JP2761906B2 - Diamond synthesis by gas phase reaction - Google Patents
Diamond synthesis by gas phase reactionInfo
- Publication number
- JP2761906B2 JP2761906B2 JP63322433A JP32243388A JP2761906B2 JP 2761906 B2 JP2761906 B2 JP 2761906B2 JP 63322433 A JP63322433 A JP 63322433A JP 32243388 A JP32243388 A JP 32243388A JP 2761906 B2 JP2761906 B2 JP 2761906B2
- Authority
- JP
- Japan
- Prior art keywords
- diamond
- gas
- gas phase
- phase reaction
- diamond synthesis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Description
【発明の詳細な説明】 〔発明の属する技術分野〕 本発明は気相反応によるダイヤモンドの合成法、特に
マイクロ波等によって活性化されたCOとH2との混合ガス
から、ダイヤモンドやダイヤモンド状炭素（以下簡単に
するために両者を含めてダイヤモンドと呼ぶ）を基体上
の析出する方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for synthesizing diamond by a gas phase reaction, particularly from a mixed gas of CO and H 2 activated by microwaves or the like to obtain diamond or diamond-like carbon. (Hereinafter referred to as diamond for simplicity) on a substrate.
〔従来の技術〕 マイクロ波、高周波により、或いは加熱により活性化
された炭素含有気相からの析出によるダイヤモンドの合
成が近年各産業分野において感心を集め、析出速度や生
成物の形態の最適化のための研究が、特にこの数年盛ん
に行われている。これらの工程では主としてCH4を水素
で希釈した混合ガスが反応ガスとして用いられている
が、ダイヤモンドと共に、安定相である非ダイヤモンド
炭素（黒鉛・不定形炭素）が析出するのが避けられな
い。この場合、活性化された水素は非ダイヤモンド炭素
を除去する作用を持つと解釈されているが、その速度は
一般にあまり大きくない。従って、ダイヤモンドの析出
工程はこの水素による非ダイヤモンド炭素の除去段階に
よって律速きれ、100％純粋なダイヤモンド膜の形成速
度は１μm/hr以下に抑えられ、しかも結晶性は必ずしも
満足できるものではない。近年、酸素や水蒸気等、ある
種の添加物の使用が、形成速度向上のために有効である
ことが知られている。しかし本発明者等の実験によれ
ば、CH4−H2へのO2の添加について、例えば３％のCH4の
場合にはCH4量に対するO2添加比が〜40％の狭い範囲に
限られ、最適な流量比を得るための調節が困難である。
その上析出物の結晶性には目立った向上が見られない。
一方１％以上の酸素を添加すると自形性の良好なダイヤ
モンドが得られるが、この際の析出速度は無添加の場合
と同等か、或いはそれを下回る。この様に酸素の添加に
よって、ダイヤモンドの析出速度と結晶性の両者を同時
に改善することはできない。水蒸気の添加の場合も同様
の傾向が認められる。[Prior art] The synthesis of diamond by precipitation from a carbon-containing gas phase activated by microwaves, high-frequency waves, or by heating has recently attracted interest in various industrial fields, and optimized the deposition rate and product morphology. Research has been actively conducted, especially in recent years. In these steps, a mixed gas obtained by diluting CH 4 with hydrogen is mainly used as a reaction gas. However, it is inevitable that non-diamond carbon (graphite and amorphous carbon), which is a stable phase, is deposited together with diamond. In this case, the activated hydrogen is interpreted to have the effect of removing non-diamond carbon, but the rate is generally not very high. Therefore, the diamond deposition process can be controlled by the step of removing non-diamond carbon with hydrogen, the formation rate of a 100% pure diamond film is suppressed to 1 μm / hr or less, and the crystallinity is not always satisfactory. In recent years, it has been known that the use of certain additives such as oxygen and water vapor is effective for improving the formation rate. However, according to experiments of the present inventors, CH 4 for the addition of O 2 to -H 2, in a narrow range O 2 addition ratio is 40% for CH 4 amount in the case of example 3% CH 4 Limited and difficult to adjust to obtain the optimal flow ratio.
In addition, there is no noticeable improvement in the crystallinity of the precipitate.
On the other hand, when 1% or more of oxygen is added, a diamond having good self-formity can be obtained, but the deposition rate at this time is equal to or lower than the case of no addition. Thus, the addition of oxygen cannot simultaneously improve both the diamond deposition rate and the crystallinity. A similar tendency is observed in the case of adding steam.
従って本発明はこの様な従来技術の問題を解決するこ
とによって、析出速度が大きくかつ得られるダイヤモン
ドの結晶性も良好な気相反応工程を提供することを目的
とする。Accordingly, an object of the present invention is to provide a gas phase reaction process in which the deposition rate is high and the crystallinity of the obtained diamond is good by solving the problems of the prior art.
