JPS58142285A - Charged particle detector - Google Patents

Abstract

PURPOSE:To enable a separate detection of secondary electrons and secondary ions by arranging an acceleration electrode for electrons and anions, a magnetic field type deflector therebehind and an anion detecting means and an electron ray detecting means each at different positions behind the deflector. CONSTITUTION:A primary ion beam 7 projected from an ion source irradiates a sample 8 to generate secondary electrons 9 and secondary ions 10 from the surface thereof. The secondary electrons 9 and secondary ions 10 in the negative polarity are accelerated in the direction of a detector with an acceleration electrode 1 to which a positive voltage of about 10kV to accelerate them to reach the inside of a magnetic field (vertical to this paper) formed with the magnetic field type deflector 2 provided behind the acceleration electrode 1. The magnetic field deflects the orbit of the secondary electrons 9 significantly therein because of a small specific charge thereof on the other hand, the secondary ions 10 passing through the magnetic field almost travels straight, hence depicting an orbit as indicated by 10 in the drawing because the specific charge thereof is so large as more than 1,000 times as compared with the secondary electrons 9 to lower the deflection sensitivity. Thus, the magnetic field type deflector 2 is provided on the orbit where the secondary electrons 9 and the secondary ions 10 pass to deflect the orbit of the secondary electrons 9 significantly. These electrons 9 and ions 10 are introduced to respective detectors for separate detection thereof, which enables separate detection of two kinds of signals of the secondary electrons 9 and the secondary ions 10.

Description

【発明の詳細な説明】 本発明は、２次電子と２次イオンを分離して検出する荷
電粒子検出器に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a charged particle detector that separates and detects secondary electrons and secondary ions.

一般に１次ビームにイオンを使用し、そのイオンビーム
を試料上に照射すると２次電子、２次イオン等が発生す
る。これらのうち２次電子を検出してＣＲＴ上に試料の
拡大像を表示して観察する装置として走査イオン顕微鏡
がある。而して、この２次電子を検出する検出器にはシ
ンチレータが使用されているが、１次イオンビームの照
射によって２次電子と同様に高電圧で加速されたエネル
ギーの大きな２次イオンがシンチレータに入射する。２
次イオンがシンチレータに入射すると、イオンによるス
パッタ効果によりシンチレータ表面を蒸着により形成さ
れたアルミニューム等の金属薄膜が損傷を受は長時間使
用すると検出器の性能が劣化するという欠点があった。Generally, ions are used as a primary beam, and when a sample is irradiated with the ion beam, secondary electrons, secondary ions, etc. are generated. Among these, a scanning ion microscope is an apparatus that detects secondary electrons and displays an enlarged image of a sample on a CRT for observation. A scintillator is used as a detector to detect these secondary electrons, and high-energy secondary ions that are accelerated at a high voltage by irradiation with the primary ion beam are transferred to the scintillator. incident on . 2
When the next ion enters the scintillator, the sputtering effect of the ions damages the thin metal film, such as aluminum, formed by vapor deposition on the surface of the scintillator, resulting in deterioration of the performance of the detector when used for a long time.

又２次電子と２次イオンは夫々別の試料情報を含んでい
るため、これら２種の信号を筒金して検出するよりも分
離して検出することにより、より意味のある表面情報が
得られる。Furthermore, since secondary electrons and secondary ions each contain different sample information, more meaningful surface information can be obtained by detecting these two types of signals separately rather than by detecting them together. It will be done.

本発明は上述した点に鑑みてなされたもので電子と負イ
オンを加速する加速電極と、該加速電極の後方に設けら
れた磁界型偏向器と、該偏向器の後方の異った位置に設
けられた負イオン検出手段及び電子線検出手段とを備え
ることにより、２次電子と２次イオンを分離して検出す
るようにしたものである。The present invention has been made in view of the above points, and includes an accelerating electrode that accelerates electrons and negative ions, a magnetic field type deflector provided behind the accelerating electrode, and a magnetic field type deflector provided at different positions behind the deflector. By providing negative ion detection means and electron beam detection means, secondary electrons and secondary ions can be separated and detected.

以下本発明の実施例を添付図面に基づき詳説する。Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

図は本発明の概略図で、１はイオンビーム照射によって
試料面より発生する２次電子及び負極性の２次イオンを
検出器に導くための加速電極、２はシンチレータ３の前
方に設けられた磁界型偏向器、３は２次電子を光に変換
するシンチレータ、４はライトガイド、５は光を電気信
号に変換するフォトマル、６は２次イオンを電気信号に
変換するチャンネルトロンである。The figure is a schematic diagram of the present invention, in which 1 is an acceleration electrode for guiding secondary electrons and negative polarity secondary ions generated from the sample surface by ion beam irradiation to the detector, and 2 is an accelerating electrode provided in front of a scintillator 3. A magnetic field type deflector, 3 a scintillator that converts secondary electrons into light, 4 a light guide, 5 a photomultiplier that converts light into an electrical signal, and 6 a channeltron that converts secondary ions into an electrical signal.

以上の構成において、イオン源（図示せず）より投射さ
れた１次イオンビーム７は、試料８に照射され試料表面
より２次電子及び２次イオンを発生する。この２次電子
及び負極性の２次イオンは、これらを加速するための約
１０ＫＶの正の電圧が印加された加速電極１によって、
・検出器の方向に加速され加速電−１の後方に設けられ
た磁界型偏向器２によって作られる（紙面に垂直）磁界
内に達する。この磁界内において２次電子は比電荷が小
さいため磁界によって木き：く軌道が偏向され図面中９
に示す軌道を描く。一方磁界内を通過する２次イオンは
２次電子に比較して１０００倍以上も比電荷が大きいた
め、その偏向感度が低く殆んど直進して図面中１０に示
す軌道を描く。In the above configuration, the primary ion beam 7 projected from the ion source (not shown) is irradiated onto the sample 8 and generates secondary electrons and secondary ions from the sample surface. These secondary electrons and negative secondary ions are accelerated by an accelerating electrode 1 to which a positive voltage of about 10 KV is applied.
- It is accelerated in the direction of the detector and reaches the magnetic field (perpendicular to the plane of the paper) created by the magnetic field type deflector 2 provided behind the accelerating electron 1. In this magnetic field, secondary electrons have a small specific charge, so their orbits are deflected by the magnetic field, which is shown in the figure.
Draw the trajectory shown in . On the other hand, secondary ions passing through the magnetic field have a specific charge more than 1000 times larger than secondary electrons, so their deflection sensitivity is low and they travel almost straight, tracing a trajectory shown at 10 in the drawing.

このように、磁界型偏向器２によって２次電子。In this way, secondary electrons are generated by the magnetic field type deflector 2.

２茨イオンが分離され２次イオーンと分離された２次電
子は、シンチレータｊによって光に変換され・ライトガ
イド４を通って７オトマル５により電気信号に変換され
て取り、出゛さり′る。又２次イオンは、偏向磁場を通
過してチャンネルトロン６に入射して検出され電気信号
に変換された取り出される。The two thorny ions are separated, and the secondary electrons separated from the secondary ions are converted into light by a scintillator j, pass through a light guide 4, are converted into an electric signal by a seven-electrode 5, and are taken out. Further, the secondary ions pass through the deflection magnetic field, enter the channeltron 6, are detected, are converted into electrical signals, and are extracted.

このように、本発明は２次電子、２次イオンが通過する
軌道上に磁界型偏向器を設けて、該偏向器によって２次
電子の軌道を大きく偏向し、２次電子と２次イオンを夫
々専用の検出器に導いて、これらを分離して検出するこ
とにより２次電子と２次イオンの２種類の信号を分離し
て検出することができる。又、２次電子検出器のイオン
照射による損傷を防止し、２次電子と２次イオンの異な
る信号からなる画像を観察することができ、２種類の信
号を分離することができるため画像のＳ／間が向上し、
より物理的、化学的意味のある鮮明な試料拡大像を観察
することができる。As described above, the present invention provides a magnetic field type deflector on the trajectory through which the secondary electrons and secondary ions pass, and uses the deflector to greatly deflect the trajectory of the secondary electrons, thereby making it possible to reduce the secondary electrons and secondary ions. By guiding them to dedicated detectors and detecting them separately, it is possible to separate and detect two types of signals: secondary electrons and secondary ions. In addition, it is possible to prevent damage to the secondary electron detector due to ion irradiation, to observe images consisting of different signals of secondary electrons and secondary ions, and to separate the two types of signals. / The interval has improved,
A clear enlarged sample image with more physical and chemical meaning can be observed.

【図面の簡単な説明】[Brief explanation of drawings]

図面は本発明の一実施例を示す概略図である。 １：加速電極、２：磁界型偏向器、３：シンチレータ、
４ニライトガイド、５：フォトマル、６：チャンネルト
ロン、７：１次イオンビーム、８：試料、９：２次電子
、１０：２次イオン。 特許出願人 日本電子株式会社 代表者　加勢　忠雄 手続補正ｍ　　醐訓 昭和５７年５月３１日 特許庁長官　　島１）春樹　殿 １、事件の表示 昭和５７年特許願第２５４９１号 ２、発明の名称 荷電粒子検出器 ３、補正をする者 事件との関係　特許出願人 住所　東京都昭島市中神町１４１８番皓（Ｔ　Ｅ　Ｌ　
０４２５　（４３）　１１６５）４、補正命令の日付 昭和５７年５月２５日□ 〈１）明細書第１頁第１０行目に「発明の詳細な名称」
とあるを「発明の詳細な説明」と補正する。 （２）明細書第４頁第８行目に「変換された取り」とあ
るを「変換されて取り」と補正する。 以　　上The drawings are schematic diagrams showing one embodiment of the present invention. 1: accelerating electrode, 2: magnetic field deflector, 3: scintillator,
4 Nilight guide, 5: Photomaru, 6: Channeltron, 7: Primary ion beam, 8: Sample, 9: Secondary electron, 10: Secondary ion. Patent Applicant JEOL Ltd. Representative Tadao Kase Procedural Amendment M May 31, 1980 Commissioner of the Patent Office Shima 1) Haruki Tono 1, Indication of the Case 1982 Patent Application No. 25491 2, Name of the Invention Charge Particle detector 3, relationship with the case of the person making the amendment Patent applicant address: 1418 Hao, Nakagami-cho, Akishima-shi, Tokyo (T.E.L.
0425 (43) 1165) 4. Date of amendment order: May 25, 1982 □ (1) "Detailed title of the invention" on page 1, line 10 of the specification
The text should be amended to read "detailed description of the invention." (2) In the 8th line of page 4 of the specification, the phrase "converted to" is amended to read "converted to". that's all

Claims (1)

【特許請求の範囲】[Claims] 電子と負イオンを加速する加速電極と、該加速電極の後
方に設けられた磁界型偏向器と、該偏向器の後方の異っ
た位置に設けられた負イオン検出手段及び電子線検出手
段とを具備した荷電粒子検出■。An accelerating electrode that accelerates electrons and negative ions, a magnetic field type deflector provided behind the accelerating electrode, and negative ion detection means and electron beam detection means provided at different positions behind the deflector. Charged particle detection equipped with ■.