TW495911B - Method of using inorganic antireflection coating layer to manufacture contact window and reduce device damage - Google Patents

Abstract

A forming method of silicon-oxynitride dielectric antireflection coating (DARC) layer or silicon oxide layer for passivation is disclosed in the present invention. The invented method is suitable for use after the dielectric layer is treated by a planarization polishing process (CMP process) and before a planarization process is conducted onto the conducting layer to form a contact window structure. At first, micro-scratch is generated after the dielectric layer on the semiconductor substrate is undergone with a polishing treatment. In the invention, a silicon-oxynitride DARC layer or silicon oxide layer for passivation is formed on the dielectric layer in order to fill up the micro-scratch. Then, by using a selective etching procedure, the first opening is fabricated in the passivation layer and the dielectric layer. After a conducting layer is formed and undergone with a planarization polishing procedure, interconnects can be formed inside the first opening, in which the passivation silicon-oxynitride DARC layer or silicon oxide layer is used as the stop layer of CMP process such that it is capable of avoiding the generation of micro-scratch in the dielectric layer.

Description

495911 V. Description of the invention (1) ~-[Field of the invention] The present invention relates to a method for manufacturing a contact window structure using an anti-reflection coating layer and a chemical mechanical polishing process in a semiconductor device, and particularly there is A method for manufacturing a contact window structure in an interlayer dielectric layer (ILD) or a metal interlayer dielectric layer (IMD) using an anti-reflective coating layer formed of silicon oxynitride or silicon oxide and a chemical mechanical polishing process. [Known Technology] A chemical mechanical polishing (CMP) planarization process is used to flatten the dielectric layer and reduce the height of metal layers in semiconductor devices. However, these CMP private sequences will cause micro scratches (m i c r 0 s c r a t c h e s) in the electrical layer, resulting in a reduction in optical lithography performance and component defects. The inventors of this case have discovered the shortcomings of Houbin in Figures 8A to 8D. FIG. 8A shows a chemical mechanical polishing (CMP) process 209 performed on the dielectric layer 214 over the metal line 211 on the substrate 10. FIG. 8B shows the micro scratches 216 discovered by the inventor of the present invention after the procedure. Next, on the dielectric layer 214 and the micro-scratch 216, an organic bottom anti-reflection coating (organic BARC) layer 218 and a photoresist layer 224 are formed. Then, an exposure range g is performed on the organic BARC layer 218 and the photoresist layer 224 to define a photoresist opening y5 (shown as a dotted line). Among them, one of the problems found by the inventors of this case is that the reflection effect caused by the micro-scratch can deteriorate the photoresist pattern. Next, a contact opening 226 is etched into the dielectric layer 214. Then, the photoresist layer 224 is removed. ,

495911 V. Description of the invention (2) 230 Preface As shown in FIG. 8C, a barrier layer 2 28 and a metal layer are formed on the surface of the dielectric layer 214 and filled into the contact opening 226. The barrier layer 2 2 8 and the metal layer 2 3 0 will fill part of the micro scratches 2 丨 6. FIG. 8D shows that a CMP process is performed on the metal layer 230 and the barrier layer 28 to form a metal plug 3 2 3. However, the micro-scratch 2 1 β is still filled with the metal layer 2 3 0 and the barrier layer 2 2 8. These filled micro scratches 2 1 6 may cause component defects, short circuits with overlapping metal wires, and optical defects. In addition, the CMP process applied to the metal layer also generates new micro-scratches. These new micro-scratches also cause similar problems. Therefore, it is necessary to develop a new process method to avoid the occurrence of undesired micro-brake marks in the dielectric layer when the CMP process of the semiconductor device contact window structure is fabricated. The importance of overcoming many of the above-mentioned deficiencies can be confirmed by a large number of technological developments on this subject, which are published in relevant patents and technical literature. The closest and obviously related technology development in patents can be found in US Patent No. 5,766,974 (Sardella)-Method of making a dielectric structure for facilitating overetching of metal without damage to inter-level dielectric, which reveals an inter-layer dielectric The integrated circuit with a thin silicon oxynitride layer on top of the dielectric layer provides a stop layer for a while and prevents the metal layer from being over-etched. U.S. Patent No. 5,767,018 (Bel 1) discloses a polycrystalline silicon etching process using an anti-reflection coating (ARC) layer. US Patent No. 5,354,712 (Ho)-Method for forming interconnect

