16 is the schematic diagram that shows the polishing characteristic of the polishing pad that uses the different conditioner discs grindings with two shown in the 15B of Figure 15 A;

Figure 17 is the flow chart that shows according to the CMP (Chemical Mechanical Polishing) process of first embodiment of the invention;

Figure 18 is the schematic diagram of demonstration according to the polishing characteristic of the copper film of first embodiment of the invention;

Figure 19 A-19E is the schematic diagram that shows according to the process for fabrication of semiconductor device in the second embodiment of the invention;

Figure 20 A-20C shows according to the CMP (Chemical Mechanical Polishing) process in the third embodiment of the invention with according to the flow chart of the CMP (Chemical Mechanical Polishing) process of a comparative example;

Figure 21 explains the schematic diagram that uses the polishing evaluation method in third embodiment of the invention;

Figure 22 is the schematic diagram that is presented at the polishing evaluation result in the third embodiment of the invention;

Figure 23 explains the schematic diagram that uses the polishing evaluation method in fourth embodiment of the invention;

Figure 24 shows the effect schematic diagram of comparing the planarization technology that is obtained by the present invention with conventional situation;

Figure 25 shows the schematic diagram of comparing with conventional situation by the quantity of the flaw on the planar surface that the present invention obtained;

Figure 26 is the schematic diagram of demonstration according to the structure of the CMP device of fifth embodiment of the invention;

Figure 27 is the flow chart that shows the example of the CMP device execution glossing that uses Figure 26;

Figure 28 is the schematic diagram of remodeling that shows the CMP device of Figure 26;

Figure 29 is the schematic diagram that the difference of the CMP device of demonstration Figure 26 is retrofited; And

Figure 30 is the schematic diagram of demonstration according to the structure of the trimming device of sixth embodiment of the invention.

Embodiment

[principle]

At first, the principle of the present invention of explaining and in investigation, being found by the present inventor, this principle constitutes basis of the present invention.

Fig. 7 be illustrated in abrasive grains in the situation of using the polishing pad that foam structure is arranged among Fig. 3 in slurries concentration and the relation between the polishing speed.

In experiment, silica dispersed is prepared slurries in pure water, simultaneously the concentration of silica granule is changed into 5,10 and 15wt% the time, and investigated the polishing speed of formed plasma oxide film on silicon wafer.Thereby, use the CMP device 10 among Fig. 2, when the aforementioned slurries with 200ml/min flow rate are provided, by polish pressure being set to 3psi and realizing polishing with velocity of rotation rotation polishing carrier 13 and the polishing platen 11 of 90pm and 80rpm.

With reference to figure 7, obtain the result who represents that polishing speed concentration common and abrasive grains changes pro rata.And, can find that from the result of Fig. 7 the lowering of concentration of the abrasive grains in slurries is to 5wt% or more hour, although depend on the diameter of abrasive grains, polishing speed has significantly descended.

Can reckon with that from the result of Fig. 7 when the lowering of concentration of the abrasive grains in the slurries was following to a certain degree, polishing speed obviously descended, for example the profile or the particle diameter of abrasive grains decide this degree by the composition of slurries or the characteristic of grinding.

Fig. 8 is illustrated in the result under the situation of carrying out similar experiment on the copper film, and this copper film forms on silicon substrate by silicon dioxide film.

With reference to figure 8, in this experiment by polish pressure is set at 3psi, the velocity of rotation of polishing carrier 13 is set at 80rpm, and the velocity of rotation of polishing platen 11 is set at 70rpm, and is the slurries of 200ml/min by flow rate is provided, and comes polishing of copper film.In the experiment of Fig. 8, the abrasive grains in the slurries is set at 3.5wt%.Under the situation of polishing of copper film, similar with the situation of polishing oxide-film, same polishing condition also is applied on the polishing pad of the polishing pad of closed cellular foam structure and non-foam body structure.

As can be seen from Figure 8, compare, use the polishing speed that polishing pad obtained of non-foam body structure 33.5% the ratio that significantly descended with the polishing pad that uses foam structure.This reduction that is appreciated that polishing speed obviously reflects the low concentration level of abrasive grains in the slurries.

Similarly, when using the polishing pad of non-foam body structure or when the concentration step-down of the abrasive grains in the slurries, the polishing speed reduction can be caused, and the high polishing speed that obtains to expect might be difficult to.

On the other hand, (promptly use the situation of the polishing pad of non-foam body structure for solving both of these case, and the situation of using slurries when using the polishing pad of non-foam body structure simultaneously) method of the problem that reduces of the polishing speed that is taken place down with low concentration abrasive grains, can contemplate, on pad interface, form groove by the conditioner discs among Fig. 2 15.

Shown in Fig. 9 A, use the polishing pad of non-foam body structure, polishing pad does not have foams (pore), and compares with the polishing pad that foam structure is arranged shown in Fig. 9 B, and the quantity of the slurries 16 that kept on polishing pad 12 surfaces must reduce.Therefore, under the situation of the polishing pad that uses the non-foam body structure, there is the polishing pad of foam structure to compare with use, the quantity that is provided to the slurries of semiconductor wafer surface that will be polished must become less, the reduction of earlier in respect of figures 6 described polishing speeds can take place as a result.

Therefore,, can imagine, form sulculus on polishing pad 12 surfaces, use these channelization polishing pads to replace foams by conditioner discs 15 in order as the polishing pad that foam structure is arranged, in the polishing pad of non-foam body structure, to keep slurries.

Figure 10 is the sectional view that shows the conditioner discs 15 that uses traditionally.

With reference to Figure 10, conditioner discs 15 is formed by substrate 15A, and by alloy-layer 15B with hard abrasive grains 15C for example diamond hold on substrate 15A.Usually, analogs such as use stainless steel use diamond as abrasive grains 15C as substrate 15A.And, use the Ni alloy as the alloy-layer 15B that abrasive grains 15C is held on substrate 15A usually.Can be implemented in substrate 15A by electronic deposition technology, electroplating technology or diffusion technology formation alloy-layer 15B and go up fixedly abrasive grains 15C.

Characteristic that it should be noted that this conditioner discs 15 is mainly decided by hard abrasive grains and its arrangement.

Hereinafter, use diamond as the conditioner discs 15 in the situation of hard abrasive grains 15C with explaining.

Use this conditioner discs 15, the polishing characteristic of polishing pad can produce very big variation along with the size and dimension of employed diamond particles in conditioner discs.

