CN114196406B - Etching liquid and preparation method and application thereof - Google Patents

Etching liquid and preparation method and application thereof Download PDF

Info

Publication number
CN114196406B
CN114196406B CN202111368823.6A CN202111368823A CN114196406B CN 114196406 B CN114196406 B CN 114196406B CN 202111368823 A CN202111368823 A CN 202111368823A CN 114196406 B CN114196406 B CN 114196406B
Authority
CN
China
Prior art keywords
etching
silicon nitride
nitride film
percent
phosphoric acid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202111368823.6A
Other languages
Chinese (zh)
Other versions
CN114196406A (en
Inventor
高和平
黎立桂
陈当家
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huangpu Institute of Materials
Original Assignee
Huangpu Institute of Materials
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Huangpu Institute of Materials filed Critical Huangpu Institute of Materials
Priority to CN202111368823.6A priority Critical patent/CN114196406B/en
Publication of CN114196406A publication Critical patent/CN114196406A/en
Application granted granted Critical
Publication of CN114196406B publication Critical patent/CN114196406B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K13/00—Etching, surface-brightening or pickling compositions
    • C09K13/04—Etching, surface-brightening or pickling compositions containing an inorganic acid
    • C09K13/06—Etching, surface-brightening or pickling compositions containing an inorganic acid with organic material
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K13/00—Etching, surface-brightening or pickling compositions
    • C09K13/04—Etching, surface-brightening or pickling compositions containing an inorganic acid
    • C09K13/08—Etching, surface-brightening or pickling compositions containing an inorganic acid containing a fluorine compound
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
    • H01L21/3105—After-treatment
    • H01L21/311—Etching the insulating layers by chemical or physical means
    • H01L21/31105—Etching inorganic layers
    • H01L21/31111—Etching inorganic layers by chemical means
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Weting (AREA)

Abstract

The invention relates to an etching liquid, which comprises the following components in percentage by weight: 70 to 85 percent of phosphoric acid, 0.1 to 1.5 percent of sulfuric acid, 0.1 to 5 percent of tetramethyl ammonium hydroxide, 0.5 to 6.8 percent of hydroxyethylidene diphosphonic acid, 0.2 to 8 percent of ammonium salt and 6 to 29.1 percent of water. The etching liquid can remove the silicon nitride film with high selectivity, has high etching rate to the silicon nitride film, can inhibit the etching to the silicon dioxide film in a laminated structure consisting of the silicon nitride film and the silicon dioxide film in a memory chip, has long service life and can adapt to the manufacturing process of rapidly increasing the number of the laminated structure layers of a memory. Compared with the traditional method of using a phosphoric acid aqueous solution with a single component as the etching liquid, the etching liquid has higher etching selectivity to the silicon nitride film and stronger etching selectivity.

