US20080203060A1 - Etching method and etching composition useful for the method - Google Patents

Etching method and etching composition useful for the method Download PDF

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US20080203060A1
US20080203060A1 US12/039,050 US3905008A US2008203060A1 US 20080203060 A1 US20080203060 A1 US 20080203060A1 US 3905008 A US3905008 A US 3905008A US 2008203060 A1 US2008203060 A1 US 2008203060A1
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etching
silicon nitride
silicon
fluoride
composition
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Yasushi Hara
Akinori Shimono
Fumiharu Takahashi
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Tosoh Corp
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Tosoh Corp
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    • 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
    • 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

Definitions

  • the present invention relates to an etching composition for silicon nitride. More particularly, it relates to a composition capable of etching silicon nitride to be used for an insulating film for e.g. semiconductor devices or flat panel displays.
  • Silicon nitride is a very important compound as a ceramic material or a material for semiconductors.
  • a step wherein it is required to selectively etch only silicon nitride without presenting any damage to silicon oxide.
  • high purity phosphoric acid is mainly used.
  • high purity phosphoric acid has had a problem that when it is used at a high temperature of at least 150° C., damage to silicon oxide tends to be substantial.
  • hexafluorosilicic acid is a volatile substance, and at the operation temperature of at least 150° C., hexafluorosilicic acid tends to be volatile, whereby no constant effect of its addition is obtainable, and continuous use of such an etchant has been difficult. Further, in a case where hexafluorosilicic acid is added, precipitation of an insoluble silicon compound from the etchant tends to be accelerated, and it has been problematic to use it in an industrial operation.
  • a method for etching silicon nitride at a temperature of not higher than 100° C. a method of adding fluorosilicic acid or a fluorosilicate to an etchant comprising phosphoric acid, hydrofluoric acid and nitric acid, is disclosed.
  • an etching composition having both hydrofluoric acid and nitric acid added to phosphoric acid the damage to silicon oxide as another semiconductor material tends to be large, and it is problematic to use such a method for a semiconductor process, and such an adverse effect has been more remarkable when it is used at a high temperature.
  • Patent Document 1 JP-A-6-349808
  • Patent Document 2 JP-A-2000-133631
  • Patent Document 3 JP-A-8-64574
  • Patent Document 4 JP-B-3-20895
  • the present inventors have conducted an extensive study with respect to etching of silicon nitride and as a result, have found that with an etching composition comprising a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof, a silicon compound and/or a fluoride thereof, and water, it is possible to prevent the damage and precipitation of silicon oxide better than a conventional phosphoric acid etchant, and silicon nitride can be removed by etching constantly for a long period of time.
  • the present invention has been accomplished on the basis of this discovery.
  • the etching method for silicon nitride of the present invention employs a composition comprising a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof, a silicon compound and/or a fluoride thereof, and water.
  • the phosphorus compound and/or a fluoride thereof to be used in the etching method of the present invention is phosphoric acid or phosphorus fluoride.
  • the phosphoric acid or phosphorus fluoride to be used is not particularly limited, and one commonly available, may be used.
  • the phosphorus fluoride to be used in the etching method of the present invention is preferably at least one member selected from the group consisting of phosphorus trifluoride, phosphorus pentafluoride, HPF 6 , a fluorophosphoric acid such as HPO 2 F 2 or H 2 PO 3 F, and a fluorophosphate such as ammonium fluorophosphate.
  • the boron compound and/or a fluoride thereof to be used in the etching method of the present invention is preferably at least one member selected from the group consisting of boric acid, a borate such as ammonium borate, boron trifluoride, HBF 4 , a fluoroboric acid such as HBF 3 (OH), HBF 2 (OH) 2 or HBF(OH) 3 , and a fluoroborate such as ammonium fluoroborate.
  • the etching method of the present invention preferably employs a composition comprising phosphoric acid, from 0.001 to 10 wt % of a boron compound and/or phosphorus fluoride and from 1 to 30 wt % of water, particularly preferably a composition comprising from 0.001 to 1 wt % of a boron compound and from 15 to 30 wt % of water.
  • the boron compound and/or phosphorus fluoride is less than 0.001 wt %, the effect to prevent precipitation of silicon oxide tends to be small, and if more than 10 wt % of the boron compound and/or phosphorus fluoride is incorporated, the material which should not be etched, such as a silicon oxide film, is likely to be etched. Further, if water is less than 1 wt %, the etching rate of silicon nitride tends to be low, and if water exceeds 30 wt %, the boiling point of the etching composition tends to be low, and it tends to be difficult to maintain the temperature suitable for etching. Industrially, the boron compound and/or phosphorus fluoride is particularly preferably within a range of from 0.01 to 0.2 wt %.
  • the boron content in the composition to be used in the etching method of the present invention is preferably at least 0.014 wt %, more preferably from 0.014 wt % to 10 wt %, particularly preferably from 0.014 wt % to 5 wt %, from the viewpoint of the etching rate of silicon nitride, prevention of precipitation of silicon oxide and stability of selectivity.
  • the silicon compound and/or a fluoride thereof in the composition to be used in the etching method of the present invention is particularly preferably silicic acid, a silicate, hexafluorosilicic acid, a hexafluorosilicate, an alkoxysilane such as tetraethoxysilane or tetramethoxysilane, or an alkylsilane such as methyltrimethoxysilane, but a soluble silicon compound other than these may also be used.
  • an ammonium salt is preferred.
  • Silicic acid or a silicate may be one obtained by adding silicon oxide or the like to sulfuric acid or phosphoric acid, followed by heating for dissolution.