For example, at the diameter of diamond lap particle 15C less and diamond particles have granular and etc. under the situation of square shape, being used for the power of abrasive grains of grinding and polishing pad can reduce, and the polishing speed that polishing pad can occur reduces and the quantity of grinding and polishing pad reduces.In this case, the life-span of polishing pad 12 is certain to prolong; Yet but can not repair fully polishing pad.

On the contrary, using under the irregular situation of diamond particles as abrasive grains 15C with sharp shape, the polishing speed that handled polishing pad can take place increases, and might realize the finishing of the satisfaction with regard to polishing pad validity.On the other hand, the life-span reduction of polishing pad 12 and the production cost of semiconductor device can take place increases.And this sharp-pointed diamond lap particle is ruptured or grinding cracks easily, and also can increase the appearance of scratch.When causing scratch, can dark indentation occur on the surface of Semiconductor substrate, and will inevitably reduce the output of semiconductor device product.

It should be noted that the available product that is used for all types of conditioner discs on the market, wherein general granular diamond lap particle is usually used in this commercially available conditioner discs.Therefore, according to circumstances use the conditioner discs of the coarse diamond particles of carrying.When the conditioner discs that uses the coarse diamond particles of carrying is repaired, compare with the conditioner discs situation of using carrying granular gold hard rock abrasive grains, can form darker groove on the surface of polishing pad 12.

Usually, the foams that are used for the polishing pad that foam structure is arranged as shown in Figure 3 have several microns to tens microns hole dimension.On the other hand, the diamond lap particle 15C among Figure 10 has the size of at least 50 μ m, and normally 100 μ m to the size of hundreds of micron.Therefore, by using this conditioner discs, might form the deep trouth of the degree of depth in pad interface greater than the hole dimension of foams.

Effective equally by the finishing that conditioner discs among Figure 10 15 is realized with the situation of repairing polishing pad with foam structure, and might keep more slurries in pad interface.

Therefore, by the conditioner discs 15 in the CMP device of conditioner discs conduct in Fig. 2 that uses the coarse diamond particles of carrying, no matter be before use face with reference to the described polishing pad that foam structure is arranged of Fig. 3 as the situation of polishing pad 12 or under the situation of using the polishing pad of described non-foam body structure with reference to Fig. 5, can expect to increase polishing speed.Therefore, owing to form deep trouth, might for a long time a large amount of abrasive grains that comprised in the slurries be remained on polishing pad 12 surfaces on the surface of polishing pad 12.

Figure 11 A is that polishing pad 12 surfaces that are illustrated in the non-foam body structure do not form under the situation of under the state of groove Semiconductor substrate 21 being polished, the schematic diagram of relation between abrasive grains in Semiconductor substrate 21, the slurries 16 and the polishing pad 12, and Figure 11 B is illustrated in by conditioner discs 15 under the situation of the polishing pad 12 surface formation deep trouths of same non-foam body structure, the schematic diagram of relation between abrasive grains in Semiconductor substrate 21, the slurries 16 and the polishing pad 12.

With reference to figure 11A, it should be noted that, do not forming on the polishing pad 12 under the situation of groove, Semiconductor substrate 21 contacts the polishing pad that provides slurries via the thin layer of the abrasive grains in the slurries 16, the wherein levigate gradually and wearing and tearing of pressure in the polished technology of abrasive grains in the slurries 16 and friction.

Here, as long as provide new abrasive grains to replace the abrasive grains that wears away along polishing pad 12 surfaces, just can not go wrong, and the control slurries are difficult along the Surface runoff of polishing pad 12, and can appear at the situation that exhausts abrasive grains in the special area of polishing pad 12.In this case, when chemico-mechanical polishing has been carried out a very long time, descend gradually along with polishing speed can take place for the wearing and tearing of abrasive grains.

On the other hand, form under the situation of groove in pad interface at the conditioner discs 15 that passes through shown in Figure 11 B, formed groove can keep abrasive grains a large amount of in the slurries 16, even and the abrasive grains wearing and tearing occur new abrasive grains can be added to this position during polishing.Therefore, can not cause the reduction of polishing speed and might stably finish chemico-mechanical polishing one long period.

Therefore, the polishing speed of semiconductor wafer can change along with the surface state of the polishing pad 12 that is used for chemical mechanical polish process technology, and the surface state of polishing pad 12 is subjected to being used for the influence of surface state of the conditioner discs 15 of chemico-mechanical polishing.Therefore, the arrangement of the diamond particles 15C in conditioner discs not simultaneously, even conditioner discs uses identical diamond particles, the surface state of polishing pad 12 can be different.

Figure 12 A-12D illustrates several examples of the conditioner discs of the arrangement that has changed diamond lap particle 15C, and wherein aforesaid those parts are represented with identical Reference numeral and omitted description to it.

With reference to figure 12A, the diamond crystal that forms abrasive grains 15C in this example is oriented to its flat plane of crystal towards the top.On the other hand, for the example of Figure 12 B, diamond crystal is oriented to its turning towards the top.Use the structure of Figure 12 B, the turning of diamond lap particle 15C is towards the top, thereby might be more effectively to the polishing pad cutting.

And, in the example of Figure 12 C, in conditioner discs 15, increased the density of diamond lap particle 15C, and in the example of Figure 12 D,, reduced the thickness of the fixed bed 15B of the diamond lap particle 15C that holds in order to increase the exposure of abrasive grains 15C.

In any of these structures, all might be than the surface of grinding and polishing pad 12 more effectively of the structure among Figure 12 A.And, for the structure of Figure 12 B and 12D, increased the degree of depth at polishing pad 12 surperficial formed grooves.

Figure 13 A is illustrated in the state of pad interface under the situation on polishing pad 12 surfaces that the conditioner discs that uses Figure 12 A grinds the non-foam body structure, and Figure 13 B is illustrated in the state of pad interface under the situation on polishing pad 12 surfaces that the conditioner discs that uses Figure 12 B or 12D grinds the non-foam body structure.

Can notice from these, use and come the polishing speed of polishing of semiconductor wafers to change along with the arrangement of the diamond lap particle 15C on the substrate 15A that is formed on the conditioner discs 15 with the trimmed polishing pad of this conditioner discs.And, when diamond lap particle 15C relatively is seated in the situation of situation and identical diamond lap particle 15C randomize on the substrate 15A regularly, although use identical diamond particles in both cases, can obtain higher polishing speed in the situation of diamond lap particle randomize.

For the method for on conditioner discs, arranging diamond particles, for example, can be with reference to Japanese Laid-Open Patent Application 2002-187065.

