Etching method using hexafluoropropene

Abstract

This disclosure aims to provide a new etching method using hexafluoropropene. [Solution] An etching method using hexafluoropropene.

Description

[Technical Field]

[0001] This disclosure relates to an etching method using hexafluoropropene. [Background technology]

[0002] Patent Document 1 discloses a method for etching silicon-based materials such as silicon oxide films and / or low dielectric constant films containing silicon using hexafluoropropene. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication Number WO02 / 021586-A1 [Overview of the project] [Problems that the invention aims to solve]

[0004] This disclosure aims to provide a new etching method using hexafluoropropene. [Means for solving the problem]

[0005] This disclosure includes the following components:

[0006] Section 1. (1) Hexafluoropropene, and (2) Hexafluorocyclopropane, pentafluoropropene, and hexafluoro At least one selected from the group consisting of dimers and / or trimmers derived from olopropene Seed components Etching gas containing [this substance].

[0007] Section 2. With respect to the total amount of etching gas, The above (1) contains 95% to 99.99999% by volume of hexafluoropropene, At least one component selected from the group consisting of the above (2) hexafluorocyclopropane, pentafluoropropene, and dimers and / or trimers derived from hexafluoropropene is contained at 1 volume ppm to 1,000 volume ppm, The etching gas according to item 1 above.

[0008] Item 3. Etching a silicon-based material on which a silicon oxide film or a silicon nitride film is formed with the gas plasma of the etching gas according to item 1 above. An etching method.

[0009] Item 4. The above etching gas and (3) An inert gas are separately and continuously supplied to generate an etching mixed gas in the chamber, The etching method according to item 3 above for etching a silicon-based material.

[0010] Item 5. The above etching gas and (4) An oxidizing gas and / or a reducing gas are separately and continuously supplied to generate an etching mixed gas in the chamber, The etching method according to item 3 above for etching a silicon-based material.

[0011] Item 6. The above etching gas and (3) An inert gas, and (4) An oxidizing gas and / or a reducing gas are separately and continuously supplied to generate an etching mixed gas in the chamber, The etching method according to item 3 above for etching a silicon-based material.

[0012] Item 7. The silicon-based material is a substrate for semiconductor manufacturing. The etching method according to any one of items 3 to 6 above.​​​​​

[0013] The etching gas of the present disclosure contains at least one component selected from the group consisting of (1) hexafluoropropene and (2) hexafluorocyclopropane, pentafluoropropene, and dimers and / or trimers derived from hexafluoropropene. When using the etching gas of the present disclosure to perform hole etching on a silicon-based material containing a silicon oxide film (SiO2 film) or a silicon nitride film (SiN film), side etching can be reduced, and etching can be performed while maintaining a good processed shape of the hole (deep hole). 示のエッチングガスを用いて、シリコン酸化膜(SiO2膜)、或はシリコン窒化膜(SiN膜 )を含有するシリコン系材料に対して、ホールエッチングを行うと、サイドエッチングを低減させる事が出来、ホール(深孔)の加工形状を良好に保持したエッチングを行う事が出来る。

Effect of the Invention

[0014] According to the present disclosure, a new etching method using hexafluoropropene can be provided.

Mode for Carrying Out the Invention

[0015] In this specification, "contains" is a concept that encompasses any of "comprise", "consist essentially of", and "consist of". In this specification, when a numerical range is indicated as "A to B", it means "A or more and B or less". In this specification, when expressions such as parts and % are used, these represent parts by mass, parts by weight, mass %, or weight % (wt%).

[0016] [1] Etching gas Conventionally, in semiconductor manufacturing, hexafluoropropene has been used as an etching gas to perform etching of deep holes (holes).

[0017] However, when using hexafluoropropene alone as the etching gas during hole etching, side etching occurs, and the processed shape of the hole cannot be adequately maintained, requiring further investigation. Currently, there are processes that use hexafluoro-1,3-butadiene (C4F6) to maintain the processed shape of the hole, but hexafluoro-1,3-butadiene is an expensive gas, which increases the cost of hole etching.

[0018] This disclosure includes etching gases containing hexafluoropropene, which are used to etch semiconductor manufacturing substrates during semiconductor manufacturing.