Description

Etching liquid and preparation method and application thereof
Technical Field
The invention relates to the technical field of chip manufacturing, in particular to etching liquid and a preparation method and application thereof.
Background
Silicon nitride is widely used in the chip processing industry as an insulating layer or top barrier layer to prevent contaminants from diffusing into the chip, and in order to alleviate the problem of mismatch in thermal expansion rates between the silicon nitride layer and the bottom silicon substrate, a thin silicon dioxide layer is grown on the silicon substrate, and then the silicon nitride layer is grown thereon to form a stacked body in which one or more thin films are alternately stacked. In addition, both the silicon oxide film and the silicon nitride film can be used for forming a hard mask like a metal wiring conductive pattern.
In the storage chip market, the memory is required to maximize the storage capacity and minimize the storage volume as much as possible, so that the storage density is continuously increased, the manufacturing process of the chip is more and more complicated, and accordingly, the more the stacked structure of silicon dioxide and silicon nitride is in the memory chip, which puts higher requirements on the ratio (selection ratio) of the etching rates of the silicon nitride film and the silicon dioxide film.
In the conventional art, a silicon nitride film can be etched using hydrofluoric acid and a buffered oxide etchant, but the etching rate is slow even at high temperatures and is often adversely affected by extreme etching conditions. In addition, in the conventional technology, a single phosphoric acid aqueous solution is usually used for etching the silicon nitride film and the silicon dioxide film, but when the single phosphoric acid aqueous solution is used for etching, the ratio (selectivity) of the etching rates of the silicon nitride film and the silicon dioxide film is only about 40, the selectivity is low, and the defects that the selectivity is obviously reduced due to more particles and precipitates generated during etching exist, and the like, cannot meet the production requirements of the high-end DRAM and NAND Flash memory at present.
Disclosure of Invention
Accordingly, it is necessary to provide an etching solution capable of improving the removal selectivity of a silicon nitride film in a laminated structure of a silicon oxide film and a silicon nitride film, and a preparation method and application thereof.
The invention provides an etching liquid which comprises the following components in percentage by weight:
Figure BDA0003361554410000021
in one embodiment, the composition comprises the following components in percentage by weight:
Figure BDA0003361554410000022
in one embodiment, the composition comprises the following components in percentage by weight:
Figure BDA0003361554410000023
Figure BDA0003361554410000031
in one embodiment, the composition comprises the following components in percentage by weight:
Figure BDA0003361554410000032
in one embodiment, the phosphoric acid is electronic grade phosphoric acid, and the purity of the phosphoric acid is 99-99.9%; and/or
The sulfuric acid is electronic grade sulfuric acid, and the purity of the sulfuric acid is 98-99%; and/or
The ammonium salt is one or a mixture of ammonium polyphosphate, tributylammonium pyrophosphate, tetraethylammonium hexafluorophosphate and ammonium sulfate.
The invention also provides a preparation method of the etching solution in any one of the embodiments, which comprises the following steps:
mixing the components.
In one embodiment, the mixed mixture is filtered.
The invention also provides an etching method, which is characterized in that the etching liquid in any embodiment is adopted to etch the functional layer arranged on the substrate, wherein the functional layer comprises a silicon nitride film or alternatively stacked silicon nitride films and silicon dioxide films.
In one embodiment, the temperature of the etching is 160 ℃ to 164 ℃.
In one embodiment, the ratio of the etching rate of the etching liquid to the silicon nitride film to the etching rate to the silicon dioxide film is (85-165): 1.
the invention also provides application of the etching solution in the chip manufacturing.
The etching liquid can remove the silicon nitride film with high selectivity, has high etching rate to the silicon nitride film, can inhibit the etching to the silicon dioxide film in a laminated structure consisting of the silicon nitride film and the silicon dioxide film in a memory chip, has long service life and can adapt to the manufacturing process of rapidly increasing the number of the laminated structure layers of a memory. Compared with the traditional method of using a phosphoric acid aqueous solution with a single component as the etching liquid, the etching liquid has higher etching selectivity on the silicon nitride film and stronger etching selectivity.
Detailed Description
In order to facilitate understanding of the present invention, the following describes the etching solution of the present invention, its preparation method and application more fully with reference to the following examples. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In the present invention, the technical features described in the open type include a closed technical solution including the listed features, and also include an open technical solution including the listed features.
An embodiment of the present invention provides an etching solution, which comprises the following components by weight:
Figure BDA0003361554410000041
Figure BDA0003361554410000051
the phosphoric acid has good uniformity and high selectivity for etching the silicon nitride film and the silicon dioxide film. Further, the weight percentage of phosphoric acid may be, for example, but is not limited to, 70%, 73%, 75%, 78%, 80%, 82%, 85%, etc.
The sulfuric acid is beneficial to improving the etching rate selectivity of the etching liquid to the silicon nitride film and the silicon dioxide film. Further, the weight percentage of sulfuric acid may be, for example, but not limited to, 0.1%, 0.2%, 0.6%, 0.8%, 1.0%, 1.2%, 1.5%, and the like.
The tetramethyl ammonium hydroxide can promote the etching of the silicon nitride film, and further improve the etching rate of the silicon nitride film. Further, the weight percentage of tetramethylammonium hydroxide may be, for example, but not limited to, 0.1%, 0.5%, 0.8%, 1.0%, 1.2%, 1.5%, 1.8%, 2.0%, 2.5%, 3.0%, 3.4%, 4.0%, 4.2%, 4.5%, 5.0%, and the like.
The hydroxyethylidene diphosphonic acid can be adsorbed on the surface of the silicon dioxide film layer in the etching process, so that the etching of the silicon dioxide film layer is inhibited, the etching rate of the etching liquid to the silicon dioxide film is reduced, and the etching rate selection ratio of the silicon nitride film to the silicon dioxide film is further improved. Further, the weight percentage of hydroxyethylidene diphosphonic acid may be, for example, but not limited to, 0.5%, 0.8%, 1.0%, 1.2%, 1.5%, 1.8%, 2.0%, 2.5%, 3.0%, 3.4%, 4.0%, 4.2%, 4.5%, 5.0%, 5.2%, 5.4%, 6.0%, 6.2%, 6.8%, and the like.
The ammonium salt can improve the stability of the etching solution. Further, the weight percentage of the ammonium salt may be, for example, but not limited to, 0.2%, 0.5%, 0.8%, 1.0%, 1.2%, 1.5%, 1.8%, 2.0%, 2.5%, 3.0%, 3.4%, 4.0%, 4.2%, 4.5%, 5.0%, 5.2%, 5.5%, 6.0%, 6.2%, 6.5%, 7.0%, 7.5%, 8.0%, and the like.
Further, the weight percentage of water may be, for example, but not limited to, 6%, 6.2%, 6.5%, 7.2%, 9%, 10%, 11%, 13%, 15%, 18%, 19%, 20%, 21%, 22%, 23%, 5.2%, 25%, 26.5%, 27%, 28%, 29%, 29.1%, and the like.
Phosphoric acid, sulfuric acid, tetramethylammonium hydroxide, hydroxyethylidene diphosphonic acid, ammonium salt and water are prepared into etching liquid according to specific weight percentage, so that the silicon nitride film can be removed at high speed, the silicon nitride film in the laminated structure has high etching speed selection ratio aiming at the laminated structure consisting of the silicon nitride film and the silicon dioxide film, the service life of the etching liquid is long, and the etching liquid can be suitable for the manufacturing process of rapidly increasing the number of layers in the laminated structure of the memory.
In a specific example, the etching solution comprises the following components in percentage by weight:
Figure BDA0003361554410000061
in a specific example, the etching solution comprises the following components in percentage by weight:
Figure BDA0003361554410000062
in a specific example, the etching solution comprises the following components in percentage by weight:
Figure BDA0003361554410000063
Figure BDA0003361554410000071
in one particular example, the phosphoric acid is electronic grade phosphoric acid, which has a purity of 99% to 99.9%. The purity of the electronic grade phosphoric acid is high, and the performance reliability of a finished product after a film layer in a chip is etched is guaranteed.
In one particular example, the sulfuric acid is electronic grade sulfuric acid, which has a purity of 98% to 99%. The purity of the electronic-grade sulfuric acid is high, and the performance reliability of a finished product after a film layer in a chip is etched can be further ensured.
In a particular example, the ammonium salt can be, but is not limited to, a mixture of one or more of ammonium polyphosphate, tributylammonium pyrophosphate, tetraethylammonium hexafluorophosphate, and ammonium sulfate. The screened and selected ammonium salt can provide a buffering synergistic effect, and is favorable for further improving the stability of the etching solution.
Further, the ammonium salt is ammonium polyphosphate.
Further, the weight percentage of nitrogen in the ammonium polyphosphate is more than 24 percent, P 2 O 5 Is greater than 49% by weight. Within the range, the ammonium polyphosphate has low polymerization degree and good water solubility, and is beneficial to preparing etching solution with higher purity.
In one particular example, the water may be, but is not limited to, deionized water, ultrapure water, or a mixture of one or more of pure water. Preferably, the water is deionized water.
An embodiment of the present invention further provides a method for preparing the etching solution in any one of the above examples, including the following steps:
mixing the components.
Further, phosphoric acid, sulfuric acid, tetramethylammonium hydroxide, hydroxyethylidene diphosphonic acid, an ammonium salt, and water are mixed.
Further, phosphoric acid, sulfuric acid, tetramethylammonium hydroxide, hydroxyethylidene diphosphonic acid, ammonium salt and water are prepared according to the following weight percentages:
Figure BDA0003361554410000081
furthermore, the phosphoric acid, the sulfuric acid, the tetramethylammonium hydroxide, the hydroxyethylidene diphosphonic acid, the ammonium salt and the water are prepared according to the following weight percentage:
Figure BDA0003361554410000082
furthermore, the phosphoric acid, the sulfuric acid, the tetramethylammonium hydroxide, the hydroxyethylidene diphosphonic acid, the ammonium salt and the water are prepared according to the following weight percentage:
Figure BDA0003361554410000083
Figure BDA0003361554410000091
furthermore, the phosphoric acid, the sulfuric acid, the tetramethylammonium hydroxide, the hydroxyethylidene diphosphonic acid, the ammonium salt and the water are prepared according to the following weight percentage:
Figure BDA0003361554410000092
optionally, the phosphoric acid is electronic grade phosphoric acid, and the purity of the phosphoric acid is 99-99.9%.
Alternatively, the phosphoric acid may be at other concentrations, and equivalent conversions may be calculated.
Optionally, the sulfuric acid is electronic grade sulfuric acid, and the purity of the sulfuric acid is 98% -99%.
Alternatively, the sulfuric acid may be at other concentrations, and equivalent conversions may be calculated.
In one specific example, phosphoric acid, sulfuric acid, tetramethylammonium hydroxide, hydroxyethylidene diphosphonic acid, ammonium salts, and water are mixed and the resulting mixture is filtered. Insoluble impurities in the etching liquid can be removed through filtering, the purity of the etching liquid is improved, and the etching speed of the etching liquid on the silicon nitride film is improved.
Further, the filtration is carried out by using a filter of 0.1 to 0.5. Mu.m. Further, filtration was performed using a 0.22 μm filter.
Optionally, the material of the filtering membrane in the filter may be, but is not limited to, one of polytetraethylene or polyvinylidene fluoride.
An embodiment of the present invention also provides an etching method for etching a functional layer provided on a substrate, the functional layer including a silicon nitride film, or a silicon nitride film and a silicon dioxide film alternately stacked, using the etching solution in any of the above examples.
It is to be understood that the silicon nitride film and the silicon oxide film alternately stacked may be formed by a conventional method. For example, the following methods may be employed, but are not limited to: respectively growing a silicon nitride film and a silicon dioxide film on the surface of the substrate in a PECVD mode, and patterning the silicon nitride film and the silicon dioxide film by a dry etching method.
Further, a stacked structure is formed by alternately stacking silicon nitride films and silicon dioxide films. Further, a silicon dioxide film layer grows on the surface of the substrate, a silicon nitride film layer is formed on the silicon dioxide film layer, a silicon dioxide film layer is formed on the silicon nitride film layer, and the silicon dioxide film layers are alternately stacked in sequence to form a stacked structure. The laminated structure has at least one layer, even tens of layers and hundreds of layers.
Optionally, the substrate is a silicon wafer.
In one specific example, the temperature of the etch is 160 ℃ to 164 ℃. The temperature range is the optimum temperature for etching the silicon nitride film by the etching liquid, the silicon nitride film can be efficiently etched by the etching liquid, and the etching liquid has high etching rate selection ratio to the silicon nitride film in the laminated structure of the silicon nitride film and the silicon dioxide film.
In a specific example, the ratio of the etching rate of the etching liquid to the silicon nitride film to the etching rate to the silicon dioxide film is (85 to 165): 1.
the etching liquid can remove the silicon nitride film with high selectivity, has high etching rate to the silicon nitride film, can inhibit the etching to the silicon dioxide film aiming at the laminated structure consisting of the silicon nitride film and the silicon dioxide film in the memory chip, has long service life and can adapt to the manufacturing process of rapidly increasing the number of the laminated structure layers of the memory. Compared with the traditional method of using a phosphoric acid aqueous solution with a single component as the etching liquid, the etching liquid has higher etching selectivity to the silicon nitride film and stronger etching selectivity.
The invention also provides application of the etching solution in any one of the above examples in chip manufacturing.
The etching solution, the preparation method and the application thereof of the present invention will be described in detail with reference to the following specific examples, wherein all the raw materials can be commercially available in the following specific examples unless otherwise specified.
Wherein, the phosphoric acid manufacturer is Jiangyin Ruma electronic material GmbH, and the purity is 99%;
the sulfuric acid manufacturer is Jiangyin Ruma electronic materials GmbH, and the purity is 98%;
the ammonium polyphosphate is produced by Jinan Peiteng chemical Co., ltd, wherein the weight percentage of nitrogen is more than 24%, and P is 2 O 5 Is greater than 49% by weight.
Example 1:
preparing an etching solution: adding 70 percent of phosphoric acid into a batching tank, stirring, sequentially adding 0.1 percent of sulfuric acid, 0.1 percent of tetramethylammonium hydroxide, 0.5 percent of hydroxyethylidene diphosphonic acid, 0.2 percent of ammonium polyphosphate and 29.1 percent of deionized water, stirring all the materials until the materials are completely and uniformly dissolved, then filtering the materials by a polyvinylidene fluoride membrane with the diameter of 0.22 mu m, and discharging the materials.
Example 2:
preparing etching liquid: adding 75 percent of phosphoric acid into a material preparation tank, sequentially adding 0.6 percent of sulfuric acid, 2.0 percent of tetramethyl ammonium hydroxide, 3.4 percent of hydroxy ethylidene diphosphonic acid, 8.0 percent of ammonium polyphosphate and 11 percent of deionized water under stirring, stirring the materials until the materials are completely and uniformly dissolved, filtering the materials by using a polyvinylidene fluoride membrane with the diameter of 0.22 mu m, and discharging the materials.
Example 3:
preparing etching liquid: adding 80% phosphoric acid into a material preparation tank, stirring, sequentially adding 1.5% sulfuric acid, 5.0% tetramethylammonium hydroxide, 6.8% hydroxyethylidene diphosphonic acid, 0.5% ammonium polyphosphate and 6.2% deionized water, stirring until all the materials are completely and uniformly dissolved, then filtering by using a polyvinylidene fluoride membrane with the diameter of 0.22 mu m, and discharging.
Example 4:
preparing an etching solution: adding 85 percent of phosphoric acid into a mixing tank, sequentially adding 1.0 percent of sulfuric acid, 1.0 percent of tetramethyl ammonium hydroxide, 5.4 percent of hydroxy ethylidene diphosphonic acid, 1.0 percent of ammonium polyphosphate and 6.6 percent of deionized water under stirring, stirring all the materials until all the materials are completely and uniformly dissolved, then filtering the materials by using a polyvinylidene fluoride membrane with the diameter of 0.22 mu m, and discharging the materials.
Example 5:
preparing an etching solution: adding 85 percent of phosphoric acid into a mixing tank, sequentially adding 0.8 percent of sulfuric acid, 0.5 percent of tetramethyl ammonium hydroxide, 2.5 percent of hydroxy ethylidene diphosphonic acid, 4.0 percent of ammonium polyphosphate and 7.2 percent of deionized water under stirring, stirring all the materials until all the materials are completely and uniformly dissolved, then filtering the materials by using a polyvinylidene fluoride membrane with the diameter of 0.22 mu m, and discharging the materials.
Comparative example 1:
preparing an etching solution: adding 85% phosphoric acid into a mixing tank, stirring, sequentially adding 0.8% sulfuric acid, 4.0% ammonium polyphosphate and 10.2% deionized water, stirring until all the substances are completely and uniformly dissolved, filtering by using a polyvinylidene fluoride membrane with the diameter of 0.22 mu m, and discharging.
Comparative example 2:
preparing etching liquid: according to the weight percentage, 70 percent of phosphoric acid is put into a batching tank, stirred, then 30 percent of deionized water is added, all the materials are stirred until the materials are completely and uniformly dissolved, and then a polyvinylidene fluoride membrane with the diameter of 0.22 mu m is used for filtering and discharging.
Comparative example 3:
preparing an etching solution: according to the weight percentage, 75 percent of phosphoric acid is put into a batching tank, stirred, then 25 percent of deionized water is added, all the materials are stirred until the materials are completely and uniformly dissolved, and then a polyvinylidene fluoride membrane with the diameter of 0.22 mu m is used for filtering and discharging.
Comparative example 4:
preparing an etching solution: according to the weight percentage, 80 percent of phosphoric acid is put into a batching tank, stirred and then added with 20 percent of deionized water, all the materials are stirred until being completely and uniformly dissolved, and then filtered by a polyvinylidene fluoride membrane with the diameter of 0.22 mu m, and the materials are discharged.
Comparative example 5:
preparing an etching solution: according to the weight percentage, 85 percent of phosphoric acid is put into a batching tank, stirred, then 15 percent of deionized water is added, all the materials are stirred until all the materials are dissolved evenly, and then filtered by a polyvinylidene fluoride membrane with the diameter of 0.22 mu m, and the materials are discharged.
The etching rate selection ratios and the service lives of the etching solutions prepared in the examples 1 to 5 and the comparative examples 1 to 5 and the etching effects of the laminated structures with different layers are tested, and the test results are shown in tables 1 to 7.
The test method comprises the following steps:
1. etching rate selection ratio test:
1. preparation of an etching sample:
respectively growing on the surface of the intrinsic silicon by a PECVD mode
Figure BDA0003361554410000131
And a silicon nitride film of
Figure BDA0003361554410000132
Followed by forming a patterned silicon nitride film and a silicon oxide film by a dry etching method.
2. Etching conditions are as follows:
etching temperature: 162 +/-2 ℃.
Etching the container: and (5) corroding the slot with polytetrafluoroethylene.
Etching time: for 10min.
3. The speed measuring method comprises the following steps:
and measuring the thickness change of the film before and after etching by using a three-dimensional white light interferometer, and respectively calculating the etching rate of the etching solution to the silicon nitride film and the silicon dioxide film. The etching rate selection ratio is the ratio of the etching rate E/R of the etching liquid to the silicon nitride film to the etching rate E/R to the silicon dioxide film.
2. And (3) checking the service life of the etching liquid:
when the etching liquid is used for etching the silicon nitride film and the silicon dioxide film, the etched metabolic products contain silicate, the concentration of the silicate is increased along with the prolonging of the etching time, and the etching selectivity of the etching liquid on the silicon nitride film is weakened. The method comprises the steps of adding sodium silicate with different contents into etching liquid, simulating a test environment with continuously prolonged etching time, testing the etching rate of the etching liquid to a silicon nitride film and a silicon dioxide film, calculating the change condition of the etching rate selection ratio, and further analyzing the service life of the etching liquid.
And (3) testing conditions are as follows: respectively adding (0 ppm/50ppm/100ppm/200ppm/400ppm/800 ppm) sodium silicate powder into the initial etching solution, uniformly mixing, carrying out an etching experiment according to a method of 'I, etching rate selectivity test', respectively testing the etching rate E/R of the etching solution to the silicon nitride film and the etching rate E/R of the etching solution to the silicon dioxide film, and calculating the etching rate selectivity.
The results of the etch rate selectivity test are shown in tables 1-5.
3. Testing the etching effect of the silicon wafer with the laminated structure of the silicon nitride film and the silicon dioxide film with different layers:
etching an object: making a businessIn place of the silicon wafer having the laminated structure, the film thicknesses of the silicon oxide film and the silicon nitride film in each layer structure are set to be equal
Figure BDA0003361554410000143
The number of layers of the laminated structure is respectively as follows: 32 layers, 64 layers, 128 layers.
The test method comprises the following steps: the etching temperature is 162 +/-2 ℃, the etching time is 15min, the silicon wafer is cleaned and dried after the etching is finished, the etching condition is observed by a TEM, and the etching effect is shown in Table 7.
TABLE 1 etching rate selection ratio of etching liquid to silicon nitride film and silicon dioxide film without adding sodium silicate to the initial liquid
Figure BDA0003361554410000141
TABLE 2 etching rate selectivity ratio of etching liquid to silicon nitride film and silicon dioxide film in the case of adding 50ppm of sodium silicate to the initial liquid
Figure BDA0003361554410000142
Figure BDA0003361554410000151
TABLE 3 etching rate selectivity ratio of etching liquid to silicon nitride film and silicon dioxide film in the case of adding 100ppm of sodium silicate to the initial liquid
Figure BDA0003361554410000152
TABLE 4 etching Rate selection ratio of etching liquid to silicon nitride film and silicon dioxide film in the case of adding 200ppm of sodium silicate to the initial liquid
Figure BDA0003361554410000153
Figure BDA0003361554410000161
TABLE 5 etching Rate selection ratio of etching liquid to silicon nitride film and silicon dioxide film in the case of adding 400ppm of sodium silicate to the initial liquid
Figure BDA0003361554410000162
TABLE 6 etching Rate selection ratio of etching liquid to silicon nitride film and silicon dioxide film in the case where 800ppm of sodium silicate was added to the initial liquid
Figure BDA0003361554410000163
TABLE 7 etching Effect of silicon wafer having silicon nitride film and silicon dioxide film laminated structure with different number of layers
Figure BDA0003361554410000164
Figure BDA0003361554410000171
Rating standard: the grade A is the etching completion of the silicon nitride film layer, and the silicon dioxide film layer is not damaged; the B level is the etching completion of the silicon nitride film layer, and the silicon dioxide film layer is damaged; the C level is that the silicon nitride film layer is not etched and the silicon dioxide film is damaged.
As can be seen from tables 1 to 6, in examples 1 to 5, the etching rate selectivity of the etching solution to the silicon nitride film layer is very high from the beginning of etching to the time of etching, and reaches (85 to 165): 1, compared with comparative examples 1 to 5, the etching solution has more excellent etching selectivity, and the etching selectivity is still obvious along with the prolonging of the etching time, which shows that the service life of the etching solution is long.
In comparison between example 5 and comparative example 1, the etching rate selectivity ratio of example 5 is (95-127): 1, and the etching rate selectivity ratio of comparative example 1 is (44-46): 1, so that the etching selectivity of the etching solution to the silicon nitride film can be further improved by the tetramethylammonium hydroxide and the hydroxyethylidene diphosphonic acid.
Compared with the comparative example 1 and the comparative example 5, the etching rate selectivity of the comparative example 1 is maintained at (44-46): 1 along with the prolonging of the etching time, and the etching rate selectivity of the comparative example 5 is reduced from 40 to 34.
As can be seen from table 7, the etching solutions in examples 1 to 5 have good etching effects on 32 silicon nitride films and silicon dioxide film laminated structure silicon wafers, and further increase to 128 layers, the etching solutions can still complete etching of the silicon nitride films, and in examples 2 to 4, the silicon dioxide films can be also not damaged, while the etching solutions in comparative examples 1 to 5 have poor etching effects on the silicon nitride films, and it can be seen that the etching solutions in examples 1 to 5 can be better applied to the chip laminated structures with the increasing number of layers.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (11)

1. The etching liquid is characterized by comprising the following components in percentage by weight:
Figure FDA0004046667750000011
2. the etching solution according to claim 1, comprising the following components in percentage by weight:
Figure FDA0004046667750000012
3. the etching solution according to claim 2, comprising the following components in percentage by weight:
Figure FDA0004046667750000013
4. the etching solution according to claim 2, comprising the following components in percentage by weight:
Figure FDA0004046667750000014
Figure FDA0004046667750000021
5. the etching solution of any one of claims 1 to 4, wherein the phosphoric acid is electronic grade phosphoric acid, and the purity of the phosphoric acid is 99 to 99.9 percent; and/or
The sulfuric acid is electronic grade sulfuric acid, and the purity of the sulfuric acid is 98-99%.
6. A method for preparing the etching solution according to any one of claims 1 to 5, comprising the steps of:
mixing the components.
7. The method according to claim 6, wherein the mixed mixture is filtered.
8. An etching method characterized in that a functional layer provided on a substrate is etched using the etching liquid according to any one of claims 1 to 5, the functional layer comprising a silicon nitride film, or a silicon nitride film and a silicon dioxide film which are alternately laminated.
9. The etching method according to claim 8, wherein the etching temperature is 160 ℃ to 164 ℃.
10. The etching method according to any one of claims 8 to 9, wherein a ratio of an etching rate of the etching liquid to the silicon nitride film to an etching rate to the silicon oxide film is (85 to 165): 1.
11. use of the etching solution of any one of claims 1 to 5 in the manufacture of chips.
CN202111368823.6A 2021-11-18 2021-11-18 Etching liquid and preparation method and application thereof Active CN114196406B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111368823.6A CN114196406B (en) 2021-11-18 2021-11-18 Etching liquid and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111368823.6A CN114196406B (en) 2021-11-18 2021-11-18 Etching liquid and preparation method and application thereof