Figure 14 is presented at the time dependent figure of polishing speed in the case, promptly, by using two conditioner discs 15A shown in Figure 15 A and the 15B and 15B to repair the commercially available foam structure polishing pad that has respectively, and when using polishing pad after being trimmed like this, use the CMP device among Fig. 2 to come article on plasma body oxide-film to polish as polishing pad.In the experiment of Figure 14, when the concentration with the abrasive grains in the slurries is set at 18wt%, by polish pressure is set at 4psi, the velocity of rotation of polishing carrier 13 and the velocity of rotation of polishing platen 11 are set at 90rpm and 80rpm respectively and flow rate is provided is that the slurries of 200ml min polish.And, be set at 5psi by pressure and carry out finishing polishing pad with conditioner discs 15, wherein when each polishing silicon dioxide film, use this finishing.

With reference to figure 15A, it should be noted that conditioner discs A is corresponding with the dish among Figure 12 A, therefore, be generally granular diamond crystal and be used as abrasive grains 15C.Therefore, abrasive grains 15C has given prominence to the distance of 50-100 μ m from fixed bed 15B.In contrast, conditioner discs B is corresponding with the dish among Figure 12 B or the 12D, and diamond crystal coarse and in irregular shape is used as abrasive grains 15C.Therefore, abrasive grains 15C has given prominence to the distance of 100-200 μ m from fixed bed 15B.Therefore,, it should be noted that diamond lap particle 15C is seated on the substrate 15A at random, therefore realized big grinding rate polishing pad 14 for the conditioner discs B among Figure 15 B.

On the other hand, for the conditioner discs A among Figure 15 A, diamond lap particle 15C arranges with the formal rule ground of grid.As a result, under the situation of using the trimming polished pad 12 of conditioner discs B, compare with the situation of using conditioner discs A, the grinding rate of polishing pad 12 has increased twice.

With reference to Figure 14, under the situation of using the trimming polished pad 12 of conditioner discs B, polishing speed becomes big immediately after finishing, and can believe, this be because, compare with the dish A situation that is used to repair, under the situation of use dish B, can realize the surface that polishing pad 12 is more coarse.On the other hand, slurries have comprised the abrasive grains of the high concentration with about 18wt%, and as can be seen, polishing speed has only increased by 10%.

On the other hand, can find a kind of phenomenon as seen from Figure 14, that is, when continue using the trimming polished pad 12 of conditioner discs B and the time of always repairing surpasses about 5 hours, the polishing speed of silicon dioxide film sharply descends.On the other hand, when using the polishing pad repaired by conditioner discs A, can see,, still can obtain stable polishing speed even reached 9 hours when the whole finishing time as polishing pad 12.

Can believe that this is because the quick wearing and tearing of polishing pad 12 cause.Particularly, because the very large grinding rate of conditioner discs B, polishing pad 12 wearing and tearing and also reduce rapidly fast when using conditioner discs B in the degree of depth of the formed groove of pad interface.Therefore, can not effectively slurries be offered semiconductor wafer.

Under the situation of the trimming polished pad 12 of use dish A, can realize little grinding rate, even and repair and carried out also can on polishing pad, occurring hardly after a very long time wearing and tearing to polishing pad.Therefore, the groove of the pad interface degree of depth of can remaining valid very over a long time, the result continues stably slurries to be offered semiconductor wafer surface, thereby can realize stable polishing.

Next, use copper film similarly to test.

In this experiment, the polishing pad of non-foam body structure is as polishing pad 12, in that flow rate is provided is when 200ml/min and concentration are the slurries of abrasive grains of 2wt%, by polish pressure is set at 3psi, and rotate polishing carrier 13 with the velocity of rotation of 80rpm and 70rpm respectively and polishing platen 11 polishes.And use dish A and B wherein under any situation of use dish A and B, are set at 5psi with this pressure and repair as conditioner discs 15 trimming polished pads 12.

Figure 16 is illustrated in polishing speed and the relation between the time of finishing always that this experiment obtains.

With reference to Figure 16, as can be seen, come under the situation of polishing of copper film in conjunction with the low slurries that grind concentration at the polishing pad that uses the non-foam body structure, the polishing pad that foam structure is arranged with use is compared in conjunction with the situation that the slurries of high concentration abrasive grains polish oxide-film, and the effect of conditioner discs B seems more remarkable.As can be seen, polishing speed has increased about 70% on maximum.

Use this structure, on the other hand, when polishing speed became very big as described, the life-span of polishing pad became very short, and can confirm when total finishing time surpasses 6 hours, can complete obiteration at the handled groove of pad interface.On the other hand, under the situation of using conditioner discs A, still keep enough degree of depth even carried out 16 hours grooves on the polishing pad when finishing.Can estimate, can occur 4 hours on the life-span of polishing pad 12 or difference for more time.

Therefore, according to the investigation that constitutes basis of the present invention, can find, when the polishing pad of slurries that use low grinding concentration or use non-foam body structure, might avoid the minimizing of polishing speed, also find the lost of life of polishing pad when using conditioner discs B simultaneously.And can observe, under the situation of using conditioner discs B, the polishing uniformity of semiconductor wafer reduces.

Therefore, the present invention eliminates aforesaid problem by using with two different surfaces states as two different trim process of feature when trimming polished pad.

[first embodiment]

Hereinafter, will describe the first embodiment of the present invention with reference to Figure 17 and table 1, wherein table 1 is represented the condition of trim process, and Figure 17 is the flow chart that shows according to the chemico-mechanical polishing of the first embodiment of the present invention.In the present embodiment, come polishing of copper film with the CMP device among Fig. 2.

Table 1

	Adjust	Polishing	Quicken	Readjust
	Adjust	Polishing	Quicken	Readjust	Conditioner discs	B	A	B	B
The rotation (rpm) of dish	87	87	87	87	Conditioner discs	B	A	B	B
The rotation (rpm) of dish	87	87	87	87	The pressure of dish	9	5	5	9
The finishing time (sec)	1800	24	Arbitrarily	600	The pressure of dish	9	5	5	9
The finishing time (sec)	1800	24	Arbitrarily	600	The rotation of platen (rpm)	70	70	70	70

With reference to Figure 17, the new polishing pad that is provided is installed on the polishing platen 11 as polishing pad 12, and the conditioner discs B of foregoing Figure 15 B is installed on the CMP device 10 as conditioner discs 15 adjustment (break-in) of beginning polishing pad 12.

In this step, polishing platen 11 rotates with the velocity of rotation of the 70rpm shown in the table 1, and is promoted against polishing pad 12 by the motive force with 9lbs (pound) with the conditioner discs 15 that the velocity of rotation of 87rpm is rotated.With this understanding, the adjustment of polishing pad 12 has been carried out 1800 seconds." beginning to adjust " in the reference table 1.

Next, in the step 2 of Figure 17, conditioner discs 15 is transformed to dish A Figure 15 A from the dish B of Figure 15 B, and offering flow rate is when 200ml/min and grinding concentration are the slurries of 2wt%, by polish pressure is set at 3psi, the velocity of rotation that the velocity of rotation of polishing carrier 13 is set at 80rpm and polishing platen 11 is set at 70rpm and comes polishing of copper film.In this step, also carry out the measurement of polishing speed.

In step 2, should be noted that the velocity of rotation of conditioner discs 15 is set at 87rpm and carries out the finishing of 24 seconds polishing pad under the finishing pressure of 5lb." wafer polishing " in the reference table 2.

Next, in step 2, obtained after the wafer polishing speed, in the experiment of Figure 16, quickened finishing, be used for obtaining always to repair the time.When offering pure water, repair by repairing this acceleration of carrying out one period scheduled time." acceleration " in the reference table 1.

And, in the embodiment of Figure 16,,, in step 4, carry out wafer polishing when reaching predetermined total finishing during the time as the result who quickens in the step 3, therefore, obtained polishing speed.

And in step 5, along with the decline of polishing speed, conditioner discs transforms to dish B from dish A, and adjusts polishing pad once more 600 seconds under the condition of " the readjusting " shown in the table 1.

And in Figure 17, therefore the flow process of repeating step 1-step 5 after step 6, obtains the data of polishing speed.

Figure 18 shows the polishing speed by the copper film that experiment obtained of Figure 17, the polishing speed of the copper film when wherein " dish A " expression only will coil A and is used as the situation of conditioner discs, the polishing speed of the copper film when " dish B " expression only will coil B as the situation of conditioner discs 15, and the polishing speed of the copper film of " dish A+B " expression when being used for that dish A and dish B be used as the situation of conditioner discs 15.

With reference to Figure 18, in the experiment of " dish A+B ", readjust by the time shown in the arrow according to the flow chart of Figure 17, wherein note, when obtaining high polishing speed immediately after adjusting, when conditioner discs 15 was transformed to dish A and continues to use this polishing pad, polishing speed descended gradually.

Therefore, in the experiment of " dish A+B ", when polishing speed has dropped to a certain degree, will coil B, continue to adjust polishing pad a period of time to recover polishing speed near initial burnishing speed as conditioner discs 15.And, all be used as under the situation of conditioner discs 15 at dish A and dish B, can confirm to access the life-span of the almost equal polishing pad of the situation of repairing with use dish A only.

And, under the situation that only use dish B repairs, when total finishing time surpasses about 6 hours, polishing pad 12 wearing and tearing.And, under the situation that only use dish A repairs, can only obtain low polishing speed.

Therefore, by coiling A and dish B in conjunction with the finishing of finishing polishing pad 12, high polishing speed and the long-life that might realize polishing pad.

And, in the experiment of the flow chart of Figure 17, (wherein, use CMP device 10 conversion simultaneously among Fig. 2 to polish) as the dish A and the dish B of conditioner discs 15, there is such CMP device, it might install two or more conditioner discs simultaneously.In this case, might finish the glossing identical and not have the conversion conditioner discs with glossing shown in Figure 15.And, might drive two conditioner discs simultaneously and carry out different dressing processes simultaneously.

[second embodiment]

Next, will be with reference to the production process of semiconductor device that comprise copper enchasing technology of figure 19A-19E description as the second embodiment of the present invention.

With reference to figure 19A, SiO ₂, analogs such as SiOC, SiC, SiON, SiN, BPSG dielectric film 21 on the Semiconductor substrate (not shown), form so that cover for example unshowned transistor of active device that is formed on the semiconductor liner.Dielectric film 21 can be formed directly on the semiconductor liner or be formed on the dielectric film that is formed on the Semiconductor substrate.

Then, in the step of Figure 19 B, be formed in the dielectric film 21 by etch process with the corresponding interconnected groove 21G of interconnection pattern that expects.Under the situation of dual-damascene technics, through hole is formed among the interconnected groove 21G and exposes the conductive layer that is positioned at below the dielectric film 21.And in the step of Figure 19 C, (TaN, barrier metal film 22 TiN) covers and comprises side surface and the lower surface of interconnected groove 21G by tantalum (Ta), titanium (Ti) or its nitride on the surface of dielectric film 21.

Next, in the step of Figure 19 D, copper film 23 forms and the interconnected groove 21G of filling on barrier metal film 22.Should be noted that this formation of finishing copper film 23 by sputtering technology or electroplating technology or the combination of the two.

And, in the step of step 19E, use the CMP device among Fig. 2 that copper film 23 and barrier metal film 22 are removed from the surface of dielectric film 21 together, thereby obtain copper pattern 23G is embedded to interconnected groove 21G via barrier metal film 22 interconnect architecture.

In the present embodiment, the polishing pad of use non-foam body structure and slurries carry out the CMP technology among Figure 19 E, and the gluey silica in these slurries is dispersed in the solvent as abrasive grains with the concentration of 1.5wt%.For this solvent; can use organic acid (forming compound with copper), oxidant (being used for the copper oxidation) and corrosion inhibitor (can form diaphragm on the copper surface) are joined the mixture that ultra-pure water forms, perhaps use hydrogen peroxide and organic acid are joined the mixture that forms in the ultra-pure water.

And under the situation of adjusting polishing pad 12, present embodiment uses the dish B of Figure 15 B as conditioner discs 15, and the dish A among Figure 15 A is used as conditioner discs 15 when carrying out common polishing.

[the 3rd embodiment]

Figure 20 A is the flow chart of demonstration and the corresponding experiment of third embodiment of the invention.

With reference to figure 20A, on the CMP device 10 in the polishing pad installation diagram 2 of non-foam body structure, as the polishing pad in the step 11 of present embodiment 12, and in aforementioned table 1 under the condition of " adjustment ", use dish B among Figure 15 B to carry out the adjustment of polishing pad 12 as conditioner discs 15.

Next, step 12, the dish A among Figure 15 A is as conditioner discs 15, at aforementioned polishing condition (polish pressure=3psi; Carrier velocity of rotation=80rpm; Platen velocity of rotation=70rpm; During the down trimming polished pad 12 of slurry speed=200ml/min), the copper film 23 among polishing Figure 19 E.And under the condition of table 1 (wafer polishing) trimming polished pad 12.

Further, in step 13, use dish A quickens trimming polished pad 12 as conditioner discs 15 under the condition of table 1 (acceleration), in step 14, readjusts polishing pad 12 under the condition of table 1 (readjusting).

Further, in step 15, polishing of copper film 23 under the condition identical with the situation of step 12.

