JP3818567B2 - Method for producing synthetic quartz glass ingot - Google Patents
Method for producing synthetic quartz glass ingot Download PDFInfo
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- JP3818567B2 JP3818567B2 JP27897899A JP27897899A JP3818567B2 JP 3818567 B2 JP3818567 B2 JP 3818567B2 JP 27897899 A JP27897899 A JP 27897899A JP 27897899 A JP27897899 A JP 27897899A JP 3818567 B2 JP3818567 B2 JP 3818567B2
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- Prior art keywords
- gas
- quartz glass
- synthetic quartz
- silicon compound
- glass ingot
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- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 title claims description 58
- 238000004519 manufacturing process Methods 0.000 title claims description 18
- 239000007789 gas Substances 0.000 claims description 40
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 22
- 229910001882 dioxygen Inorganic materials 0.000 claims description 22
- 150000003377 silicon compounds Chemical class 0.000 claims description 18
- 239000012159 carrier gas Substances 0.000 claims description 13
- 238000006460 hydrolysis reaction Methods 0.000 claims description 7
- 239000000377 silicon dioxide Substances 0.000 claims description 7
- 239000010419 fine particle Substances 0.000 claims description 6
- 239000006060 molten glass Substances 0.000 claims 1
- 239000002994 raw material Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 7
- 230000007423 decrease Effects 0.000 description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000005049 silicon tetrachloride Substances 0.000 description 4
- 229910003902 SiCl 4 Inorganic materials 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000009835 boiling Methods 0.000 description 1
- SLLGVCUQYRMELA-UHFFFAOYSA-N chlorosilicon Chemical compound Cl[Si] SLLGVCUQYRMELA-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 238000001459 lithography Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- FDNAPBUWERUEDA-UHFFFAOYSA-N silicon tetrachloride Chemical compound Cl[Si](Cl)(Cl)Cl FDNAPBUWERUEDA-UHFFFAOYSA-N 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
- 238000004017 vitrification Methods 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B19/00—Other methods of shaping glass