本発明の要旨とするところは、COとH2との混合ガスを
反応室内に導き、活性化された混合系から反応室内に置
かれた基体上にダイヤモンドないしダイヤモンド状炭素
を析出させる方法において、反応室に導かれる上記混合
ガスにH2の分量に対して２％以上30％以下のCO2ガスを
添加することを特徴とする、気相反応によるダイヤモン
ド合成法にある。ダイヤモンド（ダイヤモンド状炭素）
の析出速度は、粒子状・膜状ともにCOの添加割合と共に
上昇し、そして抵下する。結晶性の点からは、CO濃度が
高くなると、結晶面上に二次結晶の成長が見られ、自形
性は低下する。The gist of the present invention is to introduce a mixed gas of CO and H 2 into a reaction chamber, and to deposit diamond or diamond-like carbon on a substrate placed in the reaction chamber from the activated mixed system, A diamond synthesis method based on a gas phase reaction, characterized in that a CO 2 gas of 2% or more and 30% or less based on the amount of H 2 is added to the mixed gas introduced into the reaction chamber. Diamond (diamond-like carbon)
The rate of precipitation increases and decreases with the addition ratio of CO in both the particulate form and the film form. From the viewpoint of crystallinity, when the CO concentration increases, secondary crystals grow on the crystal plane, and the self-formity decreases.
本発明方法において使用する本質的二次ガスCO−H2は
H2に対して15〜100％（容量）のCOを含有することがで
きる。５％以下では実用的な析出速度が得られず、また
15％を超えると不定形炭素が共祈するので好ましくな
い。Essentially secondary gas CO-H 2 used in the process of the present invention
It may contain CO 15 to 100% (volume) with respect to H 2. If it is less than 5%, a practical deposition rate cannot be obtained, and
If it exceeds 15%, amorphous carbon is not preferred because it prays together.
この際、上記混合ガスにCO2を比較的少量添加するこ
とにより、析出速度、結晶性、純度を更に向上させ、或
いは良好な結晶性が確保される析出速度範囲を拡大する
ことができる。CO2の添加濃度が高いと結晶性および純
度は改善されるが、高すぎると成長速度は低下する。所
望の用途・目的に応じて、上記範囲内でH2の流量および
CO比、並びにこれに対するCO2の添加割合を選ぶ。At this time, by adding a relatively small amount of CO 2 to the mixed gas, the deposition rate, crystallinity, and purity can be further improved, or the deposition rate range in which good crystallinity is ensured can be expanded. If the added concentration of CO 2 is high, the crystallinity and purity are improved, but if it is too high, the growth rate is reduced. Depending on the desired application and purpose, the flow rate and H 2 in the above range
The CO ratio and the proportion of CO 2 added thereto are selected.
次に本発明を実際の例に即して説明する。第１図は本
発明の実施に用い得る装置の概略を示す模式図、第２図
は本発明方法により生成されるダイヤモンド粒子の形状
を例示する電子顕微鏡写真である。図において石英管か
ら成る縦形反応室１は導波管２を介してマグネトロン３
と連結されている。管１は下部において減圧用の真空ポ
ンプ４と連係され、上部には反応ガス導入のための配管
５が接続されている。管１の中にはダイヤモンド析出基
体としてのSiウェーファを保持するための台６が設置さ
れている。台６付近の管１壁には冷却水を通すためのス
リーブ７を設けることができる。水素ガス、CO、およ
び、CO2ガスは、それぞれの供給源８、９、10から、調
合器11を介して供給することができる。Next, the present invention will be described with reference to actual examples. FIG. 1 is a schematic diagram showing an outline of an apparatus that can be used for carrying out the present invention, and FIG. 2 is an electron micrograph illustrating the shape of diamond particles produced by the method of the present invention. In the figure, a vertical reaction chamber 1 made of a quartz tube is connected to a magnetron 3 via a waveguide 2.
Is linked to The lower part of the pipe 1 is linked to a vacuum pump 4 for reducing pressure, and the upper part is connected to a pipe 5 for introducing a reaction gas. A table 6 for holding a Si wafer as a diamond deposition substrate is provided in the tube 1. A sleeve 7 for passing cooling water can be provided on the wall of the pipe 1 near the base 6. Hydrogen gas, CO, and CO 2 gas can be supplied from respective sources 8, 9, 10 via a blender 11.
