TW525223B - Method for removing photoresist and residual polymer from polysilicon gate - Google Patents

Abstract

A dry-wet-dry three step process for cleaning a polysilicon gate is used to remove a photoresist layer and a residual polymer from the gate, and comprises: using a high temperature dry process (plasma ash removal) to remove most of the photoresist and polymer, in which the plasma used can be fluorine-containing oxygen and nitrogen/hydrogen; using a wet ash removal process to dissolve the polymer located at the blind corner left by the plasma bombardment and soften the hardened photoresist; using oxygen and nitrogen/hydrogen plasma to remove the pollutants remained in the high temperature, thereby completely cleaning off the photoresist and the residual polymer without damaging the gate structure.

Description

525223 V. Description of the invention (1) 5 -1 Field of invention: The present invention relates to a method for manufacturing integrated circuit (IC) components, and more particularly to a method for manufacturing polycrystalline silicon silicide gates. Furthermore, it relates to a method for removing photoresist and residual polymer by using a dry-wet-dry three-stage cleaning step after gate fabrication and after an etching process. 5-2 Background of the Invention: In the filmmaking technology, which is a circuit for the transfer of photoresist. And in this layer and others to ensure that the wafer is produced in a good manner and wet cleaning solution. At present, it is added, and it is moved to the coating for the surface layer. After a well-like connection, the pollutants have the application of road components and dyes. The nozzles are used to oxidize and oxidize the integrated circuit. The photosensitive material on the map is formed on the active areas of the wafer through a photomask. Active area fixation is the cleanliness of the surface of the residual solution. Both rate and efficiency are good for removing photoresistive methods. Among them, wet dissociated impurities, or most often in the I C. process like hydrogen peroxide (the design of the h2 circuit is wiped on the surface of the wafer or plasma etched these transferred graphic windows or interconnects must also be Clean the wafer thoroughly. The method is roughly divided into the method of dipping the cleaning solution of IC components. The cleaning solution is mixed with sulfuric acid and sulfuric acid. It is a kind of micro-resistance. Two types of cleaning are possible: dry washing with appropriate washing acid solution, liquid, etc., but 525223 V. Description of the invention (2) The point is that the photoresist etching rate is too low. And the wet method has its advantages in cleaning The obstacle comes from the surface tension of the liquid itself. The surface tension of the liquid here limits the depth to which the cleaning liquid penetrates into the object to be cleaned. Therefore, for a comparable object, the wet method can't clean its surface. The introduction of complete η :; can just make up for it. The dry method basically uses the gaseous program generated by in: and the light effect reaction and its power transmission wood to enter the reaction. It is generally used for teaching of surface decontamination. (Commonly known as plasma Ash plasma ashing) ::::: etcM〇g milk, the RI;) in the system: Ϊ ΐ 5 drive size larger, much more expensive than the wet etching. In the case of silicified metal gates, + Dangan people are used as etching plutonium, due to the polymerization. And there is sea bass :: Using some heavy polymers can make the slope of the side wall in the silver engraving ^ ^^ Extremely selective and poor control that needs to be removed during extreme cleaning. Therefore, the gate compound and the barrier layer are also important in the removal of the gate compound. The residual poly ash after etching can not be used to detect this residue. Traditional dry and wet removal, that is, to improve the cleanliness of the dry type, including chemical Program tests (such as the effect of polymer film in the evaluation range of gas # 2 li) and found that pure oxygen ash removal has a pause in removal. Lt: The ash removal process can be performed slowly or even, which can significantly improve the cleaning; 2: If gaseous materials are added in the plasma ash removal program,… force attack, but after cleaning, it will be 525223. 5. Description of the invention (3) The gate oxide layer will make the oxide layer thinner. It is a polycrystalline stone gate. This fluorine-containing plasma will also etch away titanium-containing layers such as titanium silicide and silicon nitride from the side wall, causing damage to the gate structure. In addition, it was found that The ash program has better cleaning effect, but it is not as good as the high temperature program in terms of ash removal rate and cleaning ability. Based on the above evaluation, the present invention is directed to polycrystalline silicon silicide gates, especially titanium-containing gates. Propose a cleaning method, this side It can effectively remove the photoresist layer and the residual polymer together without undue damage to the gate structure. Then, it provides a clean wafer surface and the next process step, so as not to cause the component to be gradually damaged, so as to improve the component. The credibility of manufacturing. '5-3 Purpose and summary of the invention: The present invention proposes a dry-thirsty-dry two-stage cleaning method for polycrystalline stone metallized metal gates. Program, this program can remove # 卩 日 疏 i / ”,, 一一 一 卞, 丨, & remove the nine resistance layer and the residual solvent (bingong,, and agent) from the gate. 田 办 刎 、 同Knife / in one example γ 'day by day, the metal leisure pole Shang Tao Guzhong ri day and the gate is formed by heavy polymer etching. Erosion / complexity first resistance removal. First, use a high resistance layer and make resistance And polymer removal, this high temperature is about] Second: A) method will most of the photo-oxygen and nitrogen / hydrogen, and these two kinds of electricity = available plasma contains fluoride, this dry process continues 7 = Such as ^ carbon, etc. Κ ίshirt Fengli. Second, use wet

525223 V. Description of the invention (4) The method of ash removal will be located in the electropolymerization, cover, and clearing, by the way, the hardened photoresist; Polymerization residue Finally, the remaining steps are cleaned in a dry process. It is carried out at 250 ° C. The plasma used is to remove the rabbit wood. This step is also completed in the cleaning procedure. , ~ Lice and nitrogen / hydrogen. In the cleaning procedure of this step, the gate electrode does not damage the body structure. The addition of plasma, and the limitation of the cleaning effect can prevent the cleaning body from using the dry-wet-dry three photoresist layer and residual polymer, Can be cleared completely under Exhaust =. In particular, it is improved with fluorine, and the ash removal time and the deformation of the reaction chamber during the procedure. 5-4 Schematic description of the invention ... The contents of the disclosure disclosed in the present invention can be explained through the following examples and related diagrams. The first diagram shows the relevant positions of the gate layers and photoresist layers on a polycrystalline titanium silicide gate. This gate will be used as the cleaning body in the embodiment of the present invention; the second and third figures show the gate structure after etching, the photoresist layer on it has been partially removed, and the entire structure is now covered with a layer of residual polymer: The second figure is a flowchart of the cleaning procedure proposed by the present invention.

525223

1 〇 Base layer 2 〇Gate oxide layer 3 〇Polycrystalline silicon layer 4 0 Barrier layer 50 seconds metallization layer 60 Dielectric straight layer 7 0 Photoresist layer 8 〇Residual polymer layer 3 0 1First cleaning step 3 0 2 The second cleaning step 3 0 3 The third cleaning step 5-5 Detailed description of the invention: What is disclosed in the present invention is a method for manufacturing a c element and a metal gate. However, in the following embodiments, the description will be made as to polycrystalline silicon to specifically disclose the present invention. Familiarize yourself with this: detailed manufacturing process. Equivalent changes in internal details cannot be described here. This * test§ can be understood, that is, not repeated here to avoid lengthy. A known procedure is to describe the dry-wet-dry cleaning process of the present invention and the power-lifting process by using the manufacture of polycrystalline silicon silicide gates. A preferred embodiment is described first with reference to the first figure. This embodiment ^ a ^ ^ Gates, formed on a high-conductor assembly, a bulk, polycrystalline silicified metal bean soil & 0, are formed through various deposition procedures. This gate

525223 5. Description of the invention (6) ^ ~-It is preferable to include a gate oxide layer 20, a polycrystalline silicon layer 30, a barrier, a silicide metal layer 50, and a dielectric layer 60. Each layer of the gate sinks to the second gate ^ ^ ^ ^ ㈣ Technology 'The mask transfers a layer of light _ ° θ If the gate here is called a titanium silicide gate, its barrier layer 40 is mostly composed of titanium nitride (TiN), The silicided metal layer 50 usually contains titanium silicide (nsi). * In ΐ = ϊ2, use the photoresistor 7 ° to define the gate structure and perform the rest. Engraving 1. There are poles for the polycrystalline silicon silicided metal gate layer, so ^: 丨 II: The slope of the etched side wall can be well controlled, so the use of etchant is often heavy polymer. In addition, an insecticide is dissolved away, but the remaining photoresist layer 70 is fetched by J ,, and D beams, and the gate structure formed by the etchant is formed, as shown in the second figure. As shown. ... to remove the remaining photoresist layer 70 and height 4, ^ m ^ out of the dry-wet-dry cleaning procedure, straight flow description: two: the far layer 80, the cleaning steps known in the present invention (see box 301) Yes; of which-the first photoresist and polymer 8. This step two :; two "methods to remove most of the first" and the electric energy used contains oxygen and ions "temperature is about 25. May contain traces of fluoride, lice oxygen, these plasmas also damage the interpolar layer, in addition to 歹 四 four gasification carbon (⑹. And in order to avoid the bell. Because of the fluorine-containing electricity will be ^ 2 and added Limitation, it is best to control the metal and oxide support in about 7 seconds; it is not bad to have high efficiency, but also to such a high temperature, its reaction characteristics: 'What's more, this program is focused on not controlling, so it is obvious. Therefore, If the ash removal time is further on the side of the electrode: A ^ ^ After the pollutants are quickly removed, they will react from the gate / the structure layer of the body, such as the gate 525223 5. Invention description (7) Oxidation layer 2. The gate structure of the titanium nitride chip results in 'f: the second layer 2 becomes the object of its erosion. The program also has the function of damage reaction rate and cleanliness. Because the deformation of ^ ^ = can indirectly affect the ash removal speed deformation. The shorter the ash removal day is, the more difficult the reaction room is: (see square / _302) Shooting dead angle using wet plasma at non-high temperature: hydration. There are some areas on the round surface on the wall. Many, blue and dead corners are located near the side / month surrounding the reaction chamber. Residual polymer, according to the present invention, 佶 H, is a bucket, and the wet ash removal here does not use ancient ㈤, and θ ,, uses a wet method. 22 to 25 t, the next # 彳-^ 回, dish And 疋 at a temperature close to room temperature, to avoid the epipolar oxidation; the purpose is to control the stability of the wet etching etch rate, wet process Ϊ; 'f. In addition, although the photoresist does not dissolve in this cleaning process and hardens The photoresist is soaked in order to facilitate the removal of the lower part: the subsequent μ (step (see box 3 0 3) again uses the high-temperature dry method to increase production. This step removes all the photoresist and polymer. Its ash removal : i 襞 ίϊ ° Λ'Λ Its plasma package / with oxygen and nitrogen / chlorine. Here, 'Do not mess, so there is no invasion of the gate layer There are concerns. Moreover, the remaining pollutants have been soaked and softened by the wet process, so this process can easily remove the trace residues completely. Using the three steps of dry-wet-dry proposed by the present invention During the cleaning process, the photoresist layer and residual polymer on the gate electrode can be completely removed without damaging the structure of the body. Especially with the addition of a fluorine-containing plasma, the cleaning effect

