JPH05124897A - Litao3 single crystal material - Google Patents
Litao3 single crystal materialInfo
- Publication number
- JPH05124897A JPH05124897A JP28679991A JP28679991A JPH05124897A JP H05124897 A JPH05124897 A JP H05124897A JP 28679991 A JP28679991 A JP 28679991A JP 28679991 A JP28679991 A JP 28679991A JP H05124897 A JPH05124897 A JP H05124897A
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- single crystal
- litao
- pores
- crystal material
- average particle
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、単結晶の製造に使用さ
れる原材料に係り、特にＬｉＴａＯ3 などの酸化物単結
晶をチョコラルスキー法により引き上げて製造する際に
使用される単結晶材料に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raw material used for producing a single crystal, and more particularly to a single crystal material used for producing an oxide single crystal such as LiTaO 3 by pulling it by the Czochralski method. ..
【０００２】[0002]
【従来の技術】従来より、ＬｉＴａＯ3 、ＬｉＮｂ
Ｏ3 、あるいはＬｉ2 Ｂ4 Ｏ7 などの酸化物単結晶の製
造方法の一つとして、チョコラルスキー法と呼ばれる引
き上げ方法が知られている。このチョコラルスキー法
は、PtあるいはＰｔ−Ｒｈなどの貴金属製の溶融るつぼ
に原料を収容し、この原料を、溶融るつぼに周設した高
周波コイルなどの加熱手段により加熱溶融した後、種子
結晶を原料融液に接触させ、この種子結晶を回転させな
がら引き上げることにより、単結晶を育成する方法であ
る。2. Description of the Related Art LiTaO 3 , LiNb have hitherto been used.
A pulling method called Czochralski method is known as one of methods for producing an oxide single crystal such as O 3 or Li 2 B 4 O 7 . In the Czochralski method, a raw material is contained in a melting crucible made of a noble metal such as Pt or Pt-Rh, and the raw material is heated and melted by a heating means such as a high frequency coil provided around the melting crucible, and then a seed crystal is used as a raw material. This is a method of growing a single crystal by bringing it into contact with a melt and pulling it while rotating this seed crystal.
【０００３】[0003]
【発明が解決しようとする課題】このチョコラルスキー
法によりＬｉＴａＯ3 単結晶を製造するにあたっては、
得られた結晶内に大きさ、位置、数などの不規則な気泡
が発生することがあり、このような気泡の発生が、製造
歩留まりを低下させる原因の一つとなっていた。このよ
うに結晶内にランダムに生じる気泡は、内部全体に発生
することから、通称全ポアと呼ばれている。原料融液に
温度変動が生じた場合にこのような気泡（以下全ポアと
記す）が発生することがあるが、原料融液の温度制御だ
けでは全ポアの発生を防止できないのが現状である。そ
のため、他の要因に対する考察を進めて、このような全
ポアの発生をできるだけ少なくすることが望まれてい
た。In producing a LiTaO 3 single crystal by the Czochralski method,
Irregular bubbles such as size, position, and number may be generated in the obtained crystal, and the generation of such bubbles is one of the causes for lowering the manufacturing yield. The bubbles randomly generated in the crystal as described above are generally called all pores because they are generated in the entire inside. Such bubbles (hereinafter referred to as all pores) may occur when the temperature of the raw material melt fluctuates, but the current situation is that the control of the temperature of the raw material melt alone cannot prevent the generation of all pores. .. Therefore, it has been desired to further consider other factors and reduce the occurrence of all such pores as much as possible.
【０００４】本発明はこのような事情に対処してなされ
たものであり、全ポアの発生率を低減し製造歩留まりを
向上し得るＬｉＴａＯ3 単結晶材料を提供することをそ
の目的とする。The present invention has been made in view of such circumstances, and an object thereof is to provide a LiTaO 3 single crystal material capable of reducing the generation rate of all pores and improving the manufacturing yield.
【０００５】[0005]
【課題を解決するための手段】本発明は、チョコラルス
キー法によるＬｉＴａＯ3 単結晶製造において、原材料
として工業的に入手されるＴａ2 Ｏ5 およびＬｉ2 ＣＯ
3 粉末の粒径に着目して成されたものである。The present invention provides Ta 2 O 5 and Li 2 CO which are industrially available as raw materials in the production of LiTaO 3 single crystals by the Czochralski method.
It was made by focusing on the particle size of the three powders.
【０００６】現在のところ、引き上げ法によるＬｉＴａ
Ｏ3 単結晶材料としては、Ｔａ2 Ｏ5 およびＬｉ2 ＣＯ
3 が使用されている。Ｌｉ2 ＣＯ3 の粒径は通常２０μ
m 程度であって水分の吸着も少なく安定した粒子と考え
られる。一方Ｔａ2 Ｏ5 は、サブミクロンオーダーの平
均粒子径（通気法による）を有し、Ｌｉ2 ＣＯ3 に比較
して活性な微粒子である。そこで、引き上げ法によるＬ
ｉＴａＯ3 単結晶製造における、単結晶材料中のＴａ2
Ｏ5 の平均粒子径と引き上げられたＬｉＴａＯ3 単結晶
の全ポア発生率とを比較し検討を行った。その結果、平
均粒子径（通気法による）が０．７０〜０．８０μm の
範囲内のＴａ2 Ｏ5 粉末を使用してＬｉＴａＯ3 単結晶
を引き上げた場合に、全ポアの発生件数率が低減される
ことが判明した。At present, LiTa by the pulling method is used.
As the O 3 single crystal material, Ta 2 O 5 and Li 2 CO
3 is used. The particle size of Li 2 CO 3 is usually 20μ
It is considered to be a stable particle with a size of about m and little water adsorption. On the other hand, Ta 2 O 5 has an average particle size on the order of submicrons (according to the aeration method) and is an active fine particle as compared with Li 2 CO 3 . Therefore, L by the pulling method
Ta 2 in a single crystal material in iTaO 3 single crystal production
An examination was conducted by comparing the average particle diameter of O 5 with the total pore generation rate of the pulled LiTaO 3 single crystal. As a result, when the LiTaO 3 single crystal was pulled up using Ta 2 O 5 powder having an average particle size (according to the aeration method) within the range of 0.70 to 0.80 μm, the number of occurrences of all pores was reduced. Turned out to be.
【０００７】ＬｉＴａＯ3 単結晶材料として使用される
Ｔａ2 Ｏ5 の平均粒子径は０．７０〜０．８０μm が好
ましく、より好ましい範囲は０．７０〜０．７５μm で
ある。Ｐｔ−Ｒｈるつぼ内で溶融される際に、Ｔａ2 Ｏ
5 の平均粒子径が０．８０μm より大きい場合には、加
熱時に溶解しにくなって融液内部からのガスの発散も不
十分となり、気泡（全ポア）を生じやすくなる。同一時
間の加熱では粒子径が小さいほど溶解しやすいが、Ｔａ
2 Ｏ5 の平均粒子径が０．７０μm より小さい場合には
Ｌｉ2 ＣＯ3 との混合性が極端に悪くなり、材料の偏析
を生み、最終製品において不良品となってしまうため、
好ましくない。The average particle size of Ta 2 O 5 used as the LiTaO 3 single crystal material is preferably 0.70 to 0.80 μm, more preferably 0.70 to 0.75 μm. When melted in a Pt-Rh crucible, Ta 2 O
When the average particle diameter of 5 is larger than 0.80 μm, it becomes difficult to melt upon heating and gas diffusion from the inside of the melt becomes insufficient, and bubbles (all pores) are easily generated. When heated for the same time, the smaller the particle size, the easier the dissolution.
When the average particle size of 2 O 5 is smaller than 0.70 μm, the miscibility with Li 2 CO 3 becomes extremely poor, segregation of the material occurs, and the final product becomes a defective product.
Not preferable.
【０００８】なお、単結晶材料中の不純物含有量と全ポ
アの発生件数率との関係を検討し、その結果を図２、図
３、および図４に示した。図２は不純物として含まれる
Si含有量と全ポアの発生件数率との関係、図３は不純物
として含まれるAl含有量と全ポアの発生件数率との関
係、および図４は水分含有量と全ポアの発生件数率との
関係を、それぞれ示している。これらの図から明らかな
ように、Ｔａ2 Ｏ5 の平均粒子径以外の因子は全ポアの
発生件数率に影響を及ぼしていないことが理解される。The relationship between the content of impurities in the single crystal material and the rate of occurrence of all pores was examined, and the results are shown in FIGS. 2, 3 and 4. 2 is included as an impurity
The relationship between the Si content and the total pore occurrence rate, Fig. 3 is the relationship between the Al content contained as impurities and the total pore occurrence rate, and Fig. 4 is the water content and the total pore occurrence rate. , Respectively, are shown. As is clear from these figures, it is understood that the factors other than the average particle size of Ta 2 O 5 do not affect the incidence rate of all pores.
【０００９】すなわち本発明は、Ｐｔ−Ｒｈるつぼを用
いた引上げ法によりＬｉＴａＯ3 単結晶を製造するＴａ
2 Ｏ5 およびＬｉ2 ＣＯ3 を主体とするＬｉＴａＯ3 単
結晶材料において、Ｔａ2 Ｏ5 の平均粒子径（通気法に
よる）を０．７０〜０．８０μm としたことを特徴とす
る。That is, according to the present invention, Ta for producing a LiTaO 3 single crystal by the pulling method using a Pt-Rh crucible is used.
A LiTaO 3 single crystal material mainly composed of 2 O 5 and Li 2 CO 3 is characterized in that the average particle diameter of Ta 2 O 5 (by aeration method) is 0.70 to 0.80 μm.
【００１０】[0010]
【作用】このように構成された本発明のＬｉＴａＯ3 単
結晶材料においては、Ｔａ2 Ｏ5 の平均粒子径（通気法
による）を０．７０〜０．８０μm としたことにより、
Ｌｉ2 ＣＯ3 との混合性を良好に保ちつつ加熱時に溶解
しやすく、かつ溶融時の融液内部からのガスの発散も十
分に行わせることが可能になる。In the LiTaO 3 single crystal material of the present invention thus constituted, the average particle diameter of Ta 2 O 5 (by the aeration method) is set to 0.70 to 0.80 μm.
It becomes possible to easily dissolve during heating while maintaining good miscibility with Li 2 CO 3 , and to sufficiently diffuse gas from the inside of the melt during melting.
【００１１】このため、全ポアの発生率が低減され、高
品質なＬｉＴａＯ3単結晶を高歩留まりで製造すること
が可能になる。Therefore, the generation rate of all pores is reduced, and it becomes possible to manufacture a high quality LiTaO 3 single crystal with a high yield.
【００１２】[0012]
【実施例】以下、本発明を実施例にしたがって説明す
る。EXAMPLES The present invention will be described below with reference to examples.
【００１３】実施例 単結晶材料を収容する溶融るつぼとして、（外径１２４
mm、高さ１２２mm、厚さ２mmのＰｔ−Ｒｈるつぼ（Rh含
有率30％）を用い、Ｔａ2 Ｏ5 （平均粒子径０．７０〜
０．７５μm 、三井金属社製）およびＬｉ2 ＣＯ3 粉末
のそれぞれを８．９kg、および５７．０kg秤量し、Ｖブ
レンダにて混合し、これらを予め７０kg/cm2 程度の圧
力でプレスし焼結後粉砕して溶融るつぼに収容した。な
お、上記単結晶材料に含まれる不純物は併せて、Ｓｉが
２ ppm、Ａｌが１ ppm、Ｆｅが１ ppm、Ｃｕが１ ppm、
そしてＮｂが５ ppm以下であった。同様に、上記単結晶
材料の水分含量は原料受入れ時に０．０４％、秤量混合
時に０．０４％であった。EXAMPLE As a melting crucible for containing a single crystal material, an outer diameter of 124
mm, height 122 mm, thickness 2 mm Pt-Rh crucible (Rh content 30%), Ta 2 O 5 (average particle size 0.70
0.75 μm, manufactured by Mitsui Kinzoku Co., Ltd.) and Li 2 CO 3 powder were weighed 8.9 kg and 57.0 kg respectively, mixed with a V blender, and pre-pressed at a pressure of about 70 kg / cm 2 and baked. After tying, it was ground and stored in a melting crucible. In addition, the impurities contained in the above single crystal material are 2 ppm for Si, 1 ppm for Al, 1 ppm for Fe, and 1 ppm for Cu.
And Nb was 5 ppm or less. Similarly, the water content of the single crystal material was 0.04% when the raw materials were received and 0.04% when weighed and mixed.
【００１４】上記した単結晶材料を、Ｐｔ−Ｒｈるつぼ
に周設した高周波コイルによりm.p.である１６５０℃以
上に加熱溶融し、１時間ガス出しを行って混入空気の除
去を行った後、＜１１１＞を持つ種子結晶を溶融した原
材料と馴染ませ、種子結晶を１０ rpmで回転させながら
ＬｉＴａＯ3 単結晶の引き上げを行った。The above-mentioned single crystal material was heated and melted to mp of 1650 ° C. or higher by a high frequency coil provided around a Pt-Rh crucible, degassed for 1 hour to remove entrained air, and then <111. The seed crystal having > was made compatible with the molten raw material, and the LiTaO 3 single crystal was pulled up while rotating the seed crystal at 10 rpm.
【００１５】引き上げ速度は５．４mm/hr とし、15時間
に亘り結晶の育成を行った。結晶の直径が３インチにな
るまで引き上げて肩部分の形成を行い、その後直胴部の
育成を開始した。直胴部を約80mm引き上げた時点で原料
融液から育成した単結晶を切り離し、冷却を行った。The pulling rate was 5.4 mm / hr, and the crystal was grown for 15 hours. The shoulder was formed by pulling the crystal up to a diameter of 3 inches, and then the straight body portion was started to grow. When the straight body part was pulled up by about 80 mm, the single crystal grown from the raw material melt was separated and cooled.
【００１６】このようにして得られたＬｉＴａＯ3 単結
晶には、気泡や割れなどは見られなかった。さらに、引
き上げ軸に平行に直径 4mm、長さ75mmの結晶を切り出し
てその両端面を研磨後、トワイマン−グリ―ン干渉計で
結晶縦方向の歪を観察したところ殆ど歪は観察されず、
光学歪の非常に少ない高品質な結晶が得られた。No bubbles or cracks were observed in the LiTaO 3 single crystal thus obtained. Furthermore, a crystal having a diameter of 4 mm and a length of 75 mm was cut out parallel to the pulling axis, and after polishing both end faces thereof, almost no distortion was observed when observing the crystal longitudinal strain with a Twyman-Green interferometer,
High quality crystals with very little optical distortion were obtained.
【００１７】なお、上記した実施例を含めて、本発明の
単結晶材料を使用して１３８Lot のＬｉＴａＯ3 単結晶
の引き上げを行なったところ、気泡（全ポア）の発生件
数率は、０．７％であった。In addition, when the 138Lot LiTaO 3 single crystal was pulled up using the single crystal material of the present invention including the above-mentioned examples, the occurrence rate of bubbles (total pores) was 0.7. %Met.
【００１８】比較例１ ＬｉＴａＯ3 単結晶材料として、平均粒子径が本発明に
従わない（０．６１〜０．６９μm ）のＴａ2 Ｏ5 粉末
を用いて、実施例１と同様にしてＬｉＴａＯ3 単結晶の
引き上げを行なったところ、引き上げられたＬｉＴａＯ
3 単結晶に気泡（全ポア）の発生がみられた。Comparative Example 1 As a LiTaO 3 single crystal material, Ta 2 O 5 powder having an average particle size (0.61 to 0.69 μm) not according to the present invention was used, and LiTaO 3 was processed in the same manner as in Example 1. When the single crystal was pulled up, the pulled LiTaO
Generation of bubbles (all pores) was observed in 3 single crystals.
【００１９】比較例２ ＬｉＴａＯ3 単結晶材料として、平均粒子径が本発明に
従わない（０．８１〜０．９０μm ）Ｔａ2 Ｏ5 粉末を
用いて、実施例１と同様にしてＬｉＴａＯ3 単結晶の引
き上げを行なったところ、引き上げられたＬｉＴａＯ3
単結晶に気泡（全ポア）の発生がみられた。[0019] Comparative Example 2 LiTaO 3 single crystal material, the average particle diameter is not according to the invention (0.81~0.90μm) Ta 2 O 5 powder with, LiTaO 3 single in the same manner as in Example 1 When the crystal was pulled up, the LiTaO 3
Generation of bubbles (all pores) was observed in the single crystal.
【００２０】なお、上記した比較例１および２を含め
て、平均粒子径が本発明に従わないＴａ2 Ｏ5 粉末を用
いた３０７Lot のＬｉＴａＯ3 単結晶の引き上げを行な
ったところ、気泡（全ポア）の発生件数率は６．２％に
も達した。In addition, when the LiTaO 3 single crystal of 307 Lot using the Ta 2 O 5 powder not having the average particle diameter according to the present invention including the above Comparative Examples 1 and 2 was pulled, bubbles (all pores) The incidence rate of) has reached 6.2%.
【００２１】また、図１には、実施例を含めて１３８Lo
t の、および比較例１および２を含めて３０７Lot のＬ
ｉＴａＯ3 単結晶の引き上げを行った際の、Ｔａ2 Ｏ5
粉末の平均粒子径（通気法による）と全ポアの発生件数
率との関係を示してある。図１からも明らかなように本
発明によれば、全ポアの発生件数率が６．２％から０．
７％へと低減された。Further, in FIG. 1, 138Lo including the embodiment is shown.
t and 307 Lot including Comparative Examples 1 and 2
Ta 2 O 5 when the iTaO 3 single crystal was pulled up
The relationship between the average particle size of the powder (by the aeration method) and the rate of occurrence of all pores is shown. As is clear from FIG. 1, according to the present invention, the occurrence rate of all pores is 6.2% to 0.1%.
It was reduced to 7%.
【００２２】[0022]
【発明の効果】以上説明したように本発明によれば、Ｔ
ａ2 Ｏ5粉末の平均粒子径（通気法による）を0.70〜0.8
0μm としたことにより、引き上げたＬｉＴａＯ3 単結
晶における気泡（全ポア）の発生率を低減し得るため、
良好な品質のＬｉＴａＯ3 単結晶が高歩留まりで得られ
る。As described above, according to the present invention, T
a 2 average particle diameter of the O 5 powder (by insufflation) from 0.70 to 0.8
By setting the thickness to 0 μm, the generation rate of bubbles (total pores) in the pulled LiTaO 3 single crystal can be reduced,
A good quality LiTaO 3 single crystal can be obtained with a high yield.
【図１】Ｔａ2 Ｏ5 粉末の平均粒子径と全ポアの発生件
数率との関係を示す図である。FIG. 1 is a diagram showing the relationship between the average particle size of Ta 2 O 5 powder and the number of occurrences of all pores.
【図２】Ｔａ2 Ｏ5 粉末に不純物として含まれるSi含有
量と全ポアの発生件数率との関係を示す図である。FIG. 2 is a diagram showing the relationship between the content of Si contained in Ta 2 O 5 powder as an impurity and the rate of occurrence of all pores.
【図３】Ｔａ2 Ｏ5 粉末に不純物として含まれるAl含有
量と全ポアの発生件数率との関係を示す図である。FIG. 3 is a diagram showing the relationship between the content of Al contained as an impurity in Ta 2 O 5 powder and the rate of occurrence of all pores.
【図４】Ｔａ2 Ｏ5 粉末の水分含有量と全ポアの発生件
数率との関係を示す図である。FIG. 4 is a diagram showing the relationship between the water content of Ta 2 O 5 powder and the rate of occurrence of all pores.
Claims (1)
りＬｉＴａＯ3 単結晶を製造するＴａ2 Ｏ5 およびＬｉ
2 Ｏ3 を主体とするＬｉＴａＯ3 単結晶材料において、 Ｔａ2 Ｏ5 の平均粒子径（通気法による）を０．７０〜
０．８０μm としたことを特徴とするＬｉＴａＯ3 単結
晶材料。1. Ta 2 O 5 and Li for producing a LiTaO 3 single crystal by the pulling method using a Pt-Rh crucible.
In the LiTaO 3 single crystal material mainly composed of 2 O 3 , the average particle size of Ta 2 O 5 (by the aeration method) is 0.70 to
A LiTaO 3 single crystal material having a thickness of 0.80 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3286799A JP3015552B2 (en) | 1991-10-31 | 1991-10-31 | LiTaO3 single crystal material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3286799A JP3015552B2 (en) | 1991-10-31 | 1991-10-31 | LiTaO3 single crystal material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05124897A true JPH05124897A (en) | 1993-05-21 |
| JP3015552B2 JP3015552B2 (en) | 2000-03-06 |
Family
ID=17709198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3286799A Expired - Fee Related JP3015552B2 (en) | 1991-10-31 | 1991-10-31 | LiTaO3 single crystal material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3015552B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002167299A (en) * | 2000-11-29 | 2002-06-11 | Hitachi Metals Ltd | Method of growing single crystal |
| US7544248B2 (en) | 2003-04-08 | 2009-06-09 | Sumitomo Metal Mining Co., Ltd. | Lithium tantalate substrate and method of manufacturing same |
| CN116905087A (en) * | 2023-09-13 | 2023-10-20 | 天通控股股份有限公司 | Growth method of lithium tantalate crystal |
-
1991
- 1991-10-31 JP JP3286799A patent/JP3015552B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002167299A (en) * | 2000-11-29 | 2002-06-11 | Hitachi Metals Ltd | Method of growing single crystal |
| US7544248B2 (en) | 2003-04-08 | 2009-06-09 | Sumitomo Metal Mining Co., Ltd. | Lithium tantalate substrate and method of manufacturing same |
| US7544247B2 (en) | 2003-04-08 | 2009-06-09 | Sumitomo Metal Mining Co., Ltd. | Lithium tantalate substrate and method of manufacturing same |
| US7544246B2 (en) | 2003-04-08 | 2009-06-09 | Sumitomo Metal Mining Co., Ltd. | Lithium tantalate substrate and method of manufacturing same |
| CN116905087A (en) * | 2023-09-13 | 2023-10-20 | 天通控股股份有限公司 | Growth method of lithium tantalate crystal |
| CN116905087B (en) * | 2023-09-13 | 2023-11-28 | 天通控股股份有限公司 | Growth method of lithium tantalate crystal |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3015552B2 (en) | 2000-03-06 |
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