In the present embodiment, for the effect of the technology of evaluation graph 20A, carry out the comparative experiments of the technology of the technology of Figure 20 B and Figure 20 C.

In the experiment in Figure 20 B, the polishing pad of non-foam body structure uses with dish B, and except having omitted the step 14 (readjusting) among Figure 20 A, carries out similar glossing.

Therefore,, carry out similarly adjusting, as under the state of conditioner discs 15, in step 22, carry out and the similar polishing of step 12 copper film 23 at mounting disc B with the adjustment of step 11 in step 21.

Further, in step 23, as under the state of conditioner discs 15, carry out the acceleration finishing according to the condition of table 1 at mounting disc B.Further, in step 24, skip the step 14 among Figure 20 A, with the same condition of step 22 under carry out and step 15 accordingly to the polishing of copper film 23.

And in the experiment of Figure 20 C, the step 14 (readjusting) in omitting Figure 20 A, use dish A and the polishing pad that is combined with foam structure similarly polish.

Therefore, in step 31, use dish A carries out with step 11 as conditioner discs 15 and similarly adjusts, in step 32, carries out under the state of A as conditioner discs 15 installations and the similar polishing to copper film 23 of step 12 will coil.

Further, in step 33, when state that holding tray A installs as conditioner discs 15, quicken finishing according to the condition of table 1.And, in step 34, skip the step 14 of Figure 20 A, and under the condition identical, carry out with step 15 corresponding copper film 23 polishings with step 32.

Figure 21 illustrates the method for the polished like this mosaic texture of assessment.

In using the handled copper enchasing structure of CMP technology, owing to compare with the polishing speed of the dielectric film that constitutes interlayer insulating film, the polishing speed of copper is bigger, and trend is that different being formed on of difference in level that is called pit inlayed in the formed zone of interconnect pattern.On the other hand, in order to realize the high reliability of semiconductor device, expectation suppresses the formation of this pit as far as possible.

Therefore, use present embodiment, as shown in figure 21,, obtain evaluation the glossing of Figure 20 A-20C by measuring the horizontal plane difference between the zone that the zone that do not form interconnect pattern and formation inlays interconnect pattern.Therefore, should be noted that measuring is to carry out on the middle part of substrate and periphery.

The result of planar survey before Figure 22 illustrates.

With reference to Figure 22, should be noted that (A) is corresponding with the technology of Figure 20 A and therefore corresponding with the technology of present embodiment, can see that wherein measured horizontal plane difference is very little, even and after quickening finishing, also can not increase horizontal plane difference.

On the contrary, with corresponding Figure 22 of the situation of Figure 20 B (B) in, only will coil B uses with the polishing pad of non-foam body structure, notice that wherein the horizontal plane difference that first glossing in the step 22 is caused is less, thereby obtains a good result, and after step 23 under the situation quickening to repair, can see, can find that horizontal plane difference significantly increases, especially in the outer part office of Semiconductor substrate.Can believe that this is that the result has almost eliminated groove because polishing pad 12 is worn causedly in the contacted outer part of the periphery office of itself and Semiconductor substrate.

Can believe that this has reflected such a case, that is, because the grinding rate of use dish B polishing pad is bigger, so the groove on the polishing pad just disappeared in very short time, and therefore, slurries can not be provided to pad interface sufficiently, and polishing performance worsens as a result.

On the other hand, (C) among Figure 22 illustrates the polishing pad and the dish A situation about combining of foam structure, wherein notes not having big difference between step 32 and step 34, and compare with the technology among Figure 20 B, polishes that self is more stable.Yet, as can be seen, comparing with the technology among Figure 20 A, the difference in level dissident is through increasing quite greatly.

Therefore, by use dish B when adjusting polishing pad as conditioner discs 15 with by use dish A when the normal polishing, when using the hard polishing pad of non-foam body structure and when using the slurries of low concentration abrasive grains, present embodiment might be realized big and stable polishing speed, and can not shorten the life-span of polishing pad.Therefore, can realize to suppress the CMP (Chemical Mechanical Polishing) process that pit formed and suppressed the scratch appearance.

For the present invention, dielectric film 21 can be Si, SiO, SiO ₂, in SiOC, SiC, SiON, SiN, BPSG or its combined films any one.And, replace copper film 23, can use the film of W, Ti, Al, Ta, Ag, Au, Pt, Ru, polysilicon, amorphous silicon or its oxide or nitride.

And though the formation of adopting the front to describe CMP (Chemical Mechanical Polishing) process and mosaic texture connects when making an explanation, the present invention does not limit therewith, and the present invention can also be applied in the formation of STI (shallow trench isolation from) structure or analog.

[the 4th embodiment]

In the fourth embodiment of the present invention, in CMP device 10 shown in Figure 2, use the polishing pad of non-foam body structure shown in Figure 5 to implement to form the experiment of copper pattern by mosaic technology.

By with this experiment of the similar process implementing of technology of earlier figures 1A-1E, therefore, on silicon substrate, to form the oxide-film 21 of the thick step of 500nm with Figure 1A corresponding step.

Further, with the corresponding step of the step of Figure 1B, interconnected groove 21G forms at interval with width and the 0.15 μ m of 0.9 μ m, then, with Fig. 1 C corresponding step in form the barrier metal film 22 of 10nm thickness.And, with Fig. 1 D corresponding step in, deposition 1000nm thick copper layer 23.

Further, with the corresponding step of Fig. 1 E, use the polishing pad of non-foam body structure to come polish copper layer 23.Therefore, the duration of determining the polishing of copper layer 23 according to the sample of making specially for the measurement polishing speed (specimen).

More specifically,, form the thick barrier metal film of 10nm, do not deposit the thick copper film of 10000nm and prepare sample with oxide film patternization with on oxide-film at oxide-film by on silicon substrate, forming the thick oxide-film of 100nm.Further, determine polishing time by obtaining the time that the degree of depth of copper layer jettisoning 650nm on the sample and 950nm is required, thus in the duration that is obtained, with Fig. 1 E corresponding step in the aforesaid copper layer 23 of polishing.

And, there is the polishing pad (IC-1000 of Nitta Haa company) of foam structure, similarly to polish in order to determine effect of the present invention, to use as the polishing pad 12 of the CMP device 10 among Fig. 2, be formed for the sample of compare test.

Following table 2 illustrates the composition of the slurries that are used to polish, and table 3 illustrates polishing condition.

