CN102816529A - Tungsten chemical-mechanical polishing solution being beneficial for cleaning after polishing - Google Patents
Tungsten chemical-mechanical polishing solution being beneficial for cleaning after polishing Download PDFInfo
- Publication number
- CN102816529A CN102816529A CN 201110152812 CN201110152812A CN102816529A CN 102816529 A CN102816529 A CN 102816529A CN 201110152812 CN201110152812 CN 201110152812 CN 201110152812 A CN201110152812 A CN 201110152812A CN 102816529 A CN102816529 A CN 102816529A
- Authority
- CN
- China
- Prior art keywords
- chemical mechanical
- mechanical polishing
- polishing liquid
- polishing
- tungsten
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The invention discloses a tungsten chemical-mechanical polishing solution being beneficial for cleaning after polishing. The polishing solution comprises a grinding agent, silver ions, sulfate ions, an oxidant and a quaternary ammonium salt cationic surfactant. The polishing solution has very high tungsten-polishing speed, simultaneously improves cleaning effect of silicon wafer surfaces after chemical-mechanical polishing, reduces static corrosion to tungsten of the polishing solution, and can significantly reduce surface defects of chips.
Description
Technical field
The present invention relates to a kind of chemical mechanical polishing liquid, relate in particular to a kind of chemical mechanical polishing liquid back cleaning of the polishing of being beneficial to and that have raising polish tungsten speed that has.
Background technology
Along with the continuous development of semiconductor technology, and the continuous increase of large-scale integrated circuit interconnection layer, it is particularly crucial that the planarization of conductive layer and insulating medium layer becomes.Twentieth century eighties, be considered to the effective means of present overall planarization by chemically machinery polished (CMP) technology of IBM Corporation's initiative.
Chemically machinery polished (CMP) is by chemical action, mechanical effect and these two kinds effect be combined intos.It is usually by a grinding stage that has polishing pad, and a grinding head that is used for carries chips is formed.Wherein grinding head is fixed chip, and the front with chip is pressed on the polishing pad then.When carrying out chemically machinery polished, grinding head linearity on polishing pad moves or rotates along the heading the same with grinding stage.Meanwhile, the slurries that contain abrasive are dripped on the polishing pad, and are tiled on the polishing pad because of centrifugation.Chip surface is realized overall planarization under machinery and chemical dual effect.
Main mechanism to metal level chemically machinery polished (CMP) is considered to: oxygenant is earlier with the oxidation on metal surface film forming; The abrasive that with silicon-dioxide and aluminum oxide is representative is removed this layer sull machinery; It is oxidized to produce new metallic surface continuation, these two kinds collaborative the carrying out of effect.
The metal interconnection of IC interior structure realizes through multilayer is interconnected.Have insulation layer between every layer of metal level, normally silicon-dioxide.The binding of the metal between the different layers realizes that through via (path) these via (path) are tungsten (tungsten via) normally.Between insulation layer, have adhesive linkage (adhesion layer) at tungsten usually, material commonly used is TiN or Ti.In the actual course of processing,, in interlayer insulating film (ILD), form via (path) with the way of etch (etching); Arriving at needs banded lead or device; Form very thin adhesive linkage (adhesion layer) on the surface of insulation layer (ILD) and via (path) then, then, fill tungsten (tungsten) among the via (path); At last, the unnecessary tungsten in upper strata is removed with the method for chemically machinery polished.Form tungsten plug (tungstenplugs) by this method.
Chemically machinery polished (CMP) for tungsten has several different methods:
1991; F.B.Kaufman etc. have reported that the Tripotassium iron hexacyanide is used for the method for tungsten chemically machinery polished (" Chemical Mechanical Polishing for Fabricating Patterned W MetalFeatures as Chip Interconnects "; Journal of the Electro chemical Society; Vol.138, No.11, in November, 1991).
USP 5340370 discloses a kind of prescription that is used for tungsten chemically machinery polished (CMP); Wherein contain the 0.1M Tripotassium iron hexacyanide, because the Tripotassium iron hexacyanide is under UV-light or sun exposure, and in acidic medium; Can decomposite the prussic acid of severe toxicity, thereby limit it and be widely used.
USP 5527423, USP 6008119, USP 6284151 grades disclose the (NO with Fe
3)
3, alumina system is used for the method for tungsten mechanical polishing (CMP).This polishing body ties up to product defects (defect) aspect and exists significantly not enough.The iron nitrate of high density makes the pH value of polishing fluid be strongly-acid, severe corrosion equipment simultaneously.In addition, the conduct of the iron ion of high density is metals ion movably, has seriously reduced the safety of semiconductor components and devices.
USP 5958288 discloses iron nitrate has been used as catalyzer, and hydrogen peroxide is used as oxygenant, carries out the method for tungsten chemically machinery polished.Because the existence of iron ion, and the Fenton reaction takes place between the ydrogen peroxide 50, ydrogen peroxide 50 can be rapidly and decomposition failure tempestuously, so there is the problem of poor stability in this polishing fluid.
USP 5980775 and USP 6068787 are on USP 5958288 bases; Add organic acid and make stablizer; Improved the rate of decomposition of hydrogen peroxide, but hydrogen peroxide decomposition speed is still higher, hydrogen peroxide concentration can reduce more than 10% in common two weeks; Cause polishing velocity to descend, polishing fluid is decomposition failure gradually.
After using above-mentioned polishing fluid to carry out chemically machinery polished; Silicon chip surface has residual (the for example Tungsten oxide 99.999) or the like of residual, organic residual, the MOX of abrasive particles (particle); These residual need removing through further cleaning, this cleaning step is called Post-CMPcleaning (cleaning after the chemically machinery polished).If this step cleaning performance is bad, the particle residue of silicon chip surface can cause product defects (defect), causes waste product, influences yield.
Contriver of the present invention has adopted and has been different from disclosed, the new tungsten chemically machinery polished system of above each patent: silver ions, sulfate radical are under the effect of ydrogen peroxide 50; Can produce very high polishing velocity to tungsten; And this polishing body cording has the highly stable advantage of ydrogen peroxide 50; The concentration of ydrogen peroxide 50 hardly can be in time prolongation and change (decomposition), but be to use this polishing fluid, can be the same with other various types of polishing fluids; The residual silicon chip surface that is adsorbed on easily of polishing by product and particle (abrasive grains) increases the weight of the burden of post-CMP cleaning (cleaning after the chemically machinery polished).A kind of result causes chip surface defective (defect) to raise, and another kind of result lost efficacy the equipment unit of Post-CMP cleaning in advance, needed frequent change, had improved production cost.
But be to use this polishing fluid, can be the same with other various types of polishing fluids, the residual silicon chip surface that is adsorbed on easily of polishing by product and particle (abrasive grains) increases the weight of the burden of post-CMP cleaning (cleaning after the chemically machinery polished).A kind of result causes chip surface defective (defect) to raise, and another kind of result lost efficacy the equipment unit of Post-CMP cleaning in advance, needed frequent change, had improved production cost.Therefore, how in high speed polishing tungsten, can improve the cleansing power of silicon chip surface, significantly reduce the chip surface defective and be still a problem that needs research.
Summary of the invention
The present invention is in the tungsten polishing system of abrasive, silver ions, sulfate ion and superoxide; Further added quaternary cationics; Can make this polishing fluid in the very high tungsten polishing velocity of maintenance; Further improve the cleansing power of silicon chip surface, significantly reduced the chip surface defective.
Particularly, the chemical mechanical polishing liquid of high speed polishing tungsten of the present invention comprises: abrasive, in polishing fluid, dissociate the material of silver ions, in polishing fluid, dissociate material, oxygenant and the quaternary cationics of sulfate ion.
In the present invention; Said quaternary cationics is preferably and contains a C8～C16 alkyl quaternary ammonium salts on the N atom at least; Can be that quaternary ammonium salt is the nitrate salt or the vitriol of quaternary ammonium hydroxide, like dodecyl trimethylammonium ammonium sulfate, dodecyl trimethylammonium an ammonium nitrate, octyl trimethylammonium ammonium sulfate and/or cetyl trimethyl ammonium sulfate; Its content in polishing fluid is preferably 20～600ppm, more preferably 200～400ppm.
In the present invention, said abrasive can be a kind of or any multiple compsn in silicon sol, aerosil, aluminum oxide and the cerium oxide, and its mass percent in polishing fluid is 0.1～10%.
In the present invention, the said material that in polishing fluid, dissociates silver ions is selected from the soluble silver salt of Sulfuric acid disilver salt, Silver Nitrate, tachyol and/or silver perchlorate, and it is 0.05～0.3% that its content in polishing fluid is preferably mass percent.
In the present invention, the said material that in polishing fluid, dissociates sulfate ion can be a vitriol, like vitriolate of tartar, sodium sulfate; And be preferably nonmetal vitriol, more preferably ammonium sulfate.
In the present invention, said oxygenant can be persulphate, superoxide etc., is preferably hydrogen peroxide; Its mass percent in polishing fluid is preferably 0.1～5%; Further be preferably 1～2%.
As required, polishing fluid of the present invention can also add pH value regulator, and said polishing fluid pH value is preferably 0.5～5.
Chemical mechanical polishing liquid of the present invention is used for the polishing of tungsten, has higher polishing speed, and the silicon face pollution is few, is easy to the cleaning of silicon face, has reduced the chip surface defective.
Description of drawings
Fig. 1 shows is to carry out after the polishing of tungsten with the photo behind the deionized water rinsing silicon chip surface with Comparative Examples 1 polishing fluid;
Fig. 2 shows is to carry out after the polishing of tungsten with the photo behind the deionized water rinsing silicon chip surface with embodiment 1 polishing fluid.
Embodiment
Through specific embodiment, polishing fluid of the present invention is carried out detailed introduction and explanation below, so that better understand the present invention, but following embodiment does not limit the scope of the invention.
Table 1 has provided the embodiment of the invention 1～12 and contrast polishing fluid main ingredient and quality percentage composition thereof; By listed component and content thereof in the table; In deionized water, mix, be transferred to required pH value, can make chemical mechanical polishing liquid with pH regulator agent (nitric acid or Pottasium Hydroxide).
Table 1, the embodiment of the invention 1～12 polishing fluid and Comparative Examples polishing fluid component and mass content
Wherein, in embodiment 6, Sulfuric acid disilver salt self had both contained silver ions, also contained sulfate ion, but the mol ratio of silver ions and sulfate ion is restricted to 1: 1 in the polishing fluid.
The foregoing description and Comparative Examples polishing fluid are carried out chemically machinery polished to tungsten; Polishing condition: polishing machine platform is Logitech (Britain) 1PM52 type, polytex polishing pad, 4cm * 4cm square wafer (Wafer); Grinding pressure 4psi, polishing fluid rate of addition 100ml/ minute.Concrete polish results is seen table 2.
The embodiment of the invention and Comparative Examples polishing fluid carry out the tungsten polishing; Deionized water rinsing silicon chip surface then, and compare, Fig. 1 has shown that Comparative Examples 1 polishing fluid carries out the polishing of tungsten; Use the photo (opticmicroscope behind the deionized water rinsing silicon chip surface then; Amplify 100 times, details in a play not acted out on stage, but told through dialogues), the white bright spot of silicon chip surface is the residual particles that is difficult to rinse out; Fig. 2 has shown that the embodiment of the invention 1 polishing fluid carries out the polishing of tungsten, uses the photo (opticmicroscope amplifies 100 times, details in a play not acted out on stage, but told through dialogues) behind the deionized water rinsing silicon chip surface then, and silicon chip surface does not have particle absorption; Contrast two photos, can obviously find, add after the cats product, the cleaning that helps silicon chip surface is had significant technique effect.
