CN100335969C - Method of treatment of porous dielectric films to reduce damage during cleaning - Google Patents

Abstract

An apparatus, method, and system are disclosed for reducing damage when handling films of low-k dielectric materials during cleaning of microelectronic components. The present invention cleans the porous low-k dielectric material film by adopting first passivation treatment and then cleaning solution treatment for the treatment of the microelectronic component, so that the damage to the dielectric material is minimal while having high selectivity.

Description

Treatments to Reduce Damage During Cleaning of Porous Dielectric Films

related application

This patent application is a continuation-in-part of U.S. copending application serial number 10/379,984, filed March 4, 2003, and entitled "Method of passing of flow dielectric materials in wafer processing." This patent application claims priority to a co-pending U.S. Provisional Patent Application under 35 U.S.C. films to reduce damage during cleaning". This provisional patent application, serial number 60/372,822, filed April 12, 2002, entitled "Method of treatment of porous dielectric films to reduce damage during cleaning" and this application, filed March 4, 2003 US Patent Application Ser. No. 10/379,984, entitled "Method of passing of low dielectric materials in wafer processing," is hereby incorporated by reference.

field of invention

The invention relates to the field of cleaning of dielectric thin films. More specifically, the present invention relates to systems, apparatus, and methods for reducing damage to processing thin films of low-k dielectric materials during cleaning.

Background of the invention

In semiconductor technology, new developments include the use of low-k dielectric materials instead of dielectric materials to isolate interconnects. Low-k dielectric materials are currently being used as interlayer dielectric materials. Low-k dielectric materials mainly include three categories: inorganic materials (SiO ₂ -based materials); hybrid materials (organofunctionalized inorganic matrices), and organic materials. This change to using low-k dielectric materials requires improvements in photoresist stripping technology to meet higher demands for cleaning and residue removal without increasing cost and impacting yield.

Interconnect structures built by using low-k dielectric materials to isolate the interconnects have smaller geometries, resulting in faster integrated circuits. Porous low-k dielectric materials are a special class of these low-k dielectric materials. When lines and vias are etched in porous low-k dielectric materials, silanol groups tend to form on the surface of these lines and vias. Silanol groups are also readily formed in the voids of the porous low-k dielectric adjacent to these lines and vias.

In the case of low-k dielectric materials, which are inorganic and hybrid materials, cleaning these materials presents challenges to conventional cleaning methods that remove residues by dissolving them or slightly etching the dielectric material. However, for low-k dielectric materials, the increased surface area due to porosity greatly increases the sensitivity to these cleaning regimes, which reduces the selectivity of the regime to etch residues. Conventional dry cleaning methods such as ashing also have unacceptable disadvantages because the ashing plasma tends to affect the organic components of the mixture material, thereby increasing the dielectric constant.

Two basic methods are currently used: wet and dry. Dry methods are typically used for stripping and wet methods are generally used for cleaning. Wet methods use acids, bases, or solvents, which require several processing steps to remove residues. The dry method is the best choice when processing organic photoresist materials. Even with dry stripping, wet processing is still required after stripping to remove the inorganic residue left after the dry process.

In the manufacture of semiconductors, a layer of low-k dielectric material is typically patterned by one or more etching and ashing steps using a photoresist mask. These films, after etching or because of their physical properties, tend to have a large number of silanol functional groups on their surface and, because of their porosity, present a large material surface area during cleaning relative to the cleaning means. This raises the problem that mass etching of low-k dielectric material films often results in destruction of low-k dielectric material films with multiple cleaning steps.

To remove these silanol groups, etch and photoresist residues in wires and vias, and bulk photoresist from exposed surfaces of low-k dielectric materials, a cleaning process is performed after wire and via etching . During the cleaning process, a weak etchant is generally used to remove a single layer of low-k dielectric material in order to release etch residues, photoresist, and photoresist blocks. It has been found that this cleaning process results in unacceptably high etch rates for porous low-k dielectric materials. This is true even when the porous low-k dielectric material is exposed to a weak etchant. Where silanol groups are present, weak etchants have been found to remove much more than a single layer of low-k dielectric material.

Current high-dose injection cleaning techniques are problematic. When this cleaning technique is used, the resist is heavily injected, hydrogen is dissociated from the top third of the resist, and an extremely carburized layer is produced. This carbide layer is difficult to remove and does not etch away quickly. In addition, there is also a bulk resist with volatile components underneath.