Page 10 525223 5. Description of the invention (8) is improved, and the limitation of the ash removal time in the program can prevent the deformation of the cleaning body and the reaction chamber. The above are merely preferred embodiments of the present invention, and are not intended to limit the scope of patent application for the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the following Within the scope of patent application.

Claims (1)

525223 6. Scope of patent application 1. A method for removing photoresist layer and residual polymer from a semiconductor device, at least comprising: cleaning the device by a first dry method, thereby removing most of the photoresist layer and the polymer, The first dry method uses a plasma to remove ash. The plasma contains fluorine-containing oxygen and fluorine-containing nitrogen / hydrogen. The component is wet-deashed to remove most of the remaining polymer and impregnate the remaining one. Photoresist; and cleaning the element by a second dry method to remove all remaining photoresist layers and the polymer, the second dry method uses a plasma to remove ash, the plasma containing oxygen and nitrogen / hydrogen. 2. The method according to item 1 of the patent application range, wherein the semiconductor element includes a polycrystalline silicon metal gate. 3. For the method of claim 1 in the scope of patent application, wherein the first dry ash removal is performed at about 250 ° C. 4. The method according to item 1 of the patent application range, wherein the above-mentioned wet ash removal is performed at about 22 to 25 ° C. 5. The method according to item 1 of the scope of patent application, wherein the above-mentioned second dry ash removal is performed at 250 ° C. 6 · The method according to item 1 of the patent application scope, wherein the first dry method Page 12 525223 6. The scope of patent application The fluorine-containing gas contains carbon tetrafluoride (cf4). 7. The method according to item 1 of the patent application scope, wherein the first dry method is performed for about 7 seconds. 8. The method according to item 2 of the patent application, wherein the polycrystalline silicon silicide gate further comprises at least one layer of titanium compound. 9. A method for removing a photoresist layer and residual polymer from a polysilicon metal gate, at least comprising: cleaning the gate by a first dry method at a first temperature, thereby removing most of the photoresist layer and The polymer, the first dry method uses a plasma to remove ash, and the plasma contains fluorine-containing oxygen and fluorine-containing nitrogen / hydrogen; at a second temperature lower than the first temperature, the wet ash is removed. A gate to clear most of the remaining polymer and soak the remaining photoresist; and clean the gate by a second dry method at a temperature close to the first temperature to remove all the remaining light The barrier layer and the polymer, the second dry method uses a plasma to remove ash, the plasma contains oxygen and nitrogen / hydrogen. 10. The method according to item 9 of the scope of patent application, wherein the polycrystalline silicon silicide gate includes at least one layer of cyanide. 11 · The method according to item 9 of the scope of patent application, wherein the first dry method Page 13 525223 6. The scope of patent application The fluorine-containing gas contains carbon tetrafluoride (cf4). 1 2. The method according to item 9 of the scope of patent application, wherein the first dry method is performed for about 7 seconds. 1 3. The method according to item 9 of the scope of patent application, wherein the first temperature is about 2 5 (ΓC. 1 4. The method according to item 9 of the patent application range, wherein the second temperature is about 22 to 25 ° C. 15. The method according to item 10 of the patent application range, wherein the titanium compound layer includes titanium nitride and titanium oxide. Page 14