- C03B19/14—Other methods of shaping glass by gas- or vapour- phase reaction processes
- C03B19/1415—Reactant delivery systems
-
- 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
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
- Y02P40/57—Improving the yield, e-g- reduction of reject rates
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Glass Melting And Manufacturing (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、半導体装置製造のリソグラフィ工程で使用されるフォトマスク等の素材となる合成石英ガラスインゴットの製造方法に関する。
【０００２】
【従来の技術】
従来、合成石英ガラスの素材としての合成石英ガラスインゴットは、通常、液体のケイ素化合物を気化させ、流量制御しながらキャリアガスとしての酸素ガス（Ｏ2 ）と共に石英ガラスバーナに供給してその中心ノズルから噴出し、酸水素炎による気相加水分解反応で生成したシリカ微粒子をターゲット上に堆積し、溶融ガラス化して製造されている。
【０００３】
上記石英ガラスバーナとしては、同心５重管構造で、中心ノズルの内径を2.5 〜 5.0mmとしたもの（特開平７−１３８０２８号公報参照）、あるいは同心３重管構造で、中心ノズルの内径を2.0 〜 6.0mmとしたもの（特開平８−２５９２５５号公報参照）が知られている。
【０００４】
【発明が解決しようとする課題】
しかしながら、従来の合成石英ガラスインゴットの製造方法では、合成石英ガラスインゴットの出来高（単価時間当たりにできるインゴットの重量）を向上させるために原料供給量（ケイ素化合物ガスと酸素ガスの混合ガスの供給量）を増量すると、歩留まり（シリカ換算した原料使用量に対するインゴットの重量）が低下気味となり、結果的にあまり出来高が向上しない不具合がある。
そこで、本発明は、出来高を向上させるために原料供給量を増量しても歩留りを低下させない合成石英ガラスインゴットの製造方法を提供することを目的とする。
【０００５】
【課題を解決するための手段】
前記課題を解決するため、本発明の合成石英ガラスインゴットの製造方法は、ケイ素化合物ガスをキャリアガスとしての酸素ガスと共に石英ガラスバーナに供給してその中心ノズルから噴射し、酸水素炎による気相加水分解反応で生成したシリカ微粒子をターゲット上に堆積すると同時に、溶融ガラス化して合成石英ガラスインゴットを製造する方法において、前記石英ガラスバーナの中心ノズルから噴出するケイ素化合物ガスとキャリアガスとしての酸素ガスの混合ガスの流速を２０〜４０ｍ／ｓとし、かつ、ケイ素化合物ガスとキャリアガスとしての酸素ガスのモル比を１：１〜１：２とすることを特徴とする。
前記石英ガラスバーナの中心ノズルの内径 は、２．０〜６．０ｍｍであることが好ましい。
【０００６】
石英ガラスバーナの中心ノズルから噴出する混合ガスの流速が、20m/s 未満であると、生成したシリカ微粒子が中心ノズルに付着し、ノズル孔を塞ぐためインゴットの製造継続が困難となる場合が多い。一方、40m/s を超えると、生成したシリカ微粒子の拡散が大きくなって、ターゲット上への堆積率が低下し、歩留まりが低下する。
【０００７】
ケイ素化合物ガスとキャリアガスとしての酸素ガスのモル比が１：１よりケイ素化合物ガスの割合が多くなると、中心ノズル近傍での気相加水分解反応が充分に行われないため、シリカ微粒子の生成効率が悪くなり、歩留まりが低下する。一方、１：２より酸素ガスの割合が多くなると、赤色蛍光強度が比較的大きく、光の吸収が起こるため、紫外線透過率が低下する。これは、気相加水分解反応において、当該混合比率では、ケイ素化合物ガスに対し酸素ガスが過剰であることから、インゴット中の酸素過剰欠陥が多くなるためと考えられる。
【０００８】
一方、石英ガラスバーナの中心ノズルの内径が、2.0mm 未満であると、混合ガスの供給量を多くすることが困難となり、6.0mm を超えると、生成したシリカ微粒子の拡散が大きくなって歩留まりが低下する。
より好ましい中心ノズルの内径は 2.5〜4.0 mmである。
【０００９】
【発明の実施の形態】
以下、本発明の実施の形態について図面を参照して説明する。
図１、図２は本発明に係る合成石英ガラスインゴットの製造方法の実施に供した装置の模式図、図１の装置の要部の底面図である。
図中１は液体のケイ素化合物を沸点以下の一定温度に加熱して気化させ、ケイ素化合物ガスを原料ガスとして後述する石英ガラスバーナに供給する原料ガス供給装置、２は円筒状の耐火物からなる炉で、この炉２の軸心部には、石英ガラス等からなる円板状のターゲット３が昇降かつ回転可能に配置されている一方、炉２の上方には、原料ガス供給装置１から供給されるケイ素化合物ガスと図示しない酸素ガス源から流量制御して供給されるキャリアガスとしての酸素ガス (Ｏ2)の混合ガスを、上記酸素ガス源から供給される酸素ガスと図示しない水素ガス源から供給される水素ガス (Ｈ2)を燃焼させた酸水素炎による気相加水分解反応でシリカ微粒子を生成させ、これをターゲット３上に堆積し、溶融ガラス化して合成石英ガラスインゴット４とする石英ガラスバーナ５が配置されている。