[0019] The etching gas of this disclosure contains (1) hexafluoropropene as the first component. As the second component, (2) hexafluorocyclopropane, pentafluoropropene, and Furthermore, it contains at least one component selected from the group consisting of dimers and / or trimers derived from hexafluoropropene.

[0020] When etching is performed using the etching gas of this disclosure, an inert gas may be included.

[0021] When etching is performed using the etching gas of this disclosure, it may contain an oxidizing gas and / or a reducing gas.

[0022] The etching gas of this disclosure contains (1) hexafluoropropene as the first component. As the second component, (2) hexafluorocyclopropane, pentafluoropropene, and Furthermore, it contains at least one component selected from the group consisting of dimers and / or trimers derived from hexafluoropropene, and using the etching gas of this disclosure, a silicon oxide film For silicon-based materials containing a (SiO2 film) or silicon nitride film (SiN film), holes Etching allows for etching while maintaining the processed shape of the holes (deep holes) in good condition.

[0023] The etching gas of this disclosure, by containing a second component, can inexpensively improve side etching by approximately 10% to 30% during hole etching on semiconductor manufacturing substrates.

[0024] (1) Hexafluoropropene The etching gas of this disclosure contains (1) hexafluoropropene (CF3-CF=CF2, also known as hexafluoropropylene, HFP) as a first component.

[0025] The etching gas of this disclosure has (1) hexafluoropropene as its first component as its main component. It contains.

[0026] In the etching gas of this disclosure, the hexafluoropropene content is preferably 95% to 99.99999% by volume, more preferably 96% to 99.999% by volume, even more preferably 97% to 99.995% by volume, and particularly preferably 98% to 99.99% by volume, relative to the total amount (gas volume) of the etching gas of this disclosure, from the viewpoint of reducing side etching and performing etching while maintaining the processed shape of the holes well when performing hole etching using the etching gas of this disclosure.

[0027] (2) Hexafluorocyclopropane, pentafluoropropene, and hexafluoro At least one selected from the group consisting of dimers and / or trimmers derived from olopropene Seed components The etching gas of this disclosure comprises (2) hexafluorocyclopropane as a second component. It contains at least one component selected from the group consisting of pentafluoropropene and dimers and / or trimers derived from hexafluoropropene.

[0028] (2-1) Hexafluorocyclopropane Since the etching gas of this disclosure contains hexafluorocyclopropane (c-C3F6) as a second component, when hole etching is performed using the etching gas of this disclosure, side etching can be reduced, and etching can be performed while maintaining the processed shape of the hole well.

[0029] In the etching gas of this disclosure, the content of hexafluorocyclopropane is such that, when performing hole etching using the etching gas of this disclosure, side etching is reduced, etching is performed while maintaining the processed shape of the hole well, hole clogging is suppressed, and etching is performed efficiently. The amount of ppm is preferably 0.1 ppm to 1,000 ppm relative to the total amount of s (gas volume), more preferably 1 ppm to 500 ppm, even more preferably 2.5 ppm to 250 ppm, and particularly preferably 5 ppm to 100 ppm relative to the total amount of s (gas volume).

[0030] (2-2) Pentafluoropropene The etching gas of this disclosure contains pentafluoropropene (C3HF5) as a second component. Therefore, when hole etching is performed using the etching gas of this disclosure, side etching can be reduced, and etching can be performed while maintaining the processed shape of the hole well.

[0031] The second component, pentafluoropropene, is not particularly limited, and any isomer can be used. Preferably, the pentafluoropropene used is 1,1,2,3,3-pentafluoropropene (F2C=CF-CHF2), 1,1,3,3,3-pentafluoropropene (F2C=CH-CF3), (E / Z)-1,2,3,3,3-pentafluoro-1-propene (HFC=CF-CF3), etc.

[0032] The etching gas of this disclosure contains pentafluoropropene (including isomers) alone. They may be used individually, or two or more may be mixed (blended) together.

[0033] In the etching gas of this disclosure, the pentafluoropropene content is preferably 1 volume ppm to 1,000 volume ppm, more preferably 5 volume ppm to 500 volume ppm, and even more preferably 10 volume ppm to 100 volume ppm, relative to the total amount (gas volume) of the etching gas of this disclosure, in order to reduce side etching and maintain the processed shape of the holes when performing hole etching using the etching gas of this disclosure, and in order to suppress hole clogging in the processed shape. Particularly preferred is a concentration of 20 ppm by volume to 50 ppm by product.

