200947496 六、發明說明： 【發明所屬之技術領域】 本發明，係有關於藉由供給氣體並施加電弧電壓而產 生電漿，並從此電漿而產生離子束的離子源，例如，係有 關於在半導體用離子注入裝置或FPD ( Flat Panel Display )製造用離子注入裝置中所使用之離子源。 φ 【先前技術】 一般之被廣泛使用的離子源，係將電漿容器作爲陽極 ，並將藉由通電而放出熱電子的燈絲作爲陰極，而激勵電 弧放電，並將原料氣體作電漿化，藉由此，而產生電漿。 此電漿中之正的荷電粒子，係從被設置在電漿容器處之細 長的開口部、或是從連續之複數的開口部，來作爲離子束 而被拉出。此時，係在與離子束之拉出方向垂直的方向上 ，而施加磁場。 Θ 在此種離子源中，一般而言，係被指摘有以下之技術 性要求。 所產生之電漿密度係爲略均一。 爲了增加離子束之電流，而使作爲離子束而被拉出之 開口部近旁的電漿密度增加。 會經由電漿中之離子的衝突而磨耗的燈絲，係作爲消 耗品而爲低成本。 燈絲，係爲能夠長期間作使用的磨耗耐性高且粗的線 材。 -5- 200947496 例如，係週知有：爲了在電漿容器內使電漿密度成爲 略均一，而有必要以使磁場之強度在電漿容器近旁而成爲 略均一（磁場之變動係爲數％以下）的方式，來對磁石之 設計、製作以及調整作考慮。 又，係週知有：爲了使開口部近旁之電槳密度增加， 使燈絲接近於從開口部所延長之電漿容器的壁面之位置處 一事，係爲有效。 進而，爲了降低燈絲之成本，係以藉由彎曲加工來製 0 作燈絲之線材爲理想。作爲燈絲之線材，係使用將融點爲 高且磨耗耐性爲高之鎢或鉬作爲主成分（質量％爲90% 以上）的材料。此時，由於鎢或鉬的融點係爲高，因此， 爲了得到可塑性，係有必要在高溫下對線材作加工。因此 ，作爲線材，係使用線徑爲略2mm以下者。 另一方面，在日本專利第3075 129號公報中，係記載 有一種離子源，其之燈絲，係在身爲電漿容器之電漿產生 處理室的內部，而被朝向被形成有離子拉出口之離子拉出 Q 面的方向而彎曲。藉由此，成爲能夠使離子束增大。 進而，在日本特開2007-311118號公報中，係作爲一 種離子束之電流爲大且身爲陰極之燈絲的壽命爲長的離子 源，而記載有一種：將用以進行電漿密度之分布控制的燈 絲’沿著電漿容器之長度方向而複數並排設置的離子源。 【發明內容】 [發明所欲解決之課題] -6- 200947496 在此種狀況下，爲了將離子束之電流更加增大，除了 使用在日本專利第3075129號公報中所記載的手段以外， 亦可以考慮將離子源之離子束的拉出用之開口部擴大。但 是，依存於開口部之擴大方法，亦會有離子束之射度（ emittance、在所拉出之離子束的前進方向上的荷電例子之 運動的分散特性）惡化成無法作爲離子注入裝置之離子束 來使用的程度之情形。因此，無法隨便的將開口部擴大。 φ 另一方面，亦可考慮：藉由離子源之尺寸擴大，而將電漿 容器擴大並不使射度惡化地來將開口部細長地擴大，並使 離子束之電流增大。於此情況，係更強地要求使磁場之強 度在電漿容器之近旁成爲略均一。一般而言，爲了形成磁 場，係在具有100〜150 mm之長度的電漿容器之長度方向 上，而配置一對之磁石，但是，由於對於作用在電漿容器 處之高電壓或高溫，係需要作爲其之對策的空間或是構件 ，因此，此磁石間之配置距離，係成爲 500〜600mm。要 〇 將此種磁石間之距離爲長的寬廣空間藉由離子源之尺寸擴 大而增廣一事，在設定略均一之磁場一事上而言，係爲困 難。因此，係有必要不使磁石間之距離增大地來將電漿容 器作擴大。 另一方面，將在燈絲中所使用之鎢或是鉬的線材彎曲 爲特定之形狀的彎曲加工，係由於線材之融點係爲高，故 爲困難。於先前技術中，代替線材，係將板材藉由使用有 金屬線電極之放電加工而切斷爲複雜之形狀，而進行燈絲 之加工。因此’爲了以低成本來進行彎曲加工並製作燈絲 200947496 ，係有必要並不使用板材而使用線材，且其之線徑係有必 要抑制在2mm左右。另一方面，當爲了並不改變燈絲之 形狀而設爲曲率半徑爲大之平緩形狀，而將尺寸作了擴大 的情況時，對應於燈絲之尺寸，電漿容器亦成爲需要增大 ，而並不實用。又，由於燈絲係成爲產生電漿之熱電子的 放出原，並對電漿之密度造成影響，因此，先前技術之燈 絲，係成爲包含有彎曲部分之特定的複雜形狀。因此，係 期望有一種：所產生之電漿的密度係與先前技術同等，且 在加工上係爲單純之形狀，並盡可能地具有粗線徑的燈絲 〇 進而，燈絲之形狀，由於係爲爲了達成所期望之電漿 的密度而配合於離子源之各種尺寸所作了設定者，因此， 由於離子源之各種尺寸會因爲歷時變化或是熱膨脹等而改 變，故會成爲無法得到所期望之電漿的密度。係期望有一 種：就算是離子源之各種尺寸產生改變，亦不會對電漿之 密度造成影響，亦即是能夠產生穩健（Robust )性爲高的 離子束之離子源的構成。 又，燈絲，在電漿產生中，係會暴露在電漿中並被磨 耗，而使線徑變細。因此，在燈絲中之對於熱電子的放出 有所關連的溫度爲高之部分，係會隨著磨耗而改變，伴隨 於此，熱電子之放出位置亦會改變。其結果，由於所產生 之電漿的位置亦會改變，因此，從電漿所拉出之離子束的 電流亦會改變，而無法得到安定之離子束的電流。亦即是 ，因應於離子源之使用，離子束之電流亦會逐漸的變化。 -8- 200947496 故而，係期望有一種：就算是由於燈絲 化，離子束之電流亦不太會受到影響， 健（Robust)性爲高之離子束的離子源 因此，本發明，係考慮上述之背景 不需將磁石間之距離增廣，便能夠擴大 以低成本來製作燈絲，並進而對於離子 化或是燈絲之磨耗而穩健性爲高之離子 〇 [用以解決課題之手段] 爲了達成上述目的，本發明，係提 其係藉由供給氣體並施加電弧電壓而產 漿來產生離子束。該離子源，其特徵爲 一對之磁石，係形成施加在與離子束之 方向上的磁場；和（B)電漿容器，係 之內部空間，係被設置在前述一對之磁 ® 氣體而產生電漿，而用以拉出離子束之 在沿著前述內部空間內之前述一對之磁 伸的第1壁面上；和（C )燈絲，係從 作電性絕緣並沿著前述一對之磁石的配 2壁面而被立起設置，並藉由通電而將 內部空間中；和（D)電源，係使電流 ，並且，（E)立起設置有前述燈絲之補 爲朝向與前述第i壁面所朝向之方向爲 述燈絲，係從前述第2壁面而朝向與前 之磨耗等的歷時變 亦即是能夠產生穩 之構成。 ，而以提供一種： 電漿容器，且能夠 源之尺寸的各種變 源爲目的。 供以下之離子源， 生電漿，並由此電 ，具備有：（A) 拉出方向相正交之 具有：具備導體面 石之間，並被供給 開口部，係被設置 石的配置方向而延 被與前述電漿容器 置方向而延伸之第 熱電子放出至前述 流動於前述燈絲處 订述第2壁面，係 相異方向的面，前 述一對之磁石的配 -9 - 200947496 置方向相異之方向來立起設置，（F )進而，前述燈絲， 係以在前述燈絲之中央部而成爲迴圈形狀的方式而被折返 ，當從相對於形成前述迴圈形狀之面而爲垂直的方向而視 之時，係具備有在前述迴圈形狀之基部處而並不相接觸地 交叉爲X狀的部分。 此時’較理想，前述內部空間，係成爲直方體形狀， 前述第2壁面，係爲與前述第1壁面相對向之壁面。 又，較理想，前述燈絲，係以使前述形成迴圏形狀之 面相對於前述一對之磁石的磁場之方向而成爲略垂直的方 式，而作立起設置。 進而，較理想，在前述電漿容器之前述內部空間的前 述配置方向之兩端部處，將熱電子作反射的反射板，係以 與前述燈絲之迴圈形狀相對向的方式而被設置，前述迴圈 形狀之尺寸，係爲較前述反射板之尺寸更小。 又，較理想，前述燈絲，係爲將棒狀之線材作彎曲加 工所製作者，並爲由鎢、鉬、以及以鎢或是鉬爲主成分的 合金之中，所選擇的金屬。 進而，較理想，前述燈絲之線徑，係爲較2mm更大 〇 又，較理想，前述燈絲之交叉爲X狀的部分之交叉 角度，係爲70〜1 10度。 進而，較理想，前述燈絲之前端部與前述第1壁面間 之距離，係爲2〜3mm。 -10- 200947496 [發明之效果] 在本發明之離子源中，燈絲，係被構成爲：以在燈絲 之中央部處成爲迴圈形狀的方式而被折返，當從相對於成 爲迴圈形狀之面而爲垂直的方向而視之時，在此迴圈形狀 之基部處，係具備有並不相互接觸地而交叉爲X狀之部 分。故而，經由交叉爲X狀之部分的相互所產生之熱， 其之相互的交叉部分係被加熱，而此加熱係亦會傳導至迴 0 圈形狀之部分，因此，在迴圈形狀爲廣之部分係成爲高溫 並放出熱電子，而電漿亦爲在廣範圍內而和緩的產生。故 而，就算是離子源之各種尺寸等由於歷時變化或熱膨脹等 而產生變化，從上述電漿中所拉出之離子源的電流所受到 之影響亦爲小。又，由於熱電子係從迴圈形狀之寬廣的部 分而被放出，因此，就算是燈絲有所磨耗，所產生之電漿 的範圍亦不會有大的變化。故而，就算是燈絲有所磨耗， 從電漿中所拉出之離子源的電流所受到之影響亦爲小。 Φ 又，燈絲，由於係爲成爲迴圈形狀以及X狀之形狀 ，而相較於先前技術之複雜的形狀，係成爲單純的形狀， 因此，就算是難以進行彎曲加工之粗的線材，亦能夠容易 地進行加工。故而，能夠以低成本而提供壽命長之燈絲。 進而，燈絲之立起設置的第2壁面，係爲朝向與第1 壁面所面向之方向爲相異方向的面，而燈絲，係成爲從前 述第2壁面而立起設置於與一對之磁石的配置方向相異的 方向上之構成。特別是，係成爲從與具備有將離子束拉出 之開口部的第1壁面相對向之壁面而將燈絲作立起設置的 200947496 構成。故而，相異於先前技術中之在電漿容器的磁石之配 置方向的兩端部處而安裝燈絲之構成，在此兩端部分處’ 用以設置燈絲之支持構件或是絕緣構件的空間係成爲不必 要。故而，能夠將此空間所佔據的部分使用在電漿容器之 尺寸擴大中。 進而，藉由採用將與具備有將離子束拉出之開口部的 第1壁面相對向之壁面作爲第2壁面，並將燈絲作立起設 置的構成，能夠使燈絲之前端的位置接近於具備有開口部 之第1壁面的近旁，而能夠在開口部近旁產生密度爲高之 電漿》 進而，由於係爲將燈絲從第2壁面而立起設置的構成 ，因此，像是爲了減低由於燈絲之熱傳導所致的熱損失而 進行的對於燈絲之通過電漿容器的腳部之長度的調整；或 是爲了防止在燈絲腳部處之堆積物的附著所進行的套管之 設置等，係能夠與電漿容器之尺寸相獨立地而自由的進行 【實施方式】 以下，根據在添附之圖面中所展示的理想實施形態， 對本發明之離子源作詳細說明。圖1，係爲展示本發明之 離子源的其中一種實施形態之構成的圖。 離子源1，係爲一種燃燒源，其係藉由供給原料氣體 G並放電，而產生電漿P，並藉由從此電漿P來拉出離子 ，而產生離子束B。離子源1，係如圖1中所示一般，具 -12- 200947496 備有電漿容器10;和燈絲12;和反射板14、16;和原料 氣體供給口 18;和離子束拉出口 20;和拉出電極22、24 :以及磁石26、28。電漿容器10，係被收容在未圖示之 離子注入裝置的減壓容器內，在電漿容器10內，係成爲 被減壓至1〇_2〜10 _3 (Pa)的狀態。 電漿容器10，係爲具備有直方體形狀之內部空間的 放電箱。電漿容器10，係藉由具備有耐高溫性之導電性 Φ 材料所構成。在本發明中，內部空間，係並不被限定於直 方體形狀，而亦可爲多角柱形狀或是圓柱形狀。當圓柱形 狀的情況時，本發明中之壁面，係指切平面。 從電漿容器10之內部空間的壁面起，而立起設置有 突出於內部空間之燈絲1 2。燈絲1 2，係從與被設置有離 子束拉出口 20之壁面30相對向的壁面32起而被立起設 置。燈絲1 2，係藉由從鎢、鉬、以鎢或是鉬爲主成分的 合金之中所選擇的金屬所構成。特別是，從耐磨耗性之觀 β 點來看，係以藉由鎢來構成爲理想。 電漿容器10，在一方向（圖1之水平方向）上爲較 長，此長度方向，係與磁石26、28之配置方向爲一致。 如此這般地將燈絲12之立起設置的壁面設爲與被設 置有離子束拉出口 20之壁面（第1壁面）30相對向的壁 面（第2壁面）32之原因，係因爲能夠並不使磁石26與 磁石28間的距離變廣便將電漿容器1〇在長度方向上作擴 大之故。亦即是，當如同先前技術一般，而將燈絲1 2從 面向於磁石26、28之配置方向的壁面（亦即是，電漿容 -13- 200947496 器ι〇之長度方向的端部之壁面）來立起設置於內部空間 中時，在電漿容器10之長度方向的端部處，係成爲需要 燈絲支持構件或是絕緣構件等的配置空間。故而，如同離 子源1 一般’藉由將燈絲12從與被設置有離子束拉出口 2 0之壁面3 0相對向的壁面3 2來作立起設置，由於燈絲 支持構件或是絕緣構件等的配置空間係成爲不必要，因此 ，能夠將此成爲不必要之配置空間使用在電漿容器10之 長度方向的尺寸之擴大中。 進而，像是爲了減低由於燈絲12之熱傳導所致的熱 損失而進行的對於燈絲12之通過電漿容器10的腳部之長 度的調整；或是爲了防止在燈絲腳部處之堆積物的附著所 進行的套管之設置等，係能夠與電漿容器10之尺寸相獨 立地而自由的進行。 如此這般，係從與被設置有離子束拉出口 20之壁面 30相對向的壁面32起而將燈絲12立起設置。此時，係 使燈絲12之前端部相對於壁面30而接近至2〜3mm的範 圍內。藉由此，而在離子束拉出口 20近旁處使電漿P之 密度增大，而能夠使離子束B之電流增大。 另外，在本發明中，係並不被限定於將燈絲1 2從與 被設置有離子束拉出口 20之壁面30相對向的壁面32起 而作立起設置的構成。亦可從具備有與圖1之紙面相平行 的面之壁面來將燈絲1 2作立起設置。在本發明中，燈絲 12,係只要是朝向與被設置有離子束拉出口（開口部 之壁面30所面向之方向（壁面30之垂線方向）相異的方 -14- 200947496 向，並且是從沿著一對之磁石26、28間的配置方向而延 伸之壁面來立起設置於與一對之磁石26、28相異之方向 上即可。但是，從能夠使在燈絲1 2中所流動之電流的對 於離子束B而造成之影響成爲最小的觀點上來看，係以將 燈絲12設置在距離離子束拉出口 20最遠的壁面32上之 構成爲理想。 燈絲1 2，係進而被構成爲形成迴圈形狀。關於此點 φ ，係於後述。 在燈絲1 2之對面側以及背面側、亦即是在電槳容器 10之內部空間的磁石26、28之配置方向的兩端部之壁面 處，係被設置有反射板14、16。反射板14、16，係由具 備有耐高溫性之金屬製構件所成，並經由未被圖示之夾鉗 構件或絕緣構件，而被固定設匱在電漿容器10處。反射 板1 4、1 6，係以略佔有電漿容器1 0的內部空間之剖面的 方式而被設置。 © 在電漿容器1〇之壁面31處，係被設置有原料氣體供 給口 18。所期望之原料氣體，係藉由未圖示之控制閥而 被控制在一定之流量，並被導入至電漿容器10之內部空 間中。 在電漿容器10之外側，係以與被設置在壁面30處之 離子束拉出口 20相對向的方式，而被設置有拉出電極22 、24。拉出電極22、24，係具備有與離子拉出口 20相同 形狀之開口部，並經由未圖示之絕緣構件，來對於電漿容 器10而精密地作定位並固定。拉出電極22、24，由於暴 -15- 200947496 露在離子束B中之機會係爲多，因此，係以使用高融點且 耐熱性爲高之材料爲理想。例如，係可使用石墨、鎢、鉬 等，但是，從經濟性以及加工性之觀點而言，係適合使用 鎳。離子束B，係藉由電漿容器10之壁面30與拉出電極 22間的電位差，而使離子從電漿P而被分離並被拉出， 而形成離子束B。 在拉出電極22、24之間，係被施加有數1000V之電 壓。離子束B與壁面等衝突而產生的低速之電子，係經由 @ 離子束B之電荷而被捕捉，並滯留而分佈，但是，藉由在 拉出電極22、24之間施加上述之數1000V的電壓，藉由 拉出電極22拉出電極24之間的電位差，能夠防止上述電 子被照射至電漿容器10之外側壁面處。 在電漿容器10之外側，係被設置有一對之磁石26、 28，以使電漿容器10內之磁場沿著磁石26、28之配置方 向而成爲略均一（磁場之變動爲數％以內）的方式，來配 置磁石26、28，並進而制訂磁石之形狀。在磁石26、28 Q 處，係以使磁力線從電漿容器10的長度方向之其中一端 而朝向另外一端來通過的方式，而配置N極、S極，磁石 26、28,係藉由以磁透率爲高之電磁軟鐵等所製作的未圖 示之旁軛（return yoke)，來連接磁石26、28之外側。 磁石26、28，係使用有永久磁石或是電磁石。但是，爲 了使磁場成爲可作調整，係以使用電磁石爲理想。 在燈絲12處，係以成爲能夠放出熱電子的方式，而 被連接有燈絲電源3 3。燈絲電源3 3之正極以及負極，係 -16- 200947496 被與燈絲1 2相連接，在燈絲1 2處，係流動有數1 00 A之 電流。藉由此，將燈絲12加熱，並放出熱電子。燈絲電 源33之正極，係被連接於反射板14、16處。 進而，在燈絲電源3 3之負極與電漿容器1 0之間，係 被連接有電弧放電電源34，在電漿容器10處，係被施加 有數10〜數100V之電弧電壓。 電源36，係爲用以將離子束B拉出之拉出電源，正 φ 極係被連接於電漿容器10，而負極係被連接於拉出電極 24，並被施加有數千V〜數十萬V之電壓。進而，被連接 有：在拉出電極22與拉出電極24之間對電壓作設定，並 以使電子不會照射至電漿容器10之外側壁面的方式，而 在拉出電極22與拉出電極24之間施加數1 000V之電壓 的電源3 8。 燈絲電源3 3之電流以及電弧放電電源3 4之電弧電壓 ，係以使離子束B之電流成爲安定的方式，而經由未圖示 Ο 之控制裝置而被調整。或者是，在燈絲電源3 3中所流動 之電流和在電源3 6中所流動之電流，係經由未圖示之控 制裝置而被調整。在能夠簡單地作調整的觀點上，係以對 於在燈絲電源3 3中所流動之電流和在電源3 6中所流動之 電流進行調整爲理想。 在此種離子源1中，燈絲12，係如圖2之（a)、( b)所示一般，以在燈絲12之中央部處而構成迴圈形狀 40的方式而被作折返。當從相對於成爲迴圏形狀40之面 而爲垂直的方向而視之時，在迴圏形狀40之基部42處， -17- 200947496 係具備有並不相互接觸地而交叉爲χ狀之部分。燈絲12 之形成迴圈形狀40的面，相對於圖1中所示之磁石26、 28的磁場之方向，係爲略垂直、實質性垂直。進而’迴 圈形狀40之迴圈尺寸，係較反射板14、16之尺寸爲更小 。此係爲了成爲能夠將從燈絲1 2之迴圈形狀40的部分所 放出之熱電子有效率地作反射並使熱電子能夠進行往返運 動之故。 此種燈絲12，係藉由彎曲加工而製作出形狀。燈絲 @ 12之形狀，由於係僅單純的成爲迴圈形狀40，並在迴圈 形狀40之基部42處而交叉爲X狀，因此，就算是鎢或 鉬等之融點爲高的線材，或進而爲線徑超過2mm之粗的 線材，亦能夠無困難地進行加工。 如圖2 ( b )中所示一般，燈絲12所交叉之基部42 的交叉角度，係以成爲90度左右爲理想，但是，依存於 加工，係亦可爲70〜110度之範圍。又，在燈絲12之穿 過壁面的角部處，係以如圖2(b)中所示一般，使燈絲 0 1 2之線成爲平行爲理想，但是，亦可並非爲平行。 將燈絲12設爲迴圈形狀40的原因，係因爲：相較於 先前技術之燈絲的形狀，其形狀係爲單純，而容易進行彎 曲加工，其結果，相較於先前技術，能夠使用更粗的線徑 、亦即是使用超過2mm之線徑，除此之外，當從燈絲12 所放出之熱電子在反射板14、16之間進行螺旋運動時， 使燈絲不會成爲熱電子之螺旋運動的妨礙，而能夠將經由 熱電子所作出之電漿的密度有效率地增大之故。圖2(b -18 - 200947496 )中，藉由迴圏形狀40所包圍之區域（斜線區域）a, 係不會成爲熱電子之通過的妨礙。 又，在先前技術之燈絲中，燈絲之溫度，係僅會在將 燈絲作了折返之中央部份處變高，因此，因應於溫度而決 定放出量之熱電子的放出部分，係被限制在作了折返之狹 窄的範圍內。故而，經由從狹窄之範圍所放出的熱電子而 產生之密度爲高的電漿，係被局部存在化，而藉由對此局 ❹ 部存在化之電漿作拉出，能夠使離子束之電流增大。但是 ，若是隨著燈絲之磨耗的進展而燈絲之溫度爲高的部分之 位置有所改變，則密度爲高之電漿的位置亦會從初始之位 置而有所偏移，因此，從配合於初始之位置而設定的離子 束拉出口所被拉出之離子束的電流，係會大幅度的改變。 又，由於係配合於局部存在化之電漿的初始之位置，而對 離子源1之各種尺寸作設定，因此，當離子源1之各種尺 寸等由於歷時變化或是熱膨脹等而有所改變的情況時，從 Ο 配合於所產生之電漿的初始之位置而設定的離子束拉出口 所被拉出之離子束的電流，亦會大幅度的改變。 但是，在燈絲12之迴圈形狀40的基部42處，藉由 使燈絲12如圖2(b)所示一般地而交叉爲X狀，在此交 叉部分處，由於燈絲12彼此係相互接近，因此，藉由在 此部分處之相互的輻射導熱，燈絲1 2彼此係被加熱，且 由於亦會熱傳導至迴圈形狀40之部分處，因此，熱損失 係減少。故而，藉由如同燈絲1 2 —般地而設爲迴圈形狀 40，且使其交叉爲X狀，從基部42起直到構成迴圈形狀 -19- 200947496 40之寬廣部分的溫度分佈，係成爲平緩，而構成迴圏形 狀40之寬廣部分，係成爲放出熱電子之高溫部分。藉由 此，相較於先前技術，由於熱電子之放出部分係變廣，因 此，電漿之產生區域係不會被局部存在化，而會在廣範圍 內而平緩地分佈。故而，就算是離子源1之各種尺寸等由 於歷時變化或熱膨脹等而產生變化，從在廣範圍內而平緩 地分佈之電漿中所拉出之離子束B的電流，亦不會受到大 的影響。亦即是，相對於離子源之各種尺寸的變化，離子 束B之電流的穩健性係爲高。 就算是在燈絲1 2有所磨耗的情況時，亦由於放出熱 電子之燈絲溫度爲高的部分係爲迴圈形狀40之寬廣的部 分，因此，亦不會有所產生之電漿從初始之位置而大幅度 偏移的情形。故而，所拉出之離子束的電流，係不會有大 幅度變化。如此這般，在離子源1中，就算是燈絲12有 所磨耗，離子束B之電流亦不會受到大的影響。亦即是， 相對於燈絲1 2之磨耗，離子束B之電流的穩健性係爲高 〇 在此種離子源1中，藉由在燈絲12中流動電流並使 燈絲發熱而成爲高溫，熱電子係從燈絲1 2之構成迴圈形 狀40的部分而被放出，此熱電子，係沿著磁場之方向， 而在反射板14、16之間一面進行螺旋運動一面作往返。 此時’原料氣體G係從原料氣體供給口 18而被導入，在 電弧電源34處施加特定之電壓，藉由使原料氣體G與熱 電子相衝突，原料氣體G之原子係帶電，並產生電漿P。 -20- 200947496 此時，在燈絲12之迴圈形狀40的區域A中，由於 熱電子係自由地通過，因此，熱電子’係成爲能夠在反射 板14、16之間進行往返運動。故而，電漿P，係在包含 有燈絲12之迴圈形狀40的周邊區域31中，而以平緩之 分佈來產生。所產生之電漿P，係成爲以反射板14、16 作爲兩端之圓柱形狀。而後，在拉出電極22、24處施加 特定之電壓，並從離子束拉出口 20來將離子束B拉出。 0 就算是燈絲1 2由於電漿P而有所磨耗，燈絲1 2之輻 射熱電子的部分，由於係如同上述一般而爲寬廣，因此， 電漿P之產生區域係不會有大的變化。故而，從電漿P所 拉出之離子束B的電流，係不會受到大的影響。又，經由 燈絲12，由於係產生在廣範圍中而平緩地分佈之電漿， 故而，就算是離子源1之各種尺寸等由於歷時變化或熱膨 脹等而產生變化，從此電漿中所拉出之離子束B的電流， 亦不會受到大的影響。 ❹ 以上，雖係針對本發明之離子源而作了詳細說明，但 是，本發明係並不被限定於上述之實施形態，在不脫離本 發明之主旨的範圍內，不用說，係可進行各種之改良或是 變更。 【圖式簡單說明】 [圖1]展示本發明之離子源的其中一種實施形態之構 成的圖。 [圖2] ( a) 、( b)，係爲用以對在圖1所示之離子 源中所使用的燈絲之形狀作說明的圖。 -21 - 200947496 【主要元件符號說明】 1 :離子源 1 0 :電漿容器 1 2 :燈絲 14、1 6 :反射板 1 8 :原料氣體供給口 20 :離子束拉出口 22、24 :拉出電極 2 6、2 8 :磁石 3 0、3 2 :壁面 3 3 :燈絲電源 3 4 :電弧電源 36、38 :電源 40 :迴圈形狀 -22-200947496 VI. Description of the Invention: [Technical Field] The present invention relates to an ion source which generates a plasma by supplying a gas and applying an arc voltage, and generates an ion beam from the plasma, for example, An ion source used in an ion implantation apparatus for semiconductor or an ion implantation apparatus for manufacturing an FPD (Flat Panel Display). φ [Prior Art] Generally, a widely used ion source uses a plasma container as an anode, and a filament that emits hot electrons by energization as a cathode, excites an arc discharge, and plasmas the material gas. By this, plasma is generated. The positive charged particles in the plasma are pulled out as ion beams from the elongated openings provided in the plasma container or from a plurality of consecutive openings. At this time, a magnetic field is applied in a direction perpendicular to the direction in which the ion beam is pulled out. Θ In this type of ion source, in general, it is referred to the following technical requirements. The resulting plasma density is slightly uniform. In order to increase the current of the ion beam, the density of the plasma near the opening which is pulled out as an ion beam is increased. The filament that is worn by the collision of ions in the plasma is low cost as a consumable product. The filament is a wire having a high abrasion resistance and a thick wire which can be used for a long period of time. -5- 200947496 For example, it is known that in order to make the plasma density slightly uniform in the plasma container, it is necessary to make the strength of the magnetic field slightly uniform in the vicinity of the plasma container (the variation of the magnetic field is several %) The following) is a way to consider the design, fabrication, and adjustment of the magnet. Further, it is known that the filament is close to the position of the wall surface of the plasma container extended from the opening in order to increase the density of the electric blade near the opening. Further, in order to reduce the cost of the filament, it is preferable to use a bending process to make a wire for the filament. As the wire material of the filament, a material having tungsten or molybdenum having a high melting point and high abrasion resistance as a main component (% by mass or more) is used. At this time, since the melting point of tungsten or molybdenum is high, in order to obtain plasticity, it is necessary to process the wire at a high temperature. Therefore, as the wire rod, a wire diameter of 2 mm or less is used. On the other hand, Japanese Patent No. 3075129 discloses an ion source in which a filament is formed inside a plasma generating processing chamber which is a plasma container, and is formed with an ion pulling opening. The ions are bent out of the direction of the Q plane. Thereby, the ion beam can be increased. Further, Japanese Laid-Open Patent Publication No. 2007-311118 discloses an ion source in which the current of the ion beam is large and the life of the filament as the cathode is long, and a type of plasma density distribution is described. The controlled filament 'is an ion source arranged side by side along the length of the plasma container. [Problems to be Solved by the Invention] -6-200947496 In this case, in order to further increase the current of the ion beam, in addition to the means described in Japanese Patent No. 3075129, It is considered to enlarge the opening for pulling out the ion beam of the ion source. However, depending on the method of expanding the opening, the ion beam's irradiance (dispersion characteristic of the movement of the charged example in the advancing direction of the extracted ion beam) is deteriorated into an ion which cannot be used as an ion implantation apparatus. The extent to which the bundle is used. Therefore, the opening portion cannot be easily expanded. φ On the other hand, it is conceivable that the size of the ion source is enlarged, and the plasma container is enlarged, the opening is elongated and the current of the ion beam is increased without deteriorating the radiance. In this case, it is more strongly required that the strength of the magnetic field be slightly uniform near the plasma container. In general, in order to form a magnetic field, a pair of magnets are disposed in the longitudinal direction of the plasma container having a length of 100 to 150 mm, but due to the high voltage or high temperature acting on the plasma container, There is a need for a space or a member for countermeasures. Therefore, the arrangement distance between the magnets is 500 to 600 mm. It is difficult to set a slightly uniform magnetic field by widening the size of the long space between the magnets by expanding the size of the ion source. Therefore, it is necessary to enlarge the plasma container without increasing the distance between the magnets. On the other hand, bending of a wire of tungsten or molybdenum used in a filament into a specific shape is difficult because the melting point of the wire is high. In the prior art, instead of the wire, the sheet is processed into a complicated shape by electric discharge machining using a wire electrode, and the filament is processed. Therefore, in order to perform bending processing at a low cost and to manufacture the filament 200947496, it is necessary to use a wire material without using a plate material, and the wire diameter thereof is necessarily suppressed to about 2 mm. On the other hand, when the size is enlarged in order to increase the size of the filament in order to change the shape of the filament without changing the shape of the filament, the plasma container also needs to be enlarged corresponding to the size of the filament, and Not practical. Further, since the filament is a discharge source of the hot electrons generating the plasma and affects the density of the plasma, the prior art filament is a specific complicated shape including the curved portion. Therefore, it is desirable to have a density of the plasma generated as in the prior art, and to be a simple shape in processing, and to have a filament having a thick wire diameter as much as possible, and the shape of the filament is In order to achieve the desired density of the plasma, the various sizes of the ion source are set. Therefore, since various sizes of the ion source may change due to diachronic changes or thermal expansion, etc., the desired electricity may not be obtained. The density of the pulp. It is desirable to have a configuration that does not affect the density of the plasma even if the ion source is changed in various sizes, that is, an ion source capable of generating a robust (high) ion beam. Moreover, the filament, in the plasma generation, is exposed to the plasma and is worn to make the wire diameter thin. Therefore, the temperature at which the temperature of the filament is related to the release of the hot electrons is high, and the temperature changes depending on the wear, and accordingly, the position at which the hot electrons are emitted changes. As a result, since the position of the generated plasma also changes, the current of the ion beam pulled out from the plasma also changes, and the current of the stabilized ion beam cannot be obtained. That is, the current of the ion beam will gradually change in response to the use of the ion source. -8- 200947496 Therefore, it is desirable to have an ion source that is less affected by the ion beam current even if it is filamentized, and the ion source of the ion beam is high. Therefore, the present invention considers the above. In the background, it is not necessary to increase the distance between the magnets, and it is possible to expand the filaments at a low cost, and further improve the ionization or the abrasion of the filaments with high robustness. [Means for solving the problem] The object of the invention is to produce an ion beam by slurrying by supplying a gas and applying an arc voltage. The ion source is characterized in that a pair of magnets form a magnetic field applied in a direction opposite to the ion beam; and (B) a plasma container, the internal space of which is disposed in the pair of magnetic gas Producing a plasma to pull out the ion beam on the first wall surface of the pair of magnetic extensions along the aforementioned inner space; and (C) the filament is electrically insulated and along the aforementioned pair The magnet is placed upright with the wall surface, and is placed in the internal space by energization; and (D) the power source is supplied with current, and (E) is provided with the aforementioned filament complementing direction and the foregoing The direction in which the wall surface is oriented is the filament, which is a structure that can be stabilized from the second wall surface toward the front wear. In order to provide a kind of: a plasma container, and for various purposes of the size of the source. For the following ion source, the plasma is generated, and the battery is electrically connected thereto. (A) The direction in which the pull-out direction is orthogonal is: the direction in which the conductor faces are provided and the openings are supplied, and the arrangement direction of the stones is set. And the first hot electrons extending in the direction in which the plasma container is placed are discharged to the surface on which the second wall surface is disposed in the filament, and the surface of the pair of magnets is arranged in the direction of the pair of magnets. (F) Further, the filament is folded back so as to have a loop shape at a central portion of the filament, and is perpendicular to a surface forming the loop shape. In the case of the direction, it is provided with a portion which is formed in the base portion of the loop shape and intersects in an X shape without being in contact with each other. In this case, it is preferable that the internal space has a rectangular parallelepiped shape, and the second wall surface is a wall surface facing the first wall surface. Further, it is preferable that the filament is erected so that the surface forming the returning shape is slightly perpendicular to the direction of the magnetic field of the pair of magnets. Furthermore, it is preferable that the reflecting plate that reflects the hot electrons is provided so as to face the loop shape of the filament at both end portions of the internal space of the plasma container in the arrangement direction. The size of the loop shape is smaller than the size of the reflector. Further, it is preferable that the filament is a member obtained by bending a rod-shaped wire material and is selected from the group consisting of tungsten, molybdenum, and an alloy containing tungsten or molybdenum as a main component. Further, it is preferable that the wire diameter of the filament is larger than 2 mm, and it is preferable that the intersection angle of the X-shaped intersection of the filaments is 70 to 10 degrees. Further, preferably, the distance between the front end portion of the filament and the first wall surface is 2 to 3 mm. -10-200947496 [Effects of the Invention] In the ion source of the present invention, the filament is configured to be folded back so as to be in a loop shape at the central portion of the filament, and to be in a shape of a loop. When the surface is viewed in the vertical direction, the base portion of the loop shape is provided with a portion that does not contact each other and intersects in an X shape. Therefore, the heat generated by the mutual intersection of the X-shaped portions is heated, and the heating system is also conducted to the portion of the 0-turn shape, so that the shape of the loop is wide. Part of the system is at a high temperature and emits hot electrons, and the plasma is also produced in a wide range. Therefore, even if various sizes of the ion source change due to diachronic changes or thermal expansion, the influence of the current of the ion source pulled out from the plasma is small. Further, since the hot electrons are discharged from a wide portion of the loop shape, even if the filament is worn, the range of the generated plasma does not largely change. Therefore, even if the filament is worn, the current of the ion source pulled from the plasma is also affected. Φ Further, since the filament is in the shape of a loop and an X-shape, it has a simple shape compared to the complicated shape of the prior art, and therefore, even if it is a thick wire which is difficult to bend, Easy to process. Therefore, it is possible to provide a filament having a long life at a low cost. Further, the second wall surface on which the filament is erected is a surface that faces the direction in which the first wall surface faces, and the filament is erected from the second wall surface and is provided on the pair of magnets. The configuration in the direction in which the directions are different. In particular, it is constituted by 200947496 which is provided by erecting a filament from a wall surface facing the first wall surface of the opening in which the ion beam is pulled out. Therefore, it is different from the configuration in the prior art in which the filament is installed at both ends of the direction of the arrangement of the magnets of the plasma container, and at both end portions, the space system for setting the support member of the filament or the insulating member Become unnecessary. Therefore, the portion occupied by this space can be used in the size expansion of the plasma container. Further, by adopting a configuration in which a wall surface facing the first wall surface including the opening portion through which the ion beam is pulled out is used as the second wall surface, and the filament is erected, the position of the front end of the filament can be made close to In the vicinity of the first wall surface of the opening, a plasma having a high density can be generated in the vicinity of the opening, and further, since the filament is erected from the second wall surface, it is intended to reduce heat conduction due to the filament. The adjustment of the length of the filament through the plasma container caused by the heat loss; or the arrangement of the sleeve to prevent the adhesion of the deposit at the foot of the filament, etc. The size of the slurry container is independently and freely carried out. [Embodiment] Hereinafter, the ion source of the present invention will be described in detail based on a preferred embodiment shown in the attached drawings. Fig. 1 is a view showing the constitution of one embodiment of an ion source of the present invention. The ion source 1 is a combustion source which generates a plasma P by supplying a material gas G and discharging it, and extracts ions from the plasma P to generate an ion beam B. Ion source 1, as shown in Figure 1, generally with -12-200947496 provided with plasma container 10; and filament 12; and reflectors 14, 16, and raw material gas supply port 18; and ion beam pull-out 20; And pulling out the electrodes 22, 24: and the magnets 26, 28. The plasma container 10 is housed in a decompression container of an ion implantation apparatus (not shown), and is decompressed to a state of 1 〇 2 to 10 _3 (Pa) in the plasma container 10. The plasma container 10 is a discharge box having an internal space having a rectangular parallelepiped shape. The plasma container 10 is composed of a conductive Φ material having high temperature resistance. In the present invention, the internal space is not limited to the shape of a rectangular body, but may be a polygonal column shape or a cylindrical shape. In the case of a cylindrical shape, the wall surface in the present invention means a tangential plane. From the wall surface of the internal space of the plasma vessel 10, a filament 12 projecting from the internal space is erected. The filament 12 is erected from the wall surface 32 opposed to the wall surface 30 on which the ion beam pull-out port 20 is provided. The filament 12 is composed of a metal selected from the group consisting of tungsten, molybdenum, tungsten or molybdenum as a main component. In particular, from the point of view of the abrasion resistance, it is preferable to constitute it by tungsten. The plasma container 10 is long in one direction (horizontal direction in Fig. 1), and this length direction coincides with the arrangement direction of the magnets 26, 28. In this way, the wall surface on which the filament 12 is erected is used as the wall surface (second wall surface) 32 facing the wall surface (first wall surface) 30 of the ion beam extraction port 20, because When the distance between the magnet 26 and the magnet 28 is widened, the plasma container 1 is enlarged in the longitudinal direction. That is, as in the prior art, the wall of the filament 12 from the direction facing the arrangement direction of the magnets 26, 28 (i.e., the wall of the end of the length of the plasma volume - 13 - 200947496 ι 〇) When it is placed in the internal space, it is an arrangement space in which the filament support member or the insulating member or the like is required at the end portion of the plasma container 10 in the longitudinal direction. Therefore, as with the ion source 1, generally, the filament 12 is erected from the wall surface 3 2 opposed to the wall surface 30 where the ion beam extraction port 20 is provided, due to the filament supporting member or the insulating member or the like. Since the arrangement space is unnecessary, it is possible to use this arrangement space which is unnecessary in the expansion of the dimension of the plasma container 10 in the longitudinal direction. Further, it is intended to reduce the length of the filament 12 passing through the leg portion of the plasma container 10 in order to reduce heat loss due to heat conduction of the filament 12, or to prevent adhesion of deposits at the foot of the filament. The arrangement of the sleeves to be performed and the like can be performed freely independently of the size of the plasma container 10. In this manner, the filament 12 is erected from the wall surface 32 opposed to the wall surface 30 on which the ion beam pull-out port 20 is provided. At this time, the front end portion of the filament 12 is brought close to the range of 2 to 3 mm with respect to the wall surface 30. Thereby, the density of the plasma P is increased near the ion beam pulling outlet 20, and the current of the ion beam B can be increased. Further, in the present invention, it is not limited to the configuration in which the filament 12 is erected from the wall surface 32 opposed to the wall surface 30 on which the ion beam extraction port 20 is provided. The filament 12 may be erected from a wall surface having a surface parallel to the paper surface of Fig. 1. In the present invention, the filament 12 is oriented so as to face the ion beam pull-out port (the direction in which the wall surface 30 of the opening portion faces (the perpendicular direction of the wall surface 30) is different from the direction of the square-14-200947496, and is The wall surface extending along the direction in which the pair of magnets 26 and 28 are arranged may be erected in a direction different from the pair of magnets 26 and 28. However, it is possible to flow in the filament 12 From the viewpoint of minimizing the influence of the current on the ion beam B, it is preferable to provide the filament 12 on the wall surface 32 farthest from the ion beam pull-out port 20. The filament 12 is further configured. In order to form the loop shape, the point φ will be described later. On the opposite side and the back side of the filament 12, that is, at both ends of the arrangement direction of the magnets 26 and 28 in the internal space of the electric paddle container 10. Reflectors 14 and 16 are provided on the wall surface. The reflectors 14 and 16 are made of a metal member having high temperature resistance and are fixed by a clamp member or an insulating member (not shown). Set at the plasma container 10. Reflector 1 4 and 1 6 are provided so as to occupy a section of the internal space of the plasma container 10. © The wall surface 31 of the plasma container 1 is provided with a material gas supply port 18. The raw material gas is controlled to a constant flow rate by a control valve (not shown), and is introduced into the internal space of the plasma container 10. On the outer side of the plasma container 10, it is disposed on the wall surface 30. The ion beam pull-out port 20 is opposed to each other, and the pull-out electrodes 22 and 24 are provided. The pull-out electrodes 22 and 24 are provided with openings having the same shape as the ion pull-out port 20, and are not shown. The insulating member is precisely positioned and fixed to the plasma container 10. The electrodes 22 and 24 are pulled out, and the chance of exposure to the ion beam B is large due to the violent -15-200947496, so the high melting point is used. It is preferable that a material having high heat resistance is used. For example, graphite, tungsten, molybdenum or the like can be used, but from the viewpoint of economy and workability, nickel is suitably used. The ion beam B is made of a plasma container. The potential difference between the wall 30 of the 10 and the pull-out electrode 22, The ions are separated from the plasma P and pulled out to form an ion beam B. Between the pull-out electrodes 22, 24, a voltage of several 1000 V is applied. The ion beam B collides with the wall surface and the like to generate a low speed. The electrons are trapped by the charge of the @ ion beam B and are retained and distributed. However, by applying the above-mentioned voltage of 1000 V between the pull-out electrodes 22 and 24, the electrode is pulled out by the pull-out electrode 22. The potential difference between 24 can prevent the above-mentioned electrons from being irradiated to the outer wall surface of the plasma container 10. On the outer side of the plasma container 10, a pair of magnets 26, 28 are provided to make the magnetic field in the plasma container 10 The magnets 26 and 28 are arranged so as to be slightly uniform (the magnetic field fluctuates within a few %) along the arrangement direction of the magnets 26 and 28, and the shape of the magnet is further determined. At the magnets 26 and 28 Q, the magnetic poles are passed from one end of the plasma vessel 10 toward the other end, and the N poles and the S poles are arranged, and the magnets 26 and 28 are arranged by magnetic A return yoke (not shown) made of a high-voltage electromagnetic soft iron or the like is connected to the outside of the magnets 26 and 28. Magnets 26 and 28 use permanent magnets or electromagnets. However, in order to make the magnetic field adjustable, it is desirable to use an electromagnet. At the filament 12, a filament power source 33 is connected so as to be capable of emitting hot electrons. The positive and negative electrodes of the filament power supply 3 3 are connected to the filament 12, and at the filament 12, there is a current of several hundred A. Thereby, the filament 12 is heated and the hot electrons are released. The anode of the filament power source 33 is connected to the reflectors 14, 16. Further, an arc discharge power source 34 is connected between the negative electrode of the filament power source 3 3 and the plasma container 10, and an arc voltage of 10 to several 100 V is applied to the plasma container 10. The power source 36 is a pull-out power source for pulling the ion beam B out, the positive φ pole is connected to the plasma container 10, and the negative electrode is connected to the pull-out electrode 24, and is applied with thousands of V to 100,000 V voltage. Further, a voltage is set between the drawing electrode 22 and the drawing electrode 24 so that the electrons are not irradiated to the outer wall surface of the plasma container 10, and the electrode 22 is pulled out and pulled out. A power supply 38 having a voltage of 1 000 V is applied between the electrodes 24. The current of the filament power source 3 3 and the arc voltage of the arc discharge power source 34 are adjusted so that the current of the ion beam B is stabilized by a control device not shown. Alternatively, the current flowing through the filament power source 3 3 and the current flowing in the power source 36 are adjusted by a control device not shown. In terms of being able to be easily adjusted, it is desirable to adjust the current flowing in the filament power source 3 3 and the current flowing in the power source 36. In the ion source 1, the filament 12 is folded back so as to form the loop shape 40 at the central portion of the filament 12 as shown in Figs. 2(a) and 2(b). When viewed from a direction perpendicular to the surface which becomes the return shape 40, at the base portion 42 of the return shape 40, -17-200947496 is provided with a portion which does not contact each other and intersects with a meandering shape. . The face of the filament 12 forming the loop shape 40 is slightly perpendicular and substantially perpendicular to the direction of the magnetic field of the magnets 26, 28 shown in FIG. Further, the loop size of the loop shape 40 is smaller than the size of the reflectors 14, 16. This is because the hot electrons emitted from the portion of the loop shape 40 of the filament 12 can be efficiently reflected and the hot electrons can be moved back and forth. Such a filament 12 is formed into a shape by bending. The shape of the filament @ 12 is simply a loop shape 40 and intersects in the X shape at the base portion 42 of the loop shape 40, so that the melting point of tungsten or molybdenum is high, or Furthermore, it is also possible to process a thick wire having a wire diameter of more than 2 mm without difficulty. As shown in Fig. 2(b), the angle of intersection of the base portions 42 where the filaments 12 intersect is preferably about 90 degrees. However, depending on the processing, it may be in the range of 70 to 110 degrees. Further, at the corner portion of the filament 12 which passes through the wall surface, it is preferable to make the filament 0 1 2 line parallel as shown in Fig. 2(b), but it may not be parallel. The reason why the filament 12 is set to the loop shape 40 is that the shape is simple compared to the shape of the filament of the prior art, and the bending process is easy, and as a result, it is possible to use coarser than the prior art. The wire diameter, that is, the wire diameter exceeding 2 mm is used. In addition, when the hot electrons emitted from the filament 12 are spirally moved between the reflecting plates 14, 16, the filament does not become a spiral of hot electrons. The hindrance of motion can increase the density of the plasma made by the hot electrons efficiently. In Fig. 2 (b-18 - 200947496), the region (hatched region) a surrounded by the return shape 40 does not interfere with the passage of hot electrons. Further, in the filament of the prior art, the temperature of the filament is increased only at the central portion where the filament is folded back. Therefore, the discharge portion of the hot electron which determines the amount of discharge in response to the temperature is limited to Made a narrow range of reentry. Therefore, the plasma having a high density generated by the hot electrons emitted from the narrow range is locally present, and the ion beam can be pulled out by the presence of the plasma which is present in the crucible. The current increases. However, if the position of the portion where the temperature of the filament is high changes as the wear of the filament progresses, the position of the plasma having a high density is also shifted from the initial position, and therefore, The current of the ion beam pulled out by the ion beam pulling outlet set at the initial position is greatly changed. Further, since the various sizes of the ion source 1 are set in accordance with the initial position of the partially existing plasma, the various sizes and the like of the ion source 1 are changed due to changes in duration or thermal expansion. In the case, the current of the ion beam pulled out from the ion beam pull-out port set in accordance with the initial position of the generated plasma is also greatly changed. However, at the base portion 42 of the loop shape 40 of the filament 12, the filaments 12 are generally X-shaped as shown in Fig. 2(b), at which the filaments 12 are close to each other, Therefore, the filaments 12 are heated by each other by the mutual radiation heat conduction at this portion, and since heat is also conducted to the portion of the loop shape 40, the heat loss is reduced. Therefore, by setting the loop shape 40 as in the case of the filament 12 and crossing it into an X shape, the temperature distribution from the base portion 42 to the wide portion constituting the loop shape -19-200947496 40 becomes It is gentle, and forms a wide part of the shape of the retracement 40, which is a high temperature portion for emitting hot electrons. As a result, compared with the prior art, since the emission portion of the hot electrons is broadened, the plasma generation region is not locally present, but is distributed gently over a wide range. Therefore, even if the various sizes and the like of the ion source 1 are changed by the diachronic change or the thermal expansion or the like, the current of the ion beam B pulled out from the plasma which is gently distributed over a wide range is not greatly affected. influences. That is, the robustness of the current of the ion beam B is high with respect to variations in various sizes of the ion source. Even in the case where the filament 12 is worn, the portion where the filament temperature at which the hot electrons are emitted is high is a wide portion of the loop shape 40, and therefore, the plasma is not generated from the initial one. A situation where the position is greatly shifted. Therefore, the current of the extracted ion beam does not change greatly. As such, in the ion source 1, even if the filament 12 is worn, the current of the ion beam B is not greatly affected. That is, the robustness of the current of the ion beam B is higher than the abrasion of the filament 12 in the ion source 1, and the high temperature is generated by flowing a current in the filament 12 and heating the filament. It is discharged from the portion of the filament 12 which constitutes the loop shape 40, and the hot electrons are reciprocated while being spirally moved between the reflectors 14 and 16 in the direction of the magnetic field. At this time, the raw material gas G is introduced from the raw material gas supply port 18, and a specific voltage is applied to the arc power source 34. By causing the source gas G to collide with the hot electrons, the atomic system of the source gas G is charged and generates electricity. Pulp P. -20- 200947496 At this time, in the region A of the loop shape 40 of the filament 12, since the hot electrons pass freely, the hot electrons are able to reciprocate between the reflecting plates 14, 16. Therefore, the plasma P is generated in the peripheral region 31 including the loop shape 40 of the filament 12, and is produced in a gentle distribution. The generated plasma P has a cylindrical shape with the reflection plates 14 and 16 as both ends. Then, a specific voltage is applied to the pull-out electrodes 22, 24, and the ion beam B is pulled out from the ion beam pull-out port 20. 0 Even if the filament 1 2 is worn due to the plasma P, the portion of the filament 12 radiating the hot electrons is broad as described above, and therefore, the area where the plasma P is generated does not largely change. Therefore, the current of the ion beam B pulled out from the plasma P is not greatly affected. Further, since the filaments 12 are generated by a wide range of plasmas which are gently distributed, even if various sizes of the ion source 1 are changed due to diachronic changes or thermal expansion, etc., they are pulled out from the plasma. The current of the ion beam B is also not greatly affected. The above is described in detail with respect to the ion source of the present invention. However, the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the scope of the present invention. Improvement or change. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the configuration of one embodiment of an ion source of the present invention. [Fig. 2] (a) and (b) are diagrams for explaining the shape of a filament used in the ion source shown in Fig. 1. -21 - 200947496 [Explanation of main component symbols] 1 : Ion source 1 0 : Plasma container 1 2 : Filament 14 , 1 6 : Reflector 1 8 : Raw material gas supply port 20 : Ion beam pull-out port 22, 24 : Pull-out Electrode 2 6 , 2 8 : magnet 3 0, 3 2 : wall 3 3 : filament power supply 3 4 : arc power supply 36, 38 : power supply 40 : loop shape -22-