TWI224557B - Etching process for low-k organic film - Google Patents

Abstract

Disclosed is a simplified process for etching a low-k organic film. The process of the present invention comprises: first providing a dielectric layer of low k on a substrate, and then forming a hard mask on the dielectric layer. Then, a photoresist layer is deposited on the hard mask and a contact or via is formed by transfer of pattern. Thereafter, a photoresist dry etching is carried out with the photoresist serving as a mask, while at the same time, the photoresist is removed. Finally, internal wiring is formed by using the hard mask as the mask for dry etching for low-k organic film and subsequent semiconductor manufacturing process is then carried out.

Description

1224557

5 -1 Field of invention: Method for leaving the binding film with organic low-medium species in device manufacturing process. The present invention relates to an application of a semiconductor electric constant material, in particular to a 5-2 invention background sheet: a rule of law When it has been transferred to the deep sub-micron field, the interconnect lines and related processes on the chip have become efficient and reliable. The key to the manufacturing cost of the circuit. For every — ▲ again. The lower cost requirement leads the lead on the wire = :: and can make the transmission of the signal on the internal connection line a result of the reduction of attention. In order to reduce the Rc extension of the interconnecting wire ::: People accept that it is used as a thin dielectric layer, and the main low dielectric constant materials can be organic polymers, such as FLARE, SILK and so on. Several materials are based on spin-coating because of the traditional etching block layer material, which is removed after engraving. However, the organic dielectric constant 7 two-resistance layer is usually etched. These traditional spin-coated organic dielectric materials: characteristics and Similar to the photoresist layer, it is limited. The first step is to show the miscellaneous steps in the integration of the H plasma process at the oxygen plasma to protect the low impedance. This requires a difficult method. There is a special film. -A solution to this difficulty. A hard mask is used to deposit only the f-film, and then deposit the edge-protecting organic dielectric layer to remove the photoresist. 1224557 V. Damage caused by the description of the invention (2). However, lateral etching is still unavoidable. Figures A through C show the detailed flow of lateral etching of organic low dielectric constant materials in various ways. / ^ As shown in the first A Figure 0, the pattern is transferred to the next, using an oxygen plasma, resulting in organic low dielectric as shown in the first C Figure. The profile, as shown in the second A picture, is shown in a hole A picture after the dielectric constant layer 1 2 layer 16 and the trench 4 and the hard photoresist layer. Then the dielectric constant layer 1 3 forms a via hole, such as the photoresist layer 3 0, which is etched in the same lateral direction. Connected as shown in Figure D. P and the layer 2 4 and the side with layer 2 0 2 are shown in double inlay. One stop — 〇 After absorbing water, the method is etched, as shown. The following picture will make the picture, the photoresist layer 1 process will remove the photoresistance constant layer layer 1 result to the second D picture and the 13 series are stopped by the engraving, which can prevent the pattern from being exposed through exposure. The barrier layer 1 6 is dry-etched. As shown in Figure 2B, the trench C of the second C is exposed. After the exposure, the low dielectric constant is often removed, and at the same time, it is etched. Separate the cover layer (cap gas. In the formation and transfer to the photoresist layer, the low dielectric constant is often lowered by the oxygen, which causes the organic low-grade organic compound to be formed. The dry etching is performed on several layers 1 and 2. The first layer due to carbon B picture and change the 'organic low' layer in the etching wheel) 1 photoresist layer 3 0 layer, such as the second, organic low dielectric layer 12, the slurry process to remove the dielectric constant profile, such as the second # Solve The method is to choose an organic low-dielectric layer with a low carbon-containing thin film (between B and I 2 0 /)). There is no oxygen plasma with a ratio of Γ7 and a few 疋. In the traditional dual-mosaic technology, this organic Low dielectric