495911 V. Description of the invention (3) Structures for integrated circuits teaches the use of chemically mechanically polished dielectric layers. U.S. Patent No. 5,6,74,784 (31, et al.) Discloses a method for forming a grinding stop layer for use in CMP procedures. [Summary of the Invention] In view of this, it is an object of the present invention to provide a method for using a silicon oxynitride (Si ON) layer to cover a micro scratch generated by a chemical mechanical polishing process on a dielectric layer. Another object of the present invention is to provide a dielectric anti-reflective coating (DARC) silicon oxynitride layer to avoid the use of chemical mechanical polishing treatment on the dielectric layer in the process of forming the contact window structure. Micro scratches occur. To achieve the above and other objectives, the present invention proposes a method for forming protective nitrogen on a dielectric layer after chemically treating the energetic layer = 2 and before performing a planarization polishing treatment on the conductive layer and before Shi Xilu or J structure. Oxidation ancestor i = envy ^ S method. The present invention has two (1) silicon oxynitride (SiON) and (2) silicon oxide suitable for the protective layer 20. The method of the present invention is as follows: A method for making a dielectric layer anti-reflection coating (DARC), oxidized stone, or a contact opening (con tact / via) is as follows. ^ A dielectric layer 14 is overlaid on a semiconductor structure 10, which is a dielectric layer. /; 1 on the electrical layer 14, so as to fill the micro-scratch in the dielectric layer 14. A photoresist layer 24 is formed to cover the aforementioned DARC layer 495911 V. Invention description (4). An exposure and development process is performed on the photoresist layer 24 to form a first photoresist opening 26. Then, the silicon DARC layer 20 and the dielectric layer 14 are sequentially described through the first photoresist opening 26 to form a first opening 28. This first opening may expose a contact area on the substrate or a wire on the substrate. Next, I ^ photoresist layer 24. A conductive layer 30 (for example, a metal layer) is formed to cover the nitrogen oxide L stone layer DARC layer 20 and fill the first opening 28. Then, a chemical mechanical polishing (CMP) process is performed on the conductive layer to remove the oxynitride dream and to form a layer ⑼ of the electrical layer 30 while leaving a portion filled in the first opening 28 to form an interconnect 32 Among them, the oxynitride darcan 42c is used as a termination layer of the CMP process, whereby the oxynitride darcan can be used to generate micro scratches in the galvanic layer 14. The reference mark in the summary of the invention = is not used to limit the patent scope of the present invention, * is only for better understanding of the connotation. As mentioned above, the protective layer 20 of the present invention may be replaced by a silicon oxide layer formed by an electropolymerization of a methyl emulsion phase deposition process.

The present invention provides the following advantages. The protective silicon oxynitride (or PE-silicon oxide) layer 20 of the present invention provides extremely high anti-reflection characteristics, especially when used in the ice lithography (DUV) optical lithography process. The DARC II of the present invention eliminates the need to use organic BARC. Compared with the SIN ARC layer, the present invention has better anti-reflection characteristics. m & Furthermore, the silicon oxynitride layer of the present invention can fill the micro-scratches caused by the previous chemical mechanical polishing planarization process in the dielectric layer. The silicon oxynitride DARC layer of the present invention is a CMP treatment applied to the metal layer. The polishing termination layer is excellent at M: f. This silicon oxynitride DARC layer avoids micro-scratching due to chemical mechanical polishing procedures.