[0034] (2-3) Dimers and / or trimers derived from hexafluoropropene Since the etching gas of this disclosure contains a hexafluoropropene-derived dimer and / or trimer as a second component, when hole etching is performed using the etching gas of this disclosure, side etching can be reduced, and etching can be performed while maintaining the processed shape of the hole well.

[0035] In the etching gas of this disclosure, the dimer and / or trimer derived from the second component, hexafluoropropene, is a product prepared from hexafluoropropene (C3F6) and is a different component from the first component (1) hexafluoropropene (HFP).

[0036] (a) Method for preparing dimers derived from hexafluoropropene The dimer derived from hexafluoropropene exists in the form of cis and trans isomers as shown below, and either isomer can be used in the etching gas of this disclosure, regardless of their relative abundance.

[0037] Compounds represented by formula (I) are, unless otherwise specified, cis and trans isomers. This shall include both of the above.

[0038] [ka]

[0039] The hexafluoropropene dimer is (E)-1,1,1,2,3,4,5,5,5-nonafluoro-4-(triph (Z)-1,1,1,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)-2-pentene, and / or 1,1,1,3,4,4,5,5,5-nonafluoro-2-(trifluoromethyl) May contain methyl-2-pentene.

[0040] Dimers derived from hexafluoropropene are prepared, for example, by the method described in Japanese Patent Application Publication No. 6-234672.

[0041] The total amount of hexafluoropropene (HFP)-derived dimers (the sum of compounds represented by formulas (I), (II), and (III) (a mixture of HFP dimers), hereinafter referred to as "total amount of HFP dimers" In the above, the proportion of the compound represented by formula (I) is preferably, in order, 1% by mass or more, 10% by mass or more, 30% by mass or more, 40% by mass or more, and 45% by mass or more, relative to the total amount of HFP dimer, and particularly preferably 50% by mass or more. The proportion of the compound represented by formula (I) is, relative to the total amount of HFP dimer The amount may be 85% by mass or more. A higher mixing ratio results in a lower viscosity of the HFP dimer mixture.

[0042] The proportions of the compound represented by formula (I) are preferably, in order of total amount of HFP dimer, 99% by mass or less, 90% by mass or less, 85% by mass or less (or less), 80% by mass or less, and 70% by mass or less. Particularly preferably, it is 60% by mass or less.

[0043] The blending ratio of the compound represented by formula (I) is adjusted to, for example, 10% to 90% by mass, 10% to 85% by mass, 10% to less than 85% by mass, 20% to less than 85% by mass, 30% to 90% by mass, 30% to less than 85% by mass, 35% to 85% by mass, 35% to 60% by mass, 40% to less than 85% by mass, 40% to 80% by mass, 50% to less than 85% by mass, 50% to 60% by mass, 55% to 80% by mass, 60% to 75% by mass, and 65% to 70% by mass, relative to the total amount of HFP dimer.

[0044] The blending ratio of the compound represented by formula (I) is preferably, in order of total amount of HFP dimer, 30% to 90% by mass, 40% to less than 85% by mass, 40% to 80% by mass, and 45% by mass or less. The amount is 70% by mass or less, and is particularly preferably 50% by mass or more and 60% by mass or less.

[0045] (b) Method for preparing trimmers derived from hexafluoropropene The trimmers derived from hexafluoropropene have the isomers shown below, and any of these isomers can be used in the etching gas of this disclosure, regardless of their relative abundance.

[0046] The compound represented by formula (I) is, unless otherwise specified, the E-isomer (I-(E)) of the diastereomer. This includes both ) and Z-form (I-(Z)).

[0047] [ka]

[0048] Trimers derived from hexafluoropropene are appropriately selected according to the desired abundance ratio and prepared, for example, by the method described in Chem Bar (1973), Vol. 106, pp2950-2959.