Publications (2)

Publication Number Publication Date
CN114196406A CN114196406A (en) 2022-03-18
CN114196406B true CN114196406B (en) 2023-03-14

Family

ID=80647966

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111368823.6A Active CN114196406B (en) 2021-11-18 2021-11-18 Etching liquid and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN114196406B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102007196A (en) * 2008-03-07 2011-04-06 高级技术材料公司 Non-selective oxide etch wet clean composition and method of use
CN103208421A (en) * 2013-03-14 2013-07-17 上海华力微电子有限公司 Method for improving etching selection ratio of silicon nitride layer to oxide layer
CN105908188A (en) * 2016-05-23 2016-08-31 杭州格林达化学有限公司 Hydrogen peroxide system etching liquid for TFT copper-molybdenum lamination
CN108570678A (en) * 2018-04-13 2018-09-25 深圳达诚清洗剂有限公司 A kind of metal etch liquid applied to copper-molybdenum film layer
KR20210119641A (en) * 2020-03-25 2021-10-06 주식회사 이엔에프테크놀로지 Silicon nitride layer etching composition

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102007196A (en) * 2008-03-07 2011-04-06 高级技术材料公司 Non-selective oxide etch wet clean composition and method of use
CN103208421A (en) * 2013-03-14 2013-07-17 上海华力微电子有限公司 Method for improving etching selection ratio of silicon nitride layer to oxide layer
CN105908188A (en) * 2016-05-23 2016-08-31 杭州格林达化学有限公司 Hydrogen peroxide system etching liquid for TFT copper-molybdenum lamination
CN108570678A (en) * 2018-04-13 2018-09-25 深圳达诚清洗剂有限公司 A kind of metal etch liquid applied to copper-molybdenum film layer
KR20210119641A (en) * 2020-03-25 2021-10-06 주식회사 이엔에프테크놀로지 Silicon nitride layer etching composition

Also Published As

Publication number Publication date
CN114196406A (en) 2022-03-18

Similar Documents

Publication Publication Date Title
US9673342B2 (en) Textured silicon substrate and method
CN111961472B (en) High-selectivity silicon nitride etching solution, and preparation method and application thereof
CN114395395B (en) Silicon nitride etching liquid with high selectivity ratio and preparation method and application thereof
CN112410888B (en) Etching liquid and etching method for back of ultrathin wafer
CN113518817B (en) Silicon nitride film etching composition
CN114196406B (en) Etching liquid and preparation method and application thereof
CN114891509A (en) High-selectivity buffer oxide etching solution
CN110846040A (en) High-silicon-content phosphate etching solution and preparation method thereof
US7780868B2 (en) Alkaline etching solution for semiconductor wafers and alkaline etching method
TW201938767A (en) Composition having suppressed alumina damage and production method for semiconductor substrate using same
WO2024007627A1 (en) C-free high-selectivity silicon nitride etching solution
CN111849487B (en) High-selectivity silicon nitride etching solution, and preparation method and application thereof
CN107354513B (en) High-efficiency stable germanium single crystal wafer etching process
CN116333744A (en) Semiconductor silicon wafer etching solution, and preparation method and application thereof
CN111925801B (en) High-selectivity silicon nitride etching solution, preparation method and application thereof
SG192473A1 (en) Integrated circuit system including nitride layer technology
CN111925800B (en) Etching solution composition, preparation method and application thereof
CN111925805B (en) Etching solution composition, preparation method and application thereof
CN111925799B (en) High-selectivity etching solution, and preparation method and application thereof
CN111925798B (en) Etching solution composition, preparation method and application thereof
CN111925804A (en) High-selectivity silicon nitride etching solution, and preparation method and application thereof
CN111925802A (en) Silicon etching liquid, preparation method and application thereof
SU1660407A1 (en) Niobatic barium-strontium pickling agent
CN111925803B (en) High-selectivity silicon nitride etching solution, and preparation method and application thereof
CN111925797B (en) High-selectivity silicon nitride etching solution, and preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant