JPH05101770A - Field emission type cathode - Google Patents
Field emission type cathodeInfo
- Publication number
- JPH05101770A JPH05101770A JP28417391A JP28417391A JPH05101770A JP H05101770 A JPH05101770 A JP H05101770A JP 28417391 A JP28417391 A JP 28417391A JP 28417391 A JP28417391 A JP 28417391A JP H05101770 A JPH05101770 A JP H05101770A
- Authority
- JP
- Japan
- Prior art keywords
- tip
- field emission
- type cathode
- emission type
- less
- 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.)
- Pending
Links
- 239000000463 material Substances 0.000 claims abstract description 16
- 229910052723 transition metal Inorganic materials 0.000 claims abstract description 4
- 150000003624 transition metals Chemical class 0.000 claims abstract description 4
- 238000005530 etching Methods 0.000 abstract description 4
- 229910052758 niobium Inorganic materials 0.000 abstract description 4
- 229910052715 tantalum Inorganic materials 0.000 abstract description 3
- 229910052721 tungsten Inorganic materials 0.000 abstract description 3
- 229910052735 hafnium Inorganic materials 0.000 abstract description 2
- 229910052750 molybdenum Inorganic materials 0.000 abstract description 2
- 229910052720 vanadium Inorganic materials 0.000 abstract description 2
- 230000008018 melting Effects 0.000 abstract 1
- 238000002844 melting Methods 0.000 abstract 1
- 229910052751 metal Inorganic materials 0.000 abstract 1
- 239000002184 metal Substances 0.000 abstract 1
- 239000000126 substance Substances 0.000 abstract 1
- 229910052719 titanium Inorganic materials 0.000 abstract 1
- 229910052726 zirconium Inorganic materials 0.000 abstract 1
- 230000005684 electric field Effects 0.000 description 5
- 238000010894 electron beam technology Methods 0.000 description 5
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 239000010955 niobium Substances 0.000 description 2
- 239000003870 refractory metal Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- UNASZPQZIFZUSI-UHFFFAOYSA-N methylidyneniobium Chemical compound [Nb]#C UNASZPQZIFZUSI-UHFFFAOYSA-N 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Landscapes
- Electron Sources, Ion Sources (AREA)
- Cold Cathode And The Manufacture (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は電界放射型陰極に関す
る。FIELD OF THE INVENTION The present invention relates to a field emission cathode.
【０００２】[0002]
【従来の技術及びその問題点】走査型電子顕微鏡、電子
顕微鏡、電子ビーム加工装置の電子ビーム応用機器にお
いて、最終電子ビーム径が小さく、かつ高輝度のサブミ
クロン電子源が要望されている。電界放射型陰極は１０
9 Ａ／ｃｍ2 ・str という高輝度の電子ビームが得られ
るため次世代の電子ビーム源として期待されている。電
界放射型陰極は、曲率半径０．５μｍ以下に加工した針
状の電子放射材料（以下、チップという）に強電界をか
け電子を取り出す。チップの先端の曲率半径が大きくな
るほど、外部からかける電界は強くなる。先端の曲率半
径が０．５μｍ以上になると外部からかける電界が大き
くなり、２×１０-8Ｐａという高真空下でも放電を起こ
してしまう。このために、外部からかける電界をできる
だけ小さくしたいという要求がある。また低電界で陰極
を作動させることで、ビームの安定性がますことが期待
できる。2. Description of the Related Art In a scanning electron microscope, an electron microscope, and an electron beam application device such as an electron beam processing apparatus, a submicron electron source having a small final electron beam diameter and high brightness is required. The field emission type cathode is 10
It is expected as a next-generation electron beam source because it can obtain an electron beam with a high brightness of 9 A / cm 2 · str. In the field emission type cathode, a strong electric field is applied to a needle-shaped electron emission material (hereinafter, referred to as a chip) processed to have a radius of curvature of 0.5 μm or less to extract electrons. The larger the radius of curvature of the tip of the chip, the stronger the electric field applied from the outside. When the radius of curvature of the tip is 0.5 μm or more, the electric field applied from the outside is large, and discharge occurs even under a high vacuum of 2 × 10 −8 Pa. Therefore, there is a demand to minimize the electric field applied from the outside. Further, by operating the cathode in a low electric field, the stability of the beam can be expected to increase.
【０００３】[0003]
【発明の目的】本発明は、従来にない低電圧で使用でき
る電界放射型陰極を提供することを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a field emission type cathode which can be used at an unprecedentedly low voltage.
【０００４】[0004]
【問題点を解決するための手段】本発明は、先端が曲率
半径５０ｎｍ以下である針状の電子放射材料を具備して
なる電界放射型陰極に関する。本発明の電子放射材料と
しては特に制限はないが、仕事関数が小さく、機械的に
硬く、異方性の強い物質が望ましい。例えば、Ｔｉ、Ｚ
ｒ、Ｈｆ、Ｖ、Ｎｂ、Ｔａ等の遷移金属の炭化物やＷ、
Ｍｏ、Ｔａ、Ｎｂ、Ｉｒ等の高融点金属等が挙げられ
る。The present invention relates to a field emission type cathode comprising a needle-shaped electron emitting material having a tip with a radius of curvature of 50 nm or less. The electron emitting material of the present invention is not particularly limited, but a material having a small work function, mechanical hardness, and strong anisotropy is desirable. For example, Ti, Z
Carbides of transition metals such as r, Hf, V, Nb, and Ta, and W,
Refractory metals such as Mo, Ta, Nb, and Ir can be used.
【０００５】本発明の電子放射材料は、角柱状、または
円柱状に加工した材料を用いて、初めに劈開面を利用し
ある程度尖った先端を作り、この先端をエッチング溶液
中で異方性エッチングを施すことにより得られる。この
ようにすることで、先端の曲率半径が５０ｎｍ以下の曲
率半径を持つチップを再現性良く得ることが出来る。エ
ッチング溶液としては、遷移金属炭化物の場合には、フ
ッ酸と硝酸の混合液、高融点金属の場合には、水酸化カ
リウム、水酸化ナトリウム等のアルカリ水溶液が用いら
れる。The electron-emitting material of the present invention is a material processed into a prismatic shape or a cylindrical shape, and a cleaved surface is first used to form a pointed tip, and this tip is anisotropically etched in an etching solution. It is obtained by applying. By doing so, a tip having a radius of curvature of the tip of 50 nm or less can be obtained with good reproducibility. As the etching solution, in the case of transition metal carbide, a mixed solution of hydrofluoric acid and nitric acid, and in the case of refractory metal, an alkaline aqueous solution such as potassium hydroxide or sodium hydroxide is used.
【０００６】[0006]
【実施例】以下に本発明の実施例を示す。 実施例１ 曲率半径３０ｎｍの先端をもつ炭化チタン単結晶の電子
放射材料を用いて電界放射型陰極を作り、２×１０-8Ｐ
ａの真空中で電子放射を行なった。印加電圧５００Ｖで
電子放出が起こっていることを確認できた。１μＡを取
り出した状態で、１％以上のノイズが入らない時間は６
分間であった。EXAMPLES Examples of the present invention will be shown below. Example 1 A field emission type cathode was prepared by using an electron emission material of titanium carbide single crystal having a tip with a radius of curvature of 30 nm and 2 × 10 −8 P
Electron emission was performed in the vacuum of a. It was confirmed that electron emission occurred at an applied voltage of 500V. With 1 μA taken out, the time that 1% or more of noise does not enter is 6
It was a minute.
【０００７】実施例２ 曲率半径４０ｎｍの先端をもつタングステン単結晶の電
子放射材料を用いて電界放射型陰極を作り、２×１０-8
Ｐａの真空中で電子放射を行なった。印加電圧８００Ｖ
で電子放出が起こっていることを確認できた。１μＡを
取り出した状態で、１％以上のノイズが入らない時間は
３分間であった。Example 2 A field emission type cathode was prepared by using an electron emission material of tungsten single crystal having a tip with a radius of curvature of 40 nm and 2 × 10 −8
Electron emission was performed in a vacuum of Pa. Applied voltage 800V
It was confirmed that electron emission occurred. With 1 μA taken out, the time during which 1% or more of noise did not enter was 3 minutes.
【０００８】実施例３ 曲率半径３０ｎｍの先端をもつ炭化ニオブ単結晶の電子
放射材料を用いて電界放射型陰極を作り、２×１０-8Ｐ
ａの真空中で電子放射を行なった。印加電圧７００Ｖで
電子放出が起こっていることを確認できた。１μＡを取
り出した状態で、１％以上のノイズが入らない時間は５
分間であった。Example 3 A field emission type cathode was prepared by using a niobium carbide single crystal electron emitting material having a tip with a radius of curvature of 30 nm, and 2 × 10 -8 P
Electron emission was performed in the vacuum of a. It was confirmed that electron emission occurred at an applied voltage of 700V. With 1 μA taken out, the time for which 1% or more of noise does not enter is 5
It was a minute.
【０００９】比較例１ 先端の曲率半径が５００ｎｍであること以外は実施例１
と同様の電界放射型陰極を作り、同様の真空度で電子放
射を行なった。印加電圧８ｋＶで放電を起こし、陰極が
破壊した。Comparative Example 1 Example 1 except that the radius of curvature of the tip is 500 nm.
A field emission type cathode similar to that was prepared, and electron emission was performed at the same degree of vacuum. Discharge occurred at an applied voltage of 8 kV, and the cathode was destroyed.
【００１０】比較例２ 先端の曲率半径が３００ｎｍであること以外は実施例１
と同様の電界放射型陰極を作り、同様の真空度で電子放
射を行なった。印加電圧３ｋＶで電子放射が起こってい
ることを確認できた。１μＡを取り出した状態で、１％
以上のノイズが入らない時間は１０秒であった。Comparative Example 2 Example 1 except that the radius of curvature of the tip is 300 nm.
A field emission type cathode similar to that was prepared, and electron emission was performed at the same degree of vacuum. It was confirmed that electron emission occurred at an applied voltage of 3 kV. 1% with 1 μA taken out
The time during which the above noise did not enter was 10 seconds.
【００１１】比較例３ 先端の曲率半径が３００ｎｍであること以外は実施例２
と同様の電界放射型陰極を作り、同様の真空度で電子放
射を行なった。印加電圧４ｋＶで電子放射が起こってい
ることを確認できた。１μＡを取り出した状態で、１％
以上のノイズが入らない時間は５秒であった。Comparative Example 3 Example 2 except that the radius of curvature of the tip is 300 nm.
A field emission type cathode similar to that was prepared, and electron emission was performed at the same degree of vacuum. It was confirmed that electron emission occurred at an applied voltage of 4 kV. 1% with 1 μA taken out
The time when the above noise did not enter was 5 seconds.
【００１２】[0012]
【発明の効果】本発明によれば、電子放射材料の先端の
曲率半径を５０ｎｍ以下にすることで、低電圧で作動
し、しかも、非常に安定な電界放射型陰極を作製するこ
とができる。According to the present invention, by setting the radius of curvature of the tip of the electron emitting material to 50 nm or less, a field emission type cathode which operates at a low voltage and is very stable can be manufactured.
Claims (2)
の電子放射材料を具備してなる電界放射型陰極。1. A field emission cathode comprising a needle-shaped electron emission material having a tip with a radius of curvature of 50 nm or less.
ことを特徴とする請求項１の電界放射型陰極。2. The field emission type cathode according to claim 1, wherein the electron emitting material comprises a transition metal carbide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28417391A JPH05101770A (en) | 1991-10-04 | 1991-10-04 | Field emission type cathode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28417391A JPH05101770A (en) | 1991-10-04 | 1991-10-04 | Field emission type cathode |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05101770A true JPH05101770A (en) | 1993-04-23 |
Family
ID=17675129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28417391A Pending JPH05101770A (en) | 1991-10-04 | 1991-10-04 | Field emission type cathode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05101770A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5969363A (en) * | 1997-04-11 | 1999-10-19 | Hitachi, Ltd. | Method for processing electron beam sources |
| JP2006294283A (en) * | 2005-04-06 | 2006-10-26 | Univ Waseda | Metal needle structure and its manufacturing method |
| JP2009134974A (en) * | 2007-11-30 | 2009-06-18 | Denki Kagaku Kogyo Kk | Electron emitting source |
-
1991
- 1991-10-04 JP JP28417391A patent/JPH05101770A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5969363A (en) * | 1997-04-11 | 1999-10-19 | Hitachi, Ltd. | Method for processing electron beam sources |
| US6340860B1 (en) | 1997-04-11 | 2002-01-22 | Hitachi, Ltd. | Method of manufacturing electron beam emitter having an electron beam emitting axis coincided with crystal axis |
| JP2006294283A (en) * | 2005-04-06 | 2006-10-26 | Univ Waseda | Metal needle structure and its manufacturing method |
| JP4742187B2 (en) * | 2005-04-06 | 2011-08-10 | 学校法人早稲田大学 | Metal needle structure and manufacturing method thereof |
| JP2009134974A (en) * | 2007-11-30 | 2009-06-18 | Denki Kagaku Kogyo Kk | Electron emitting source |
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