[0049] The total amount of trimers derived from hexafluoropropene (HFP) (the sum of compounds represented by formulas (I), (II), and (III) (a mixture of HFP trimers), hereinafter referred to as "total amount of HFP trimers") In the above, the proportion of the compound represented by formula (I) is preferably, in order, 1% by mass or more, 10% by mass or more, 30% by mass or more, 40% by mass or more, and 45% by mass or more, relative to the total amount of HFP trimer, and particularly preferably 50% by mass or more. The proportion of the compound represented by formula (I) is, in order to the total amount of HFP trimer The amount may be 85% by mass or more. In the total amount of HFP trimer, the compound represented by formula (I) A higher mixing ratio results in a lower viscosity of the HFP trimer mixture.

[0050] The proportions of the compound represented by formula (I) are preferably, in order of total amount of HFP trimer, 99% by mass or less, 90% by mass or less, 85% by mass or less (or less), 80% by mass or less, and 70% by mass or less. Particularly preferably, it is 60% by mass or less.

[0051] The blending ratio of the compound represented by formula (I) is adjusted to, for example, 10% to 90% by mass, 10% to 85% by mass, 10% to less than 85% by mass, 20% to less than 85% by mass, 30% to 90% by mass, 30% to less than 85% by mass, 35% to 85% by mass, 35% to 60% by mass, 40% to less than 85% by mass, 40% to 80% by mass, 50% to less than 85% by mass, 50% to 60% by mass, 55% to 80% by mass, 60% to 75% by mass, and 65% to 70% by mass, relative to the total amount of HFP trimer.

[0052] The blending ratio of the compound represented by formula (I) is preferably, in order of total amount of HFP trimer, 30% to 90% by mass, 40% to less than 85% by mass, 40% to 80% by mass, and 45% by mass or less. The amount is 70% by mass or less, and is particularly preferably 50% by mass or more and 60% by mass or less.

[0053] (c) Content of dimers and / or trimers The etching gas of this disclosure may be a hexafluoropropene-derived dimer and / or trimer, either used alone or as a mixture (blend) of two or more.

[0054] In the etching gas of this disclosure, the content of hexafluoropropene-derived dimers and / or trimers is preferably 0.1 volume ppm to 1,000 volume ppm relative to the total amount (gas volume) of the etching gas of this disclosure, from the viewpoint of reducing side etching, maintaining the processed shape of the holes well, and suppressing hole clogging (hole blockage) when performing hole etching using the etching gas of this disclosure. (ppm volume) is more preferably 0.5 volume ppm to 500 volume ppm, and even more preferably The concentration is preferably between 0.75 ppm and 100 ppm, and particularly preferably between 1 ppm and 50 ppm.

[0055] (2-4) Second component The etching gas of this disclosure may use at least one component selected from the group consisting of (second component) hexafluorocyclopropane, pentafluoropropene, and dimers and / or trimers derived from hexafluoropropene, either alone or in combination of two or more components. It can also be used in a mixed (blended) form.

[0056] The etching gas of this disclosure, by containing a second component, can inexpensively improve side etching (rough wall protection effect) by approximately 10% to 30% during hole etching on semiconductor manufacturing substrates. The etching gas of this disclosure can reduce the amount of side wall abrasion (side etching) of holes.

[0057] (3) Amount of etching gas used The etching gas of this disclosure contains (1) hexafluoropropene (HFP) as the first component and (2) hexafluorocyclopropane, pentafluoropropene as the second component. It contains n, and at least one component selected from the group consisting of dimers and / or trimers derived from hexafluoropropene.

[0058] The amount of etching gas used in this disclosure is preferably 2 ccm to 100 ccm, more preferably 5 ccm to 50 ccm, and even more preferably, from the viewpoint of efficiently carrying out etching. The size is 8 cm to 15 cm.

[0059] In this specification, the unit of gas consumption "ccm" refers to cubic centimetre / min (cc / min). This represents the volume (cc, cm³) when an instantaneous flow rate is maintained for 1 minute under conditions of 25°C and 1 atmosphere. 3 ) represents.

[0060] (4) Other etching gases The etching gas of this disclosure may be used as needed, from the viewpoint of promoting good etching. Other etching gases may be included.

[0061] Other etching gases are preferably high-grade etchants such as CH2F2, CHF3, C2H2F2, C2H4F2, C3H2F4, etc. The etching rate can be adjusted by using hydrofluorocarbon compounds (HFCs) such as CF4, C2F6, C3F8, C4F8, C4F6, and C5F8; perfluorocarbon compounds (PFCs) such as CF3I, C2F5I, and C3F7I; and SF6.

[0062] The etching gas of this disclosure may be used as a single etching gas or as a mixture (blend) of two or more etching gases.

[0063] [2] Method of etching This disclosure includes a method for etching a semiconductor manufacturing substrate using the etching gas of this disclosure as a gas supplied to generate plasma.

[0064] This disclosure includes a method for etching a silicon-based material on which a silicon oxide film (SiO2 film) or a silicon nitride film (SiN film) is formed using a gas plasma of the etching gas of this disclosure. ru.

[0065] The silicon-based material to be etched is preferably a semiconductor manufacturing substrate.

[0066] By using the etching gas of this disclosure, the generated gas plasma can cause holes in a silicon-based material containing a silicon oxide film (SiO2 film) or a silicon nitride film (SiN film). When etching is performed, etching can be carried out while maintaining the processed shape of the hole well. The conditions for the etching method (especially the dry etching method) are as described in the present disclosure. Aside from using S, the method can be the same as the conventional method.

[0067] (1) Examples of etching conditions The etching conditions can be, for example, as follows:

[0068] The flow rate should be adjusted to 5 ccm to 2,000 ccm, preferably 10 ccm to 1,000 ccm.

[0069] The discharge power is adjusted to 200W to 20,000W, preferably 400W to 10,000W. The high-frequency power supply should be adjusted to 13.56MHz and 0.22W. The bias power is adjusted to 25W to 15,000W, preferably 100W to 10,000W.

[0070] The pressure should be adjusted to 30 mTorr or less (3.99 Pa or less), preferably between 2 mTorr and 10 mTorr (0.266 Pa and 1.33 Pa). Unless otherwise specified, pressure refers to gauge pressure.

[0071] Electron density 10 9 cm -3 ~10 13 cm -3 Preferably, it is adjusted to 10 10 cm -3 ~10 12 cm -3 and adjusted. The electron temperature is adjusted to 2 eV to 9 eV, preferably 3 eV to 8 eV.

[0072] The wafer temperature is adjusted to -40°C to 100°C, preferably -30°C to 50°C. The chamber wall temperature is adjusted to -30°C to 300°C, preferably 20°C to 200°C.

[0073] The discharge power and the bias power also vary depending on the size of the chamber, the size of the electrode, etc. When etching a pattern such as a contact hole on a silicon oxide film or the like with an inductively coupled plasma (ICP) etching apparatus for a small-diameter wafer (chamber volume 3,500 cm 3 ), the preferable etching conditions can be as follows.

[0074] The discharge power is adjusted to 200 W to 1,000 W, preferably 300 W to 600 W. The bias power is adjusted to 50 W to 500 W, preferably 100 W to​​​​​​​​​​​Etching silicon-based materials.

[0077] The inert gas may preferably contain one or more noble gases, such as nitrogen. The noble gas may preferably contain helium, neon, argon, xenon, krypton, etc., and more preferably argon (Ar).

[0078] When etching is performed using the etching gas of this disclosure, if an inert gas is used alone, They may be used individually, or two or more may be mixed (blended) together.

[0079] Inert gases can alter the electron temperature and electron density of a plasma, allowing for control over the balance of fluorocarbon radicals and fluorocarbon ions.

[0080] When etching is performed using the etching gas of this disclosure, if an inert gas (such as Ar) is included, the amount of inert gas used is preferably 50 ccm to 500 ccm, more preferably 150 ccm to 400 ccm, and even more preferably 220 ccm to 2 It is 80 ccm.

[0081] When etching is performed using the etching gas of this disclosure, if an inert gas (such as Ar) is included, the amount of inert gas used is preferably 5 to 50 times the amount of the etching gas flow rate, and more preferably 15 to 40 times the amount of the etching gas flow rate, from the viewpoint of promoting good etching. Yes, and more preferably, 22 to 28 times the amount.

[0082] (3) Oxidizing gases and / or reducing gases When etching is performed using the etching gas of this disclosure, the etching gas of this disclosure may contain an oxidizing gas and / or a reducing gas as needed, from the viewpoint of ensuring good etching.

[0083] The etching method of the present disclosure preferably involves supplying the etching gas of the present disclosure and an oxidizing gas and / or a reducing gas separately and continuously to generate an etching mixed gas in a chamber and etching a silicon-based material.

[0084] The oxidizing gas used is preferably O2, O3, NO, N2O, NO2, SO2, COS, CO, CO2, etc. More preferably, by using oxygen (O2), a good etching shape can be obtained.

[0085] When etching is performed using the etching gas of this disclosure, if one type of oxidizing gas is used alone, They may be used individually, or two or more may be mixed (blended) together.

[0086] When etching is performed using the etching gas of this disclosure, if an oxidizing gas (such as O2) is included, the amount of oxidizing gas used is preferably 2 ccm to 100 ccm, more preferably 5 ccm to 50 ccm, and even more preferably 8 ccm, from the viewpoint of efficiently and effectively proceeding with etching. It is approximately 15 cm.

[0087] When etching is performed using the etching gas of this disclosure, if an oxidizing gas (such as O2) is included, the amount of oxidizing gas used is preferably 0.2 to 10 times the amount of the etching gas flow rate, more preferably 0.5 to 5 times, and even more preferably 0.8 to 1.5 times, from the viewpoint of efficiently and effectively carrying out etching.

[0088] The reducing gas is preferably hydrogen (H2), CO, CH4, etc., and in particular silicon nitrogen When performing hole etching on silicon-based materials containing a film (SiN film), good A specific etching shape can be obtained.

[0089] When etching is performed using the etching gas of this disclosure, if a reducing gas is used alone, They may be used individually, or two or more may be mixed (blended) together.

[0090] When etching is performed using the etching gas of this disclosure, if a reducing gas (such as H2) is included, the amount of reducing gas used is preferably 0.5 ccm to 20 ccm, more preferably 0.8 ccm to 10 ccm, and even more preferably 1 ccm to 5 ccm, from the viewpoint of efficiently and effectively carrying out etching.

[0091] When etching is performed using the etching gas of this disclosure, if a reducing gas (such as H2) is included, the amount of reducing gas used is preferably 0.05 to 2 times the amount of the etching gas flow rate, and more preferably 0.08 times, from the viewpoint of efficiently and effectively proceeding with etching. The quantity is approximately 1x the original amount, and more preferably 0.1x to 0.5x the original amount.

[0092] When etching is performed using the etching gas of this disclosure, the oxidizing gas and the reducing gas may be used individually, or two or more may be mixed (blended) together.

[0093] The etching method of the present disclosure preferably involves supplying the etching gas of the present disclosure, an inert gas, and an oxidizing gas and / or a reducing gas separately and continuously to generate an etching mixed gas in a chamber and etching a silicon-based material.

[0094] [3] Semiconductor manufacturing equipment This disclosure includes semiconductor manufacturing apparatus having a gas ejection section for etching gas of this disclosure.

[0095] [4] Semiconductor manufacturing methods This disclosure includes a semiconductor manufacturing method that involves etching a semiconductor manufacturing substrate using the etching gas of this disclosure.

[0096] [5] Use for semiconductor manufacturing This disclosure includes the use of the etching gases of this disclosure for semiconductor manufacturing, specifically for etching semiconductor manufacturing substrates.

[0097] The etching gas of this disclosure contains (1) hexafluoropropene as the first component. As the second component, (2) hexafluorocyclopropane, pentafluoropropene, and Furthermore, the present invention provides at least one component selected from the group consisting of dimers and / or trimers derived from hexafluoropropene, and uses the etching gas of this disclosure for hole etching. This process suppresses hole clogging due to the machined shape, reduces side etching, and allows etching to be performed while maintaining the machined shape of the hole (deep hole) in good condition.

[0098] The etching gas of this disclosure, by containing a second component, can inexpensively improve side etching (rough wall protection effect) by approximately 10% to 30% during hole etching on semiconductor manufacturing substrates. The etching gas of this disclosure can reduce the amount of side wall abrasion (side etching) of holes. [Examples]

[0099] The present invention will be described in detail below using examples and comparative examples. However, the present invention is not limited to these.

[0100] [1] Etching method From the gas inlet connected to the upper electrode, hexafluoropropene (HFP) and additive gas ( After introducing the second component, the process gas is excited by a high-frequency power supply (13.56 MHz, 0.22 W). Then, etching was performed.

[0101] Etching gas containing HFP and additive gases, oxygen (oxidizing gas), Ar (inert gas), water The element (reducing gas, used when etching the SiN film) is supplied from separate lines, and the chamber A mixed etching gas was formed inside, and etching was performed.

[0102] ICP (Inductive Coupled Plasma), discharge power 1,000W, bias power 300W, pressure 10mTorr, electron density 8×10 10 cm -3 ~2×10 11 cm -3 Under etching conditions of electron temperature [5eV~7eV], for silicon oxide films (SiO2 films) and silicon nitride films (SiN films) formed on a silicon substrate Etching was performed.

[0103] [2] Measurement of aspect ratio and side etching By observing the cross-section of the silicon wafer after etching with a SEM, the aspect ratio and side edges can be determined. The amount of chipping (amount of erosion of the side wall) was measured.

[0104] (1) Aspect ratio This represents the ratio of hole depth (relative value α) (etching depth / etching width (dimension)) to hole width (1) when hole etching is performed on SiO2 and SiN films. The deeper the etching (high aspect ratio etching), the larger the aspect ratio value (high aspect ratio).

[0105] (2) Side etching rate In the example, the side etching rate (relative value) is lower than that of the comparative example (an example without added gas), to the extent that side etching can be reduced. Side etching rate R = a / b * 100

[0106] [ka]

[0107] [Table 1]

[0108] [Table 2]

[0109] [Table 3]

[0110] [Table 4]

[0111] Using the etching gas of the example, a silicon-based material containing an SiO2 film and a SiN film was subjected to By performing hole etching, we were able to reduce side etching (resulting in a lower side etching rate compared to the comparative example) and perform etching while maintaining the processed shape of the holes well.

[0112] The etching gas used in the example was able to improve side etching by approximately 10% to 30% during hole etching, effectively reducing side etching.

[0113] [3] Industrial applicability The etching gas of this disclosure contains (1) hexafluoropropene as the first component. As the second component, (2) hexafluorocyclopropane, pentafluoropropene, and Furthermore, it contains at least one component selected from the group consisting of dimers and / or trimers derived from hexafluoropropene, and using the etching gas of this disclosure, a silicon oxide film For silicon-based materials containing a (SiO2 film) or silicon nitride film (SiN film), holes Etching can reduce side etching and allow etching to be performed while maintaining the processed shape of the hole (deep hole) well.

[0114] The etching gas of this disclosure, by containing a second component, can inexpensively improve side etching (rough wall protection effect) by approximately 10% to 30% during hole etching on semiconductor manufacturing substrates. The etching gas of this disclosure can reduce the amount of side wall abrasion (side etching) of holes.

Claims

1. (1) Hexafluoropropene, and (2) Hexafluorocyclopropane, pentafluoropropene, and hexafluoro At least one selected from the group consisting of dimers and / or trimmers derived from olopropene Seed components Etching gas containing [this substance].

2. With respect to the total amount of etching gas, The above (1) contains 95% to 99.99999% by volume of hexafluoropropene, The above (2) hexafluorocyclopropane, pentafluoropropene, and hexa The solution contains at least one component selected from the group consisting of dimers and / or trimers derived from fluoropropene, in an amount of 1 ppm to 1,000 ppm by volume. The etching gas according to claim 1.

3. A gas plasma of etching gas according to claim 1, wherein a silicon oxide film or silicon nitrogen film is etched. An etching method for etching a silicon-based material on which a film has been formed.

4. The etching gas and, (3) with an inert gas, The etching mixture gas is supplied separately and continuously within the chamber. The etching method according to claim 3, for etching a silicon-based material.

5. The etching gas and, (4) Oxidizing gas and / or reducing gas, The etching mixture gas is supplied separately and continuously within the chamber. The etching method according to claim 3, for etching a silicon-based material.

6. The etching gas and, (3) an inert gas, and (4) Oxidizing gas and / or reducing gas, The etching mixture gas is supplied separately and continuously within the chamber. The etching method according to claim 3, for etching a silicon-based material.

7. The etching method according to any one of claims 3 to 6, wherein the silicon-based material is a substrate for semiconductor manufacturing.

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