〔実施例］ 第１図の装置を用いた。石英管は外径48mm、管の中央
部には直径15mmの石英円板を用いた。このマグネトロン
は2.45GHzのマイクロ波を発生する。220Wのマイクロ波
で基体を約900℃に加熱し、管内に毎分100mlの割合で供
給されるH2の容量に対して15％のCOを含む混合ガスを導
入した。ガスは適宜排出して管内の圧力を約3.3KPaに保
った。この操作を約３時間続けて、第２図（ａ）に示す
ような、平均粒径10μｍの自形晶ダイヤモンド粒子を得
た。[Example] The apparatus shown in Fig. 1 was used. The quartz tube used was a quartz disk having an outer diameter of 48 mm and a central portion of the tube having a diameter of 15 mm. This magnetron generates 2.45GHz microwaves. The substrate was heated to about 900 ° C. with a microwave of 220 W and a gas mixture containing 15% CO with respect to the volume of H 2 supplied at a rate of 100 ml / min was introduced into the tube. The gas was properly discharged to maintain the pressure in the tube at about 3.3 KPa. This operation was continued for about 3 hours to obtain automorphic diamond particles having an average particle diameter of 10 μm as shown in FIG. 2 (a).
次に、上記と同様のH2流量・CO混合比に、CO2を６％
添加した混合ガスを用いて、上記の操作を繰り返した。
この場合には、３時間の同様の操作で、平均粒径32μｍ
の自形性の良いダイヤモンド粒子を得た。第２図
（ｂ）。Next, 6% of CO 2 was added to the same H 2 flow rate and CO mixture ratio as above.
The above operation was repeated using the added mixed gas.
In this case, the average particle size is 32 μm by the same operation for 3 hours.
The diamond particles having good self-formity were obtained. FIG. 2 (b).
第１図は本発明の実施に用い得る装置の概略を示す模式
図、第２図は本発明方法により得られたダイヤモンドの
析出状態を例示する電子顕微鏡写真である。 １……反応室;2……導波管;3……マグネトロン； ４……真空ポンプ;5……反応ガス導入管;6……種子粒子
台； ７……冷却水スリーブ;8〜10……ガス供給源;11……調
合器。FIG. 1 is a schematic diagram showing an outline of an apparatus that can be used for carrying out the present invention, and FIG. 2 is an electron micrograph illustrating the state of precipitation of diamond obtained by the method of the present invention. 1 ... reaction chamber; 2 ... waveguide; 3 ... magnetron; 4 ... vacuum pump; 5 ... reaction gas inlet tube; 6 ... seed particle table; 7 ... cooling water sleeve; ... gas supply source; 11 ... mixer.
フロントページの続き (56)参考文献 特開 昭63−274692（ＪＰ，Ａ) 特開 昭64−266（ＪＰ，Ａ) 特開 平１−201098（ＪＰ，Ａ) 特開 平１−317198（ＪＰ，Ａ) 特開 平１−197391（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) C30B 28/00 - 35/00Continuation of the front page (56) References JP-A-63-274692 (JP, A) JP-A-64-266 (JP, A) JP-A-1-201098 (JP, A) JP-A-1-317198 (JP) , A) JP-A-1-197391 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) C30B 28/00-35/00
Claims (1)
性化された混合系から反応室内に置かれた基体上にダイ
ヤモンドないしダイヤモンド状炭素を析出させる方法に
おいて、反応室に導かれる上記混合ガスにH2の分量に対
して２％以上30％以下のCO2ガスを添加することを特徴
とする、気相反応によるダイヤモンド合成法。In a method for introducing a mixed gas of CO and H 2 into a reaction chamber and depositing diamond or diamond-like carbon on a substrate placed in the reaction chamber from the activated mixed system, the mixed gas is introduced into the reaction chamber. A method for synthesizing diamond by a gas phase reaction, comprising adding 2% to 30% of CO 2 gas based on the amount of H 2 to the mixed gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63322433A JP2761906B2 (en) | 1988-12-21 | 1988-12-21 | Diamond synthesis by gas phase reaction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63322433A JP2761906B2 (en) | 1988-12-21 | 1988-12-21 | Diamond synthesis by gas phase reaction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02167892A JPH02167892A (en) | 1990-06-28 |
| JP2761906B2 true JP2761906B2 (en) | 1998-06-04 |
Family
ID=18143618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63322433A Expired - Fee Related JP2761906B2 (en) | 1988-12-21 | 1988-12-21 | Diamond synthesis by gas phase reaction |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2761906B2 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63274692A (en) * | 1987-05-02 | 1988-11-11 | Idemitsu Petrochem Co Ltd | Synthesis of diamond |
| JPH0667797B2 (en) * | 1987-10-12 | 1994-08-31 | 出光石油化学株式会社 | Diamond synthesis method |
| JPH01197391A (en) * | 1988-02-01 | 1989-08-09 | Idemitsu Petrochem Co Ltd | Method for synthesizing diamond |
| JPH01317198A (en) * | 1988-03-22 | 1989-12-21 | Idemitsu Petrochem Co Ltd | Method for synthesizing diamond or the like |
-
1988
- 1988-12-21 JP JP63322433A patent/JP2761906B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02167892A (en) | 1990-06-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |