TWI489550B - Patterning method and method for fabricating dual damascene opening - Google Patents

Description

Patterning method and method of manufacturing double damascene opening

This invention relates to a semiconductor process, and more particularly to a method of patterning and a method of fabricating a dual damascene opening.

With the rapid development of semiconductor process technology, in order to improve the speed and performance of components, the size of the entire circuit components must be continuously reduced, and the component's integrality is continuously improved. In general, lithography processes play a pivotal role in the overall process as semiconductors tend to shrink the design of circuit components. In the semiconductor process, the patterning of the layers of the film or the implantation of the doped regions is defined by the lithography process and determines the size of the critical dimension (CD). The patterning is usually performed by forming a pattern on the photoresist layer by a lithography process, and then using the photoresist layer as an etching mask to perform a dry or wet etching process to transfer the pattern in the photoresist layer to the lower side. The layer to be patterned.

As components continue to shrink and accumulate, and the design of integrated circuits becomes more complex, the accuracy of pattern transfer plays an important role. As the critical dimensions of the pattern become smaller and smaller, the resolution required for the lithography process is getting higher and higher. In order to meet the high resolution requirements, the thickness of the photoresist layer must be thinner and thinner. However, if the thickness of the photoresist layer is too thin, in the subsequent etching process, it is likely that the photoresist layer as an etching mask has been etched out before the pattern is completely transferred to the underlying layer to be patterned. The purpose of patterning cannot be achieved.

In addition, in the case where the component accumulation is required to be higher and higher, it is necessary to consider the change in the physical characteristics of the component to avoid the influence of the operation speed and performance of the component. As shown in FIG. 1 , an opening 104 is formed in the layer to be patterned 102 on the substrate 100 by pattern transfer using a patterned photoresist layer (not shown), if the adjacent two openings 104 are too close in pattern. It is easy to make the top critical dimension of the opening 104 too large after the etching process. After the subsequently deposited conductor layer 106 is filled into the opening 104, the structure formed in the adjacent two openings 104 may cause bridging 108 thereby causing problems in the reliability of the subsequently formed components. Moreover, since the opening pattern formed in the patterned photoresist layer may have a broad bowing profile at the opposite ends due to excessive lateral etching, the pattern of the patterned photoresist layer is transferred to the pattern to be patterned. After the layer 102 is formed, an opening 104 having an arcuate profile 110 is easily formed in the layer to be patterned 102.

Therefore, how to reduce the critical dimensions of the pattern and improve the defects such as the opening bridging and the bow profile to ensure the reliability and yield of the subsequently formed components is one of the problems that the industry is eager to solve.

In view of this, the present invention provides a patterning method that ensures the accuracy of pattern transfer.

The present invention further provides a method of making a dual damascene opening that is capable of forming an opening having a relatively flat profile.

The present invention proposes a patterning method comprising the following steps. An organic layer, a germanium-containing mask layer, and a patterned photoresist layer are sequentially formed on the material layer. The patterned photoresist layer is used as a mask to remove the mask layer. The etching step is performed using a ruthenium-containing mask layer using a reactive gas to remove the organic layer, wherein the reaction gas contains no oxygen species. The organic layer is used as a mask to remove the material layer to form an opening in the material layer. Remove the organic layer.

According to the patterning method of the embodiment of the invention, the reaction gas includes N ₂ and H ₂ .

According to the patterning method of the embodiment of the invention, the reaction gas is composed of N ₂ and H ₂ .

According to the patterning method of the embodiment of the invention, the gas flow ratio of the above N ₂ and H ₂ is from 3:1 to 1:1.

According to the patterning method of the embodiment of the invention, the etching step is performed for a time of 50 seconds to 150 seconds.

According to the patterning method of the embodiment of the invention, the organic layer comprises an I-line photoresist.

According to the patterning method of the embodiment of the invention, the opening comprises a double damascene opening, a contact window opening, a via opening or a wire opening.

The invention further provides a patterning method comprising the following steps. An organic layer, a germanium-containing mask layer, and a patterned photoresist layer are sequentially formed on the material layer. The patterned photoresist layer is used as a mask to remove the mask layer. Using a ruthenium mask as a mask, an etching step is performed using a reactive gas to remove the organic layer, wherein the reaction gas provides a reactive species, and the bonding energy of the reactive species formed by the species in the organic layer (bond) Energy) is less than the bond energy of C=O or C≡O. The organic layer is used as a mask to remove the material layer to form in the material layer Opening. Remove the organic layer.

According to the patterning method of the embodiment of the present invention, the bond energy of the single bond or the double bond formed by the reaction species and the species in the organic layer is smaller than the bond energy of C=O, and the reaction species and the organic layer The bond of the triple bond formed by the species in the species is less than the bond energy of C≡O.

The present invention further provides a method of manufacturing a dual damascene opening that includes the following steps. A substrate having at least one electrically conductive region is provided and the electrically conductive region is covered with a liner. A dielectric layer and a patterned hard mask layer are sequentially formed on the liner, and the patterned hard mask layer has an opening exposing the dielectric layer. Forming a tri-layer structure on the patterned hard mask layer, the three-layer structure filling the openings, wherein the three-layer structure comprises an organic layer stacked from bottom to top, a germanium-containing mask layer and a patterned photoresist layer . The patterned photoresist layer is used as a mask to remove the mask layer. The etching step is performed using a ruthenium-containing mask layer using a reactive gas to remove the organic layer, wherein the reaction gas contains no oxygen species. The dielectric layer is removed by using a mask containing the germanium mask and the organic layer to form a via opening exposing the liner in the dielectric layer. Remove the organic layer. The patterned hard mask layer is used as a mask to remove the dielectric layer to form a trench in the dielectric layer, and the liner exposed by the via opening is removed to expose the conductive region, wherein the trench and the via window The openings are connected.

According to the manufacturing method of the double damascene opening according to the embodiment of the invention, the reaction gas includes N ₂ and H ₂ .

According to the method of manufacturing a dual damascene opening according to an embodiment of the invention, the reaction gas is composed of N ₂ and H ₂ .

According to the manufacturing method of the double damascene opening according to the embodiment of the invention, the gas flow ratio of the above N ₂ and H ₂ is from 3:1 to 1:1.

According to the manufacturing method of the double damascene opening according to the embodiment of the invention, the etching step is performed for 50 seconds to 150 seconds.

According to a method of fabricating a dual damascene opening according to an embodiment of the invention, the organic layer comprises an I-line photoresist.

Based on the above, the patterning method of the present invention etches the organic layer using a reaction gas containing no oxygen species, or makes the bond energy of the bond formed between the reactive species in the reaction gas and the species in the organic layer small. Therefore, the patterning method of the present invention is capable of performing redeposition while etching the organic layer, while maintaining the pattern transferred to the organic layer in a predetermined shape and critical dimensions.

In addition, the method for fabricating the dual damascene opening of the present invention utilizes an organic layer having a relatively flat profile and a predetermined critical dimension as a mask to pattern the dielectric layer to form a via opening in the dielectric layer. Helps reduce the critical dimensions of the top of the opening and improve the contour of the opening.

The above described features and advantages of the present invention will be more apparent from the following description.

2A through 2D are schematic cross-sectional views showing a patterning method in accordance with an embodiment of the present invention. Referring to FIG. 2A, a substrate 200 is provided on which a material layer 202 has been formed and is intended to be patterned in the material layer 202. An organic layer 204, a germanium-containing mask layer 206, and a patterned photoresist layer 208 are sequentially formed on the material layer 202. The material of the organic layer 204 includes an I-line photoresist having a wavelength of 365 nm and the like. The germanium-containing mask layer 206 is, for example, a silicon-containing hard-mask bottom anti-reflection coating (SHB), and the material includes an organic germanium polymer for the bottom anti-reflective layer (BARC). An organosilicon polymer or polysilane. The patterned photoresist layer 208 has, for example, an opening pattern 212, and the forming method can be performed by sequentially performing exposure and development steps using a generally well-known lithography process. The material of the patterned photoresist layer 208 may be a photoresist material generally used in a lithography process, such as an ArF photoresist having a wavelength of 193 nm, which may be an acrylate type photoresist or a cycloolefin type light. Resistance, COMA type photoresist or VEMA type photoresist.