Table 2

Oxidant	Hydrogen peroxide 10.0%
Oxidant	Hydrogen peroxide 10.0%	Corrosion inhibitor	BTA (BTA) 0.2%
The material of dissolution of metals or metal oxide	Malic acid 0.2%	Corrosion inhibitor	BTA (BTA) 0.2%
The material of dissolution of metals or metal oxide	Malic acid 0.2%	Surfactant	Water-soluble polymers 0.1%
Abrasive grains	The gluey silica of 50nm diameter	Surfactant	Water-soluble polymers 0.1%
Abrasive grains	The gluey silica of 50nm diameter	Pure water	88.5％

Table 3

Polish pressure	3psi
Polish pressure	3psi	The carrier velocity of rotation	75rpm

The platen velocity of rotation	65rpm
The platen velocity of rotation	65rpm	Slurries provide speed	200ml/min

Reference table 2, preparation is used for the slurries of this experiment, be used for the polishing metal film, these slurries comprise hydrogen peroxide as oxidant, as the BTA (BTA) of corrosion inhibitor, as the malic acid of the material of dissolution of metals or metal oxide, as the water-soluble polymers of surfactant, and pure water.And slurries comprise the abrasive grains of a spot of gluey silica.

Under the situation of the polishing pad that uses this non-foam body structure, when polishing, will be difficult to stably maintain slurries, for this reason, present embodiment uses two conditioner discs 15 with conditioner discs of different surface roughness as CMP device 10 among Fig. 2, at first use coarse conditioner discs at first to form deep trouth shown in Figure 13 B in pad interface, when pad interface forms as shown in FIG. 13A shallow slot, use meticulous conditioner discs to carry out polishing afterwards.

Further, when the finishing of using meticulous conditioner discs has reached the scheduled time, reuse coarse conditioner discs and repair, afterwards, use meticulous conditioner discs to proceed finishing.Therefore, when carrying out the finishing of using coarse conditioner discs, continue polish copper layer 23.

According to this method, repair by using coarse conditioner discs, enough stably keep the deep trouth of slurries at the surface formation energy of the polishing pad of non-foam body structure, and during glossing by meticulous conditioner discs finishing, the polishing dust that is produced in the time of can removing polishing of copper film 23.And, using under the situation of coarse conditioner discs separately, the quick wearing and tearing of polishing pad can take place, and when using coarse conditioner discs off and on, can guarantee the life-span of polishing pad.

Figure 23 illustrates the profile of the mosaic texture that obtains according to this technology.

With reference to Figure 23, the mosaic texture that is obtained has the shape with similar shown in Figure 21 thus, wherein uses present embodiment to measure because the formed horizontal plane difference of polishing, and compares with the situation of using the polishing pad that foam structure is arranged among Fig. 3.

Figure 24 illustrates comparative result.

Being used for the sample of this experiment, before polishing experiments, the size of the pit defined in the different or Figure 23 of difference in level is 130-140nm.Continue the time (this duration is identical with the duration that the specimen that will not form mosaic texture is polished to the 650nm degree of depth) afterwards in the polishing that is applied to this structure, the polishing pad of foam structure is arranged and use between two kinds of situations of polishing pad of non-foam body structure in use, partly do not have substantial difference in substrate center.Yet, have in use under the situation of polishing pad of foam structure, occurred approximately at the peripheral part of substrate as can be seen-pit of 5nm.This means because erosion slight sinking occurred in the zone of interconnect pattern.

In contrast, under the situation of polishing in a duration (this time is corresponding with the degree of depth that is polished to 950nm of the sample that will be used for measuring polishing speed), as can be seen, when use has the polishing pad of foam structure, the sinking that reaches 15nm not only can appear at the peripheral part of substrate but also can appear at the core of substrate, and can not obtain smooth polished surface.

In contrast, under the situation of the polishing pad that uses the non-foam body structure, as can be seen, all significantly reduced in the quantity of the sinking of the core of substrate and peripheral part.

In this way, the sinking by the caused polished surface of erosion when the chemico-mechanical polishing metal film is effectively suppressed in the present embodiment, thereby can realize the complanation of the interconnection layer of chemico-mechanical polishing when forming multiple level interconnect architecture.

Figure 25 illustrate to Fig. 1 E corresponding inlay interconnect architecture (its by using the non-foam body structure polishing pad and have the polishing pad of foam structure to form) in the investigation result of the scratch that occurred.In this experiment, in the step of Fig. 1 E, copper layer 23 stood CMP (Chemical Mechanical Polishing) process 2 minutes, and by chemical machine polishing 2 minutes.

With reference to Figure 25, as can be seen, under the situation of the polishing pad that uses the non-foam body structure, number of scratches of seeing at substrate surface and the flaw quantity of bringing drop to 1/7 of the situation of using the polishing pad that foam structure is arranged.

And the result who should be noted that Figure 25 is that the ratio for the abrasive grains in being included in slurries is set at for the situation of the 1.0wt% shown in previous table 1.

On the other hand, have under the situation of substrate surface of projection and depression when the ratio of the abrasive grains in the slurries has increased in polishing, when using the polishing pad of non-foam body structure, polishing pad touches raised structures, causes forming the gap between recessed structure and polishing pad.Therefore, be penetrated into abrasive grains in this gap, cause the whole sinking of polished surface except in raised structures, also can in this recessed structure, causing polishing.

When the concentration of the abrasive grains in the slurries has surpassed 3wt%, it is particularly outstanding that this problem becomes, when the concentration of abrasive grains reaches 5-6wt%, although find to use the polishing pad of non-foam body structure, the sinking of the polished surface that situation occurred that uses the polishing pad that foam structure is arranged also can appear being similar to.

Reach a conclusion thus, when the polishing pad that uses the non-foam body structure carried out chemico-mechanical polishing, ideal situation was that the ratio of setting abrasive grains in the slurries is 3wt% or still less, was preferably 1wt% or still less.And, should be noted that even be that 0wt% does not promptly have abrasive grains to join under the situation in the slurries in the concentration of abrasive grains, chemico-mechanical polishing of the present invention also can rely on the surface state of polishing pad to carry out.

In aforesaid CMP (Chemical Mechanical Polishing) process of the present invention, should be noted that the temperature that also will control pad interface.

Usually, for CMP device shown in Figure 2, temperature control unit is incorporated in the polishing platen 11, therefore, in previous experiments, use this temperature control unit with the surface temperature control of polishing pad to being lower than 5 ℃ or lower and be no more than 40 ℃ scope.Carry out in the polishing of metal film at the polishing pad that uses the non-foam body structure, find that 10 to 30 ℃ scope is preferred.