Even with normal stripping techniques, popping and air bubbles can occur due to pressure buildup when cleaning is performed at slower rates. Not only does this contaminate the processing chamber, but these carbonized lumps also bond to exposed areas of the wafer surface. In addition, standard high temperature oxidation-based plasmas will not be effective in cleaning low-k dielectric materials. These high temperature and high oxygen environments oxidize and degrade the integrity of the film and material properties of low-k dielectrics.

What is needed is a method of treating porous low-k dielectric materials after etching and prior to cleaning to reduce the presence of silanol groups in the porous low-k dielectric material. The problem is to ensure that the cleaning method is sufficiently effective to clean the surface without etching or altering the low-k material.

Summary of the invention

Today's microelectronic devices, with their finer structures and higher aspect ratios, require new low-k materials. For photoresist lift-off techniques, challenges due to critical aspect ratios and shrinking dimensions need to be met. Low-k dielectric material films require unprecedented levels of cleanliness during fabrication. Low-k dielectrics differ from typical 0.25µm features where vias and wires are etched into a dielectric layer that traps residue. In addition, current photoresists produce residues that are more resistant to abrasion. The present invention provides a device, on the one hand, to clean the through-holes and connections, and on the other hand, to protect the dielectric film.

The present invention addresses the biggest challenge encountered in the art of cleaning exposed low-k materials: stripping. Polymers are used in low-k and organic resists, which restricts lift-off technology. Cleaning resists or residues from low-k dielectric materials without affecting the low-k dielectric material is complex. Typically, a hard mask is placed over the low-k dielectric material to act as an etch stop. This hard mask can also be used as a CMP stop. During etching, most of the etchant block is removed. However, there is generally considerable residue and polymer left on the sidewalls of the trenches and vias. The present invention addresses the problems related to removing these residues and polymers without etching away the low-k dielectric material.

Standard 250°F oxygen-based plasmas will not work on cleaning low-k dielectric materials. High oxygen environments can oxidize and degrade film integrity and material properties of low-k dielectrics. The present invention provides chemical cleaning without additional physical cleaning to clean the sidewall and is selective for polymers. Furthermore, the present invention addresses shortcomings in current cleaning processes by employing low temperatures in the cleaning process.

A preferred embodiment of the invention utilizes supercritical carbon dioxide (SCCO ₂ ). In another embodiment of the present invention, chemical dry method ion depletion downflow microwave plasma method is used. In yet another embodiment of the present invention, chemical wet processing is used in conjunction with the present invention to achieve high selectivity and minimize damage to low-k dielectric materials.

The present invention removes the greatest hurdle in ensuring that strippers and residue removers do not corrode or damage low-k dielectric materials. Simultaneously, the etching, which leads to widening of the opening or loss of thickness, is minimized. Furthermore, by employing the present invention, the k value of the film is maintained or decreased.

Brief description of the drawings

Figures 1A and 1B illustrate low-k dielectric materials (i.e., passivation) before and after removal of post-etch residues using a supercritical solution comprising supercritical carbon dioxide and a silicon-based passivator in accordance with the present invention. Simplified schematic diagram of the processing steps) followed by the processing steps of the cleaning solution.

Figure 2 shows a simplified schematic diagram of a supercritical wafer processing apparatus in accordance with an embodiment of the present invention.

Fig. 3 shows a detailed schematic diagram of a supercritical processing device according to an embodiment of the present invention.

4 is a schematic block diagram illustrating the generalized steps of processing a silicon dioxide-based low-k dielectric material layer in accordance with an embodiment of the present invention.

Detailed Description of Preferred Embodiments

Generally, materials with a low dielectric constant of 3.5-2.5 are called low-k dielectric materials. Porous materials with a dielectric constant of 2.5 and below are usually called ultra-low-k (ULK) dielectric materials. Both low-k dielectric materials and ultra-low-k dielectric materials are referred to as low-k dielectric materials in this application. Low-k dielectric materials are typically porous oxygen-based materials and may include organic or hydrocarbon components. Examples of low-k dielectric materials include, but are not limited to, carbon-doped oxide (COD), spin-on-glass (SOG), and fluorinated silicon glass (FSG) materials. These porous low-k dielectric material films typically contain carbon and hydrogen and are deposited by methods such as spin coating or CVD. These films are treated by means of this method to produce a film which is resistant to damage during the cleaning process and usually have a SiOx _- based or _SiOx - _{CxHy -} based inorganic matrix.

According to the method of the present invention, the patterned low-k dielectric material layer is formed by depositing a continuous low-k dielectric material layer, and the pattern is etched on the low-k dielectric material by photolithography, and the supercritical carbon dioxide and A supercritical solution composed of a silicon-based passivator is used to remove post-etch residues (ie, a passivation treatment step), followed by a cleaning solution treatment step.

The invention reduces or eliminates etching by adopting supercritical silylating agent to react with silanol functional group, thereby reducing the etching rate of low-k dielectric material film in cleaning process. The method of the present invention preferably passivates the patterned low-k dielectric material layer by end-capping silanol groups on the surface and/or within the low-k dielectric material bulk to produce a more hydrophobic and more Patterned low-k dielectric materials that resist contamination and/or are less reactive. After said passivation, in the method of the invention, the film is preferably cleaned to minimize etching of the film by the cleaning solution. According to an embodiment of the present invention, the passivation treatment step is independent of the cleaning treatment after the supercritical etching, or is performed synchronously with the cleaning treatment after the supercritical etching. Furthermore, according to an embodiment of the present invention, the cleaning solution treatment step may be performed after the passivation treatment step. According to an embodiment of the present invention, the supercritical silylating agent comprises supercritical carbon dioxide and a certain amount of passivating agent, preferably a silylating agent. The silylating agent preferably includes a silane structure (R ₁ )(R ₂ )(R ₃ )SiNH(R ₄ ), wherein R ₁ , R ₂ , R ₃ can be the same or selected from the group H, alkyl, aryl , propyl, phenyl and/or their derivatives and halogen (Cl, Br, F, I) are independently selected. R ₄ may be (SiR ₁ R ₂ R ₃ ) besides being independently selected from the group H, alkyl, aryl, propyl, phenyl and/or derivatives thereof. In another embodiment, the silylation agent comprises a tetravalent organosilicon compound in which silicon atoms are pyramidally coordinated into 4 ligands at positions 1, 2, 3 and 4. In yet another embodiment, the silylating agent includes a silazane structure, which can be expressed as an amine structure with two organosilicon groups coordinated to the nitrogen of the amine.

The silylating agent can be introduced into supercritical carbon dioxide (SCCO ₂ ) by itself or through a carrier solvent to produce a supercritical silylating agent, such as N,N-dimethylacetamide (DMAC), γ-butyrol Gamma-butyrolacetone (BLO), dimethyl sulfoxide (DMSO), ethylene carbonate (EC), N-methylpyrrolidone (NMP), dimethylpiperidone, propylene carbonate, ethanol or their The combination. Preferably _SCCO2 is used as the carrier liquid for the silylation agent. By using SCCO ₂ as the carrier liquid, the silylating agent can be easily and quickly delivered to the whole film to ensure its complete and rapid reaction with the whole film.

It will be clear to those of ordinary skill in the art that combinations of supercritical passivation solutions with any number of silylating agents and silylating agents are within the scope of the present invention.

Thermodynamic conditions are variable: processing temperatures are between 25 and 200°C and pressures are between 700 and 9000 psi. While supercritical _CO2 is preferred, liquid _CO2 may be used under certain circumstances. The silylating agent preferably includes hexamethyldisilazane. Alternatively the silylation agent includes organochlorosilanes. In addition, silylating agents may also include hydrolyzed alkoxysilanes. Typical processing times are between 15 seconds and 10 minutes.

Figures 1A and 1B show simplified schematics of low-k dielectric materials before and after removal of post-etch residue (i.e., passivation processing step) using a supercritical solution consisting of supercritical carbon dioxide and a silicon-based passivator, followed by Cleaning solution treatment step. The patterned low-k dielectric material 100 in FIG. 1A shows the patterned low-k dielectric material 100 before the post-etch residue is removed, and FIG. 1B shows the low-k dielectric material 100 after the post-etch residue is removed. Specifically, etchant resist 110 and sidewall polymer residue 120 can be seen on top of low-k dielectric material 130 in FIG. 1A prior to the supercritical carbon dioxide cleaning and cleaning solution processing steps. FIG. 1B shows the same low-k dielectric material 130 after highly selective cleaning, showing no undercut and residues removed.

FIG. 2 shows a simplified schematic diagram of a supercritical processing apparatus 200 . Apparatus 200 includes a carbon dioxide source 221 connected to an inlet line 226 through a source valve 223 that can be opened and closed to start and stop the flow of carbon dioxide from the carbon dioxide source 221 into the inlet line 226 . Incoming line 226 is preferably equipped with one or more backflow prevention valves, pumps and heaters, shown schematically as tank 220, capable of generating and/or maintaining a flow of supercritical carbon dioxide. The inlet line 226 also preferably has an inlet valve 225 that can be opened or closed to allow or prevent the flow of supercritical carbon dioxide into the process chamber 201 .

Still referring to FIG. 2, the processing chamber 201 is preferably equipped with one or more pressure valves 209 for evacuating the processing chamber 201 and/or regulating the pressure within the processing chamber. Also referring to another embodiment of the present invention, the processing chamber 201 is connected to a pump and/or a vacuum 211 for pressurizing and/or evacuating the processing chamber 201 .

Still referring to FIG. 2 , within the processing chamber 201 of the apparatus 200 there is preferably a chuck 233 for holding and/or supporting the wafer structure 213 . According to another embodiment of the present invention, the chuck 233 and/or the processing chamber 201 has one or more heaters 231 for adjusting the temperature of the wafer structure 213 and/or the temperature of the supercritical processing solution in the processing chamber 201 .

The device 200 preferably also has a circulation loop 203 connected to the treatment chamber 201 . Circulation loop 203 is preferably provided with one or more valves 215 and 215' for regulating the flow of supercritical processing solution through circulation loop 203 and process chamber 201. Circulation loop 203 is also preferably equipped with any number of backflow prevention valves, pumps and/or heaters, schematically represented by tank 205, which is used to maintain the supercritical treatment solution and to circulate the supercritical treatment solution The loop 203 and the process chamber 201 flow. According to a preferred embodiment of the present invention, the circulation loop 203 has an injection port 207 for introducing chemical reagents such as deactivating agents and solvents into the circulation loop 203 to generate supercritical treatment solution in situ.

FIG. 3 shows the supercritical treatment device 76 in more detail than that described above for FIG. 2 . Supercritical processing apparatus 76 is configured for generating supercritical cleaning, rinsing and processing solutions, and for processing wafers therein. The supercritical treatment device 76 includes a carbon dioxide container 332 , a carbon dioxide pump 334 , a treatment chamber 336 , a chemical reagent supplier 338 , a circulation pump 340 , and a waste gas collector 344 . Carbon dioxide supplier 332 is connected to process chamber 336 through carbon dioxide pump 334 and carbon dioxide pipeline 346 . The carbon dioxide line 346 includes a carbon dioxide heater 348 located between the carbon dioxide pump 334 and the process chamber 336 . The process chamber 336 includes a process chamber heater 350 . The circulation pump 340 is located on the circulation line 352 , and the circulation line 352 is connected to the processing chamber 336 through a circulation input 354 and a circulation output 356 . The chemical supply 338 is connected by a chemical supply line 358 to a circulation line 352 which includes a first infusion pump 359 . The rinse agent supplier 360 is connected to the circulation line 352 through a rinse supply line 362 which includes a second injection pump 363 . The exhaust collector 344 is connected to the processing chamber 336 by an exhaust conduit 364 .

The carbon dioxide supplier 332 , the carbon dioxide pump 334 , and the carbon dioxide heater 348 constitute a carbon dioxide supply device 349 . The chemical agent supplier 338 , the first injection pump 359 , the rinse agent supplier 360 and the second injection pump 363 constitute a chemical agent and rinse agent supply device 365 .

It will be apparent to those of ordinary skill in the art that the supercritical treatment unit 76 includes the valves, control electronics, filters, and general wiring of a typical supercritical fluid treatment system.

Still referring to FIG. 3 , the operation involves inserting a wafer (not shown) with residue thereon into wafer cavity 312 of process chamber 336 and sealing process chamber 336 . The carbon dioxide pump 334 utilizes the carbon dioxide supplied by the carbon dioxide supplier 332 to pressurize the processing chamber 336, and makes the carbon dioxide heater 348 heat the carbon dioxide while the processing chamber heater 350 heats the processing chamber 336, thereby ensuring the carbon dioxide in the processing chamber 336. The temperature of carbon dioxide is above the critical temperature. The critical temperature of carbon dioxide is 31°C. The temperature of the carbon dioxide in the processing chamber 336 is preferably in the range of 25°C to about 200°C, and preferably near 70°C during the supercritical passivation step.

In the case of reaching the initial supercritical condition, the first injection pump 359 pumps the treatment reagent such as a silylation agent from the chemical reagent supply 338 into the treatment chamber 336 through the circulation line 352, while the carbon dioxide pump also pumps the supercritical carbon dioxide. Pressurize. Upon initial addition of processing reagents to processing chamber 336, the pressure in processing chamber 336 is preferably in the range of about 700 to 9,000 psi, more preferably at or near 3,000 psi. Once in the processing chamber 336, the required amount of processing reagent has been sucked and the desired supercritical condition has been reached, the carbon dioxide pump 334 stops pressurizing the processing chamber 336, and the first injection pump 359 stops processing reagent suction into the processing chamber 336, and the circulation pump 340 starts to circulate the supercritical carbon dioxide and the cleaning solution. Finally, the circulation pump 340 starts to circulate the supercritical cleaning solution composed of supercritical carbon dioxide and treatment reagents. The pressure in processing chamber 336 at this point is preferably about 3000 psi. By circulating the supercritical cleaning solution and the supercritical processing solution, the supercritical solvent and solution are quickly replenished on the wafer surface, thereby enhancing the passivation and cleaning ratio of the surface of the low-k dielectric material layer on the wafer.

While processing a wafer (not shown) having a layer of low-k dielectric material in process chamber 336, a mechanical chuck, vacuum chuck, or other suitable holding or attaching device may be used to hold the wafer. According to an embodiment of the present invention, during the supercritical processing step, the wafer is held stationary, or rotated, whirled, or agitated in the processing chamber 336 .

After the supercritical treatment solution is circulated through the circulation line 352 and the treatment chamber 336, in order to return the conditions in the treatment chamber 336 to near the initial supercritical conditions, some of the supercritical treatment solution is discharged into the exhaust collector 344, thereby causing the The pressure in the processing chamber 336 is partially reduced. Treatment chamber 336 is preferably subjected to at least one such depressurization and compression cycle before the supercritical treatment solution is completely discharged into collector 344 . After the pressure chamber 336 has been vented, a second supercritical processing step is performed, or the wafer is removed from the processing chamber 336 and wafer processing continues in a second processing apparatus or module (not shown).

Figure 4 is an outline of the processing of a substrate structure comprising a patterned low-k dielectric material layer and post-etch or post-ash residue thereon using a supercritical cleaning and passivation solution Block diagram of the steps. In step 402, the substrate structure including the post-etch residue is placed and sealed in a processing chamber. After placing and sealing _the substrate structure in the process chamber in step 402, the process chamber is pressurized with supercritical CO ₂ to which process reagents have been added in step 404 to produce supercritical cleaning and passivation solution. The cleaning and passivating agent preferably comprises at least one organosilicon compound.

After generating the supercritical cleaning and passivation solution in step 404, in step 406, the substrate structure is maintained in the supercritical processing solution for a period of time sufficient to remove at least a portion of the residue from the substrate structure and after the residue is removed After passivating exposed surfaces. During step 406, the supercritical cleaning and passivation solution is preferably circulated through the processing chamber and/or other agitation such that the supercritical cleaning solution flows over the surface of the substrate structure. Cleaning steps can also be performed after passivation, before passivation or during passivation.

Still referring to FIG. 4, after at least a portion of the residue is removed from the substrate structure in step 406, a supercritical cleaning solution treatment step is performed in step 408, wherein the supercritical cleaning solution is preferably circulated through the processing chamber and/or other agitation , so that the supercritical solution flows over the entire surface of the substrate structure. Following the supercritical cleaning solution treatment step 408 , the treatment chamber is partially drained in step 410 . The cleaning process comprising steps 404, 406 and 408 is repeated any number of times, as indicated by the arrow connecting steps 410 to 404, to remove residues of the substrate structure and passivate exposed surfaces. According to an embodiment of the present invention, the process comprising steps 404, 406 and 408 employs fresh supercritical carbon dioxide, fresh chemical reagents, or both. Alternatively, the concentration of the cleaning reagent is varied by diluting the process chamber with supercritical carbon dioxide, adding additional cleaning reagent material, or a combination of both.

Still referring to FIG. 4 , after completion of processing steps 404 , 406 , 408 and 410 , the substrate structure is preferably subjected to a supercritical rinse solution in step 412 . The supercritical rinse solution preferably comprises supercritical _CO2 and one or more organic solvents, but may be pure supercritical _CO2 .

Still referring to FIG. 4 , after cleaning the substrate structure in steps 404 , 406 , 408 and 410 and rinsing it in step 412 , the chamber is depressurized and the substrate structure is removed from the chamber in step 414 . Alternatively, the substrate structure is cycled through one or more additional cleaning/rinsing processes comprising steps 404, 406, 408, 410, and 412 (as indicated by the arrow connecting steps 412 and 404). Still alternatively, or in addition to cycling the substrate structure through one or more additional cleaning/rinsing cycles, several rinse cycles are performed prior to the step 414 of removing the substrate structure from the processing chamber, such as in conjunction with steps 412 and 410. indicated by the arrow.

As previously described, passivating the low-k dielectric material layer in the substrate structure using a supercritical solution consisting of supercritical carbon dioxide and one or more solvents such as methanol, ethanol, and/or combinations thereof, prior to this, may Drying and/or pretreatment of the substrate structure. As previously mentioned, pretreatment of the low-k dielectric layer with a supercritical solution containing supercritical carbon dioxide with or without a co-solvent also appears to improve the adhesion of silyl groups on the surface of the low-k dielectric layer. coverage. Also, any number of cleaning and passivation steps and/or sequence changes may be performed on wafers that include post-etch residues and/or patterned low-k dielectric material layers, as will be apparent to those of ordinary skill in the art.

Those of ordinary skill in the art should understand that while the passivation method for low-k dielectric materials is firstly described here mainly with reference to post-etch treatment and/or post-etch cleaning treatment, the method of the present invention can also be used to directly passivate low-k dielectric materials. k Dielectric material. Furthermore, it will be appreciated that when processing low-k dielectric materials, a supercritical rinse step is not always required in accordance with the methods of the present invention, and for some applications prior to processing the low-k dielectric material with a supercritical passivation solution It is suitable to dry it only.

In summary, part of the technology provided by the present invention is as follows:

1. A method of treating a surface of a low-k dielectric material, comprising:

a. treating the low-k dielectric material with a supercritical silylation agent to form a passivated low-k dielectric material surface;

b. removing the supercritical silylating agent after treating the low-k dielectric material surface with the supercritical silylating agent;

c. Treating the passivated low-k dielectric material surface with a supercritical solvent; and

d. removing the supercritical solvent after treating the passivated low-k dielectric material surface with the supercritical solvent, wherein the supercritical silylation agent and the supercritical solvent will passivate the low-k dielectric material The surface is at least partially passivated.

2. The method as described in technical scheme 1, wherein the supercritical silylating agent comprises supercritical CO ₂ and a certain amount of silylating agent comprising organic groups.

3. The method according to technical scheme 2, wherein the organic group includes 5 or less carbon atoms.

4. The method as described in technical scheme 1, wherein the supercritical solvent comprises supercritical CO ₂ and the mixture of acid and fluoride.

5. The method as described in technical scheme 4, wherein the acid comprises an organic acid.

6. The method as described in technical scheme 4, wherein the acid comprises a mineral acid.

7. The method according to technical solution 1, wherein the supercritical silylating agent is a silane having the structure (R ₁ )(R ₂ )(R ₃ )SiNH(R ₄ ).

8. The method as described in technical scheme 1, wherein the supercritical silylation agent further comprises a carrier solvent.

9. The method as described in technical scheme 5, wherein the carrier solvent is selected from N, N-dimethylacetamide (DMAC), γ-butyrolactone (gamma-butyrolacetone) (BLO), dimethylsulfoxide (DMSO ), ethylene carbonate (EC), N-methylpyrrolidone (NMP), dimethylpiperidone, propylene carbonate and ethanol.

10. The method according to claim 1, wherein the surface of the low-k dielectric material is maintained at a temperature in the range of 25 to 200 degrees Celsius.

11. The method of claim 1, wherein treating the surface of the low-k dielectric material with a supercritical silylation agent comprises circulating the supercritical silylation agent on the surface of the low-k dielectric material.

12. The method according to technical solution 1, wherein treating the surface of the low-k dielectric material with a supercritical solvent comprises circulating the supercritical solvent over the entire surface of the low-k dielectric material.

13. The method of technical solution 1, wherein the supercritical silylation agent maintains a pressure in the range of 700 to 9000 psi.

14. The method according to technical solution 1, further comprising drying the low-k dielectric material before treating the low-k dielectric material with a supercritical silylation agent.

15. The method according to technical solution 14, wherein drying the surface of the low-k dielectric material comprises treating the surface of the low-k dielectric material with a supercritical drying solution comprising supercritical carbon dioxide.

16. The method according to technical solution 1, wherein the surface of the low-k dielectric material comprises silicon dioxide.

17. The method according to claim 1, wherein the low-k dielectric material surface comprises a material selected from carbon-doped oxide (COD), spin-on-glass (SOG) and fluorinated silicon glass (FSG).

18. A method of treating a dielectric surface comprising:

a. removing post-etch residue from the dielectric surface with a first supercritical cleaning solution;

b. Treating the dielectric surface with a silylation agent to form a passivated dielectric surface, wherein the silylation agent is in a second supercritical cleaning solution; and

c. Treating the passivated dielectric surface with a solvent, wherein the solvent is in the third supercritical cleaning solution.

19. The method as described in technical scheme 18, wherein the residue comprises a polymer.

20. The method according to technical solution 19, wherein the polymer is a photoresist polymer.

21. The method according to technical solution 20, wherein the photoresist polymer comprises an anti-reflective dye.

22. The method according to claim 18, wherein the dielectric surface comprises silicon dioxide.

23. The method according to claim 18, wherein the dielectric surface comprises a low-k dielectric material.

24. The method of technical solution 18, wherein the dielectric surface comprises a material selected from the group consisting of carbon-doped oxide (COD), spin-on-glass (SOG) and fluorinated silicon glass (FSG) choose.

25. The method according to technical solution 18, wherein the post-etch residue comprises an anti-reflection coating.

26. The method according to technical solution 18, wherein the silylation agent comprises an organosilicon compound.

27. The method as described in technical scheme 18, wherein the solvent comprises supercritical CO ₂ and a mixture of acid and fluoride.

28. The method according to technical solution 26, wherein the organosilicon compound reagent is a silane having the structure (R ₁ )(R ₂ )(R ₃ )SiNH(R ₄ ).

29. A method of forming a patterned low-k dielectric material layer, the method comprising:

a. Depositing a continuous layer of low-k dielectric material;

b. forming a photoresist mask on the continuous layer of low-k dielectric material;

c. patterning the continuous layer of low-k dielectric material through the photoresist mask, thereby forming a post-etch residue;

d. using a supercritical solution comprising supercritical carbon dioxide and a passivating agent to remove a portion of the post-etch residue; and

e. Use a supercritical solvent containing acid and fluoride solution to remove residual post-etch residue.

30. The method as described in technical scheme 29, wherein the supercritical solvent further comprises supercritical carbon dioxide.

31. The method according to technical solution 29, wherein the passivating agent is silicon-based.

32. The method according to technical solution 31, wherein the silicon-based passivation agent comprises organosilicon compound.

33. A method of forming a layer of dielectric material having a reduced k value, the method comprising:

a. patterning the layer of dielectric material to form a patterned layer of dielectric material having a first k value;

b. passivating the patterned layer of dielectric material with a passivating agent to form a patterned layer of reduced low-k dielectric material having a second k value; and

c. Treating the patterned reduced low-k dielectric material layer with a supercritical cleaning solvent.

34. The method according to technical solution 33, wherein the first k value is greater than 3.0.

35. The method according to technical solution 33, wherein the second k value is less than 3.0.

36. The method according to technical solution 33, wherein the difference between the first k value and the second k value is 1.0 or more.

37. The method according to technical solution 33, wherein the dielectric material includes a silicon dioxide component and a hydrocarbon component.

38. The method according to technical solution 33, wherein the passivating agent is a silylating agent containing an organic group.

39. The method as described in technical scheme 33, wherein the supercritical cleaning solvent is a solution of acid and fluoride.

40. The method according to technical solution 33, wherein the supercritical cleaning solvent is 0.1-15.0 v/v%.

Claims (42)

1. a processing has the method for the material surface of low-k, and this method comprises:

A. handle material surface with overcritical silylating agent, to form the material surface with low-k of passivation with low-k;

B. remove this overcritical silylating agent;

C. with the material surface with low-k of this passivation of a kind of supercritical solvent solution-treated; And

D. remove this supercritical solvent solution.

2. the method for claim 1, wherein this overcritical silylating agent comprises supercritical CO ₂With a certain amount of silylating agent that comprises organic group.

3. method as claimed in claim 2, wherein this organic group contains 5 or carbon atom still less.

4. the method for claim 1, wherein this supercritical solvent solution comprises supercritical CO ₂And the potpourri of acid and fluoride.

5. method as claimed in claim 4, wherein this acid comprises organic acid.

6. method as claimed in claim 4, wherein this acid comprises mineral acid.

7. the method for claim 1, wherein this overcritical silylating agent comprises having structure (R ₁) (R ₂) (R ₃) SiNH (R ₄) silane.

8. the method for claim 1, wherein this overcritical silylating agent also comprises a kind of carrier solvent.

9. method as claimed in claim 8, wherein this carrier solvent is selected from N,N-dimethylacetamide, gamma-butyrolacton, dimethyl sulfoxide, ethylene carbonate, N-Methyl pyrrolidone, lupetidine ketone, propylene carbonate and ethanol.

10. the method for claim 1, wherein this material surface remains in the scope of 25 to 200 degrees centigrade of temperature.

11. the method for claim 1 is wherein handled this material surface with overcritical silylating agent and is comprised and make the surperficial cocycle of this overcritical silylating agent at this material.

12. the method for claim 1 wherein comprises with this material surface of supercritical solvent solution-treated making the surperficial cocycle of this supercritical solvent solution at this material.

13. the method for claim 1, wherein this overcritical silylating agent keep-ups pressure 700 in the scope of 9000psi.

14. the method for claim 1 also is included in to handle with overcritical silylating agent and this material surface is carried out drying before this material surface.

15. method as claimed in claim 14 is wherein carried out drying to this material surface and is comprised with this material surface of supercritical drying solution-treated that comprises supercritical carbon dioxide.

16. the method for claim 1, wherein this material surface comprises silicon dioxide.

17. the method for claim 1, wherein this material surface comprises the material that is selected from carbon-doped oxide, spin-on-glass and fluorinated silica glass.

18. a processing has the method on the surface of low-k, this method comprises:

A. remove post-etch residue with the first overcritical cleaning solution from this surface, wherein this surface has low-k;

B. handle the surface that this has low-k with silylating agent, to form the passivation dielectric surface, wherein this silylating agent is in the second overcritical cleaning solution; And

C. with this passivation dielectric surface of solvent processing, wherein this solvent is in the 3rd overcritical cleaning solution.

19. method as claimed in claim 18, wherein this post-etch residue comprises polymkeric substance.

20. method as claimed in claim 19, wherein this polymkeric substance is the photoresist polymkeric substance.

21. method as claimed in claim 20, wherein this photoresist polymkeric substance comprises the antireflection dyestuff.

22. method as claimed in claim 18, wherein this dielectric surface comprises silicon dioxide.

23. method as claimed in claim 18, wherein this dielectric surface comprises the material with low-k.

24. method as claimed in claim 18, wherein this dielectric surface comprises the material that is selected from carbon-doped oxide, spin-on-glass and fluorinated silica glass.

25. method as claimed in claim 18, wherein this post-etch residue comprises antireflecting coating.

26. method as claimed in claim 18, wherein this silylating agent includes organic silicon compound.

27. method as claimed in claim 18, wherein this solvent comprises supercritical CO ₂And the potpourri of acid and fluoride.

28. method as claimed in claim 26, wherein these organo-silicon compound are to have structure (R ₁) (R ₂) (R ₃) SiNH (R ₄) silane.

29. one kind forms the method that patterning has the material layer of low-k, this method comprises:

A. deposition has the successive layers of the material of low-k;

B. on having the successive layers of material of low-k, this forms the photoresist mask;

C. by this photoresist mask, the successive layers of this material of patterning forms post-etch residue thus;

D. a part of using the overcritical cleaning solution contain supercritical carbon dioxide and passivator to remove this post-etch residue; And

E. use the supercritical solvent solution that comprises acid and fluoride aqueous solution to remove remaining post-etch residue.

30. method as claimed in claim 29, wherein this supercritical solvent solution also comprises supercritical carbon dioxide.

31. method as claimed in claim 29, wherein this passivator is silica-based.

32. method as claimed in claim 31, wherein this passivator includes organic silicon compound.

33. a formation has the method for the material layer of the specific inductive capacity that reduces, this method comprises:

A. this dielectric materials layer of patterning has the dielectric materials layer of the patterning of first specific inductive capacity with formation;

B. use this patterned dielectric material layer of passivator passivation, have the layer of passivation material of second specific inductive capacity with formation, wherein this second specific inductive capacity is lower than first specific inductive capacity; And

C. handle the dielectric materials layer of this passivation with overcritical cleaning solvent.

34. method as claimed in claim 33, wherein said first specific inductive capacity is greater than 3.0.

35. method as claimed in claim 33, wherein said second specific inductive capacity is less than 3.0.

36. method as claimed in claim 33, wherein first specific inductive capacity and second specific inductive capacity differ 1.0 or more.

37. method as claimed in claim 33, wherein this dielectric material comprises silica composition and hydrocarbon composition.

38. method as claimed in claim 33, wherein this passivator is the silylating agent that comprises organic group.

39. method as claimed in claim 33, wherein this overcritical cleaning solvent comprises the solution of acid and fluoride.

40. method as claimed in claim 33, wherein this overcritical cleaning solvent contains 0.1-15.0v/v%.

41. as the method for one of claim 1-32, wherein said low-k is 3.5-2.5.

42. as the method for one of claim 1-32, wherein said low-k be 2.5 or below.

Images