TW432599B - Removal of silicon hydroxide layer on polysilicon gate in integrated circuit processing - Google Patents

Abstract

A method for removing silicon hydroxide layer on polysilicon gate in integrated circuit processing includes the following steps: firstly, providing a semiconductor substrate having a doped polysilicon gate and a undoped polysilicon formed thereon, and forming a silicon hydroxide layer on the surface of polysilicon gate as an anti-reflection; next, coating a photoresist on the substrate and the silicon hydroxide layer; employing a reverse mask to remove the photoresist in the large area on the surface of polysilicon gate; then, back-etching a part of photoresist to expose the sidewall and the surface of silicon hydroxide; dry-etching the silicon hydroxide layer in which the doped polysilicon gate and the undoped polysilicon gate are protected with the residual photoresist while removing the silicon hydroxide layer; then, removing the residual photoresist until exposing the surface of the substrate; finally, clearing the surface of the doped polysilicon gate, the undoped polysilicon gate and the substrate.

Description

p43259 9 Five 'Description of the invention " ---- 5 -1 Field of the invention: The present invention relates to a method for actively purifying silicon oxynitride, in particular, to etch a curtain in a timely manner, so as to make the structure. In the bulk circuit manufacturing process, the photoresist mask for the polysilicon gate is removed to form a knot that produces a good capacitance profile. 5-2 Background of the Invention: In the process of random memory, during the process, with the progress of process technology, Inch will increasingly tend to minimize the original, especially in the dynamic random postscript system foreseeable 'future element ruler size. At present, the line width of the production line has reached the width of the sub-micron, such as 0.1 micron. The goal of manufacturing finished products is also moving towards the high accumulation of semiconductors. Looking back on the past ten years or so, since the birth of the computer, because of the extensive use of random memory (Ram) in various related areas, the demand has increased rapidly, especially in the information industry of computer hardware. At the same time, it is not only used in the information industry, it is also commonly used in large integrated circuit (LSI), very large integrated circuit (VLSI), and ultra large integrated circuit (ULSI). Undoubtedly, even in the next century, the process technology of random memory (RAM) will still occupy a very important position in the information industry.

" F4 32 59 9 Five 'invention description (2) In the process, when the chemical etching technology (Chemicaj [which is not possible, the step of-.-generally traditionally for the so-called hard light layer Uard Mask) is removed, Such as silicon oxynitride compounds, 800 C of thermostructural acid (H3P04) is added as the #etching solution of the process order for removal ... If silicon oxynitride (thallium) is used as the hard mask, it is easier to remove the oxidized stone layer, because the post (Gveretching ^ = Ga such as the first A 圊 to the -B circle 'has been doped with polycrystalline stones Xi closed pole! 2 will be deformed at the same time in Shaanxi to produce bad contours. The symbols in the other figures are &: 工 〇 is a semiconducting substrate, 1 is a gate oxide layer and 14 is a silicon oxynitride layer. / '隹 ί As stated in the soil, 'Although silicon oxynitride compounds are better for the overall process; but in the process of removing E oxide oxide compounds, if the over-etching phenomenon of the QD process cannot be effectively controlled', the polycrystalline silicon gates will affect the polycrystalline silicon interelectrodes. Function. Also in the meeting SRAM ί t: The above mentioned 'in view of the need to improve and improve the random static memory (process technology *'), so urgently-new process methods and 1 to improve the above problems' and improve component quality The purpose and summary of its invention 5-3 invention: r4 3259 9 V. Description of the invention (3) In view of the above-mentioned many disadvantages of traditional etching due to improper etching, the present invention provides a method for using a photoresist curtain to form A temporary etch curtain in order to Etching is performed to produce a structure with a good polysilicon gate profile. Another object of the present invention is to improve and increase the demand for process technology of random static memory (SRAM), especially in the deep submicron era of the next generation. The present invention Another purpose is to reduce the manufacturing cost of semiconductor integrated circuits in wafer foundries and high yields, which can effectively reduce manufacturing costs. According to the purposes described above, the nitrogen of the polycrystalline silicon gate is removed in this process. Oxygen step. First, a semiconductor substrate is provided. An un-doped polycrystalline gate is formed on the anti-reflection layer, and then a photoresist layer is coated on the substrate with a reverse mask. Remove the photoresist. Then, etch back a part of the sidewall and surface. Then, when dry-etching the nitrided sand layer, the photoresist layer that has been doped with polycrystalline silicon remains to be protected. Third, the invention provides a kind of silicon in integrated circuit The method includes the following steps: at least one doped polycrystalline silicon gate electrode, and a silicon oxynitride layer is formed on the surface of the polycrystalline silicon gate electrode and the oxynitride layer. Again, Remove the silicon oxide layer on the surface of the polysilicon gate in a large area to expose the silicon oxide layer of the silicon oxynitride layer, and when the nitrogen gate and the undoped polysilicon gate are removed, remove the remaining photoresist layer until the bottom is exposed.

_ 5. Description of the invention (4) Up to the surface of the material. Finally, the surfaces of the doped polysilicon gate and the undoped polysilicon gate and the substrate are cleaned. In order to make the above description and other objects, features and advantages of the present invention more comprehensible, the preferred embodiments are listed below and described in detail with the accompanying drawings. Explain that the list is simple and the figures from the first to the first figure A A 12 and the second. The drawings of the Lian Yi technical know-how published by the drawings are the representative symbols of the main parts in the drawings of the present invention: 10 semiconductor substrate 11 gate oxide layer 12 polysilicon gates doped 13 doped Heteropolycrystalline silicon gate 14 Silicon oxynitride 20 Semiconductor substrate 21 Gate oxide 22-Doped polycrystalline silicon gate 23 Undoped polycrystalline silicon gate 23-A Large area polycrystalline silicon gate

w 酽 4 3259 9 V. Description of the invention (5) 26 Silicon oxynitride 27 Residual photoresist layer 5-5 Detailed description of the invention: The following is a description of the present invention. The description of the present invention will first be made with reference to an exemplary structure. Some changes and advantages of the present invention will be described later, and the preferred method of manufacturing will be discussed later. Furthermore, although the present invention is not limited to the scope or application of the present invention, it should be understood that the thin dielectric layer is the main generation. Therefore, the semiconductor element of the present invention includes proof of the present invention and its applicability. And even though the present invention is described by way of examples, the present invention and in addition, 'any other changes or modifications without departing from the present invention are included in the broad meaning of the present invention to explain the scope of the present invention. Examples to teach, but these are described. Also, although the parts used in these examples may be taken as related parts, the explanation of the structure is not limited. The practicality of this preferred embodiment and the manner in which it should be applied, as well as listing a preferred one, are not limited to the examples given. Within the scope of equivalent patent application completed under the spirit of disclosure. Should be used to include all of these modifications and

In the preferred embodiment of the present invention, the formula of the silicon oxynitride of the f polycrystalline sand gate is shown in the second figure to the second F. This method of shifting the integrated circuit manufacturing process includes at least The following steps are shown in the figure.

Γ432Β9 9 V. Description of the invention (6) Plan view. First, in the preferred embodiment of the present invention, as shown in FIG. 2A, a semiconductor substrate 20 is provided. At least one doped polycrystalline silicon gate electrode 22 and an undoped polycrystalline silicon gate electrode 23 are formed at The 'and oxynitride layer 26 is used as an Anti-Reflection layer' and is formed on the surfaces of the doped polycrystalline silicon gate 22 and the undoped polycrystalline silicon gate 23. Reference numeral 21 is a gate oxide layer. Next, as shown in FIG. 2B, a conventional photoresist coating method is used to plate a photoresist layer 27 on the substrate 20 and the silicon oxynitride layer 26. Again 'as shown in Figure 2C, the photoresist layer on the surface 23-A of the polycrystalline silicon gate is removed by a conventional oxygen plasma etching method. Then, as shown in FIG. 2D, a portion of the photoresist layer 27 is etched back to expose the sidewall and surface of the It oxide layer 26. 'As shown in the figure, the oxynitride layer 26 is etched with a dried carbon compound dry button, and although the silicon oxynitride layer 26 is removed, the silicon gate electrode 22 and the undoped polycrystalline silicon gate electrode 23 are included; Said gasification of two carbons (W, which is a whole heart number. And its = ^ energy or amount,

Page 9 5. Description of the invention (7) is adjustable. Again, as shown in FIG. 2F, the remaining photoresist layer 27 is exposed until the surface removed by the substrate strip (Dry strip) is exposed. Finally, as shown in the second F1 diagram, the surface of the doped polysilicon gate 22 and the undoped # 20 are cleaned by a Uean method. He 4 miscellaneous spar spar gate 23, 23-A and substrate II In the aforementioned invention, point 'the present invention provides-a better method, using light ::: engraving: many defects-temporary The etching curtain [for etching. Its ί: is used to form 1 · It can effectively protect the polycrystalline sand gate from damage. 2. It can effectively avoid the problem of polysilicon gate stripping. And just like another object of the present invention, it is to improve the needs of the process technology of ancient memory (SRAM), especially the surface, deep static submicron era. And another object of the present invention is to use J: the high requirements and high quality of semiconductor integrated circuit manufacturing process in the generation of the factory ^ In the wafer generation, the present invention 'this nitrogen removed in the integrated circuit manufacturing process The method of silicon oxide includes at least the following steps. The first ea silicon gate semiconductor substrate has at least one doped polyisocyanate, and the couple provides one, six heteropoly silicon 32 5 9 9 V. Description of the invention (8) The gate is formed on it, An t i- Ref lection) A photoresist layer is removed from the substrate and Reverse Mask, and a part of it is etched back. Then, dry-etched nitrogen was protected by doped polycrystalline silicon layers. Again, stop. Finally, clean the surface of the substrate. The above are only within the scope of the patents completed under the spirit of the application of the present invention. And the silicon oxynitride layer is used as an anti-reflection layer (formed on the surface of the polycrystalline silicon gate. It is connected to the silicon oxynitride layer. Again, Boda e & Miner Gongdan-ren, uses a reverse mask to remove large area polycrystalline silicon Photoresist on the gate surface. Follow the photoresist layer to expose the sidewall and surface silicon oxide layer of the silicon oxynitride layer, and when the silicon oxynitride layer is removed, the open electrode and the undoped polycrystalline silicon gate with residual photoresist The remaining photoresist layer is removed until the surface of the exposed substrate is doped polycrystalline silicon gate and undoped polycrystalline silicon gate and the preferred embodiment of the present invention, which is not intended to limit the scope of profit; all others do not depart from the disclosure of the present invention All changes or modifications shall be included in the following application

Claims (1)

^ 43259 9 VI. Patent application method of siliconized silicon 1. A method for removing polycrystalline silicon in integrated circuit manufacturing process, including at least: y open-electrode nitrogen and oxygen to provide a semiconductor substrate, at least one doped on it; -A silicon oxynitride layer is formed on the doped 2: crystalline silicon interlayer to form an elegant polycrystalline silicon gate surface layer on the substrate and the oxynitride layer; 0 d d of photoresist layer to Exposing the surface of the gas &surface; 3 the side wall of the sclerosed silicon layer and removing the said oxide layer, in which the remaining photoresist layer is maintained until the gas oxide layer is removed. Residually remove the remaining photoresist layer:] = until the surface of the substrate is violated. 3 If the method of item 2 of the scope of the patent is applied today-the surface area of the polycrystalline silicon gate is removed: Step 4 is: the method of item 1 of the scope of the patent, in which the photoresist layer is recited by plasma etching The method of removing the photoresist layer in the above range of item 1 2 3, wherein the above-mentioned electric axis method is 1. If the method of the first item in the patent scope, 2 Shi Xi closed pole on the substrate, the nitrogen oxidation U contains-undoped polycrystalline 3 crystalline silicon gate on the surface. H is also formed in the undoped poly ^ " 4 32 59 9 VI. Application scope of patent 6. If the method of applying for the scope of the patent No. 1 'where the removal of the above oxynitride is by photoresist dry etching law. 7. The method according to item 6 of the scope of patent application, wherein the step of removing oxynitride is a step in which CXFY is a radical, where X is X, and Y is a positive integer. 8_ The method according to item 1 of the patent application range, wherein the removal of the residual photoresist layer is a dry stripping method. 9. The method according to item 2 of the patent application, wherein the above method further comprises cleaning the surfaces of the doped and undoped polycrystalline silicon gate and the substrate after removing the residual photoresist layer. 10. A method for removing oxynitride from polycrystalline silicon gate in integrated circuit fabrication, comprising at least: providing a semiconductor substrate, at least one doped polycrystalline silicon gate and an undoped polycrystalline silicon gate formed thereon And an argon halide silicon layer is used as an anti-reflective layer to form a silicon layer on the surface of the polycrystalline silicon gate; the main part; the side wall of the oxide second layer and a photoresist layer are coated A part of the photoresist layer engraved on the substrate and the nitrogen oxidation to remove a part of the undoped polysilicon gate surface to expose the nitrogen surface; Page 13 325 9 9 6. The scope of the patent application is dry etching the silicon oxynitride layer. When the silicon oxynitride layer is removed, the doped polycrystalline silicon gate and the undoped polycrystalline silicon interlayer are protected by the optical layer; 'Tian f removes the remaining photoresist layer until the surface of the substrate is exposed; and & wash the doped polycrystalline silicon gate and the undoped polycrystalline silicon gate and the substrate 2 is the first (1) of the range Method: The method of item # in the oxygen range, wherein the photoresist layer is removed, wherein the plasma etching method is the method of item 10 in the patent range, where the removal of the residual photoresist is to protect a, A 1 ^ 干 u dry stripping method.