TW546709B - Method to reduce the reflectivity of polysilicon layer - Google Patents

Abstract

The present invention provides a method to reduce the reflectivity of polysilicon layer, which comprises: firstly providing a semiconductor substrate; then, disposing the semiconductor substrate in the reactor of a single-wafer type chemical vapor deposition; then, introducing silicon-containing gas into the reacting chamber of the single-wafer type chemical vapor deposition, so as to form a polysilicon layer on the surface of the semiconductor substrate; next, introducing hydrogen gas into the reacting chamber of the single-wafer type chemical vapor deposition, so as to adjust the grain size on the upper surface of the polysilicon layer; further introducing oxygen and ammonia gas sequentially into the reacting chamber of the single-wafer type chemical vapor deposition, so as to form silicon oxide film and silicon nitride film on the polysilicon layer, thereby reducing the reflectivity of polysilicon layer.

Description

546709 V. Description of the invention (l). --- In the field of the invention, the present invention relates to a process technology of semiconductor device deviee ', and particularly to a reaction chamber utilizing a single wafer type chemical vapor deposition (Single — wafer «chemicai vap0r deposition chamber), that is, a method of reducing the reflectivity of the polycrystalline SiO2 layer in a situ process. Description of the Related Art In the manufacturing process steps of a semiconductor device, light is supplied by a light source of a photolithography system, passes through a photo-mask, and then the pattern on the photomask is transferred to the lower photoresist layer. . However, when the material under the photoresist layer is a high reflectivity material, such as a metal layer or a polycrystalline silicon layer, when light irradiates the above high reflectivity material, it is easy to cause improper reflection. While the resolution of the pattern is greatly destroyed, the reflection of light to affect the resolution of the pattern involves several mechanisms. In order to reduce the reflection of light and solve the above-mentioned problem, the industry proposes a method of providing an anti-ref lection layer (AL) between the multi-crystal broken layer and the photoresist layer, that is, before coating the photoresist On the surface of the highly reflective material such as the polycrystalline silicon layer, a chemical vapor deposition method or a spin coating method is first used to form a commonly-known bottom anti-reflection coating (bottom anti-reflection coating; BARC), an example is given below to illustrate the related conventional technology. Please refer to FIG. 1, which shows a low reflection formed by a conventional technique.

0702-7678TWF (N) * 91P03; Jessica.ptd Page 4 546709 V. Description of the invention (2) Flow chart of the surface of the polycrystalite layer. Fig. 1 shows a flow chart of forming a surface of a polycrystalline silicon layer having a low reflectance according to a conventional technique. The conventional technique can be represented by steps S301 to S305. First, in step S301, it means that the semiconductor substrate is placed in a reaction chamber of a batch-type chemical vapor deposition. In step S302, it is shown that Si is introduced into a batch reaction chamber 'to form a polycrystalline silicon layer over a semiconductor substrate. Next, in step S303, it is indicated that the semiconductor substrate is moved to a plasma enhanced chemical vapor deposition (PECVD) reaction chamber. Then, in step 3304, it is shown that in the reaction chamber of the plasma enhanced chemical vapor deposition, an oxynitride layer is deposited to form an anti-reflection layer on the surface of the polycrystallite layer. Then, step S305 is performed by performing a conventional photolithography process and an etching step to obtain a desired polycrystalline silicon pattern, such as a gate electrode. A chemical vapor deposition reaction chamber can simultaneously form a polycrystalline silicon layer on the surface of a plurality of semiconductor substrates (semiconductor wafers), thereby saving the process time and cost of each semiconductor wafer. However, due to the gradual reduction of the circuit density of advanced technologies in recent years, it has been difficult to withstand the inaccuracy of semiconductor process technology. For example, the polycrystalline silicon layer deposited by the reaction chamber of batch chemical vapor deposition is usually uniformly poor. Furthermore, due to the relatively large volume of the batch chemical vapor deposition reaction chamber, during the deposition of the polycrystalline silicon layer, a large number of particles and residual substances may be generated, which may cause serious problems in subsequent processes. .

0702-7678TWF (N); 91P03; Jessica.ptd 546709

Furthermore, using conventional techniques, the deposition is performed separately in order to form the above-mentioned two-phase sparite two-phase deposition: 2 anti-backlash, which will lead to) milk: Second, there is a need to provide a can reduce. Because of the shortcomings of conventional technology. H < Overview of reflectivity and improvement of the invention and purpose of rounding method 0, another object of the present invention is to provide a method for reducing the reflectance of a polycrystalline silicon layer, which can improve the uniformity of the deposited material . Furthermore, according to the method of the present invention, the single-wafer type chemical gas deposition method can be used to process or cause the polycrystalline silicon layer to react and reduce the reflectance. Therefore, the method according to the present invention can shorten the process time. ^ ^ According to the above object, the present invention provides a method for reducing the reflectance of a polycrystalline spar layer. First, a semiconductor substrate is provided, and then the semiconductor substrate is placed in a single wafer type chemical vapor deposition reactor. Then, a silicon-containing gas (for example, silane (or silane) -SiSi4) is introduced into the reaction chamber of the single-wafer chemical vapor deposition to form a polycrystalline silicon layer on the surface of the semiconductor substrate. Next, hydrogen is introduced into the single-wafer type chemical vapor deposition reaction chamber to adjust the grain size of the upper surface of the polycrystalline silicon layer. Furthermore, oxygen is introduced into the reaction chamber of the single-wafer chemical vapor deposition to form a silicon dioxide film above the polycrystalline second layer, thereby reducing the reflectance of the polycrystalline silicon layer.

0702-7678TWF (N); 91P03; Jessica.ptd Page 6 546709 V. Description of the invention (4) Furthermore, the method of reducing the reflectance of the polycrystalline silicon layer described above can also be introduced after the formation of a monolithic oxide film. Gas is placed in the reaction chamber of the single-wafer chemical vapor deposition to process the surface of the polycrystalline silicon layer to form a silicon nitride film. Furthermore, the method for reducing the reflectivity of the polycrystalline silicon layer further includes introducing nitrous oxide into the reaction chamber of the single-wafer chemical vapor deposition to treat the surface of the polycrystalline silicon layer to form an oxynitride compound. In the method of the thin film, in the above method for reducing the reflectance of the polycrystalline stone layer, the thickness of the polycrystalline stone layer is between 500 Angstroms and 2500 Angstroms. Moreover, the deposition temperature of the polycrystalline silicon layer is preferably between 350 ° C and 680 ° C. The deposition pressure is between 150mtorr and 400mtorr. Furthermore, in order to further reduce the reflectivity of the polycrystalline silicon layer, the method for reducing the reflectivity of the polycrystalline silicon layer may further include the following steps: moving the semiconductor substrate to a plasma-enhanced chemical vapor phase A reaction chamber for deposition; and forming an arsine silicide film on the surface of the silicon dioxide film. According to the above object, the present invention provides another inverse method for reducing a polycrystalline silicon layer. First, a semiconductor substrate is provided. Then, the above semiconductor substrate is placed in a single-wafer type chemical vapor deposition reactor, and then an internal guide: a silicon gas in the above single-wafer chemical vapor deposition reaction chamber: 丄 1 the semiconductor substrate The surface is formed-a polycrystalline silicon layer. Then, cyanide rolling and nitrous oxide are introduced into the above-mentioned single-pass reaction chamber M to form a thin layer of silicon oxynitride on the above-mentioned complex crystal # where the milk phase is deposited and the silicon oxide layer is formed.

546709

5. Description of the invention (5) Membrane. EXAMPLES [First Example] The following is a cross-sectional view of a process for reducing the reflectance of a polycrystalline silicon layer shown in FIGS. 4A to 4D to describe a first embodiment of the present invention. First, please refer to FIG. 4A, and provide a semiconductor substrate 100 (semiconductor wafer) made of a single crystal silicon material, and then place it in a single-wafer type CVD reaction Indoor, 7 columns, if using a single wafer type machine manufactured by Applied Materials (AMAT) company, the trade name is "TPCC" (Thermal Pr ^ eess Common Centura). ○ Next, please refer to Figure 4B Silane is introduced into the reaction chamber of the single-wafer chemical vapor deposition to form a polycrystalline silicon layer 10 2 ′ on the surface of the semiconductor substrate 100 with a thickness of about 500 angstroms to 2500 angstroms. The deposition temperature of the spar evening layer 102 is controlled at about 3500 to 680 ° C, and the deposition pressure is controlled at about 500mtorr to 400mtorr. Then, referring to FIG. 4C, hydrogen (h2) is introduced into the single-wafer chemical vapor deposition reaction chamber to adjust the size of the silicon crystal grains on the upper surface of the polycrystalline silicon layer. After that, oxygen (〇2) is introduced into the reaction chamber of the single-wafer chemical vapor deposition to form a di-titanium oxide thin film 104 on the surface of the polycrystalline silicon layer 〇2, thereby reducing polycrystalline silicon. Reflectivity on the surface of layer 1 〇 2 Secondly, please refer to Figure 4D. In order to further reduce the reflectance on the surface of the polycrystalline stone layer 102, it is best to add nitrogen oxide (NH3) and / or nitrous oxide

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(Chemical) is introduced into the single-wafer chemical vapor deposition reaction chamber, so that a nitrided silicon nitride or silicon oxynitride-containing silicon compound is formed over the polycrystalline silicon layer 10 on which the silicon dioxide film 104 has been formed. Nitrogen thin film 〇〇6. Fig. 2 shows a flow chart of forming a polycrystalline stone layer surface with a low reflectance according to the first embodiment of the present invention. This embodiment can also be represented by steps 3401 ~ 5. First, in step 8401, a semiconductor substrate is placed in a single-wafer chemical vapor deposition reaction chamber. Step S402 refers to introducing S1 & into the reaction chamber to form a polycrystalline silicon layer over the semiconductor substrate. Next, step S403 indicates that hydrogen is introduced into the reaction chamber to adjust the silicon grain size on the surface of the polycrystalline silicon layer. Step S404 indicates that oxygen is introduced into the reaction to form a silicon dioxide film on the surface of the polycrystalline silicon layer. Finally, in step S405, ammonia gas (not nitrogen and / or nitrous oxide (N2O)) is introduced into the reaction chamber to reduce the reflectance of the polycrystalline silicon layer. [Second Embodiment] The following uses the fifth The process cross-sectional views of the process for reducing the reflectance of the polycrystalline silicon layer shown in Figures A to 5D are used to illustrate the second embodiment of the present invention. First, please refer to Figure 5A to provide a single crystal silicon material. Semiconductor substrate 200 (semiconductor wafer), and then place it in a single-wafer type CVD reaction chamber, such as a single crystal manufactured by Applied Materials (AMAT) Round type machine, trade name is “TPCCn (Thermal Process Common Centura).” Next, “Please refer to FIG. 5B”, introduce silane into the above single wafer chemical vapor deposition reaction chamber to Semiconductor substrate

0702-7678TWF (N); 91P03; Jessica.ptd Page 546709 V. Description of the invention (7) 200 A polycrystalline silicon layer having a thickness of about 50q Angstroms to 2500 Angstroms is formed on the surface of the polycrystalline silicon layer 202 The deposition temperature of 2 0 2 was controlled to be approximately 350 ° C to 680 ° C and the deposition pressure was controlled to be 150 mtorr to 400 mtorr. Then, "Please refer to Fig. 5 (: figure, introduce the ammonia gas (〇3) and / or nitrous oxide (\ 0) into the above-mentioned single wafer-type chemical vapor deposition reaction chamber" to the above-mentioned polymorphite The layer 2 02 forms a nitrogen-containing thin film 204 composed of a nitride nitride or an oxynitride compound. The nitrogen-containing thin film 204 can reduce the reflectance of the polycrystalline silicon layer 202, and is similar to the polycrystalline silicon layer. 02 is deposited in the same reaction chamber. Next, the semiconductor substrate 200 is moved to a plasma enhanced chemical vapor deposition (PECVD) reaction chamber. The surface of the nitrogen thin film 204 is formed of an oxy-silicon compound layer 2 06 as an anti-reflection layer to further reduce the reflectance of the polycrystalline silicon layer 2 0. FIG. 3 shows the formation according to the second embodiment of the present invention. The flowchart of the surface of the polycrystalline silicon layer with low reflectivity can also be expressed in steps s501 to S505. First, in step S501, the semiconductor substrate is placed on a single wafer type chemical vapor deposition. Reaction chamber. Step S 5 〇2 It is shown that Si Η * is introduced into the reaction to form a polycrystalline second layer above the semiconductor substrate. Next, step S503 indicates that ammonia gas and / or nitrous oxide are introduced into the reaction chamber to reduce the reflection of the polycrystalline silicon layer. Rate, step S504 means that the semiconductor substrate is moved to a plasma enhanced chemical vapor deposition reaction chamber. Finally, in step s505, a silicon oxynitride layer is deposited on the above-mentioned polycrystalline silicon layer as a precaution Reflective layer.

0702-7678TWF (N); 91P03; Jessica.ptd Page 10 546709 V. Description of the invention (8) Features and effects of the invention According to the present invention, the method of using the reflectivity of a single low polycrystalline silicon layer: The reaction chamber is decreasing. Sentence & 的 Uniformity of sedimentary material, according to the method of the present invention. A one-phase deposition method is used to process or make a polycrystalline stone a wafer-type chemical gas. Therefore, the method according to the present invention generates a reaction and reduces the reflectance. 4 The old one is short enough. Although the present invention has been better, it takes a short time. Limiting the present invention, any study 2 2 j is disclosed as above, but it is not used within the scope of God. When it can be changed ===, without departing from the scope of the present invention, the scope of patent application is attached. The scope of protection of the invention is determined by J Gangu.

M6709 Schematic Description In order to make the present invention obvious and easy to understand, the following special enumeration—Ϊ and other purposes, features, and advantages can be described in more detail as follows: The Nujia embodiment, with the accompanying drawings, is the first The figure shows the flow chart of the 4-layer surface of root practice. Technology to form complex sand crystals with low reflectivity complex sand 2 / VI Flow chart of forming the surface of a silicon layer with low reflectivity according to the first embodiment of the present invention. Machide 3 shows the flow of the Taiyi text. 1 is a flow chart of forming the surface of a crystalline silicon layer having a low reflectance in the second embodiment of the present invention. 4A to 4D are cross-sectional views of a process for reducing the reflectance of the polycrystalline silicon layer according to the first embodiment. FIG. 5A and FIG. 5D are cross-sectional views of a process for reducing the reflectance of the polycrystallite layer according to the second embodiment of the present invention. Explanation of symbols: 100, 200 ~ semiconductor substrate; 102, 202 ~ multicrystalline silicon layer; 104 ~ monoxide film; 106,204 ~ nitrogen-containing film; 206 ~ nitrogen silicon compound Floor.

Claims (1)

546709 9111U71 Application for patent Step-A method for reducing the reflectivity of a polycrystalline silicon layer, including at least the following providing a semiconductor substrate; $ 0 !! The above semiconductor substrate is placed in a single-wafer type chemical vapor deposition-& introducing a silicon-containing gas to the above The reaction of the single-wafer chemical vapor deposition is to aim at forming a polycrystalline silicon layer on the surface of the semiconductor substrate; 10; the compound is being killed in the reaction chamber of the single-wafer chemical vapor deposition; The size of the crystal grains on the upper surface of the silicon layer; ^ oxygen is introduced into the single-wafer chemical vapor deposition reaction chamber, and a silicon dioxide film is formed over the 5 polycrystalline silicon layer on f; and A single-wafer chemical vapor deposition reaction chamber to form a silicon nitride film on the surface of the silicon dioxide film. 2. The method for reducing the reflectance of the polycrystalline silicon layer as described in item 1 of the stated patent scope, further comprising introducing nitrous oxide into the reaction chamber M of the single-wafer chemical vapor deposition to deal with the above-mentioned A step of crystallizing the surface of the silicon layer to form a thin film of oxynitride compound. 3. The method for reducing the reflectance of the polycrystalline silicon layer according to item 1 of the scope of the patent application, wherein the thickness of the polycrystalline silicon layer is between 50 Angstroms and 2500 Angstroms. 4. The method for reducing the reflectance of the polycrystalline silicon layer as described in item 1 of the scope of the patent application, wherein the deposition temperature of the polycrystalline silicon layer is between about 350 ° C and 680 ° C. 5 · Reduce the reflection of the polycrystalline stone layer as described in item 1 of the scope of patent application 13th Yellow 546709 Case No. 9111U71 Amendment 6. Method for applying patent coverage rate, in which the deposition pressure of the polycrystalline stone layer above is approximately 150mtorr to 400mtorr. 6. The method for reducing the reflectance of a polycrystalline spar layer as described in item 1 of the scope of the patent application, wherein the above-mentioned silicon-containing system silane. 7. A method for reducing the reflectance of a polycrystalline silicon layer, including at least the following steps: providing a semiconductor substrate; placing the semiconductor substrate in an earlier SA-type chemical vapor deposition reactor; introducing a silicon-containing gas to the above A single-wafer chemical vapor deposition reaction chamber to form a polycrystalline silicon layer on the surface of the semiconductor substrate; and introducing ammonia and nitrous oxide into the single-wafer chemical vapor deposition reaction chamber to An oxynitride compound film is formed over the polycrystallite layer. 8. The method for reducing the reflectance of the polycrystalline silicon layer as described in item 7 of the scope of the patent application, wherein the thickness of the polycrystalline silicon layer is between 500 angstroms and 2500 angstroms. Lu 9 · The method for reducing the reflectance of a polycrystalline stone layer as described in item 7 of the scope of patent application, wherein the deposition temperature of the polycrystalline stone layer is between about 3 50 ° C and 6 8 0 ° C. between. I 0 · The method for reducing the reflectance of a polycrystalline silicon layer as described in item 7 of the scope of the patent application, wherein the above polycrystalline; the deposition pressure of the layer is between 150mtorr and 400mtorr. II · Reduce the reflection of the polycrystalline silicon layer as described in item 7 of the scope of patent application 0702-7678TWFl (N); 91P03; Jessica.ptc Page 14 546709 Case No. 91111471 Amendment 6. Method for applying for a patent coverage rate, in which the above-mentioned silanes are silanes. __ Page 15 0702-7678TWFl (N); 91P03; Jessica.ptc