TW518643B - High density plasma chemical vapor deposition chamber and method of forming chamber season film - Google Patents

Abstract

This invention discloses a high density plasma chemical vapor deposition chamber and a method of forming chamber season film, which is suitable for producing intermetal dielectric layer using fluorosilicate glass as the dielectric material. The chamber has an inner wall and a silicon oxynitride season film covering the inner wall of the chamber. The formation of the season film comprises: using cleaning gas to clean the chamber, and then forming the silicon oxynitride season film on the surface of the chamber inner wall. The silicon oxynitride season film is a season film with hardness and toughness. Therefore, contamination of particles peeling off from the chamber can be effectively reduced when performing fluorosilicate glass deposition process.

Description

518643, invention description (1) The present invention relates to the field of semiconductor manufacturing, and particularly refers to the manufacture of an inter metal dieiectric layer with fluorosilicate glass (hereinafter referred to as FSG) as a dielectric material. 'Hereinafter referred to as the IMD layer), a protective film (season film) is formed on the inner wall surface of a chemical vapor deposition (hereinafter referred to as CVD) chemical vapor deposition (CVD) chamber of a high density plasma (HDP) Method. In today's deep sub-micron processes, the integration of integrated circuits is getting more and more south ', making the area of the substrate for the transistor need to be continuously reduced to increase the density. Therefore, the current semiconductor process widely uses three-dimensional architecture, such as multilayer metal The interconnect is used to connect the components. The dielectric material used to isolate the metal layers is called IMD. Now, a material with a low dielectric constant, such as FSG, is used as the IMD layer between the two metal layers. The coupling capacitance between the metal layers is reduced to reduce the RC delay time and increase the transmission speed. Generally, HDP-CVD is used to deposit the FMD IMD layer on the wafer. Before FSG deposition is performed on each wafer, the HDP-CVD reaction chamber is first purged with a cleaning gas to remove the reaction residues attached to the reaction chamber to reduce particle contamination during the process.

contamination), and then a deposition process is used to form an undoped silicon glass (USG) silicon dioxide (Si 02) protective film (season film) on the wall surface of the reaction chamber. As shown in FIG. 1, the reaction chamber The wall 10 and the USG protective film 12 covering the wall surface of the reaction chamber. After the wafer 30 is placed in the electrostatic chuck 50 in the reaction chamber,

518643 V. Description of the invention (2) The bombardment of ion ’A r +) heats the reaction chamber to 425 ° C to facilitate the subsequent HDP-CVD. Therefore, the protective film 12 is mainly to prevent the ion wall from damaging the reaction chamber. After the reaction chamber is heated to 425 ° C, the HDP-CVD deposition process can be performed to form an FMD IMD layer on the wafer 30. After the deposition of the IMD layer of a wafer is completed, the wafer 30 is taken out, and then the reaction is cleaned to remove the protective film covering the inner surface of the reaction chamber, and then the above steps are repeated to form another wafer. FSG imd layer. This traditional process and the USG protective film have the following disadvantages: 1. Since the time for cleaning the reaction chamber occupies about half of the entire FSG deposition process, the above-mentioned cleaning of the reaction chamber can only perform the FSG deposition process once, and its capacity Can't improve. 2. Although the USG protective film 12 can prevent ion bombardment from heating the reaction chamber: damage to the inner wall of the reaction chamber, the USG protective film 12 under the ion bombardment will cause some of the protective film to peel off, and the peeled particles will fall on the wafer 3 〇 will cause subsequent formation of IMD layer leaving a cavity, this cavity is a fatal defect in the process, which will greatly reduce the yield of wafer manufacturing. In view of this, the object of the present invention is to provide a method for forming a protective layer for an HDp_CVD reaction chamber. Through the protective layer proposed by the present invention, the productivity of the FSG deposition process can be effectively improved. Another object of the present invention is to provide a HDP ^ CVD reaction chamber with silicon oxynitride (Si ON) protection. The FSG deposition process in the reaction chamber can reduce the pollution of exfoliated particles and improve the yield of wafer manufacturing. To achieve the above-mentioned object, the present invention provides a HDP-CVD reaction chamber and a method of forming and inverting a protective layer, which is suitable for manufacturing fsg as a dielectric material.

518643

The group reacts to have a reaction chamber inner wall and a Si ON protective layer covering the inner wall surface. The formation of the companion μ 牛 _, J response to humans, and area μ] · ~ The step characteristic of the wind β thin layer is first cleaned with a cleaning gas such as SOCrCe, for example, with trifluoride lice (NFS) The reaction chamber is followed by the formation of a Si ON protective layer on the surface of the reaction chamber. The s 1 ON protective layer is a relatively tough protective film, which can effectively reduce the pollution caused by the peeling particles in the reaction chamber during the FSG deposition process. In addition, because the Si ON protective layer is not easy to peel off, the present invention proposes Protective layer for HDP-CVD reaction chamber, can pass through 3 times

After the FSG deposition process, the reaction chamber needs to be cleaned without causing pollution, that is, between two reaction chamber cleanings, a continuous FSG deposition process of 3 wafers can be performed, which will greatly increase production capacity. . Brief description of the drawings: In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below and described in detail with the accompanying drawings as follows: Figure 1 is a traditional HDP -Cross section view of the CVD reaction chamber and a partially enlarged view of the reaction chamber wall; Figure 2 is a schematic cross section view of the HDP-CVD reaction chamber and a partially enlarged reaction chamber wall according to an embodiment of the present invention. Icon description: 12 ~ USG protective film; 22 ~ first USG layer; 26 to second USG layer; 30 to wafer; 10 to reaction chamber wall; 20 to reaction chamber wall; 24 to FSG layer; 28 to SiON protective layer;

518643 V. Description of the invention (4) 50 ~~ electrostatic chuck. According to a preferred embodiment of the HDP-CVD reaction chamber and the method for forming a protective layer of the reaction chamber according to the present invention, it is suitable for manufacturing an IMD layer using FSG as a dielectric material. The reaction chamber has a reaction chamber wall and a reaction chamber. Si ON protective layer covered by the wall surface. The method for forming the Si 0N protective layer is to provide an HDP-CVD reaction chamber for manufacturing an IMI layer with FSG as a dielectric material. The reaction chamber is cleaned with a cleaning gas containing a fluorine source, such as NF3, and the adhesion The reaction residues in the reaction chamber are removed, and the protective layer covering the wall surface of the reaction chamber was removed to reduce particulate pollution during the process. Next, a thin film deposition method is used to form a Si ON protective layer on the surface of the reaction chamber. Since the atomic bonding energy between Si-N is greater than the atomic bonding energy between Si_〇, the Si ON protective layer will It is tougher than the Si 02 protective layer formed by USG. When the temperature of the reaction chamber is heated to 45 ° by ion bombardment, the S1 ON protection layer can protect the reaction chamber from direct ion impact and extend the life of the reaction chamber. Because the SiON protective layer is tougher than the traditional Si02 protective layer, it can withstand ion bombardment and is not easy to cause spalling, which can effectively reduce the pollution of exfoliated particles. In addition, in order to be able to clean the FSG deposition process of the incoming wafers in the two reaction chambers to increase productivity, it is best to first cover an FSG layer on the wall of the reaction chamber to allow For three consecutive FSG deposition processes, the initial FSG gas partial pressure is approximately the same, and there is no inconsistency between degrees and degrees. However, because the FSG layer is covered on the inner wall of the FS "= 3 dense chamber, it will be easily peeled off by ion bombardment in the ionization and reaction valleys.

518643 5. Description of the invention (5) Causes serious particulate pollution problems, so the better way is to form the FSG layer between the f reaction chamber wall and the SiON protective layer. However, the characteristics of fSG are not easy to adhere to the surface of the reaction chamber. It is best to cover the reaction chamber with a layer of US SiO2 that has good adhesion to the surface of the reaction chamber and the FSG layer. On the other hand, because the chemical bond ratio between fSG and SiON is so different, it is best to form another "USG Si02 layer" between the FSG layer and the SiON layer. In other words, referring to Figure 2, After cleaning the reaction chamber, 'first deposit a thickness of about 350,000 a to 4,500 A on the inner wall surface of the reaction chamber wall 20', generally, the first USG layer 22, preferably 4000 A, and then over the first USG layer 22 Deposition thickness is about 50〇a ~ 100 0 A, generally 700 A is the preferred FSG layer 24, and then deposited on the FSG layer 24 to form a thickness of about 40 0 0 A ~ 50 0 0 A, generally 4500 A is the preferred second USG layer 26, and finally a thickness of about 500 A to 100 A is deposited on the second USG layer 26. Generally, 640 A is the preferred SiON protective layer 28. After the Si ON protective layer 28 is shown in FIG. 2, the wafer 30 is placed in an electrostatic chuck 50 in the reaction chamber, and then reversed by Ar + bombardment. The reaction chamber is heated to 425 ° C to facilitate the subsequent HDP-CVD. At this time, the "protective layer 28" can protect the reaction chamber wall 20 from direct ion impact, and the month b can reduce the pollution of exfoliated particles. After the reaction chamber is heated to 4 2 5 ° c, the HDP-CVD deposition process can be performed to form a 10 layer of FSG on the wafer 30. After the deposition of the IMD layer on one wafer is completed, the wafer 30 is taken out, and the above steps of placing the wafer, heating the reaction chamber, and depositing and forming the MD layer are repeated, so that the IMD layers of the other two wafers are completed. . After three HDP-CVD FSG deposition processes, the reaction chamber must be cleaned again to completely

518643

f In addition to the various films covering the inner surface of the reaction chamber and the reaction residues attached to the inside of the reaction chamber, it is formed as shown in Fig. 2 and includes a protective layer of SiO. The steps of heating the reaction chamber and depositing the I MD layer are performed. To sum up, according to the HDP-CVD reaction chamber and the method for forming a reaction-to-protection layer according to the present invention, the tough Si ON protection layer can effectively reduce the pollution caused by the peeling particles in the reaction chamber. Analysis and measurement formulas such as the Wafer Acceptance Test (WAT) can verify that the protective layer of the reaction chamber formed according to the present invention can indeed improve the yield of the wafer compared to the traditional method, and because丨 〇N protective layer is not easy to peel off, after three FSG deposition processes, it is necessary to react to the first three evaluations without opening > pollution, in other words, between the two reaction chamber cleaning The FSG deposition process for 3 wafers in a row will greatly increase production capacity. Although the present invention has been disclosed as above with a specific embodiment, it is only for the purpose of clarifying the technical content of the present invention, rather than limiting the present invention to the embodiment in a narrow sense. Any person skilled in the art will not depart from the spirit and scope of the present invention. As some changes and retouching can be made, the protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims (1)

518643 6. Scope of patent application I. Method for forming high-density plasma plasma wind *, the steps include ... providing a high-density plasma chemical finish for the protective layer of the reaction chamber deposition phase 4 fluorite glass as the dielectric Material-Inner Gold: Intermediate chamber 'is used to manufacture to clean the reaction chamber with a cleaning gas; a silicon oxynitride protective layer is formed on the inner wall surface.凊 The method for forming a protective layer of a high-density plasma chemical vapor deposition reaction chamber described in item 1 of the patent scope, further comprising the following steps to form an IH glass layer on the surface of the inner wall and the above-mentioned silicon oxynitride protective layer ' Its thickness is generally 00A-4500 A; =: a 3 mouse silica glass layer is formed between the undoped stone oxide glass layer and the above-mentioned oxynitride protective layer, and its thickness is generally 50A to 100%. 〇A · and 'A second undoped silica glass layer is formed between the fluorine-containing silica glass layer and the above-mentioned silicon oxynitride protective layer, and the thickness thereof is generally 4,000a to 50000A. 3. The method for forming a protective layer of a high-density plasma chemical vapor deposition reaction chamber as described in item 1 of the scope of the patent application, wherein the thickness of the above-mentioned nitrogen oxide is generally 500 A to 1 000 A. Xibao Λ layer < 4 · The method for forming a high-density plasma chemical gas (phase protective reaction layer protection layer) as described in item 2 of the scope of the patent application, wherein the thickness of the aforementioned silicon oxynitride accompanied trout is preferably 640A. No. 5 of the Yubao floor. · Form high-density plasma chemical gas 0503-6452TWF; TSMC2001-0144; mflin.ptd page 11 518643 as described in item 2 of the scope of patent application. Method, in which the thickness of the upper layer is generally better than 4000 A., L undoped Shixi glass 6. The method for forming a protective layer of the ancient ~ -phase deposition reaction chamber as described in the second item of the patent application scope, wherein The polymer chemical gasity is generally better than 700 A. The thickness of the gas-containing silica glass layer 7. The method for forming a protective layer for a high-phase deposition reaction chamber as described in item 2 of the patent application scope, wherein the thickness of the upper / layer is substantially 4500 A is preferred. The second is no replacement of broken glass. 8 · The method for forming a protective layer of a high-density plasma chemical gas reaction chamber as described in item 丨 of the application scope, wherein the cleaning gas is tri-gas nitrogen ( NF3). 9. One kind The method of less contamination caused by particles peeled off from the protective layer of the reaction chamber is suitable for manufacturing a metal dielectric layer using fluorine-containing silicon glass as a dielectric material by a high-density plasma chemical vapor deposition method. The steps include: A cleaning gas is used to clean the reaction chamber; a first non-doped silica glass layer is formed on the inner surface of the reaction chamber; a first stone-doped glass layer is formed on the first non-doped stone-xi glass layer; A brother—an undoped stone glass sound is formed on the fluorine-containing stone glass layer; and θ ′ forms a oxynitride protective layer on the first undoped stone glass layer. The method for reducing contamination caused by peeling particles of the protective layer of the reaction chamber according to item 9, wherein the thickness of the first undoped silica glass layer ′ is generally 3500A to 4500A, and the thickness of the above fluorite-containing glass layer is Roughly 500A ~ 1000A, the second undoped stone 518643 The scope of six patent applications _________ The thickness of the glass layer is generally 4,000 A to 50000A, and the thickness of the silicon protective layer is generally 500A to 10 ()) and the nitrogen Oxidation 11. The method of reducing the pollution caused by exfoliated particles as described in item 10 of the scope of the patent application, wherein the thickness of the upper layer to the length of the protective layer is preferably about 6 40 A. 12. The method for reducing the oxynitride layer as described in item 10 of the scope of patent application, reducing the pollution caused by exfoliated particles, wherein the thickness of the above-mentioned protective layer to the protective layer is generally about 4000 A. …, Polysilica glass 13. Please request the method for reducing pollution caused by the protective layer of the reaction chamber and particles in the scope of the patent, in which the above-mentioned fluorine-containing silica glass is preferably about 70 Α.知 知 # 14 · The method for reducing pollution caused by peeling off particles of the protective layer of the reaction chamber as described in the scope of the patent application, wherein the thickness of the above-mentioned second undoped silica glass layer is roughly 4500A. . 15 · The method for reducing pollution caused by peeling particles of the protective layer of the reaction chamber as described in item 9 of the scope of the patent application, wherein the cleaning gas is nitrogen trifluoride (NF3) 〇16 ·-a high-density plasma chemical gas A phase deposition reaction chamber is suitable for manufacturing an inner metal dielectric layer using fluorine-containing silica glass as a dielectric material. The reaction chamber includes: a reaction chamber wall; and a silicon oxynitride protective layer covering the surface of the reaction chamber wall. To reduce the pollution caused by the exfoliated particles in the reaction chamber, the thickness of the silicon oxynitride protective layer is generally 500 A to 1 000 A. 518643 1 7 · The high-density plasma chemical vapor deposition reaction chamber as described in item 16 of the scope of the patent application, further comprising a first non-doped stone glass layer formed on the inner wall surface of the reaction chamber. The thickness is generally 3500A ~ 4500A; a fluorine-containing silicon glass layer is formed on the first undoped silica glass layer, and the thickness is generally 500A ~ 1000A; and a second undoped A silica glass layer is formed between the fluorine-containing silica glass layer and the above-mentioned silicon oxynitride protective layer, and its thickness is generally 4000A to 5000 A 〇1 8 · High-density electricity as described in item 16 of the scope of patent application In the slurry chemical vapor deposition reaction chamber, the thickness of the aforementioned silicon oxynitride protective layer is preferably about 640 A. 19 · The high-density plasma chemical vapor deposition reaction chamber according to item 16 of the scope of the patent application, wherein the thickness of the first undoped silica glass layer is generally about 4 000 A. 20 · The high-density plasma chemical vapor deposition reaction chamber described in item 16 of the scope of the patent application, wherein the thickness of the fluorine-containing silica glass layer is generally about 70 0 A. 21 · The high-density plasma chemical vapor deposition reaction chamber described in item 6 of the patent application range, wherein the thickness of the second non-building heterogeneous silica glass layer is generally about 4500 A. 0503-6452TWF; TSMC2001-0144; mf1 in.ptd p. 14