Page 7 5 Description of the invention (5) Layers, in one aspect, the oxynitride Rc or rat fossil / nitroxite stack of the present invention. μ 于 Mouse fossil evening ^ γ \. rjt t:; Known process technology The present invention can achieve these understanding of the present invention "points and attached drawings, can be further-step [Simplified description of the drawings] In order to make this The above-mentioned invention of the invention is obvious and easy to understand. Here are some detailed descriptions as follows, among which the same areas, and parts: other purposes, features, and advantages can be further embodiment, and in conjunction with the attached drawings, reference numerals represent phases §1 unit,

Figures 1 to 6 are a series of cross-sectional views showing a method for manufacturing a silicon oxynitride DARC layer and a contact window opening according to the present invention; Figure 7 is a cross-sectional view showing a preferred embodiment according to the present invention, wherein One opening is a pair of dual damascene structures; and Figures 8A to 8D are a series of cross-sectional views showing the formation of contact window openings in a conventional manner. Among them, micro-scratching due to chemical mechanical polishing treatment The marks may deteriorate the photo performance. [Detailed description of the preferred embodiment] In the following description, a number of clear and detailed values will be provided, such as flow rate, pressure setting, thickness, etc. to better understand the present invention. However, it is clear that those skilled in the art do not need these details to succeed

495911 V. Description of the invention (6) The invention is implemented. On the other hand, in order not to obscure the point of origin, 'the already well-known process is no longer known to those skilled in the art, the brother in the description :: two': keep: the same mole percentage to adapt to Different scales; = The method for forming the oxynitride Rc layer used for the contact window opening will be described below. As shown in FIG. 1, a dielectric layer 14 is formed on a half 10. The dielectric layer is an interlayer dielectric (ILD) layer and is a shore 2 electric UMD layer. That is, the ILD layer may be formed on a wafer or / other layer ^ FETs. In addition, if used as an IMD layer, the dielectric layer can be placed on a bull's head. The inventors of the present case have found that the dielectric material using the low dielectric constant (10w-k) of oxygen L formed by the 03_TEOS procedure is particularly prone to generate scratches when the dielectric acoustic or layer is subjected to a chemical mechanical polishing treatment step. Β σ metal performs a chemical mechanical polishing treatment on the dielectric layer. Machine; Η 二 _ ♦ The inventor of this case noticed a problem: the above-mentioned chemical and mechanical polishing treatment often causes micro-scratches in the dielectric layer. : The depth of the sexual scratch 16 may be between 300 and 500A. Shi Erwei: In the key step, Figure 2 shows the protection of the present invention. In the first embodiment of the invention, the protective layer is mediated by nitrogen and oxygen. Dressed. The silicon oxynitride layer 20 is formed on the dielectric layer " siliconized silicon PF-In addition, in the second embodiment of the present invention, the protective layer is formed ^

Made of fossil stone Xi Λ. In the following description, the protective layer is referred to as gas, but it should be understood that the protective layer may also be PE_silicon oxide, a silicon oxynitride DARC layer or a PE_silicon oxide layer. . 495911 V. Description of the invention (7) Micro scratches due to chemical mechanical grinding. Among them, the oxynitride DARC layer was formed by a plasma enhanced chemical vapor deposition (PECVD) process. This silicon oxynitride DARC layer 20 has several important properties. First, the oxynitride layer can be filled into the micro-scratch. Second, the silicon oxynitride layer 20 formed by the method of the present invention has excellent anti-reflection characteristics. Third, this silicon oxynitride layer is an excellent CMP process termination layer, which can prevent the CMP process from being performed too much and scratching the underlying dielectric layer.

The thickness of the silicon oxynitride DARC layer is preferably between 300 and 1400 A (tgt = 600A), and the refractive index at a wavelength of 248 nm is preferably between 2 and 2 · 3 'and the extinction coefficient is between 0.6 to 0.7, and the Mohr concentrations are 45% Si, 38% 0, 7% N, and 10% η, respectively.