Table 2, embodiment of the invention polishing fluid and the contrast of Comparative Examples polishing fluid polishing effect
Can show from the effect data of table 2 and Fig. 1,2 effect comparison; With respect to the contrast polishing fluid; The embodiment of the invention 1,2 does not have restraining effect to the polishing velocity of tungsten, simultaneously after adding quaternary cationics; Quaternary cationics has reduced the static corrosion speed of polishing fluid to tungsten effectively, has reduced dishing (dish-shaped defective), recess (depression), keyhole (lockhole) risk of tungsten.
More than specific embodiment of the present invention is described in detail, but it is just as example, the present invention is not restricted to the specific embodiment of above description.To those skilled in the art, any equivalent modifications that the present invention is carried out with substitute also all among category of the present invention.Therefore, not breaking away from impartial conversion and the modification of being done under the spirit and scope of the present invention, all should contain within the scope of the invention.
Claims (18)
1. one kind is beneficial to the tungsten chemical mechanical polishing liquid that polishing back is cleaned, and it is characterized in that: said polishing fluid comprises abrasive, in polishing fluid, dissociate the material of silver ions, in polishing fluid, dissociate material, oxygenant and the quaternary cationics of sulfate ion.
2. chemical mechanical polishing liquid as claimed in claim 1 is characterized in that: described quaternary cationics is to contain a C8～C16 alkyl quaternary ammonium salts on the N atom at least.
3. chemical mechanical polishing liquid as claimed in claim 2 is characterized in that: said quaternary ammonium salt is the nitrate salt or the vitriol of quaternary ammonium hydroxide.
4. chemical mechanical polishing liquid as claimed in claim 3 is characterized in that: described quaternary cationics is dodecyl trimethylammonium ammonium sulfate, dodecyl trimethylammonium an ammonium nitrate, octyl trimethylammonium ammonium sulfate and/or cetyl trimethyl ammonium sulfate.
5. like each described chemical mechanical polishing liquid of claim 1～4, it is characterized in that: described quaternary cationics content in polishing fluid is 20～600ppm.
6. according to chemical mechanical polishing liquid as claimed in claim 5, it is characterized in that: described quaternary cationics content in polishing fluid is 200～400ppm.
7. chemical mechanical polishing liquid as claimed in claim 1 is characterized in that: abrasive is selected from one or more in silicon sol, aerosil, aluminum oxide and the cerium oxide.
8. chemical mechanical polishing liquid as claimed in claim 7 is characterized in that: said abrasive mass percent is 0.1～10%.
9. like claim 1 or 8 described chemical mechanical polishing liquids, it is characterized in that: the said material that in polishing fluid, dissociates silver ions is the soluble silver salt of Sulfuric acid disilver salt, Silver Nitrate, tachyol and/or silver perchlorate.
10. chemical mechanical polishing liquid as claimed in claim 9 is characterized in that: said silver salt mass percent is 0.05～0.3%.
11. chemical mechanical polishing liquid as claimed in claim 1 is characterized in that: the said material that in polishing fluid, dissociates sulfate ion is a vitriol.
12. chemical mechanical polishing liquid as claimed in claim 11 is characterized in that: said vitriol is nonmetal vitriol.
13. chemical mechanical polishing liquid as claimed in claim 12 is characterized in that: said vitriol is ammonium sulfate.
14. chemical mechanical polishing liquid as claimed in claim 1 is characterized in that: said oxygenant is a hydrogen peroxide.
15. chemical mechanical polishing liquid as claimed in claim 14 is characterized in that: said oxygenant mass percent is 0.1～5%.
16. chemical mechanical polishing liquid as claimed in claim 15 is characterized in that: said oxygenant mass percent is 1～2%.
17. chemical mechanical polishing liquid as claimed in claim 1 is characterized in that: also comprise pH value regulator.
18. chemical mechanical polishing liquid as claimed in claim 17 is characterized in that: said polishing fluid pH value is 0.5～5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110152812 CN102816529A (en) | 2011-06-08 | 2011-06-08 | Tungsten chemical-mechanical polishing solution being beneficial for cleaning after polishing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110152812 CN102816529A (en) | 2011-06-08 | 2011-06-08 | Tungsten chemical-mechanical polishing solution being beneficial for cleaning after polishing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102816529A true CN102816529A (en) | 2012-12-12 |
Family
ID=47300992
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110152812 Pending CN102816529A (en) | 2011-06-08 | 2011-06-08 | Tungsten chemical-mechanical polishing solution being beneficial for cleaning after polishing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102816529A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111378373A (en) * | 2018-12-28 | 2020-07-07 | 安集微电子（上海）有限公司 | Chemical mechanical polishing solution for polishing tungsten |
| CN111378374A (en) * | 2018-12-28 | 2020-07-07 | 安集微电子科技（上海）股份有限公司 | Chemical mechanical polishing solution |
-
2011
- 2011-06-08 CN CN 201110152812 patent/CN102816529A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111378373A (en) * | 2018-12-28 | 2020-07-07 | 安集微电子（上海）有限公司 | Chemical mechanical polishing solution for polishing tungsten |
| CN111378374A (en) * | 2018-12-28 | 2020-07-07 | 安集微电子科技（上海）股份有限公司 | Chemical mechanical polishing solution |
| CN111378374B (en) * | 2018-12-28 | 2022-05-13 | 安集微电子科技（上海）股份有限公司 | Chemical mechanical polishing solution |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Matijević et al. | Colloid aspects of chemical–mechanical planarization | |
| CN1157450C (en) | Chemical mechanical polishing slurry useful for copper substrates | |
| US20080277378A1 (en) | Method for Chemical-Mechanical Planarization of Copper | |
| CA2431591A1 (en) | Composition for chemical mechanical planarization of copper, tantalum and tantalum nitride | |
| KR20110095838A (en) | A composition and slurry useful for metal cmp | |
| JP2002075927A (en) | Composition for polishing and polishing method using it | |
| EP1489650B1 (en) | Polishing composition and method for forming wiring structure | |
| CN102112567A (en) | Polishing liquid for chemical-mechanical abrading | |
| JP2002184729A (en) | Chemical mechanical polishing slurry and method of manufacturing copper wiring by use of the same | |
| CN104745086A (en) | Chemical mechanical polishing solution for barrier layer planarization, and use method thereof | |
| CN112322190A (en) | Polishing solution for multilayer copper interconnection barrier layer and preparation method thereof | |
| CN102051129B (en) | Chemical mechanical polishing solution | |
| CN102533121B (en) | A kind of chemical mechanical polishing liquid of polish tungsten | |
| CN104745088A (en) | Chemical mechanical polishing solution for barrier layer planarization, and use method thereof | |
| CN102477258B (en) | Chemically mechanical polishing liquid | |
| CN102816529A (en) | Tungsten chemical-mechanical polishing solution being beneficial for cleaning after polishing | |
| CN108250976A (en) | A kind of chemical mechanical polishing liquid | |
| JP3917593B2 (en) | Manufacturing method of semiconductor device | |
| CN113122141A (en) | Chemical mechanical polishing solution | |
| CN102816528A (en) | Chemical-mechanical polishing solution for polishing tungsten | |
| CN111378373A (en) | Chemical mechanical polishing solution for polishing tungsten | |
| CN102850937A (en) | Chemical mechanical polishing (CMP) liquid | |
| CN101747840A (en) | Chemical-mechanical polishing solution | |
| JP2004363227A (en) | Composition for chemical mechanical polishing | |
| CN102452036B (en) | A kind of tungsten CMP method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20121212 |