In view of the above, the organic layer 204, the germanium-containing mask layer 206, and the patterned photoresist layer 208, for example, collectively form a tri-layer structure 210 as a mask structure for subsequent patterning of the material layer 202. It is worth mentioning that by using the three-layer structure 210 as a mask, the thickness of the patterned photoresist layer 208 can be reduced, thereby improving the resolution and avoiding problems such as photoresist collapse.

Referring to FIG. 2B, the patterned photoresist layer 208 is used as a mask to remove the germanium-containing mask layer 206 to transfer the opening pattern 212 to the germanium-containing mask layer 206. The method of removing the germanium-containing mask layer 206 may employ a dry etching method using, for example, CF ₄ and CHF ₃ as etching gases. During the etching of the germanium-containing mask layer 206, the patterned photoresist layer 208 is also etched away at the same time. Therefore, when the opening pattern 212 is completely transferred to the ruthenium containing mask layer 206, for example, a small portion of the patterned photoresist layer 208 remains on the ruthenium containing mask layer 206 or can be completely removed.

Referring to FIG. 2C , the remaining patterned photoresist layer 208 and the germanium-containing mask layer 206 are used as masks to remove the organic layer 204 to transfer the opening pattern 212 to the organic layer 204 . After patterning of the organic layer 204 is completed, the patterned photoresist layer 208 on the germanium-containing mask layer 206 is, for example, etched away. The method of removing the organic layer 204 includes performing an etching step using a reactive gas in which the reactive gas does not contain an oxygen species, and the etching step is performed, for example, by a dry etching method.

Specifically, the reaction gas of the oxygen-free species means, for example, that the reaction gas molecules are composed of other atoms not containing oxygen atoms, that is, the reaction gas does not include a gas containing oxygen atoms such as CO or CO ₂ . In one embodiment, the reaction gas comprises nitrogen (N ₂ ) and hydrogen (H ₂ ), wherein the gas flow ratio of N ₂ and H ₂ is from 3:1 to 1:1, preferably 1.96:1. In another embodiment, the reaction gas is composed of N ₂ and H ₂ , that is, the reaction gas used in the etching step includes only N ₂ and H ₂ and does not contain other gases. When the reaction gas includes only N ₂ and H ₂ , the gas flow ratio of N ₂ and H ₂ is from 3:2 to 5:2, preferably 1.96:1.

In practice, the etching step using the reactive gas to remove the organic layer 204 is carried out, for example, at a pressure of about 10 mTorr to 30 mTorr, preferably at a pressure of about 15 mTorr. The radio frequency (RF) power source used to generate the plasma in the etching step is, for example, applying about 800 W to 1200 W on the top plate and about 200 W to 400 W on the bottom plate. Preferably, about 800 W is applied to the upper electrode plate and about 300 W is applied to the lower electrode plate. When the reaction gas comprises N ₂ and only when H _2, N ₂ gas flow rate, for example, from about 150 sccm to 350 sccm, preferably from about 265 sccm; and the H ₂ gas flow rate is for example from about 50 sccm to 200 sccm, preferably It is about 135 sccm. The time for performing the etching step is, for example, 50 seconds to 150 seconds, preferably about 85 seconds.

Specifically, during the etching step, the reaction gases N ₂ and H ₂ are dissociated in the plasma to provide a reactive species, and react with species in the organic layer 204 to form carbon nitride (CN _m ). And the product of nitrogen oxide (NO _n ), as shown in the following formula.

among them, The composition of the organic layer 204 is represented, and each of x, y, z, m, and n represents a positive integer.

When N ₂ in the reaction gas acts as a reaction species and reacts with a carbon species in the organic layer 204 to form a single bond, the bond energy of CN is about 73 kcal/mol; if a double bond is formed, the bond energy of C=N is about It is 147 kcal/mol; if a triple bond is formed, the bond energy of C≡N is about 213 kcal/mol. When N ₂ in the reaction gas acts as a reaction species and forms a single bond with the oxygen species in the organic layer 204, the bond energy of NO is about 55 kcal/mol; if a double bond is formed, the bond energy of N=O is about It is 143 kcal/mol.

However, conventionally, when etching an organic layer 204 using an etching gas containing an oxygen species, the oxygen species react with species in the organic layer 204 to form a carbon monoxide (CO) and carbon dioxide (CO ₂ ) product, as shown in the following formula.

When the O ₂ in the etching gas as a reaction species reacts with the carbon species in the organic layer 204 to form a double bond, the bond energy of C=O is about 192 kcal/mol; if a triple bond is formed, C≡O The bond energy is approximately 258 kcal/mol.

It can be seen from the above that the reactive gases N ₂ and H ₂ used in the embodiments of the present invention can provide a reactive species when the organic layer 204 is etched, and the bond energy of the bond formed between the reactive species and the species in the organic layer 204 is less than C. =O or C≡O bond energy. In detail, the bond energy of the single bond or the double bond formed by the species in the reaction species and the organic layer 204 is, for example, a bond energy smaller than C=O, and the triple bond formed by the species in the reaction species and the organic layer 204. The bond energy can be, for example, a bond energy smaller than C≡O. That is, N ₂ in the reaction gas is more likely to form a bond with the carbon or oxygen species in the organic layer 204 than O ₂ in the conventional etching gas. Therefore, in the process of etching the organic layer 204 using the reaction gas, N ₂ in the reaction gas can again form a bond with the carbon or oxygen species in the organic layer 204, resulting in a similar re-deposition effect.

As shown in FIG. 2C, when the organic layer 204 is etched using a reaction gas containing no oxygen species to transfer the opening pattern 212 to the organic layer 204, the organic layer 204 can be interrupted by radical formation of H ₂ in the reaction gas. The bonding in the middle reaches the effect of etching, and at the same time, redeposition is performed using N ₂ in the reaction gas. During the etching step, the over-etched profile in the organic layer 204 can be compensated by redeposition, and can help control the lateral etch rate, thereby effectively avoiding the opening pattern transferred into the organic layer 204. The problem of the top critical dimension of 212 being too large or forming a bowing profile occurs. As a result, the opening pattern 212 transferred into the organic layer 204 has a relatively flat profile and can maintain the predetermined shape and critical dimensions of the pattern.

Referring to FIG. 2D, with the mask layer 206 and the organic layer 204 as masks, the material layer 202 is removed to transfer the opening pattern 212 to the material layer 202, and the opening 214 is formed in the material layer 202. The opening 214 is, for example, a double damascene opening, a contact window opening, a via opening or a wire opening. The method of removing the material layer 202 is, for example, a dry etching method, and the etching gas is different depending on the kind of the material layer 202 to be etched. It is explained here that in the process of transferring the opening pattern 212 to the material layer 202, if the ruthenium-containing mask layer 206 has been etched out, the organic layer 204 can be used as an etching mask to continue etching until the opening Pattern 212 is completely transferred to material layer 202. After the opening 214 is formed, the remaining organic layer 204 is removed. The method of removing the organic layer 204 may be a dry removal method or a wet removal method.

It is explained herein that the organic layer 204 is etched by using a reactive gas containing no oxygen species to transfer the opening pattern 212 to the organic layer 204 such that the opening pattern 212 transferred into the organic layer 204 has a relatively flat profile and is predetermined The key size. Thus, the organic layer 204 is utilized as an etch mask, and the opening 214 formed in the material layer 202 can maintain a predetermined shape and critical dimensions, and thus can help to improve the subsequent bridging of components formed in the opening 214.

In addition, the above-mentioned patterning method is mainly applied in the back-end process, and the practical application of the patterning method of the present invention will be continued by taking the manufacturing method of the double damascene opening as an example. It should be noted that the flow described below is mainly for the purpose of detailing that the patterning method of the present invention is formed in a double damascene process to form a mask for defining an opening pattern, so that those skilled in the art can This is not intended to limit the scope of the invention. The arrangement, the number, and the manner in which other components such as the substrate, the plug, the wire, the opening, or the conductive region are formed may be made according to techniques known to those skilled in the art, and are not limited to the embodiments described below. . 3A-3F are cross-sectional views showing a method of fabricating a dual damascene opening in accordance with an embodiment of the present invention.

Referring to FIG. 3A, a substrate 300 having a conductive region 302 is provided, and the conductive layer 302 has been covered with a liner 304. The substrate 300 is, for example, a semiconductor substrate such as an N-type or P-type germanium substrate, a tri-five semiconductor substrate, or the like. The conductive region 302 is, for example, a metal wire in an interconnect process, such as a copper wire. The liner 304 covering the conductive region 302 prevents oxidation of the conductive region 302, such as nitrogen-doped niobium carbide (SiCN), tantalum oxide or tantalum nitride. The thickness of the liner 304 is, for example, about 150. To 350 , preferably about 250 .

Then, a dielectric layer 306, a buffer layer 308, a patterned hard mask layer 310, and a cap layer 312 are sequentially formed on the liner 304. The material of the dielectric layer 306 is, for example, an ultra low-k material (ULK), and the ultra-low dielectric constant material generally refers to a dielectric material having a dielectric constant of about 2.5 or less. The thickness of the dielectric layer 306 is, for example, about 1250. To 2250 , preferably about 1750 . The material of the buffer layer 308 is, for example, a dielectric material different from the dielectric layer 306, which may be hafnium oxynitride or hafnium oxide, preferably hafnium oxynitride. The thickness of the buffer layer 308 is, for example, about 50. To 250 , preferably about 150 . The patterned hard mask layer 310 has an opening 314 exposing the buffer layer 308, which is a pattern of subsequent trenches that are intended to be formed in the dielectric layer 306. The material of the patterned hard mask layer 310 includes a metal or metal nitride such as titanium, titanium nitride, tantalum, tantalum nitride, tungsten, tungsten nitride, or combinations thereof. In the present embodiment, the patterned hard mask layer 310 includes a titanium layer 310a and a titanium nitride layer 310b stacked from bottom to top, wherein the thickness of the titanium layer 310a and the titanium nitride layer 310b is, for example, about 25 each. To 75 Preferably, each is about 50 . The cap layer 312 is overlaid on the patterned hard mask layer 310 to protect the patterned hard mask layer 310. The material of the cap layer 312 is, for example, cerium oxide, cerium oxynitride, cerium nitride or cerium carbide, preferably cerium oxide. The thickness of the cap layer 312 is, for example, about 50 To 250 , preferably about 150 .

Thereafter, a tri-layer structure 316 is formed on the cap layer 312, and the three-layer structure 316 is filled into the opening 314. In one embodiment, the three-layer structure 316 includes an organic layer 318 stacked from bottom to top, a germanium-containing mask layer 320, and a patterned photoresist layer 322. Specifically, the material of the organic layer 318 is, for example, an I-line photoresist having a wavelength of 365 nm or the like. The thickness of the organic layer 318 is, for example, about 1000. To 3000 , preferably about 2000 . The ruthenium-containing mask layer 320 is, for example, a ruthenium-containing hard mask bottom anti-reflection layer (SHB). The thickness of the ruthenium containing mask layer 320 is, for example, about 300 To 700 , preferably about 500 . The patterned photoresist layer 322 has, for example, an opening 324 exposing the germanium-containing mask layer 320, and the opening 324 is a pattern of subsequent via openings formed in the dielectric layer 306. The material of the patterned photoresist layer 322 is, for example, an ArF photoresist having a wavelength of 193 nm. The thickness of the patterned photoresist layer 322 is, for example, about 800. To 1500 , preferably about 1100 .

Referring to FIG. 3B, the patterned photoresist layer 322 is used as a mask to remove the germanium-containing mask layer 320 to transfer the pattern of the opening 324 to the germanium-containing mask layer 320 to form the germanium-containing mask layer 320. The opening 326 of the organic layer 318 is exposed. The method of removing the germanium-containing mask layer 320 may employ a dry etching method using, for example, CF ₄ and CHF ₃ as etching gases. After forming the opening 326, the patterned photoresist layer 322, for example, still has a small portion remaining on the germanium containing mask layer 320 or can be completely removed.

Referring to FIG. 3C , the remaining patterned photoresist layer 322 and the germanium-containing mask layer 320 are used as masks to remove the organic layer 318 to form an opening 328 in the organic layer 318 exposing the buffer layer 308 . The method of removing the organic layer 318 includes performing an etching step using a reactive gas, wherein the reactive gas contains no oxygen species, and the etching step is performed, for example, by dry etching. Further, during the etching step, the reaction gas may provide a reactive species, and the bond energy of the bond formed between the reactive species and the species in the organic layer 318 is, for example, a bond energy smaller than C=O or C≡O.

Specifically, the reaction gas of the oxygen-free species means, for example, that the constituent atoms of the reaction gas do not include oxygen atoms, that is, gases containing oxygen atoms such as CO, CO ₂ or the like are excluded from the reaction gas. In one embodiment, the above reaction gas includes N ₂ and H ₂ . In another embodiment, the above reaction gas is composed of N ₂ and H ₂ and is free of other gases. The etching step is performed using a reactive gas to remove the organic layer 318, and the etching step is performed, for example, at a pressure of about 10 mTorr to 30 mTorr, preferably at a pressure of about 15 mTorr. The radio frequency (RF) power source used to generate the plasma in the etching step is, for example, applying about 800 W to 1200 W on the top plate and about 200 W to 400 W on the bottom plate. Preferably, about 800 W is applied to the upper electrode plate and about 300 W is applied to the lower electrode plate. When the reaction gas comprises N ₂ and only when H _2, N ₂ gas flow rate, for example, from about 150 sccm to 350 sccm, preferably from about 265 sccm; and the H ₂ gas flow rate is for example from about 50 sccm to 200 sccm, preferably It is about 135 sccm. The time for performing the etching step is, for example, 50 seconds to 150 seconds, preferably about 85 seconds.

It is worth mentioning that since the reaction gas used in the embodiment of the present invention does not contain an oxygen species, and the bonding energy of the bond formed between the reactive species and the species in the organic layer 318 is small, it is possible to carry out the etching reaction. The redeposition reaction is carried out using N ₂ in the reaction gas, and the etching rate is controlled. As such, the top critical dimension of the opening 328 formed in the organic layer 318 can be avoided and the contours caused by excessive lateral etching in the opening 328 can be improved, such that the opening 328 has a relatively flat profile.

Referring to FIG. 3D, the buffer layer 308 and the portion of the dielectric layer 306 are removed by using the mask layer 320 and the organic layer 318 as masks, and the opening 330 is formed in the dielectric layer 306. The method of removing the buffer layer 308 and the portion of the dielectric layer 306 is, for example, a dry etching method using, for example, C ₄ F ₈ and CF ₄ as an etching gas. In addition, during the process of etching the buffer layer 308 and the portion of the dielectric layer 306, the germanium-containing mask layer 320 is also etched and consumed. In one embodiment, the depth of the opening 330 in the dielectric layer 306 is, for example, about 400 from the upper surface of the dielectric layer 306. To 500 .