Too low even when dropping to below 0 ℃ when the pad interface temperature, for example, the pure water that is used in the slurries might freeze.When this happens, will pay close attention to the problem that the ice particle that drips on the polishing pad can cause scratch.And, in slurries, have thermally sensitive material.For example, when excessive temperature increased, etching reaction became too strong thereby reaction speed excessively raises.Therefore, the complanation of polished surface worsens.

Illustrating that by CMP (Chemical Mechanical Polishing) process polishing metal film it also is effective using the CMP (Chemical Mechanical Polishing) process of the present invention of the polishing pad of non-foam body structure for example during the situation of copper in the situation of complanation dielectric film.

For example, in the technology that forms STI (shallow trench isolation from) structure, the present invention can be used in the oxide-film of polishing filling device isolated groove.The present invention who should be noted that the polishing pad that uses the non-foam body structure is especially effective for this chemico-mechanical polishing, and the slurries chemical machinery that this chemico-mechanical polishing use comprises as the ceria of abrasive grains polishes oxide-film.

It should be noted that; similar with the slurries that offer copper; comprising slurries as the ceria of abrasive grains also comprises as surfactant and preparation (agent) with the function that forms diaphragm; wherein the situation with polish copper is opposite; this formation diaphragm forms preparation by being adhered to the nitride film surface that forms under the oxide-film, stops further polishing process.

The present invention also is effectively in the complanation of this dielectric film, for example chemico-mechanical polishing of sti structure.

[the 5th embodiment]

Figure 26 illustrates the structure according to the CMP device 10A of fifth embodiment of the invention, and it is suitable for implementing the fourth embodiment of the present invention.

Among the embodiment before the present invention, when the polishing pad that uses the non-foam body structure stably remains on pad interface with slurries, use at least two conditioner discs to repair with different surfaces state.

Now, when on the CMP device 10 that these two different conditioner discs is implemented among Fig. 2, need manually to change conditioner discs 15, and this is unpractical for the production line at semiconductor device.

On the other hand, Figure 26 illustrates the CMP device 10 that is suitable for production line, wherein, it should be noted that, for CMP device 10A, three polishing platen 11A-11C are set, on CMP device main body 100 so that can use different slurries to polish, rotating main shaft (spindle) 11S wherein also is set, so that can between these three polishing platen 11A-11C, exchange pending substrate.

Therefore, when rotating this substrate, an axle 11S picks up a pending substrate from loading disk (load cup) 11L, this substrate is pushed to be equipped with among the polishing platen 11A-11C of polishing pad of non-foam body structure any one.Therefore, the substrate supporting device 13 of the CMP device of main shaft 11S and Fig. 2 is equal to.

And CMP device 10A has trimming device, and this trimming device has at the top of moveable arm respectively and the corresponding conditioner discs 15 of polishing platen 11A-11C ₁-15 ₃By conditioner discs being pushed to corresponding polishing platen, realize being installed in the finishing of the polishing pad on the polishing platen.For CMP device 10A, only should be noted that and just can realize these finishings at an easy rate by the arm of swing trimming device.

Thus, in order to realize earlier figures 5A and two different finishings shown in the 5B by two conditioner discs, in CMP device 10A, different trimming devices is set, make these two different trimming devices comprise moveable arm, these arms have the different conditioner discs 45 corresponding with polishing pad 11A-11C in the top separately at it ₁-45 ₃Therefore, should be noted that only passing through each arm of swing just can realize by conditioner discs 45 ₁-4 ₅3 finishings of being done.

And the CMP device 10A among Figure 26 has control unit 101, is used for controlling polishing platen 11A-11C, main shaft 11S, conditioner discs 15A-15C and conditioner discs 45A-45C.

Figure 27 illustrates the schematic diagram of the order that 101 pairs of CMP devices of the control unit 10A among Figure 26 controls.

With reference to Figure 27,11A polishes at platen, and in step 11, the polishing pad of the new non-foam body structure on the polishing platen 11A stands coarse conditioner discs 45 ₁Finishing (adjustment).

Further, in step 12, when using meticulous conditioner discs 15 ₁During the polishing pad of finishing non-foam body structure surperficial, repeat polished substrate to the scheduled time.Reached the scheduled time when total finishing time, according to the adjustment in the definite execution in step 11 once more in the step 13.Therefore, at conditioner discs 15 ₁With 45 ₁Between switching control by control unit 101.

Further, in step 12, when substrate is polished or before substrate is polished, can realize the finishing of the polishing pad of non-foam body structure being carried out by conditioner discs 15A.

Figure 28 illustrates the structure according to the CMP device 10B of the remodeling of the CMP device 10A of Figure 26, is wherein represented by identical Reference numeral with corresponding those parts of the described part of reference Figure 26 and omits description to it.

For the structure of Figure 26, have conditioner discs 15 ₁Trimming device and have a conditioner discs 45 ₁Trimming device only be used for polishing platen 11A, have conditioner discs 15 ₂Trimming device and have a conditioner discs 45 ₂Trimming device only be used for polishing platen 11B, and have conditioner discs 15 ₃Trimming device and have a conditioner discs 45 ₃Trimming device only be used for polishing platen 11C, and in present embodiment shown in Figure 28, omitted and had a conditioner discs 45 among Figure 26 ₃Trimming device, the substitute is, have conditioner discs 45 ₃The arm of trimming device be configured between polishing

platen

11A and 11B, swing.Similarly, the arm that has the trimming device of conditioner discs 45B is configured to swing between polishing

platen

11B and 11C.

Therefore, for the structure of Figure 28, shared conditioner discs 45 between polishing

platen

11A and 11B ₁, and between polishing

platen

11B and 11C shared conditioner discs 45 ₂

According to this structure, might simplify the structure of CMP device 10B.

Figure 29 illustrates the structure according to the CMP device 10C of the remodeling of the CMP device 10A among Figure 26, is wherein represented by identical Reference numeral with corresponding those parts of the described part of reference Figure 26 and omits description to it.

With reference to Figure 29, have a conditioner discs 45 in the present embodiment in the deletion Figure 26 structure ₂With 45 ₃Trimming device, and setting and the coaxial swing of main shaft 11S have a conditioner discs 45 ₁Trimming device.

Therefore, might be between polishing platen 11A-11C shared single conditioner discs 45 ₁, and might simplify the structure of CMP device.

[the 6th embodiment]

Figure 30 illustrates the structure that can use the trimming devices of two different finishings of CMP device 10 enforcements among Fig. 2.

With reference to Figure 30, the top that has the arm 15a of conditioner discs 15 in the present embodiment is provided with extra conditioner discs 45, wherein on conditioner discs 15 and conditioner discs 45 is fixed to the top of arm 15a is rotationally connected the different arm 15b.