石英ガラスバーナ５は、単管タイプのもので、混合ガスが噴出される中心ノズル６の周囲を水素ガスが噴出される水素ガス噴出管７によって同心状に囲み、中心ノズル６と水素ガス噴出管７の間に酸素ガスが噴出される多数の酸素ガス噴出管８を配置して構成されており、その中心ノズル６の内径は、２〜６mmとされている。
図１において９はケイ素化合物ガスの流量を制御するマスフローコントローラで、このマスフローコントローラ９による流量は、設定部10によって設定されるものである。
又、11は原料ガス供給装置１に対する液体のケイ素化合物を追加供給する原料追加ラインである。
【００１０】
次に、上述した合成石英ガラスインゴットの製造装置を用いて合成石英ガラスインゴットを製造した具体的な実施例を比較例と共に説明する。
実施例１〜９、比較例１〜12
先ず、液体のケイ素化合物として四塩化ケイ素（SiCl4)を用い、そのガスの流量を表１、表２に示すように変えると共に、そのガスのキャリアガスとしての酸素ガスの割合（モル比）を変え(SiCl4ガス：酸素ガス＝１：0.9 〜１：2.1)、かつ、石英ガラスバーナの中心ノズルから噴出する四塩化ケイ素ガスとそのキャリアガスとしての酸素ガスの混合ガスの流速を変え (19〜41m/s)、図３の各ポイント (1)〜(21)に相当する製造条件の様々の合成石英ガラスインゴットを製造した。
得られた各合成石英ガラスインゴットの歩留まり、出来高、及び赤色(650nm) 蛍光強度（励起波長193nm)は、それぞれ表１、表２に示すようになった。
【００１１】
【表１】
【表２】
表１、表２から実施例１〜９のように、中心ノズルから噴出する混合ガスの流速を20〜40m/s とし、かつ、混合ガスにおける四塩化ケイ素ガスとキャリアガスとしての酸素ガスのモル比を１：１〜１：２とすることにより、歩留まりを62％以上で、赤色蛍光強度の低い合成石英ガラスが得られる一方、混合ガスの流速が19m/s(比較例１〜３）では、石英ガラスバーナの中心ノズルにシリカ微粒子が付着し、41m/s(比較例７〜９）では、歩留まりが58％以下となり、また、四塩化ケイ素ガスとキャリアガスとしての酸素ガスのモル比が１：0.9(比較例４〜６）では、歩留まりが59％以下となり、１：2.1(比較例10〜12）では、歩留まりが実施例１〜９と同等となるものの、赤色蛍光強度が高くて光学的特性上の不具合があることが分かる。
【００１４】
なお、上述した実施の形態においては、液体のケイ素化合物としてSiCl4 を用いる場合について説明したが、これに限定されるものではなく、他の塩化ケイ素（例えば、SiHCl3）を用いてもよい。
【００１５】
【発明の効果】
以上説明したように、本発明の合成石英ガラスインゴットの製造方法によれば、生成したシリカ微粒子が石英ガラスバーナの中心ノズルに付着したり、あるいはターゲット上に堆積せずに拡散したりせず、かつ、中心ノズル近傍での気相加水分解反応が充分に行われると共に、ケイ素化合物ガスと酸素ガスの混合比率が適正となるので、出来高を向上させるため原料供給量を増量しても、赤色発光強度を高めることなく歩留まりを高めることができる。
【図面の簡単な説明】
【図１】本発明に係る合成石英ガラスインゴットの製造方法の実施に供した装置の模式図である。
【図２】図１の装置の要部の底面図である。
【図３】本発明に係る合成石英ガラスインゴットの製造方法の実施例と比較例の製造条件を表わした説明図である。
【符号の説明】
１ 原料ガス供給装置
３ ターゲット
４ 合成石英ガラスインゴット
５ 石英ガラスバーナ
６ 中心ノズル[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a synthetic quartz glass ingot that is a material such as a photomask used in a lithography process for manufacturing a semiconductor device.
[0002]
[Prior art]
Conventionally, a synthetic quartz glass ingot as a raw material of synthetic quartz glass usually vaporizes a liquid silicon compound, supplies it to a quartz glass burner together with oxygen gas (O 2 ) as a carrier gas while controlling the flow rate, and has a central nozzle. It is manufactured by depositing silica fine particles generated by gas-phase hydrolysis reaction using oxyhydrogen flame on a target and melting into glass.
[0003]
The quartz glass burner has a concentric five-pipe structure with an inner diameter of the central nozzle of 2.5 to 5.0 mm (see Japanese Patent Laid-Open No. 7-138028), or a concentric triple pipe structure with an inner diameter of the central nozzle. Those having a thickness of 2.0 to 6.0 mm (see JP-A-8-259255) are known.
[0004]
[Problems to be solved by the invention]
However, in the conventional method for producing a synthetic quartz glass ingot, the raw material supply amount (a supply amount of a mixed gas of silicon compound gas and oxygen gas) in order to improve the output of the synthetic quartz glass ingot (the weight of the ingot made per unit time). ) Is increased, the yield (weight of the ingot relative to the amount of raw material used in terms of silica) tends to decrease, and as a result, there is a problem that the yield is not improved so much.
Therefore, an object of the present invention is to provide a method for producing a synthetic quartz glass ingot that does not decrease the yield even if the amount of raw material supply is increased in order to improve the yield.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the method for producing a synthetic quartz glass ingot according to the present invention supplies a silicon compound gas together with oxygen gas as a carrier gas to a quartz glass burner and injects it from its central nozzle, and a gas phase generated by an oxyhydrogen flame. In a method for producing a synthetic quartz glass ingot by melting and vitrifying silica fine particles generated by a hydrolysis reaction simultaneously with a target, a silicon compound gas ejected from a central nozzle of the quartz glass burner and oxygen as a carrier gas The flow rate of the gas mixture is 20 to 40 m / s, and the molar ratio of the silicon compound gas to the oxygen gas as the carrier gas is 1: 1 to 1: 2.
The inner diameter of the central nozzle of the quartz glass burner is preferably 2.0 to 6.0 mm.
[0006]
If the flow rate of the mixed gas ejected from the central nozzle of the quartz glass burner is less than 20 m / s, the generated silica particles adhere to the central nozzle and block the nozzle hole, which often makes it difficult to continue ingot production. . On the other hand, when it exceeds 40 m / s, the diffusion of the generated silica particles increases, the deposition rate on the target decreases, and the yield decreases.
[0007]
When the molar ratio of silicon compound gas to oxygen gas as a carrier gas is higher than 1: 1, the gas phase hydrolysis reaction in the vicinity of the center nozzle is not sufficiently performed. Inefficiency decreases and yield decreases. On the other hand, when the proportion of oxygen gas increases from 1: 2, the red fluorescence intensity is relatively high and light absorption occurs, so that the ultraviolet transmittance decreases. This is considered to be because oxygen excess defects in the ingot increase because the oxygen gas is excessive with respect to the silicon compound gas at the mixing ratio in the gas phase hydrolysis reaction.
[0008]
On the other hand, if the inner diameter of the central nozzle of the quartz glass burner is less than 2.0 mm, it will be difficult to increase the supply amount of the mixed gas, and if it exceeds 6.0 mm, the diffusion of the generated silica particles will increase and the yield will increase. descend.
The inner diameter of the center nozzle is more preferably 2.5 to 4.0 mm.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 and FIG. 2 are schematic views of an apparatus used for carrying out the method for manufacturing a synthetic quartz glass ingot according to the present invention, and a bottom view of the main part of the apparatus of FIG.
In the figure, 1 is a raw material gas supply device that heats and vaporizes a liquid silicon compound to a constant temperature below the boiling point, and supplies the silicon compound gas as a raw material gas to a quartz glass burner described later, and 2 is made of a cylindrical refractory. In the furnace, a disk-
The
In FIG. 1,
[0010]
Next, specific examples in which a synthetic quartz glass ingot is manufactured using the above-described synthetic quartz glass ingot manufacturing apparatus will be described together with comparative examples.
Examples 1-9, Comparative Examples 1-12
First, silicon tetrachloride (SiCl 4 ) is used as a liquid silicon compound, the gas flow rate is changed as shown in Tables 1 and 2, and the ratio (molar ratio) of oxygen gas as the carrier gas of the gas is changed. (SiCl 4 gas: oxygen gas = 1: 0.9 to 1: 2.1), and the flow rate of the mixed gas of silicon tetrachloride gas ejected from the central nozzle of the quartz glass burner and oxygen gas as its carrier gas is changed (19 Various synthetic quartz glass ingots with production conditions corresponding to the points (1) to (21) in FIG. 3 were produced.
The yield, production volume, and red (650 nm) fluorescence intensity (excitation wavelength: 193 nm) of each synthetic quartz glass ingot obtained were as shown in Tables 1 and 2, respectively.
[0011]
[Table 1]
[Table 2]
As in Examples 1 to 9 from Tables 1 and 2, the flow rate of the mixed gas ejected from the central nozzle is 20 to 40 m / s, and the moles of silicon tetrachloride gas and oxygen gas as the carrier gas in the mixed gas By setting the ratio to 1: 1 to 1: 2, a synthetic quartz glass having a yield of 62% or more and a low red fluorescence intensity can be obtained, while a mixed gas flow rate of 19 m / s (Comparative Examples 1 to 3). Silica fine particles adhere to the center nozzle of the quartz glass burner. At 41 m / s (Comparative Examples 7 to 9), the yield is 58% or less, and the molar ratio of silicon tetrachloride gas to oxygen gas as the carrier gas is In 1: 0.9 (Comparative Examples 4 to 6), the yield was 59% or less, and in 1: 2.1 (Comparative Examples 10 to 12), the yield was the same as in Examples 1 to 9, but the red fluorescence intensity was high. It can be seen that there is a defect in optical characteristics.
[0014]
In the above-described embodiment, the case where SiCl 4 is used as the liquid silicon compound has been described. However, the present invention is not limited to this, and other silicon chloride (for example, SiHCl 3 ) may be used.
[0015]
【The invention's effect】
As described above, according to the method for producing a synthetic quartz glass ingot of the present invention, the generated silica fine particles do not adhere to the center nozzle of the quartz glass burner or do not diffuse without being deposited on the target, In addition, the gas phase hydrolysis reaction in the vicinity of the center nozzle is sufficiently performed, and the mixing ratio of the silicon compound gas and the oxygen gas becomes appropriate. The yield can be increased without increasing the emission intensity.
[Brief description of the drawings]
FIG. 1 is a schematic view of an apparatus used for carrying out a method for producing a synthetic quartz glass ingot according to the present invention.
FIG. 2 is a bottom view of the main part of the apparatus of FIG.
FIG. 3 is an explanatory diagram showing manufacturing conditions of an example and a comparative example of a method for manufacturing a synthetic quartz glass ingot according to the present invention.
[Explanation of symbols]
1 Raw material
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27897899A JP3818567B2 (en) | 1999-09-30 | 1999-09-30 | Method for producing synthetic quartz glass ingot |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27897899A JP3818567B2 (en) | 1999-09-30 | 1999-09-30 | Method for producing synthetic quartz glass ingot |
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| Publication Number | Publication Date |
|---|---|
| JP2001097723A JP2001097723A (en) | 2001-04-10 |
| JP3818567B2 true JP3818567B2 (en) | 2006-09-06 |
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|---|---|---|---|
| JP27897899A Expired - Fee Related JP3818567B2 (en) | 1999-09-30 | 1999-09-30 | Method for producing synthetic quartz glass ingot |
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| Country | Link |
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| JP (1) | JP3818567B2 (en) |
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- 1999-09-30 JP JP27897899A patent/JP3818567B2/en not_active Expired - Fee Related
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| JP2001097723A (en) | 2001-04-10 |
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