Referring to FIG. 3E, the dielectric layer 306 is removed with the remaining germanium-containing mask layer 320 and the organic layer 318 as a mask to form an opening 330' in the dielectric layer 306 exposing the liner 304. The opening 330' is, for example, a via opening. The method of removing the dielectric layer 306 is, for example, a dry etching method using, for example, C ₄ F ₈ as an etching gas. Similarly, during the continuation of etching the dielectric layer 306 to deepen the via opening, the germanium-containing mask layer 320 is simultaneously etched away and the organic layer 318 is also etched to be wasted.

Referring to FIG. 3F, after the opening 330' is formed, the remaining organic layer 318 is removed to expose the patterned hard mask layer 310. The method of removing the organic layer 318 is, for example, a dry removal method or a wet removal method. In an embodiment, the method of removing the organic layer 318 may use CO ₂ as a reaction gas for ashing. Thereafter, the patterned hard mask layer 310 is used as a mask, the buffer layer 308 and a portion of the dielectric layer 306 are removed, and an opening 332 is formed in the dielectric layer 306, and then the liner 304 exposed by the opening 330' is removed. And a portion of the conductive region 302 is exposed. The opening 332 is, for example, a trench in which the opening 332 communicates with the opening 330' to form a dual damascene opening. In this step, the method of removing the buffer layer 308 and the portion of the dielectric layer 306 is, for example, a dry etching method using, for example, C ₄ F ₈ and CF ₄ as an etching gas.

After the fabrication of the dual damascene opening is completed, the patterned hard mask layer 310 can be further removed and the conductor layer can be filled in the dual damascene opening to form a dual damascene structure electrically connecting the conductive regions 302. Those skilled in the art can change the application and the application according to the foregoing embodiments, and thus will not be described again.

In summary, the patterning method of the present invention and the method of manufacturing the dual damascene opening have at least the following advantages:

1. The patterning method of the above embodiment and the method of manufacturing a dual damascene opening using a reactive gas containing no oxygen species to etch the organic layer, or a bond formed by a reaction species in the reaction gas with a species in the organic layer The energy can be made small, so that the redeposition reaction can be performed while the etching reaction is being performed to control the etching rate.

2. The patterning method of the above embodiment and the method of manufacturing a dual damascene opening can form an organic layer having a relatively flat profile and a predetermined critical dimension pattern. Therefore, the use of this organic layer as an etching mask to form an opening ensures the accuracy of pattern transfer, and reduces the critical size of the top of the opening and improves the contour of the opening.

3. The patterning method of the above embodiment and the manufacturing method of the double damascene opening can be widely applied in forming various openings, particularly in the back-end process, and can be integrated with existing semiconductor processes, the process is simple and the component reliability can be effectively improved. And yield.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100, 200, 300‧‧‧ base

102‧‧‧to be patterned

104, 214, 314, 324, 326, 328, 330, 330', 332‧‧

106‧‧‧Conductor layer

108‧‧‧Bridge

110‧‧‧ bow profile

202‧‧‧Material layer

204, 318‧‧‧ organic layer

206, 320‧‧‧矽 Cover layer

208, 322‧‧‧ patterned photoresist layer

210, 316‧‧‧ three-layer structure

212‧‧‧Open pattern

302‧‧‧Conducting area

304‧‧‧ lining

306‧‧‧Dielectric layer

308‧‧‧buffer layer

310‧‧‧ patterned hard mask layer

310a‧‧‧Titanium

310b‧‧‧Titanium nitride layer

312‧‧‧Top cover

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing the top critical dimension and the arcuate profile of an opening formed by a conventional method.

2A through 2D are schematic cross-sectional views showing a patterning method in accordance with an embodiment of the present invention.

3A-3F are cross-sectional views showing a method of fabricating a dual damascene opening in accordance with an embodiment of the present invention.

200. . . Base

202. . . Material layer

204. . . Organic layer

206. . . Covered mask

212. . . Opening pattern

Claims (17)

A patterning method includes: sequentially forming an organic layer, a germanium-containing mask layer, and a patterned photoresist layer on a material layer; removing the mask by using the patterned photoresist layer as a mask a mask layer; using the ruthenium mask as a mask, performing an etching step using a reactive gas to remove the organic layer, wherein the reaction gas does not contain an oxygen species; and the organic layer is used as a mask to remove the a material layer to form an opening in the material layer; and removing the organic layer, wherein the reaction gas is composed of N ₂ and H ₂ , and the gas flow ratio of N ₂ and H ₂ is 3:1 to 1: 1. The patterning method of claim 1, wherein the etching step is performed for a time of 50 seconds to 150 seconds. The patterning method of claim 1, wherein the organic layer comprises an I-line photoresist. The patterning method of claim 1, wherein the opening comprises a double damascene opening, a contact window opening, a via opening or a wire opening. A patterning method includes: sequentially forming an organic layer, a germanium-containing mask layer, and a patterned photoresist layer on a material layer; removing the mask by using the patterned photoresist layer as a mask Curtain layer; using the ruthenium mask as a mask, using a reactive gas for etching a step of removing the organic layer, wherein the reactive gas provides a reactive species, and the bond energy formed by the reactive species with the species in the organic layer is less than the bond of C=O or C≡O The organic layer is used as a mask to remove the material layer to form an opening in the material layer; and the organic layer is removed, wherein the reaction species form a single bond with the species in the organic layer or The bond energy of the double bond is smaller than the bond energy of C=O, and the bond energy of the triple bond formed by the reaction species and the species in the organic layer is smaller than the bond energy of C≡O. The patterning method of claim 5, wherein the reaction gas comprises N ₂ and H ₂ . The patterning method of claim 5, wherein the reaction gas is composed of N ₂ and H ₂ . The patterning method of claim 7, wherein the gas flow ratio of N ₂ and H ₂ is from 3:1 to 1:1. The patterning method of claim 5, wherein the etching step is performed for a time of 50 seconds to 150 seconds. The patterning method of claim 5, wherein the organic layer comprises an I-line photoresist. The patterning method of claim 5, wherein the opening comprises a double damascene opening, a contact window opening, a via opening or a wire opening. A method of fabricating a dual damascene opening, comprising: providing a substrate having at least one conductive region, and the conductive region is overcoated Covering a liner; sequentially forming a dielectric layer and a patterned metal hard mask layer on the liner, the patterned metal hard mask layer having an opening exposing the dielectric layer; Forming a tri-layer structure on the metal hard mask layer, the three-layer structure filling the opening, wherein the three-layer structure comprises an organic layer stacked from bottom to top, a ruthenium mask layer and a Patterning the photoresist layer; removing the ruthenium mask layer by using the patterned photoresist layer as a mask; using the ruthenium mask layer as a mask, performing an etching step using a reactive gas to remove the An organic layer, wherein the reactive gas does not contain an oxygen species; the dielectric layer is removed by using the germanium-containing mask layer and the organic layer as a mask to form a via window exposing the liner layer in the dielectric layer Opening the organic layer; and removing the dielectric layer by using the patterned metal hard mask layer as a mask to form a trench in the dielectric layer and removing the via opening The liner layer exposes the conductive region, wherein the trench is in communication with the via opening. The method of manufacturing a dual damascene opening according to claim 12, wherein the reaction gas comprises N ₂ and H ₂ . The method of manufacturing a dual damascene opening according to claim 12, wherein the reaction gas is composed of N ₂ and H ₂ . The method of manufacturing a dual damascene opening according to claim 14, wherein the gas flow ratio of N ₂ and H ₂ is from 3:1 to 1:1. The method of manufacturing a dual damascene opening according to claim 12, wherein the etching step is performed for a time of 50 seconds to 150 seconds. The method of manufacturing a dual damascene opening according to claim 12, wherein the organic layer comprises an I-line photoresist.