Therefore, by the arm 15b that rotates at arm 15a top, when trimming polished pad 12, change conditioner discs between can and coiling 45 at dish 15.

According to this structure, can use 10 two the different finishings of enforcement of traditional C MP device and not change its foundation structure.

And, the invention is not restricted to the product of semiconductor device, also can be applicable to polishing of optical element for example lens or disk.

And, the invention is not restricted to aforesaid embodiment, under situation about not departing from the scope of the present invention, can make various changes or modification.

Claims

1, a kind of method of making semiconductor device comprises the glossing of substrate, and described glossing comprises step:

When using slurries, CMP (Chemical Mechanical Polishing) process is applied to described liner on the polishing pad; With

Repair the surface of described polishing pad,

Described pre-shaping step comprises the step of grinding the described surface of described polishing pad at least by the first and second conditioner discs that have the different surfaces state respectively.

2, the method for claim 1, wherein said first and second conditioner discs form first and second surface roughnesses respectively on the described surface of described polishing pad, make the described second surface roughness of described first surface roughness ratio big.

3, the method for claim 1, wherein said first and second conditioner discs are ground the described surface of described polishing pad respectively with first and second grinding rates, make described first grinding rate bigger than described second grinding rate.

4, the method for claim 1, the described surface that described second conditioner discs grinds described polishing pad when the described substrate of each polishing wherein, wherein said first conditioner discs grinds the described surface of described polishing pad off and on.

5, method as claimed in claim 4, wherein said first conditioner discs and second conditioner discs grind the described surface of described polishing pad simultaneously.

6, the method for claim 1, wherein said first and second conditioner discs alternately grind the described surface of described polishing pad.

7, the method for claim 1 is wherein being carried out described chemico-mechanical polishing simultaneously to described substrate, described second conditioner discs grinds the described surface of described polishing pad.

8, the method for claim 1, each comprises wherein said first and second conditioner discs substrate and is installed in described suprabasil abrasive grains by fixed bed, and the shape of the described abrasive grains on described first conditioner discs is usually different with the shape of described abrasive grains on described second conditioner discs.

9, the method for claim 1, each comprises wherein said first and second conditioner discs substrate and is installed in described suprabasil abrasive grains by fixed bed, and the particle size of the described abrasive grains on described first conditioner discs is bigger than the particle size of the described abrasive grains on described second conditioner discs.

10, the method for claim 1, each comprises wherein said first and second conditioner discs substrate and constitutes the crystal that is installed in described suprabasil abrasive grains by fixed bed, and the crystal orientation of the described crystal on the crystal orientation of the described crystal on described first conditioner discs and described second conditioner discs is different.

11, the method for claim 1, each comprises wherein said first and second conditioner discs substrate and is installed in described suprabasil abrasive grains by fixed bed, and the density of the described abrasive grains of described first conditioner discs is different with the density of the described abrasive grains of described second conditioner discs.

12, the method for claim 1, each comprises wherein said first and second conditioner discs substrate and is installed in described suprabasil abrasive grains by fixed bed, and the rising height of the described abrasive grains on described first conditioner discs is usually different with the rising height of described abrasive grains on described second conditioner discs.

13, method as claimed in claim 12 wherein is equal to, or greater than 100 μ m at the described rising height of described first conditioner discs, at the described rising height of described second conditioner discs less than 100 μ m.

14, the method for claim 1, wherein said polishing pad are the non-foam body structures.

15, it is 10wt% or lower described abrasive grains that the method for claim 1, wherein said slurries comprise concentration.

16, the method for claim 1, wherein said substrate is a semiconductor wafer, described CMP (Chemical Mechanical Polishing) process is polished the surface of described semiconductor wafer.

17, the method for claim 1, wherein said substrate supporting dielectric film, wherein said CMP (Chemical Mechanical Polishing) process is polished described dielectric film.

18, the method for claim 1, wherein said substrate supporting conducting film, wherein said CMP (Chemical Mechanical Polishing) process is polished described conducting film.

19, a kind of finishing method comprises step:

Use the object on the slurries polishing polishing pad; With

Repair the surface of described polishing pad,

Described pre-shaping step comprises and uses at least the first and second conditioner discs with different surfaces state to grind the step on the described surface of described polishing pad.

20, a kind of method of making semiconductor device comprises the step of polished substrate, and the step of the described substrate of described polishing comprises:

When using slurries, flatten by make projection and depression on the described substrate surface in the CMP (Chemical Mechanical Polishing) process of carrying out on the polishing pad,

Wherein use the slurries that can suppress sunk part is polished as described slurries.

21, method as claimed in claim 20, wherein said polishing step comprises the step of repairing described pad interface, and described pre-shaping step comprises and uses at least the first and second conditioner discs with different surfaces state to grind the step on the described surface of described polishing pad.

22, method as claimed in claim 20, wherein conducting film is exposed to the described surface of described substrate, and described CMP (Chemical Mechanical Polishing) process is polished described conducting film.

23, it is 3wt% or lower described abrasive grains that method as claimed in claim 20, wherein said slurries comprise concentration.

24, it is 0.5wt% or lower described abrasive grains that method as claimed in claim 20, wherein said slurries comprise concentration.

25, method as claimed in claim 20, the described surface of wherein said substrate exposes dielectric film, and described CMP (Chemical Mechanical Polishing) process is polished described dielectric film.

26, a kind of burnishing device comprises:

One or more polishing platens, each platen rotates and carries polishing pad thereon;

The substrate supporting device, with the corresponding setting of each described polishing platen, the described substrate supporting device pending substrate of holding, and when rotating described substrate, push described substrate to described polishing pad; With

The slurries feed mechanism offers each described polishing pad with slurries,

With at least the first and second trimming devices that each described polishing pad matches, each described trimming device is held and is used to repair the conditioner discs of described polishing pad,

27, burnishing device as claimed in claim 26, wherein said at least the first and second trimming devices are used for the described polishing platen that matches with it separately.

28, burnishing device as claimed in claim 26, wherein each described trimming device matches with a plurality of polishing platens.

29, burnishing device as claimed in claim 26, wherein, in each described polishing platen, described first trimming device cooperates described polishing platen separately, and wherein said second trimming device matches with a plurality of polishing platens.

30, burnishing device as claimed in claim 26, wherein said burnishing device also comprises control unit, on each described polishing platen, described first and second trimming devices of described control unit control, so that use described first trimming device to repeat to repair the polishing pad that is installed on the described polishing platen, when reaching the scheduled time, use described second trimming device to repair described polishing pad with total finishing time with described first trimming device of box lunch.

31, burnishing device as claimed in claim 30, wherein each described trimming device carries a plurality of conditioner discs.