  • Hexafluorosilicic acid or a hexafluorosilicate may be one which is industrially available, or one obtained by reacting silicic acid with hydrofluoric acid and further converting it to its salt. By the addition of such a silicon compound, it is possible to reduce the damage to a silicon oxide film.
  • the concentration of a silicon compound in the etching method of the present invention is preferably from 0 to 0.5 wt %, particularly preferably from 0.001 to 0.1 wt %. If it is added more than 0.5 wt %, silicon oxide is likely to precipitate.
  • the silicon content in the composition in the etching method of the present invention is particularly preferably from 0.001 to 0.01 wt %, and the fluorine content is particularly preferably from 0.010 to 0.050 wt %. If the silicon content is less than 0.001 wt %, the etching rate of silicon oxide at the initial stage of batch is high, and the selectivity of the initial batch is low and tends to be hardly stabilized. On the other hand, if it is more than 0.01 wt %, the etching rate of silicon nitride will be low as the batch treatment is repeated, and the selectivity tends to be hardly stabilized.
  • etching method of the present invention high selectivity is obtainable from the initial stage of batch, and the stability is maintained over a long period of time.
  • the reason as to why such characteristics are obtainable is not necessarily clearly understood, but it is considered that in the etching composition, a composite compound of boron, silicon and fluorine (hydrofluoric acid) is formed, whereby an extremely stable state is maintained.
  • nitric acid and/or a nitrate it is preferred to add nitric acid and/or a nitrate.
  • nitric acid and/or a nitrate it is possible to reduce the damage to a silicon oxide film.
  • a phosphorus compound and/or a fluoride thereof a boric compound and/or a fluoride thereof, even when batch treatment is repeated, fluctuation of the selective etching of silicon nitride to silicon oxide is small, and the stability tends to be very high.
  • the nitrate it is preferred to use ammonium nitrate.
  • the concentration of nitric acid and/or a nitrate in the etching method of the present invention is preferably from 0 to 20 wt %, particularly from 0.0001 to 10 wt %, further preferably from 0.01 to 1 wt %, especially preferably from 0.01 to 0.2 wt %. On the other hand, if it exceeds 20 wt %, the etching rate of silicon nitride tends to decrease.
  • the etching method of the present invention exhibits an excellent performance when used for etching of silicon nitride, particularly for etching of silicon nitride to be used as an insulating film for semiconductor devices or flat panel displays.
  • silicon nitride is deposited to form a film on a semiconductor substrate by e.g. a CVD method (a chemical vapor phase deposition method), but to form an element or circuit, it is necessary to remove unnecessary portions by etching.
  • CVD method chemical vapor phase deposition method
  • the temperature for the etching method of the present invention is from 120 to 180° C., preferably from 130 to 170° C. If the temperature exceeds 180° C., a semiconductor material other than silicon nitride is likely to be damaged, and if the temperature is lower than 120° C., it tends to be difficult to carry out etching of silicon nitride at an industrially satisfactory rate.
  • the silicon concentration in the etchant becomes high.
  • a phosphorus compound and/or a fluoride thereof a boron compound and/or a fluoride thereof may additionally be added.
  • the boron compound or phosphorus fluoride may be added alone, or may be added as an etching composition of the present invention containing a boron compound and/or phosphorus fluoride.
  • the composition may be used while optionally adding at least one member selected from the group consisting of a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof, a silicon compound and/or a fluoride thereof, nitric acid and/or a nitrate, and water in the etching composition of the present invention.
  • the etching may be accelerated by using e.g. ultrasonic waves at the time of etching silicon nitride.
  • selectivity for etching of silicon nitride is high, there is no excess dissolution or precipitation of silicon oxide during etching for a long period of time, and silicon nitride can be selectively etched, whereby the productivity is high.
  • FIG. 1 is a graph showing the etching rates of silicon nitride under the conditions of Examples 11 to 13.
  • FIG. 2 is a graph showing the etching rates of silicon oxide under the conditions of Examples 11 to 13.
  • FIG. 3 is a graph showing the stability of the etching rates of silicon nitride under the conditions of Examples 11 to 13.
  • FIG. 4 is a graph showing the selectivities (silicon nitride/silicon oxide) under the conditions of Examples 11 to 13.
  • FIG. 5 is a graph showing the etching rates of silicon nitride under the conditions of Comparative Examples 2 and 3.
  • FIG. 6 is a graph showing the etching rates of silicon oxide under the conditions of Comparative Examples 2 and 3. (Negative etching rates indicate precipitation of silicon oxide.)
  • FIG. 7 is a graph showing the etching rates of silicon nitride under the conditions of Examples 9 and 10.
  • FIG. 8 is a graph showing the etching rates of silicon oxide under the conditions of Examples 9 and 10.
  • a silicon wafer (15 mm square) having SiN deposited in a thickness of 300 nm by a CVD method and a silicon wafer (15 mm square) having a thermally oxidized film formed in a thickness of 1,000 nm were immersed at 150° C. for 30 minutes in 100 g of an etching composition comprising 0.02% of fluoroboric acid, 0.002% of ammonia, 5% of water and the rest being phosphoric acid.
  • the wafers were taken out, washed with water and dried, and then the film thicknesses of SiN and the thermally oxidized film were measured by an optical interferotype film thickness meter. This operation was regarded as 1 batch and was continuously repeated for 14 batches.
