JPH0145699B2 - - Google Patents
Info
- Publication number
- JPH0145699B2 JPH0145699B2 JP57175390A JP17539082A JPH0145699B2 JP H0145699 B2 JPH0145699 B2 JP H0145699B2 JP 57175390 A JP57175390 A JP 57175390A JP 17539082 A JP17539082 A JP 17539082A JP H0145699 B2 JPH0145699 B2 JP H0145699B2
- Authority
- JP
- Japan
- Prior art keywords
- ion
- tungsten
- ion source
- ion generating
- melting point
- 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
Links
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 20
- 229910052721 tungsten Inorganic materials 0.000 claims description 20
- 239000010937 tungsten Substances 0.000 claims description 20
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 238000002844 melting Methods 0.000 claims description 6
- 230000008018 melting Effects 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims 2
- 150000002500 ions Chemical class 0.000 description 46
- 239000000523 sample Substances 0.000 description 10
- 238000010884 ion-beam technique Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 238000004458 analytical method Methods 0.000 description 4
- 238000009826 distribution Methods 0.000 description 3
- 238000011109 contamination Methods 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- -1 can be improved Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000004949 mass spectrometry Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 238000001004 secondary ion mass spectrometry Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000005211 surface analysis Methods 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
- 230000004304 visual acuity Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J27/00—Ion beam tubes
- H01J27/02—Ion sources; Ion guns
- H01J27/022—Details
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Electron Tubes For Measurement (AREA)
- Electron Sources, Ion Sources (AREA)
Description
【発明の詳細な説明】
こ発明は高輝度表面電離型イオン源およびその
製造法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high brightness surface ionization type ion source and a method for manufacturing the same.
試料面に一次イオン・ビームを照射するとき試
料表面から放出される二次イオンを質量分析して
試料表面の元素分布や状態を測定する二次イオン
質量分析法（SIMS）に用いられる装置の一例と
してイオンマイクロプロープ質量分析計
（IMMA）が知られており、この型の装置は主と
して元素の定量分析或いは線、面や深さ方向の元
素の分布を解析するのに用いられる。そして一次
イオン電流を向上させビームスポツトの大きさを
小さくすることによつて、空間的な分解能即ち試
料中の元素を検出するときの解像力、検出限界を
高め、また例えば半導体基板のキヤリヤ以外の不
純物やICチツプ等の極微量不純物の空間的分布
の分析ができるようになることが認められてお
り、従つて微量元素の分析には装置の高真空化と
共に電流密度の高にイオン源が要求される。 An example of equipment used in secondary ion mass spectrometry (SIMS), which measures the elemental distribution and state on the sample surface by mass spectrometry of the secondary ions emitted from the sample surface when the sample surface is irradiated with a primary ion beam. The ion microprobe mass spectrometer (IMMA) is known as an ion microprobe mass spectrometer (IMMA), and this type of device is mainly used for quantitative analysis of elements or for analyzing the distribution of elements in a line, plane, or depth direction. By improving the primary ion current and reducing the size of the beam spot, the spatial resolution, that is, the resolving power and detection limit when detecting elements in a sample, can be improved, and impurities other than the carrier of a semiconductor substrate can be detected. It has been recognized that it becomes possible to analyze the spatial distribution of extremely small amounts of impurities in materials such as chips and IC chips. Therefore, the analysis of trace elements requires an ion source with a high current density as well as a high vacuum in the device. Ru.
ところでプローブイオンを細いビームにして試
料表面の局部分析を行うIMMA等に用いられる
表面電離型イオン源を用いて試料表面のビームス
ポツトの大きさをある小さな値（例えば数μmφ）
に制限しようとする場合、一般にはイオン源より
発生したイオンビームを収束系に通すことで微小
スポツト寸法を得ることが考えられるが、試料表
面への到達ビーム電流値が小さくなり、表面分析
等には不利となる。試料表面に到達するビーム電
流値（最大値）は、
Ipmax＝3π2・Ｂ・d8/3／16Cs2/3
で表わされ、ここでＢは輝度、ｄはビームスポツ
トの大きさ、Csは球面収差係数であり、従つて
ビーム電流値はイオン源の輝度に比例することが
わかる。 By the way, the size of the beam spot on the sample surface can be set to a small value (for example, several μmφ) using a surface ionization type ion source used in IMMA, etc., which uses probe ions as a narrow beam to perform local analysis on the sample surface.
In general, when trying to limit the size of the spot, it is possible to obtain a minute spot size by passing the ion beam generated from the ion source through a focusing system, but this reduces the beam current value reaching the sample surface, making it difficult to use for surface analysis etc. is disadvantageous. The beam current value (maximum value) reaching the sample surface is expressed as Ipmax=3π 2・B・d 8/3 /16Cs 2/3 , where B is the brightness, d is the size of the beam spot, and Cs is the spherical aberration coefficient, and therefore it can be seen that the beam current value is proportional to the brightness of the ion source.
以上のような観点からこの種の分析において、
試料表面にできるだけ小さな径でしかもできるだ
け強い一次イオンビームスポツトを形成するため
にはイオン源の輝度をできるだけ高くする必要が
あり、高輝度のイオン源が要求される。しかしな
がら、従来提案されてきた表面電離型イオン源で
は、第１図に示すようにイオン発生部を構成して
いるポーラスタングステン１は加工上の観点から
その有効径を２mmφ程度にするのが限度であり、
それ以下にすることは実質的に困難であつた。な
お第１図において２はイオン生成部、３はヒータ
ー、４な電極を示す。またポーラスタングステン
１の周辺部からもイオン種の蒸気が起こるため、
大輝度のビームを引き出そうとすると、無駄なイ
オン種の放出が伴ない、その結果イオン源の汚染
や電気的な絶縁不良（イオン種が金属である場
合）等生じることになる。 In this type of analysis from the above perspective,
In order to form a primary ion beam spot as small as possible and as strong as possible on the sample surface, it is necessary to make the brightness of the ion source as high as possible, and a high brightness ion source is required. However, in the surface ionization type ion source that has been proposed so far, the effective diameter of the porous tungsten 1 constituting the ion generating section, as shown in Figure 1, is limited to about 2 mmφ from the viewpoint of processing. can be,
It was practically difficult to reduce it to less than that. In FIG. 1, 2 represents an ion generating section, 3 represents a heater, and 4 represents an electrode. In addition, since vapor of ionic species is generated from the surrounding area of porous tungsten 1,
Attempting to extract a beam of high brightness involves the emission of wasteful ion species, resulting in contamination of the ion source and poor electrical insulation (if the ion species are metal).
そこで、この発明は、イオン種物質の放出面積
を小さくして単位面積当りのイオン放出量を向上
するようにした高輝度表面電離型イオン源を提供
することを目的とする。 SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a high-brightness surface ionization type ion source in which the emission area of ion species material is reduced to improve the amount of ions emitted per unit area.
従つてこの発明によるイオン源においてはポー
ラスタングステンから成るイオン発生部の表面は
その中心部分を除いてタングステン等の融点の高
いイオン不透過性膜で被覆される。好ましくは、
イオン発生部は円錐形を成し、その先端部だけか
らイオン種物質が放出されるように構成される。 Therefore, in the ion source according to the present invention, the surface of the ion generating portion made of porous tungsten is coated with an ion-impermeable film having a high melting point, such as tungsten, except for the central portion thereof. Preferably,
The ion generator has a conical shape and is configured so that the ionic species material is emitted only from the tip thereof.
またこの発明の別の目的は上記のイオン源の簡
単な製造方法を提供することにある。 Another object of the present invention is to provide a simple method for manufacturing the above-mentioned ion source.
すなわちこの発明の製造方法は、ポーラスタン
グステンから成るイオン発生部をその中央部分を
除いてタングステン等の融点の高くしかもイオン
蒸気を通さない物質でスパツター蒸着することを
特徴としている。 That is, the manufacturing method of the present invention is characterized in that the ion generating portion made of porous tungsten is sputter-deposited with a material such as tungsten which has a high melting point and does not allow ion vapor to pass through, except for the central portion thereof.
またこの発明の別の特徴によれば、イオン源の
製造法は、ポーラスタングステンから成るイオン
発生部を円錐形状に形成し、その表面にタングス
テン等の融点の高くしかも発生イオン蒸気を通さ
ない物質で蒸着し、そして円錐形状のイオン発生
部の先端を切削することから成る。 According to another feature of the present invention, the ion source is manufactured by forming an ion generating section made of porous tungsten into a conical shape, and covering the surface with a material such as tungsten that has a high melting point and does not allow the generated ion vapor to pass through. It consists of depositing and cutting the tip of a conical ion generator.
このように、この発明の製造法によれば、従来
では有効径２mmφ程度が限界であつたものが0.3
〜0.5mmφまたはそれ以下のイオン放出口をもつ
イオン源を簡単かつ容易に得ることができ、また
こうして得られたこの発明によるイオン源は、一
次イオンビームスポツトの大きさを小さくできる
だけでなく、イオン発生部で発生されたイオン蒸
気が周囲に拡散せずに中央部のイオン放出口のみ
から放出されるので単位面積当りのイオン放出量
すなわち輝度が著しく向上され得る。すなわち小
さな一次イオンビームスポツトを得る場合同一径
のスポツトのビーム電流を16〜50倍に増強でき、
高感度の分析が可能となる。また発生イオンを有
効に細いイオンビームとして放出できるので余分
のイオンによる系の汚染を避けることができる。 In this way, according to the manufacturing method of the present invention, the effective diameter, which was previously limited to about 2 mmφ, can be reduced to 0.3 mmφ.
An ion source with an ion emitting port of ~0.5 mmφ or smaller can be obtained simply and easily, and the ion source thus obtained according to the present invention can not only reduce the size of the primary ion beam spot but also Since the ion vapor generated in the generation part is emitted only from the central ion emitting port without being diffused to the surroundings, the amount of ions emitted per unit area, that is, the brightness, can be significantly improved. In other words, when obtaining a small primary ion beam spot, the beam current of a spot with the same diameter can be increased by 16 to 50 times.
Highly sensitive analysis becomes possible. Furthermore, since the generated ions can be effectively emitted as a narrow ion beam, contamination of the system by excess ions can be avoided.
以下この発明を添附図面の第２，３，４図を参
照して説明する。 The present invention will be described below with reference to FIGS. 2, 3, and 4 of the accompanying drawings.
第２〜４図にはこの発明の製造方法の一実施例
を示し、第２図には、円錐形状に切削したポーラ
スタングステン５をタンタルの管状体６に電子ビ
ーム溶接する工程を示す。こうして形成された円
錐形状のイオン発生部の表面には第３図に示すよ
うにタングステン７が厚さ10μｍ程度にスパツタ
ー蒸着される。その後第４図に示すように先端部
は切り取られ、その径が0.3〜0.5mmφになるよう
にされる。切削面８は例えば電解研摩によつて孔
のつぶれた部分を取り去る。従つてイオン種の蒸
発物はこの小さな径の切削面８だけから放出され
るため高輝度のイオンビームが得られる。 2 to 4 show an embodiment of the manufacturing method of the present invention, and FIG. 2 shows a step of electron beam welding a conically cut porous tungsten 5 to a tantalum tubular body 6. As shown in FIG. 3, tungsten 7 is sputter-deposited to a thickness of about 10 μm on the surface of the conical ion generating portion thus formed. Thereafter, as shown in FIG. 4, the tip is cut off to have a diameter of 0.3 to 0.5 mm. The cut surface 8 removes the collapsed portion of the hole, for example by electrolytic polishing. Therefore, since the evaporated material of the ion species is emitted only from this small diameter cutting surface 8, a high-intensity ion beam can be obtained.
第５図には別の実施例を示し、この例では従来
形のポーラスタングステン９の表面に中央部１０
を残してタングステン１１がスパツター蒸着され
る。 FIG. 5 shows another embodiment, in which a central portion 10 is placed on the surface of a conventional porous tungsten 9
Tungsten 11 is sputter deposited leaving behind.
上記各実施例ではイオン発生部の被覆材として
タングステンについて記載してきたが、通常1200
〜1300℃程度の温度に耐えしかも発生イオン蒸気
をしや断できる導電性物質であれば任意の物質例
えばMo，Ta等を使用することができる。 In each of the above examples, tungsten has been described as the covering material for the ion generating part, but normally 1200
Any conductive material, such as Mo, Ta, etc., can be used as long as it can withstand temperatures of about 1300 DEG C. and can cut off the generated ion vapor.
第１図は従来型のイオン源を示す概略図、第２
図〜４図はこの発明のイオン源の一実施例の製造
工程を示す断面図、第５図はこの発明の別の実施
例を示す断面図である。
図中、５，９：イオン発生部、７，１１：タン
グステン被覆。
Figure 1 is a schematic diagram showing a conventional ion source;
4 to 4 are cross-sectional views showing the manufacturing process of one embodiment of the ion source of the present invention, and FIG. 5 is a cross-sectional view showing another embodiment of the present invention. In the figure, 5, 9: ion generating part, 7, 11: tungsten coating.
Claims (1)
の表面をその中央部分を除いてタングステン等の
融点の高いイオン不透過性膜で被覆し、イオン種
物質の放出面積を小さくしたことを特徴とする高
輝度表面電離型イオン源。 ２ ポーラスタングステンから成るイオン発生部
の表面をその中央部分を除いてタングステン等の
融点の高いイオン不透過性物質でスパツター蒸着
することを特徴とする高輝度表面電離型イオン源
の製造法。 ３ ポーラスタングステンから成るイオン発生部
を円錐形状に形成し、その表面上にタングステン
等の融点の高いイオン不透過性物質を蒸着し、そ
して円錐形状のイオン発生部の先端を切削してイ
オン種の放出口を形成することから成ることを特
徴とする高輝度表面電離型イオン源の製造法。[Claims] 1. The surface of the ion generating part made of porous tungsten is coated with an ion-impermeable film having a high melting point such as tungsten, except for the central part, thereby reducing the area from which the ionic species is released. High brightness surface ionization type ion source. 2. A method for producing a high-brightness surface ionization type ion source, characterized in that an ion-impermeable substance with a high melting point, such as tungsten, is sputter-deposited on the surface of an ion generating part made of porous tungsten, except for the central part. 3. An ion generating section made of porous tungsten is formed into a conical shape, an ion-impermeable substance with a high melting point such as tungsten is deposited on the surface of the ion generating section, and the tip of the conical ion generating section is cut to extract the ion species. A method for manufacturing a high-intensity surface ionization type ion source, comprising forming an emission port.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57175390A JPS5966031A (en) | 1982-10-07 | 1982-10-07 | High brightness surface ionization type ion source and its manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57175390A JPS5966031A (en) | 1982-10-07 | 1982-10-07 | High brightness surface ionization type ion source and its manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5966031A JPS5966031A (en) | 1984-04-14 |
| JPH0145699B2 true JPH0145699B2 (en) | 1989-10-04 |
Family
ID=15995260
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57175390A Granted JPS5966031A (en) | 1982-10-07 | 1982-10-07 | High brightness surface ionization type ion source and its manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5966031A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0646552B2 (en) * | 1985-09-24 | 1994-06-15 | 株式会社日立製作所 | Ion source device |
| US9941089B2 (en) * | 2014-10-13 | 2018-04-10 | Arizona Board Of Regents, A Body Corporate Of The State Of Arizona, Acting For And On Behalf Of Arizona State University | Cesium primary ion source for secondary ion mass spectrometer |
| US10672602B2 (en) | 2014-10-13 | 2020-06-02 | Arizona Board Of Regents On Behalf Of Arizona State University | Cesium primary ion source for secondary ion mass spectrometer |
-
1982
- 1982-10-07 JP JP57175390A patent/JPS5966031A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5966031A (en) | 1984-04-14 |
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