In the first embodiment of the present invention, a plasma enhanced chemical vapor deposition (PECVD) process is used to form the silicon oxynitride layer. The reaction parameters are adjusted to reduce the deposition rate to obtain A thin and uniform layer of oxynitride provides better optical lithography feature size control. For example, the temperature is between 300 and 400 ° C, the pressure is between 5 and 6 Torr, and the reaction gas velocity is SiH4: 60 to 80 seem, N20: 90 to 110 cm, He: 1900 to 2300 seem. The thickness of the p E-silicon oxide layer in the second embodiment of the present invention is preferably between 500 and 500. To 200 A. 'FIG. 3 shows a photoresist layer 24 formed on a silicon oxynitride DARC layer. The thickness of this photoresist layer 24 is preferably between 600 and 1,000 (100), and Preferably, a deep ultraviolet (DUV) photoresist layer. Page 10 495911 V. Description of the invention (8) Still referring to FIG. 3 'Exposing and developing the photoresist layer 2 4 to produce a first light Blocking opening 26, the photoresist layer 2 4 is preferably an I-line deep ultraviolet light source with a wavelength between 245 and 264 nm (line DU V Hght) for exposure. As shown in FIG. 4, the silicon oxynitride DARC layer 20 and the dielectric layer 14 are sequentially etched through the first photoresist opening 26 to form a first opening 28. This first The size of an opening 28 is between 0.2 and 0.4 mm. The above-mentioned one opening can have many types, for example, as shown in FIG. 7, the first opening can be a dual damascene shaped The opening 128 is structured, and the interconnecting wire 132 is a double inlay-type interconnecting wire. The first opening can be made by a multi-stage etching / lithography process, and the first opening can expose a contact area on the substrate or The wires on the substrate. As shown in FIG. 5, the photoresist layer 24 is removed. A ′ forms a conductive layer (for example, a metal layer) 30 and covers the silicon oxynitride DARC layer 20 and fills it. The first opening is filled. The metal layer may be a single tungsten layer or a multilayer structure composed of a barrier / adhesive layer (such as TiN) and a conductive layer (such as a tungsten layer). Basically, the conductive layer 3 〇 The composition can be determined by whether the layer is a contact window (c ontact) ’or the contact plug (via

Plug). FIG. 5 shows that a chemical mechanical polishing (CMP) process is performed on the conductive layer 30 to remove the conductive layer 30 above the silicon oxynitride D ARC layer 20 while leaving a portion filled in the first opening 28 to form interconnecting wires. 32 (i.e. con tact or

Page 11 495911 V. Description of the invention (9) via plug). Among them, the silicon oxynitride DARC layer 20 is used as a termination layer of the CMP process, whereby the silicon oxynitride D ARC layer 20 can be used to avoid micro scratches in the dielectric layer 14. Fig. 7 shows another embodiment, in which the first opening is a double inlay opening. The conductive layer forms a double inlay-type interconnecting wire. Among them, the silicon oxynitride DARC layer 120 of the present invention provides the functions described above. As everyone knows, many documents have described the detailed application of general technology used in the manufacturing process of integrated circuit components. The manufacturing steps used to manufacture the structure of the present invention can be obtained by using commercially available products to understand the content of the present invention. For illustration. However, as process conditions become apparent to those skilled in the art, those techniques are generally applicable. Furthermore, the individual steps of these processes are performed by the body circuit manufacturing equipment. For the technical information in this example is based on the future development of existing technology, the above-mentioned visible and appropriate adjustments can still be made.

Although I have used if + bismuth to define the present invention, any intention ::; = as above, but it is not within the scope and scope, and those who can do this without departing from the scope of the present invention should be attached Application and retouching, therefore, the scope of the τ India patent scope of the present invention shall prevail. < 1

Claims (2)

495911 VI. Application Patent Scope 1 · A method for forming a silicon nitride oxide (Si ON) dielectric anti-reflection coating (DARC) layer for making contact / via, including the following steps: (a) forming A dielectric layer covers a semiconductor structure; (b) a dielectric anti-reflection (dARC) layer forming a silicon oxynitride is formed on the dielectric layer; the silicon oxynitride DARC layer uses a plasma to strengthen the chemical gas Formed by a phase deposition (PECVD) process; (c) forming a photoresist layer overlying the DARC layer; (d) performing exposure and development procedures on the photoresist layer to make a first photoresist opening; ( e) sequentially etching the silicon oxynitride layer and the dielectric layer through the first photoresist opening to form a first opening; (f) removing the photoresist layer; (g) forming a conductive A layer covering the silicon oxynitride DARC layer and filling the first opening; and, (h) performing a chemical mechanical polishing (CMp) treatment on the conductive layer to remove the conductive layer above the silicon oxynitride DARC layer While leaving a portion filled in the first opening to form an interconnecting wire (interc〇nnect), of which 5 The siliconized DARC layer is used as a termination layer for the CMP process, so that the silicon nitrided DARC layer can be used to avoid the generation of microscratches in the dielectric layer. 2. As described in the patent application No. 丨The method for forming a silicon oxynitride anti-reflective coating layer for fabricating a contact window, wherein: step ⑻ further includes performing a chemical mechanical research on the dielectric layer Page 13 495911 6. The scope of the patent application, in which the chemical mechanical polishing treatment causes scratches in the dielectric layer; and the micro-step (C) of the formation further includes the filling in the micro-scratch of the dielectric layer. Silicon DARC layer. M gas emulsification 3. A method for forming a contact window by forming an anti-reflection coating layer of a silicon oxynitride medium as described in item 1 of the scope of the patent application, wherein the opening is a double damascene opening And the interconnected wires are equal to two = are interconnected wires. ', Yikan type 4. · A method for forming a contact window by forming an anti-reflection coating layer of oxynitride dielectric as described in item 1 of the scope of the patent application, wherein the dielectric; 1 thunder' is an interlayer dielectric layer (Interlevel dielectric) or _ metal exhibition called inter metal dielectgric. "Layer 5 · A method for forming a contact window by forming an anti-reflection coating layer of a silicon oxynitride dielectric as described in item 丨 of the patent application range, wherein the first electrical port exposes a contact area on the substrate or The wire on the substrate. Qi 6. A method for forming a contact window by forming an anti-reflection coating layer of a nitrogen oxide crushing medium as described in item 1 of the scope of patent application, wherein the thickness of the nitrogen & calcium carbide DARC layer is Between 300 and 1 400 A, at a wavelength of 248ηϋ: =, the emissivity is between 2 and 2.3, the extinction coefficient is between 0.6 and 0.7, and the concentration of Mojin is 45%, respectively. Si, 38% 0, 7% N, 10% η, ear 7. A method for forming a contact window by forming an anti-reflection coating layer of a oxynitride dielectric as described in item 1 of the patent application scope, wherein The thickness of the photoresist is between 60,000 and 1 000 0 A. ~ & Layer 8 · A dielectric forming oxynitride as described in item 1 of the scope of patent application 495911 A method for fabricating a contact window by using an anti-reflective coating layer, wherein the photoresist layer is subjected to an exposure process using an I-line DUV light having a wavelength between 245 and 264 nm. A method for forming a contact window by forming a dielectric anti-reflective coating layer of oxynitride as described in item 1 of the declared patent scope, wherein the size of the first photoresist opening is between 0 · 2 to 0.4 mm. 10. A method for forming a silicon nitride oxide dielectric anti-reflective coating layer for fabricating a contact window, comprising the following steps: (a) forming a dielectric layer overlying a semiconductor structure; (b) forming a dielectric layer on the semiconductor structure; The electrical layer is subjected to a chemical mechanical polishing process, wherein the 4 chemical mechanical polishing process causes micro-scratches in the dielectric layer; eight. (C) forming a dielectric anti-reflection (DARC) layer of silicon oxide gas on the two electrical layers, thereby filling the silicon oxynitride DARC layer with step (b) after chemical polishing The micro-scratch generated in the dielectric layer, the silicon oxynitride RC layer is formed using an electro-enhanced chemical vapor deposition (pEcvD) procedure; (d) forming a photoresist layer overlying the DARC layer; 1. (e) Perform exposure and development procedures on the photoresist layer to make a "photoresist opening". The photoresist layer uses an I-line Duv light source (I-line Duv) with a wavelength of 245 to 264 nm. light) for exposure; (g) removing the photoresist layer; (h) forming a conductive layer covering the silicon oxynitride DARC layer and filling (f) sequentially etching the through the first photoresist opening A silicon oxynitride DARC layer and the dielectric layer to form a first opening; Page 15 495911 6. The first opening in the scope of patent application; and (i) performing a chemical mechanical polishing (CMP) treatment on the conductive layer to remove the conductive layer above the silicon oxynitride DARC layer and leave it A portion filled in the first opening forms an interconnecting wire, wherein the silicon oxynitride DARC layer is used as a termination layer of the CMP process, whereby the silicon oxynitride DARC layer can be used to avoid microscopic formation in the dielectric layer. Scratches. 11 · A method for forming a contact window by forming a dielectric anti-reflective coating layer of oxynitride as described in item 10 of the scope of patent application, wherein the thickness of the silicon oxynitride DARC layer is between 300 and 300 1 40 0 A, the refractive index at a wavelength of 248 nm is between 2 and 2 · 3, the extinction coefficient is between 0.6 and 0 · 7, and the Mohr concentration is 45% Si, 38% 0, 7% N, 10% Η. 1 2. A method for forming a contact window by forming a dielectric anti-reflective coating layer of oxynitride as described in Item 10 of the scope of patent application, wherein the size of the first photoresist opening is between 0.2 and 〇4mm. 1 3. A method for forming a contact window by forming a dielectric anti-reflective coating layer of oxynitride as described in item 10 of the scope of patent application, wherein the opening is a double inlay opening and the interconnecting wire It is a double inlay stub-type interconnecting wire. lj. A method for forming a contact window by forming a silicon oxynitride dielectric anti-reflective coating layer as described in item 10 of the scope of patent application, wherein the dielectric layer is an interlevel dieiectric or An intermetallic dielectric layer (inter metal dielectgric), which is used 03-TEOS process to form oxides or low dielectric constant (10w-made of materials. Rock material 15 · A kind of silicon oxynitride formation as described in item 10 of the scope of patent application Page 16 495911 VI. Application for a patent range Electrostatic anti-reflection coating layer for making an opening to expose the substrate; a method in which the -th-forming an oxide stone dielectric coating or / on the substrate Of wires. The method includes the following steps: a negative coating layer is used to make a contact window (a) forming a dielectric layer and covering half (b) applying a chemical treatment to the dielectric layer; chemical mechanical polishing The mechanical polishing process' which causes the gadolinium to form a monolithic oxide layer overlying the dielectric layer and produces a Λ scratch '. Plasma is used to enhance chemical vapor deposition (' :: Shixi layered oxide layer is filled up) A micro-scratch in the dielectric layer); ... the former, and the (d) forms a photoresist layer overlying the silicon oxide layer. (0) exposes the photoresist layer and displays two photoresist openings You Caisong ~ Yun Xu, to make a (f) dielectric layer through the first photoresist opening to form a first opening. X 彳 the oxide layer and the (g) remove the A photoresist layer; (h) forming a conductive layer covering the oxygen opening; and an emulsified stone layer and filling the first (0) the conductive layer chemically: the conductive layer above the silicon oxide layer: = ρ) treatment to remove :: partially forming interconnecting wires, wherein the silicon oxide; = the termination layer of the-opening treatment, whereby the oxidation is performed as CMP produces micro-scratch. To avoid the dielectric layer 17. As described in the patent application No. 16-a kind of formation of oxidized stone dielectric dielectric p. 17 495911 6. Application of patent-quality coating layer and A method for making a contact window, wherein the dielectric layer is an interlevel dielectric or an inter metal diegric, which is an oxide or Made of a low dielectric constant (10w-k) dielectric material. 1 8 · A kind of silicon oxide dielectric coating layer for forming contact windows as described in the patent application No. 16 顼. Method, wherein the thickness of the silicon oxide layer is between 500 and 2000 A. Page 18