  • the SiN etching rate was 6.10 nm/min, and the etching rate of the thermally oxidized film was 0.03 nm/min. Even in the 14th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • This etching composition initially started in a state where it contained no soluble silicic acid, but immediately after the initiation of its use, the composition became a state where it contained soluble silicic acid.
  • the etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was found to be improved from 18 in the first batch to 130 in the 14th batch.
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition having 0.03% of hexafluorosilicic acid further added to the composition in Example 1.
  • the selectivity for silicon nitride to silicon oxide was 220 from the first batch and thus was high from the beginning.
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition wherein 0.02% of fluoroboric acid in the composition in Example 1 was changed to 0.02% of fluorophosphoric acid.
  • the SiN etching rate was 6.00 nm/min, and the etching rate of the thermally oxidized film was 0.06 nm/min. Even in the 14th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • This etching composition initially started in a state where it contained no soluble silicic acid, but immediately after the initiation of its use, the composition was in a state where it contained soluble silicic acid.
  • the etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was found to be 15 in the first batch but 100 in the 14th batch.
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition wherein in the composition in Example 1, 0.02% of fluoroboric acid was changed to 0.01% of fluoroboric acid and 0.01% of fluorophosphoric acid.
  • the SiN etching rate was 6.00 nm/min, and the etching rate of the thermally oxidized film was 0.05 nm/min. Even in the 14th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • the etching composition initially started in a state where it contained no soluble silicic acid, but immediately after the initiation of its use, the composition was in a state where it contained soluble silicic acid.
  • the etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was 16 in the first batch, but 120 in the 14th batch.
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition wherein to the composition in Example 1, 0.03% of hexafluorosilicic acid was further added.
  • the selectivity for silicon nitride to silicon oxide was 200 from the first batch and thus was high from the beginning.
  • Etching of silicon nitride was carried out under the same conditions as in Example 5 by using a composition wherein in the composition in Example 5, 0.02% of fluoroboric acid was changed to 0.05% of fluoroboric acid, and 0.1% of nitric acid was further added. 0.05% fluoroboric acid was added in an amount of 4% to every batch, and on the first batch, SiN etching rate was 5.42 nm/min, and in the 12th batch, the SiN etching rate was 5.00 nm/min, and the etching rate of the thermally oxidized film was 0.01 nm/min. Even in the 12th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found slightly etched.
  • the etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby the selectivity was 325 in the first batch and thus was high from the beginning, and it was 440 in the 12th batch and thus was maintained at a high level.
  • Etching of silicon nitride was carried out under the same conditions as in Example 5 by using a composition wherein in the composition in Example 6, 0.1% of nitric acid was changed to 1% of nitric acid.
  • the SiN etching rate was 5.57 nm/min
  • the SiN etching rate was 5.02 nm/min
  • the etching rate of the thermally oxidized film was 0.02 nm/min. Even in the 12th batch, no precipitation of silicon oxide was found in the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition wherein in the composition in Example 1, 0.02% of fluoroboric acid was changed to 0.05% of fluoroboric acid, and 0.1% of ammonium nitrate was further added.
  • the SiN etching rate was 5.44 nm/min, and in the 12th batch, the SiN etching rate was 4.99 nm/min, and the etching rate of the thermally oxidized film was 0.01 nm/min. Even in the 12th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • the etching composition initially started in a state where it contained no soluble silicic acid, but immediately after the initiation of its use, the composition was in a state where it contained soluble silicic acid.
  • the etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was 340 in the first batch and thus was high from the beginning, and it was 441 in the 12th batch.
  • Etching was carried out in the same manner as in Example 1 except that to the etching composition comprising 0.03% of hexafluorosilicic acid, 2.5% of water and the rest being phosphoric acid, 0.05% fluoroboric acid was added to every batch in an amount of 4% per batch.
  • Etching was carried out in the same manner as in Example 1 except that to the composition in Example 9, 0.1% (1,000 ppm) of nitric acid was further added.
  • Example 9 there was no decrease in the etching rate of silicon nitride, and etching of silicon oxide was also maintained to be at a very low level, but particularly after the batch was repeated, the selectivity was higher than in Example 9.
  • Example 10 Number of batches (Absence of HNO 3 ) (Presence of HNO 3 ) 1 297 325 2 197 371 3 325 519 4 338 416 5 189 242 8 150 354 10 144 206 11 106 376 12 118 439
  • Etching was carried out in the same manner as in Example 1 except that to an etching composition comprising 0.0043% of silicon, 0.0174% of fluorine, 0.015% of boron (corresponding to 0.022% of hexafluorosilicic acid and 0.086% of boric acid), 3.75% of water and the rest being phosphoric acid, 0.05% fluoroboric acid was added to every batch in an amount of 4.5% per batch, and evaluation was carried out at 155° C.
  • Etching of silicon nitride was carried out under the same conditions as in Example 11 except that silicon was 0.0039% and fluorine was 0.0158% (corresponding to 0.02% of hexafluorosilicic acid).
  • Etching of silicon nitride was carried out under the same conditions as in Example 11 except that silicon was 0.0049%, and fluorine was 0.0198% (corresponding to 0.025% of hexafluorosilicic acid).
  • Etching was carried out in the same manner as in Example 1 except that neither fluoroboric acid nor fluorophosphoric acid was added.
  • the SiN etching rate was 2.49 nm/min.
  • precipitation of silicon oxide was observed on the thermally oxidized film, and the thickness of the thermally oxidized film was found to be increased.
  • Etching was carried out in the same manner as in Example 1 by using an etching composition comprising 0.03% of hexafluorosilicic acid, 2.5% of water and the rest being phosphoric acid.
  • Etching of silicon nitride was carried out under the same conditions as in Example 5 by using a composition wherein in the composition in Example 5, 0.02% of fluoroboric acid was changed to 1% of fluoroboric acid, and further 0.1% of nitric acid was added.
  • the etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby the selectivity was very low at a level of 0.5 in the first batch and 0.7 in the 12th batch.

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Abstract

In etching of silicon nitride with a phosphorus type, if etching is carried for a long time, silicon oxide tends to precipitate, and it has been impossible to constantly carry out the etching for a long period of time.
By an etching method for silicon nitride using a composition comprising a phosphorus compound, a boron compound, a silicon compound and/or their fluorides thereof, there will be no precipitation of silicon oxide even when the composition is used for a long time. It is particularly preferred to further add nitric acid and/or a nitrate, whereby stability of selectivity will be increased.

Description

    BACKGROUND OF THE INVENTION
  • 1. Field of the Invention
  • The present invention relates to an etching composition for silicon nitride. More particularly, it relates to a composition capable of etching silicon nitride to be used for an insulating film for e.g. semiconductor devices or flat panel displays.
  • 2. Discussion of Background
  • Silicon nitride is a very important compound as a ceramic material or a material for semiconductors. In a process for producing semiconductors, there is a step wherein it is required to selectively etch only silicon nitride without presenting any damage to silicon oxide. At present, in this step, high purity phosphoric acid is mainly used. However, high purity phosphoric acid has had a problem that when it is used at a high temperature of at least 150° C., damage to silicon oxide tends to be substantial.
  • As a means to suppress such damage to silicon oxide, high purity phosphoric acid having silicon dissolved therein or phosphoric acid having hexafluorosilicic acid added thereto, has been proposed (Patent Documents 1 to 3). However, hexafluorosilicic acid is a volatile substance, and at the operation temperature of at least 150° C., hexafluorosilicic acid tends to be volatile, whereby no constant effect of its addition is obtainable, and continuous use of such an etchant has been difficult. Further, in a case where hexafluorosilicic acid is added, precipitation of an insoluble silicon compound from the etchant tends to be accelerated, and it has been problematic to use it in an industrial operation.
  • On the other hand, in a wet etching device for semiconductors, etching is carried out while removing foreign particles, etc. in the etchant by subjecting the etchant to filtration and recycling to keep it clean. Also in etching of silicon nitride with a heated phosphoric acid aqueous solution, a method of removing precipitates by similar filtration and recycling, has been proposed (Patent Document 4). However, there has been a problem that such a precipitated silicon compound tends to adhere to semiconductor wafers, etc., before being filtered off.
  • As a method for etching silicon nitride at a temperature of not higher than 100° C., a method of adding fluorosilicic acid or a fluorosilicate to an etchant comprising phosphoric acid, hydrofluoric acid and nitric acid, is disclosed. However, with an etching composition having both hydrofluoric acid and nitric acid added to phosphoric acid, the damage to silicon oxide as another semiconductor material tends to be large, and it is problematic to use such a method for a semiconductor process, and such an adverse effect has been more remarkable when it is used at a high temperature.
  • Thus, heretofore, there has been no etching composition which is capable of selectively etching silicon nitride at a high temperature constantly for a long period of time.
  • Patent Document 1: JP-A-6-349808
  • Patent Document 2: JP-A-2000-133631
  • Patent Document 3: JP-A-8-64574
  • Patent Document 4: JP-B-3-20895
    • SUMMARY OF THE INVENTION
  • In view of the above described problems, it is an object of the present invention to provide an etching method for silicon nitride, whereby frequency of replacing a phosphoric acid etchant can be reduced, i.e. a phosphoric acid etchant can be constantly used over a long period of time and whereby the damage to silicon oxide by high purity phosphoric acid and precipitation are prevented.
  • The present inventors have conducted an extensive study with respect to etching of silicon nitride and as a result, have found that with an etching composition comprising a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof, a silicon compound and/or a fluoride thereof, and water, it is possible to prevent the damage and precipitation of silicon oxide better than a conventional phosphoric acid etchant, and silicon nitride can be removed by etching constantly for a long period of time. The present invention has been accomplished on the basis of this discovery.
    • DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
  • Now, the present invention will be described in further detail.
  • The etching method for silicon nitride of the present invention employs a composition comprising a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof, a silicon compound and/or a fluoride thereof, and water.
  • The phosphorus compound and/or a fluoride thereof to be used in the etching method of the present invention is phosphoric acid or phosphorus fluoride. The phosphoric acid or phosphorus fluoride to be used, is not particularly limited, and one commonly available, may be used.
  • The phosphorus fluoride to be used in the etching method of the present invention is preferably at least one member selected from the group consisting of phosphorus trifluoride, phosphorus pentafluoride, HPF6, a fluorophosphoric acid such as HPO2F2 or H2PO3F, and a fluorophosphate such as ammonium fluorophosphate.
  • The boron compound and/or a fluoride thereof to be used in the etching method of the present invention is preferably at least one member selected from the group consisting of boric acid, a borate such as ammonium borate, boron trifluoride, HBF4, a fluoroboric acid such as HBF3(OH), HBF2(OH)2 or HBF(OH)3, and a fluoroborate such as ammonium fluoroborate.
  • The etching method of the present invention preferably employs a composition comprising phosphoric acid, from 0.001 to 10 wt % of a boron compound and/or phosphorus fluoride and from 1 to 30 wt % of water, particularly preferably a composition comprising from 0.001 to 1 wt % of a boron compound and from 15 to 30 wt % of water.
  • If the boron compound and/or phosphorus fluoride is less than 0.001 wt %, the effect to prevent precipitation of silicon oxide tends to be small, and if more than 10 wt % of the boron compound and/or phosphorus fluoride is incorporated, the material which should not be etched, such as a silicon oxide film, is likely to be etched. Further, if water is less than 1 wt %, the etching rate of silicon nitride tends to be low, and if water exceeds 30 wt %, the boiling point of the etching composition tends to be low, and it tends to be difficult to maintain the temperature suitable for etching. Industrially, the boron compound and/or phosphorus fluoride is particularly preferably within a range of from 0.01 to 0.2 wt %.
  • The boron content in the composition to be used in the etching method of the present invention is preferably at least 0.014 wt %, more preferably from 0.014 wt % to 10 wt %, particularly preferably from 0.014 wt % to 5 wt %, from the viewpoint of the etching rate of silicon nitride, prevention of precipitation of silicon oxide and stability of selectivity.
  • The silicon compound and/or a fluoride thereof in the composition to be used in the etching method of the present invention is particularly preferably silicic acid, a silicate, hexafluorosilicic acid, a hexafluorosilicate, an alkoxysilane such as tetraethoxysilane or tetramethoxysilane, or an alkylsilane such as methyltrimethoxysilane, but a soluble silicon compound other than these may also be used. As the silicate or the hexafluorosilicate, an ammonium salt is preferred. Silicic acid or a silicate may be one obtained by adding silicon oxide or the like to sulfuric acid or phosphoric acid, followed by heating for dissolution. Hexafluorosilicic acid or a hexafluorosilicate may be one which is industrially available, or one obtained by reacting silicic acid with hydrofluoric acid and further converting it to its salt. By the addition of such a silicon compound, it is possible to reduce the damage to a silicon oxide film.
  • The concentration of a silicon compound in the etching method of the present invention is preferably from 0 to 0.5 wt %, particularly preferably from 0.001 to 0.1 wt %. If it is added more than 0.5 wt %, silicon oxide is likely to precipitate.
  • The silicon content in the composition in the etching method of the present invention is particularly preferably from 0.001 to 0.01 wt %, and the fluorine content is particularly preferably from 0.010 to 0.050 wt %. If the silicon content is less than 0.001 wt %, the etching rate of silicon oxide at the initial stage of batch is high, and the selectivity of the initial batch is low and tends to be hardly stabilized. On the other hand, if it is more than 0.01 wt %, the etching rate of silicon nitride will be low as the batch treatment is repeated, and the selectivity tends to be hardly stabilized.
  • By the etching method of the present invention, high selectivity is obtainable from the initial stage of batch, and the stability is maintained over a long period of time. The reason as to why such characteristics are obtainable is not necessarily clearly understood, but it is considered that in the etching composition, a composite compound of boron, silicon and fluorine (hydrofluoric acid) is formed, whereby an extremely stable state is maintained.
  • In the etching method of the present invention, it is preferred to add nitric acid and/or a nitrate. By the addition of nitric acid and/or a nitrate, it is possible to reduce the damage to a silicon oxide film. Particularly when nitric acid and/or a nitrate is used in combination with a phosphorus compound and/or a fluoride thereof, a boric compound and/or a fluoride thereof, even when batch treatment is repeated, fluctuation of the selective etching of silicon nitride to silicon oxide is small, and the stability tends to be very high. As the nitrate, it is preferred to use ammonium nitrate. The concentration of nitric acid and/or a nitrate in the etching method of the present invention is preferably from 0 to 20 wt %, particularly from 0.0001 to 10 wt %, further preferably from 0.01 to 1 wt %, especially preferably from 0.01 to 0.2 wt %. On the other hand, if it exceeds 20 wt %, the etching rate of silicon nitride tends to decrease.
  • The etching method of the present invention exhibits an excellent performance when used for etching of silicon nitride, particularly for etching of silicon nitride to be used as an insulating film for semiconductor devices or flat panel displays. In a semiconductor device, silicon nitride is deposited to form a film on a semiconductor substrate by e.g. a CVD method (a chemical vapor phase deposition method), but to form an element or circuit, it is necessary to remove unnecessary portions by etching. By using the etching method of the present invention, it is possible to selectively etch silicon nitride constantly for a long period of time.
  • The temperature for the etching method of the present invention is from 120 to 180° C., preferably from 130 to 170° C. If the temperature exceeds 180° C., a semiconductor material other than silicon nitride is likely to be damaged, and if the temperature is lower than 120° C., it tends to be difficult to carry out etching of silicon nitride at an industrially satisfactory rate. In the etching method of the present invention, as etching of silicon nitride proceeds, the silicon concentration in the etchant becomes high. In order to is avoid such a phenomenon, a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof may additionally be added. The boron compound or phosphorus fluoride may be added alone, or may be added as an etching composition of the present invention containing a boron compound and/or phosphorus fluoride.
  • Further, in a case where batch treatment is repeated, some components of the etching composition of the present invention will be consumed or evaporated, whereby the effects of the present invention may decrease. Therefore, the composition may be used while optionally adding at least one member selected from the group consisting of a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof, a silicon compound and/or a fluoride thereof, nitric acid and/or a nitrate, and water in the etching composition of the present invention.
  • In the etching method of the present invention, the etching may be accelerated by using e.g. ultrasonic waves at the time of etching silicon nitride.
    • EFFECTS OF THE INVENTION
  • According to the etching method of the present invention, selectivity for etching of silicon nitride is high, there is no excess dissolution or precipitation of silicon oxide during etching for a long period of time, and silicon nitride can be selectively etched, whereby the productivity is high.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a graph showing the etching rates of silicon nitride under the conditions of Examples 11 to 13.
  • FIG. 2 is a graph showing the etching rates of silicon oxide under the conditions of Examples 11 to 13.
  • FIG. 3 is a graph showing the stability of the etching rates of silicon nitride under the conditions of Examples 11 to 13.
  • FIG. 4 is a graph showing the selectivities (silicon nitride/silicon oxide) under the conditions of Examples 11 to 13.
  • FIG. 5 is a graph showing the etching rates of silicon nitride under the conditions of Comparative Examples 2 and 3.
  • FIG. 6 is a graph showing the etching rates of silicon oxide under the conditions of Comparative Examples 2 and 3. (Negative etching rates indicate precipitation of silicon oxide.)
  • FIG. 7 is a graph showing the etching rates of silicon nitride under the conditions of Examples 9 and 10.
  • FIG. 8 is a graph showing the etching rates of silicon oxide under the conditions of Examples 9 and 10.
    •
  • Now, the present invention will be described in further detail with reference to Examples, but it should be understood that the present invention is by no means restricted thereto. In the following Examples, “%” means “wt %”
    • Example 1
  • A silicon wafer (15 mm square) having SiN deposited in a thickness of 300 nm by a CVD method and a silicon wafer (15 mm square) having a thermally oxidized film formed in a thickness of 1,000 nm were immersed at 150° C. for 30 minutes in 100 g of an etching composition comprising 0.02% of fluoroboric acid, 0.002% of ammonia, 5% of water and the rest being phosphoric acid. The wafers were taken out, washed with water and dried, and then the film thicknesses of SiN and the thermally oxidized film were measured by an optical interferotype film thickness meter. This operation was regarded as 1 batch and was continuously repeated for 14 batches. In the 14th batch, the SiN etching rate was 6.10 nm/min, and the etching rate of the thermally oxidized film was 0.03 nm/min. Even in the 14th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • This etching composition initially started in a state where it contained no soluble silicic acid, but immediately after the initiation of its use, the composition became a state where it contained soluble silicic acid. The etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was found to be improved from 18 in the first batch to 130 in the 14th batch.
    • Example 2
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition having 0.03% of hexafluorosilicic acid further added to the composition in Example 1.
  • Even in the 14th batch, no precipitation of silicon oxide was observed.
  • The selectivity for silicon nitride to silicon oxide was 220 from the first batch and thus was high from the beginning.
    • Example 3
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition wherein 0.02% of fluoroboric acid in the composition in Example 1 was changed to 0.02% of fluorophosphoric acid.
  • In the 14th batch, the SiN etching rate was 6.00 nm/min, and the etching rate of the thermally oxidized film was 0.06 nm/min. Even in the 14th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • This etching composition initially started in a state where it contained no soluble silicic acid, but immediately after the initiation of its use, the composition was in a state where it contained soluble silicic acid. The etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was found to be 15 in the first batch but 100 in the 14th batch.
    • Example 4
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition wherein in the composition in Example 1, 0.02% of fluoroboric acid was changed to 0.01% of fluoroboric acid and 0.01% of fluorophosphoric acid.
  • In the 14th batch, the SiN etching rate was 6.00 nm/min, and the etching rate of the thermally oxidized film was 0.05 nm/min. Even in the 14th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • The etching composition initially started in a state where it contained no soluble silicic acid, but immediately after the initiation of its use, the composition was in a state where it contained soluble silicic acid. The etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was 16 in the first batch, but 120 in the 14th batch.
    • Example 5
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition wherein to the composition in Example 1, 0.03% of hexafluorosilicic acid was further added.
  • 0.02% of fluoroboric acid was added in an amount of 4% to every batch, and even in the 14th batch, no precipitation of silicon oxide was observed.
  • The selectivity for silicon nitride to silicon oxide was 200 from the first batch and thus was high from the beginning.
    • Example 6
  • Etching of silicon nitride was carried out under the same conditions as in Example 5 by using a composition wherein in the composition in Example 5, 0.02% of fluoroboric acid was changed to 0.05% of fluoroboric acid, and 0.1% of nitric acid was further added. 0.05% fluoroboric acid was added in an amount of 4% to every batch, and on the first batch, SiN etching rate was 5.42 nm/min, and in the 12th batch, the SiN etching rate was 5.00 nm/min, and the etching rate of the thermally oxidized film was 0.01 nm/min. Even in the 12th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found slightly etched.
  • The etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby the selectivity was 325 in the first batch and thus was high from the beginning, and it was 440 in the 12th batch and thus was maintained at a high level.
    • Example 7
  • Etching of silicon nitride was carried out under the same conditions as in Example 5 by using a composition wherein in the composition in Example 6, 0.1% of nitric acid was changed to 1% of nitric acid.
  • In the first batch, the SiN etching rate was 5.57 nm/min, and in the 12th batch, the SiN etching rate was 5.02 nm/min, and the etching rate of the thermally oxidized film was 0.02 nm/min. Even in the 12th batch, no precipitation of silicon oxide was found in the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • The etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was 220 in the first batch and 328 in the 12th batch.
    • Example 8
  • Etching of silicon nitride was carried out under the same conditions as in Example 1 by using a composition wherein in the composition in Example 1, 0.02% of fluoroboric acid was changed to 0.05% of fluoroboric acid, and 0.1% of ammonium nitrate was further added.
  • In the first batch, the SiN etching rate was 5.44 nm/min, and in the 12th batch, the SiN etching rate was 4.99 nm/min, and the etching rate of the thermally oxidized film was 0.01 nm/min. Even in the 12th batch, no precipitation of silicon oxide was observed on the thermally oxidized film, and the thermally oxidized film was found to be slightly etched.
  • The etching composition initially started in a state where it contained no soluble silicic acid, but immediately after the initiation of its use, the composition was in a state where it contained soluble silicic acid. The etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby it was 340 in the first batch and thus was high from the beginning, and it was 441 in the 12th batch.
    • Example 9
  • Etching was carried out in the same manner as in Example 1 except that to the etching composition comprising 0.03% of hexafluorosilicic acid, 2.5% of water and the rest being phosphoric acid, 0.05% fluoroboric acid was added to every batch in an amount of 4% per batch.
  • Even when the batch was repeated, there was no decrease in the etching rate of silicon nitride, and etching of silicon oxide was also maintained to be at a very low level.
    • Example 10
  • Etching was carried out in the same manner as in Example 1 except that to the composition in Example 9, 0.1% (1,000 ppm) of nitric acid was further added.
  • Like in Example 9, there was no decrease in the etching rate of silicon nitride, and etching of silicon oxide was also maintained to be at a very low level, but particularly after the batch was repeated, the selectivity was higher than in Example 9.
  • TABLE 1
    Selectivity
    Example 9 Example 10
    Number of batches (Absence of HNO3) (Presence of HNO3)
    1 297 325
    2 197 371
    3 325 519
    4 338 416
    5 189 242
    8 150 354
    10 144 206
    11 106 376
    12 118 439
    • Example 11
  • Etching was carried out in the same manner as in Example 1 except that to an etching composition comprising 0.0043% of silicon, 0.0174% of fluorine, 0.015% of boron (corresponding to 0.022% of hexafluorosilicic acid and 0.086% of boric acid), 3.75% of water and the rest being phosphoric acid, 0.05% fluoroboric acid was added to every batch in an amount of 4.5% per batch, and evaluation was carried out at 155° C.
  • By this composition, a constant selectivity was obtained from the first batch, and there was no decrease in the etching rate of silicon nitride even when the is batch was repeated.
    • Example 12
  • Etching of silicon nitride was carried out under the same conditions as in Example 11 except that silicon was 0.0039% and fluorine was 0.0158% (corresponding to 0.02% of hexafluorosilicic acid).
  • There was no decrease in the etching rate of silicon nitride even when the batch was repeated, but the etching rate of the thermally oxidized film in the first and second batches was at least 0.05 nm/min and thus was larger than in Example 11.
    • Example 13
  • Etching of silicon nitride was carried out under the same conditions as in Example 11 except that silicon was 0.0049%, and fluorine was 0.0198% (corresponding to 0.025% of hexafluorosilicic acid).
  • Although etching of silicon oxide was maintained to be at a low level, a decrease in the etching rate of silicon nitride was observed up to the third batch.
    • Comparative Example 1
  • Etching was carried out in the same manner as in Example 1 except that neither fluoroboric acid nor fluorophosphoric acid was added. In the 14th batch, the SiN etching rate was 2.49 nm/min. In the 14th batch, precipitation of silicon oxide was observed on the thermally oxidized film, and the thickness of the thermally oxidized film was found to be increased.
    • Comparative Example 2
  • Etching was carried out in the same manner as in Example 1 by using an etching composition comprising 0.03% of hexafluorosilicic acid, 2.5% of water and the rest being phosphoric acid.
  • As the batch was repeated, the etching rate of silicon nitride decreased.
    • Comparative Example 3
  • To the composition in Comparative Example 2, 0.1% hexafluorosilicic acid was sequentially added to every batch in an amount of 4% per batch.
  • Even when the batch was repeated, there was no decrease in the etching rate of silicon nitride, but in the 5th batch et seq., precipitation of silicon oxide took place, and it was impossible to continue the operation.
    • Comparative Example 4
  • Etching of silicon nitride was carried out under the same conditions as in Example 5 by using a composition wherein in the composition in Example 5, 0.02% of fluoroboric acid was changed to 1% of fluoroboric acid, and further 0.1% of nitric acid was added.
  • 1.5% of fluoroboric acid was added in an amount of 4% to every batch, and in the first batch, the SiN etching rate was 45.4 nm/min, and the etching rate of the thermally oxidized film was 84.6 nm/min. In the 12th batch, the SiN etching rate was 49.0 nm/min, and the etching rate of the thermally oxidized film was 70.1 nm/min.
  • The etching selectivity for silicon nitride to silicon oxide (silicon nitride/silicon oxide) in each batch was examined, whereby the selectivity was very low at a level of 0.5 in the first batch and 0.7 in the 12th batch.
  • The entire disclosures of Japanese Patent Application No. 2007-048606 filed on Feb. 28, 2007, Japanese Patent Application No. 2007-157973 filed on Jun. 14, 2007 and Japanese Patent Application No. 2007-330109 filed on Dec. 21, 2007 including specifications, claims, drawings and summaries are incorporated herein by reference in their entireties.

Claims (11)

1. An etching method for silicon nitride, which comprises etching silicon nitride with a composition comprising a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof, a silicon compound and/or a fluoride thereof, and water.
2. The etching method for silicon nitride according to claim 1, wherein the phosphorus compound and/or a fluoride thereof is at least one member selected from the group consisting of phosphoric acid, phosphorus fluoride, phosphorus trifluoride, phosphorus pentafluoride, fluorophosphoric acid and a fluorophosphate.
3. The etching method for silicon nitride according to claim 1, wherein the boron compound and/or a fluoride thereof is at least one member selected from the group consisting of boric acid, a borate, boron fluoride, boron trifluoride, fluoroboric acid and a fluoroborate.
4. The etching method for silicon nitride according to claim 1, wherein the silicon compound and/or a fluoride thereof is at least one member selected from the group consisting of a silicon halide, hexafluorosilicic acid, a hexafluorosilicate, an alkoxysilane, an alkylsilane, silicic acid, a silicate, silicon fluoride, silicon chloride, ammonium hexafluorosilicate, tetraethoxysilane, tetramethoxysilane and methyltrimethoxysilane.
5. The etching method for silicon nitride according to claim 1, wherein the boron content in the composition is from 0.001 to 10 wt %.
6. The etching method for silicon nitride according to claim 1, wherein the silicon content in the composition is from 0.001 to 0.01 wt %.
7. The etching method for silicon nitride according to claim 1, wherein the fluorine content in the composition is from 0.010 to 0.050 wt %.
8. The etching method for silicon nitride according to claim 1, wherein the composition further contains nitric acid and/or a nitrate.
9. The etching method for silicon nitride according to claim 1, wherein etching is carried out at a temperature of from 120° C. to 180° C.
10. The etching method for silicon nitride according to claim 1, wherein at least one member selected from the group consisting of a phosphorus compound and/or a fluoride thereof, a boron compound and/or a fluoride thereof, a silicon compound and/or a fluoride thereof, nitric acid and/or a nitrate, and water, is additionally added.
11. An etching composition for silicon nitride as defined in claim 1.
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US20130011936A1 (en) * 2007-10-19 2013-01-10 International Business Machines Corporation Selective etching bath methods
US20150111390A1 (en) * 2013-10-23 2015-04-23 Taiwan Semiconductor Manufacturing Co., Ltd. Method of selectively removing silicon nitride and single wafer etching apparatus thereof
US20150214474A1 (en) * 2012-08-29 2015-07-30 Tokyo Electron Limited Etching method and substrate processing apparatus
US20160126107A1 (en) * 2014-10-30 2016-05-05 Ram Technology Co., Ltd. Etchant compositions for nitride layers and methods of manufacturing semiconductor devices using the same
US9550940B2 (en) 2012-10-16 2017-01-24 Hitachi Chemical Company, Ltd. Etching material
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US11421157B2 (en) 2019-08-21 2022-08-23 Entegris, Inc. Formulations for high selective silicon nitride etch

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3607480A (en) * 1968-12-30 1971-09-21 Texas Instruments Inc Process for etching composite layered structures including a layer of fluoride-etchable silicon nitride and a layer of silicon dioxide
US3811974A (en) * 1971-07-19 1974-05-21 North American Rockwell Silicon nitride-silicon oxide etchant
US3859222A (en) * 1971-07-19 1975-01-07 North American Rockwell Silicon nitride-silicon oxide etchant
US4980017A (en) * 1988-10-01 1990-12-25 Nisso Engineering Company, Ltd. Method for recirculating high-temperature etching solution
US5472562A (en) * 1994-08-05 1995-12-05 At&T Corp. Method of etching silicon nitride
US5965465A (en) * 1997-09-18 1999-10-12 International Business Machines Corporation Etching of silicon nitride
US6303514B1 (en) * 1998-08-28 2001-10-16 Ashland Inc. Composition and method for selectively etching a silicon nitride film
US20100244153A1 (en) * 2009-03-31 2010-09-30 Taiwan Semiconductor Manufacturing Company, Ltd. Method of fabricating spacers in a strained semiconductor device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3607480A (en) * 1968-12-30 1971-09-21 Texas Instruments Inc Process for etching composite layered structures including a layer of fluoride-etchable silicon nitride and a layer of silicon dioxide
US3811974A (en) * 1971-07-19 1974-05-21 North American Rockwell Silicon nitride-silicon oxide etchant
US3859222A (en) * 1971-07-19 1975-01-07 North American Rockwell Silicon nitride-silicon oxide etchant
US4980017A (en) * 1988-10-01 1990-12-25 Nisso Engineering Company, Ltd. Method for recirculating high-temperature etching solution
US5472562A (en) * 1994-08-05 1995-12-05 At&T Corp. Method of etching silicon nitride
US5965465A (en) * 1997-09-18 1999-10-12 International Business Machines Corporation Etching of silicon nitride
US6303514B1 (en) * 1998-08-28 2001-10-16 Ashland Inc. Composition and method for selectively etching a silicon nitride film
US20100244153A1 (en) * 2009-03-31 2010-09-30 Taiwan Semiconductor Manufacturing Company, Ltd. Method of fabricating spacers in a strained semiconductor device

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* Cited by examiner, † Cited by third party
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US9882124B2 (en) * 2012-08-29 2018-01-30 Tokyo Electron Limited Etching method and substrate processing apparatus
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US9550940B2 (en) 2012-10-16 2017-01-24 Hitachi Chemical Company, Ltd. Etching material
US10269591B2 (en) * 2013-10-23 2019-04-23 Taiwan Semiconductor Manufacturing Co., Ltd. Method of selectively removing silicon nitride and single wafer etching apparatus thereof
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US9868902B2 (en) 2014-07-17 2018-01-16 Soulbrain Co., Ltd. Composition for etching
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