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V. Description of the invention (3) The constant still shows other restrictions and numbers, (2) the photoresist removal step will cause a bottoms) the photoresist removal step will change the dielectric constant and (4) the organic low dielectric constant is required- (3) is relatively low compared with the selection of photoresistance to stop absorbing moisture. Only a cover layer is formed on the surface to prevent it due to the method in the organic low dielectric system requiring multiple layers of hard light to be exposed to the oxygen plasma. For example, the organic low dielectric constant silicon retroreflective layer 18 is formed at least, and is formed on the silicon oxide layer 18 and etched at 8 兹. As shown in the third figure a, the constant layer 12 is sampled, and then the silicon nitride layer 1 Figure B shows. Then, 5 'and the silicon oxynitride layer 14 are exposed, as shown in the third figure C.' First, the photoresist layer 31 is shown in the figure. Then the photoresist layer 3 silicon is used as a mask to etch the non-specificity of the organic low-dielectric structure, as shown in Figure 3F, and then the double-mosaic structure by chemical mechanical polishing. However, this hinders: the high carbon content in the material, the other way is to avoid organic low dielectric constant films ^ Hall No, a synthetic insulating layer to the 12 'silicon dioxide layer 17 and nitrogen oxides , 10 formed. The photoresist layer 30 is exposed to nitrogen and exposed. No dry etching on the silicon oxynitride layer 1 Then remove the photoresist, at this time, the protection of the organic low-dielectric stone layer 17 prevents the oxygen plasma from harming the silicon oxide layer 17 for the mask etching, such as the first low-dielectric constant layer 1 3 and the silicon oxide layer 1 The photoresist layer 31 is sequentially deposited, and then the photoresist layer etched with oxynitride layer 1 4 and the third step 1 from FIG. 2A to FIG. 3b are removed by oxygen plasma treatment. Next, the oxynitrite layer 1 1 5 ′ is shown in FIG. The electric Φ layers are 1 3 and 1 2. The remaining metal is deposited after the P metal and the metal layer are sequentially deposited, as shown in the third C picture. The method has complicated steps in the dual damascene technology.

Page 6 1224557 V. Description of the invention (4) 5-3 Purpose and summary of the invention: Lu Zhi •: So = i Γ in the background 'traditional narrative organic low-dielectric constant Eryi L. # Xi defect' this The invention provides-a kind of simplified meal engraving + joint question: another process of the invention is to determine the advantages of the cover layer to prevent the right trap ( The low dielectric constant layer absorbs moisture. To prevent organic money and in: another purpose is to simplify the simplified process with the same steps, 介 # ί = The purpose described above, the present invention provides an etched ## The manufacturing process of the layer. First, a substrate is provided, and on top of it: a low dielectric constant layer and a cover layer. Then, at :: into-there is a first-resistance layer 'and the photoresist layer is exposed, and the pattern is :: formed- The second layer is the military resistance of the military low-level organic low-dielectric-constant layer; they are: cladding, and etch-back the excess metal layer. / Er product one metal bright schematic 1224557 V. Description of the invention (5) First Figures A to C show the schematic diagrams of the steps in the conventional method for forming a via hole. Figure 2D shows the schematic diagrams of the steps in a traditional method of forming a dual-mosaic structure; Figures 3A to 3G show the schematic diagrams of the steps in another traditional method of forming a dual-mosaic structure; The flowchart of the invention, the fifth diagram A to fifth D show schematic diagrams of each step in the method for forming a mosaic structure according to the present invention; the sixth diagram A to sixth F show the method for forming a dual mosaic structure according to the present invention. Schematic diagram of each step. Representative symbols of the main parts: 10 substrate 1 2 organic low dielectric constant layer 13 organic low dielectric constant layer 14 overlay layer 15 silicon oxide 16 barrier layer 17 silicon oxide 1 8 silicon oxynitride 2 0 light Resist layer 3 0 Photoresist layer

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1 00 substrate 1 1 2 organic low dielectric constant layer 1 1 3 organic low dielectric constant 4 114 cover layer 116 barrier layer 1 3 〇 photoresist layer 131 photoresist layer 5-5 Detailed description of the invention: Dielectrics often provide a resistive layer. After the photoresist layer mask to the constant layer conditions will be in this embodiment. With reference to the fourth thin film of a substrate and then, a light scheme is transferred to light while performing organic low dielectric. In the fourth figure and the next figure below, the root method shows that the upper resistive layer is removed from the resistive layer and the photoresistive constant layer is mentioned in the five A diagrams to illustrate the hard resist etching. Formed on an organic low-dielectric constant layer, hard photoresist. Then the program. I engraved the process from the fifth step to the last step of the photoresist layer. The different C picture in the pattern transfer was mentioned with the simultaneous etching process with several layers and the mask was hardened to the organic step. Commentary. Photoresist removal organic low. First of all, a hard light is provided by a hard-resistance layer after exposure and an appropriate reference for a low dielectric. A fifth substrate A is provided, and a substrate 100 is formed thereon. 224557 V. Description of the invention (7) Including bottom layer 1 1 2 and top layer 1 1 4 dielectric layers. A photoresist layer 130 is then formed on the dielectric layer. The bottom layer 1 1 2 is an organic low dielectric constant film formed by any conventional spin coating method. In this embodiment, the material of the organic low-dielectric-constant film 1 12 may be (FLARE, SILK, Black diamond), and its thickness is about 600 to 100 Angstroms. The top layer 4 is a hard photoresist layer, such as emulsified silicon or silicon oxynitride 'and can be used as a cap layer to prevent absorption of moisture. The top layer 1 1 4 is preferably deposited using a conventional plasma enhanced chemical vapor deposition method (Plasma enhanced chemical vapor deposition) with a thickness of about 500 to 1000 angstroms. Here it must be: the substrate 100 in the fifth figure A is a structure with elements: the inside shape is not important to the present invention, and the invention cannot be understood because it is not described in detail. The preferred thickness is about 0.6 to 0.8 'to transfer the pattern to the photoresist layer 1. In the fifth A picture, the photoresist layer is 13 microns. 30 through negative exposure to form vias or contact windows. According to the main feature of the present invention, to the top layer 1 1 4, as shown in FIG. 5B, then, in the same etching machine, the pattern transfer on the photoresist layer 1 3 0 is shown by a conventional dry etching method. The resist layer 1 3 0 is simultaneously removed by an oxygen plasma. Plasma treatment will cause slight damage to the surface of the organic low-dielectric constant film 1 1 2, as shown in FIG. 5B. However, the injured part will be removed in the next steps. Referring to the fifth pattern C ', the pattern of the top layer 4 is transferred to the organic low-dielectric constant film 丄 丄 2 through a suitable conventional anisotropic etching method. Furthermore, a barrier layer (not shown in the figure) in the shape of the substrate 丄 i 0 is used to protect the metal layer. Up to now, Figures 5A through 5 explain the steps in Figure 4 graphically. Then, deposit an extra metal layer back to gold to complete a mosaic structure, as shown in Figure 5 ^ \ 〇The above-mentioned invention can be used to simplify in multiple steps. Then 'Introduce the double damascene system .... J silver ^ Electrical number layer 1 i 2, a barrier layer (st〇p accumulated on the substrate 1 0. i 1 Same as a cover layer 1 1 4 in the same way. Similarly, the substrate] _ 0 0 is also called / d The connector is formed on the cover layer. U 0 also has the element's substructure formed in it, such as nitrogen. It is used to prevent double setting underneath. It can also be used if the barrier layer 2 is used in the interlayer hole or contact, as long as the upper trench pattern with the barrier layer 1 1 4 is etched and the barrier layer is embedded. Etch through the organic low dielectric constant layer 1 1 window under 6. Other barrier layers, such as silicon nitride 1224557 V. Description of the invention (9) The organic low dielectric constant film has different etch barrier layers 1 1 4 For different lower materials, there is a reflective layer in f. That is, the reflected light of the incident light is eliminated when it is blocked. The selective etching process covering ^ ^ ^ is the same as that in Figure 5A. The material and characteristics of s 1 4 are the same as those of the second organic low-dielectric constant layer 16 and the cover layer 1 JL 4 in the traditional way. 丄… 1 and the increase 丄 1 will take the appropriate value. Photoresist The layer i 3 〇 has a thickness of about 0.6 to 0.8 μm. Then it is formed by the eye shape and the thickness is shifted to the photoresist layer “〇, such as the sixth: FIG .; -Hole pattern transfer diagram 荦 the same technique in the example '★ Resist layer 13 ◦ The hole pattern is transferred to the dry etching method to cover the photoresist layer 130 with oxygen depletion. Heart B4 Figure 2 Next, the hole pattern of the cover layer 1 1 4 is transferred to the two organic low-dielectric constant layers i 丄 2 and 丄 丄 3 and the barrier layer 116 by a conventional anisotropic etching method, as shown in FIG. 6C. As shown. A barrier layer (not shown in the figure) is placed between the substrate 1 () 0 and the organic low dielectric constant layer 1 12 to prevent damage caused by money engraving. The hole type is completed in the dual mosaic technology After patterning, a trench is then formed. Another layer of photoresist layer 1 3 1 is formed and the wire pattern is transferred, and the forming conditions are as shown in Figure 6A. The conventional dry etching Photoresist technology

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Description of the invention (ίο) The wiring pattern of 3 1 is transferred to the covering layer 14 and at the same time, the photoresist layer 丄 3 1 is removed by oxygen plasma treatment at the same time, as shown in FIG. 6E. However, the current pattern of the cover layer 1 1 4 is formed to the organic low dielectric constant layer 1 1 3 in the manner described in FIG. 5C to form a trench. Multiplying: The next step is to sequentially form barrier metals and deposits, and then remove excess metal by chemical mechanical grinding, such as the sixth? Figure households; shown. The above description is only within the scope of equivalent modification patents completed in the spirit of the patent application scope of the present invention.

The preferred embodiment of the invention is not limited in any way. Any other changes or modifications that do not depart from the present disclosure should be included in the following application.

Claims (1)

1224557 1. A method for etching an organic low-dielectric-constant film, the method at least comprising: providing a substrate, and sequentially forming an organic low-dielectric I · layer and a hard photoresist layer on the substrate; Forming a photoresist layer on the photoresist layer; exposing the photoresist layer for pattern transfer; etching the hard photoresist layer using the photoresist layer after the pattern transfer as a mask; removing the photoresist layer simultaneously; and The organic low dielectric constant layer is etched by using the hard photoresist layer as a mask. Among them, the above-mentioned organic low-dielectric constant is wherein the above-mentioned hard photoresist layer is oxygen, wherein the above-mentioned photoresist layer is made of oxygen. 2 As in the method of the first patent application, several layers include at least FLARE or SILK. 3. The method of applying for item 1 of the patent scope, fossil evening layer. 4. The method according to item 1 of the scope of patent application is removed by electropolymerization. ‘Removing the photoresist rice engraving machine in the substrate and the organic low media’. 5. The method according to item 1 of the patent application range further includes a barrier layer between the electric constant layers. 6. The method of applying for the first item of the patent scope and the steps of etching the hard photoresist layer are 224557. 6. The scope of applying for the patent 71-The first sub-structure of the first scope of the patent application is 70 pieces. Method, wherein the above-mentioned substrate further comprises two methods of forming an organic low-dielectric-constant material. The method includes at least providing a substrate for the mosaic structure of the w-electric layer and coating the substrate on the substrate. On the organic low-dielectric constant layer: an organic low-dielectric constant forms a photoresist layer on the cover layer; exposes the photoresist layer to transfer the pattern to the photoresist layer; and uses the photoresist layer as a mask Etching the cover layer; removing the photoresist layer at the same time; the 乂 -Hai cover layer is the organic low dielectric constant layer engraved on the mask; depositing a metal layer; and etch back the excess metal layer. The number 9 = the method of the first item in the range ', wherein the above-mentioned organic low dielectric constant layer contains at least flare or 811 ^. Dianwei: The method of the second item in the second patent application, where the hard photoresist layer is an oxygen layer, and 11. If the patent application is under the scope of the patent, the method of the eighth item in this "问 X wenle", in which the upper pulp is processed and removed . The photoresist layer is made of oxygen. Page 15 1224557 VI. Application scope of patent one ----------- 1 2 · If there are more than eight methods between the electric constant layer of the scope of patent application, the substrate A barrier layer with the organic low-intermediate dagger 3. 1 3 · If the scope of the patent application and the remaining steps of the hard photoresist layer are removed, the above steps of removing the photoresist are performed in an etching machine. The method of the above item, wherein the above-mentioned substrate further includes 1 4 · Such as the sub-structure of the 8th element of the scope of patent application 15 · A method of forming an organic 仞 public φ, structure, the method includes at least: a number of materials for the dielectric layer The double inlay is going to be knotted, and the -th-organic low-dielectric-constant low-dielectric-constant layer is formed on the barrier layer when the bottom is formed, and the: -Shidi-organic-dielectric-constant layer; 〃 ^ «在 ^ The first organic low forms a first photoresist layer on the cover layer; exposes the first photoresist layer to expose a hole-shaped layer; a bamboo / Γ] ^ pattern is transferred to the first photoresist to the first photoresist The layer is a mask to etch the cover layer; to remove the first photoresist layer at the same time; to use the cover layer as a mask to etch the second barrier layer and the first organic low dielectric constant layer; Forming a second photoresist layer; exposing the second photoresist layer, and transferring the current mouth tea to the second light Page 16 1224557 6. Patent application range resist layer; etch the cover layer using the second photoresist layer as a mask; remove the second photoresist layer at the same time; etch the second organic low with the cover layer as a mask A dielectric constant layer; depositing a metal layer; and restoring excess metal layers. 16. The method according to item 15 of the patent application range, wherein the organic low-dielectric constant layer includes at least FLARE or SILK. 17. The method according to item 15 of the patent application range, wherein the hard photoresist layer is an oxide layer. 18. The method according to item 15 of the patent application range, wherein the photoresist layer is removed by an oxygen plasma treatment. 19. According to the method of claim 15 in the scope of patent application, a barrier layer is further included between the substrate and the organic low dielectric constant layer. 20. The method according to item 15 of the scope of patent application, wherein the steps of removing the photoresist and etching the hard photoresist layer are completed in a listening etcher. 21. The method according to item 15 of the patent application range, wherein the above-mentioned substrate further includes a substructure of the element. Page 17