經濟部智慧財產局員工消費合作社印製 459265 五、發明說明（I ) [相關之專利申請案] 下列之美國專利申請案係以作爲參考方式而納入本文 ，.,如其所已經被完整提出者：申請專利案序號： ，提出申請於__’名稱爲"用以改進能量純度 及植入一致性並且用以使被植入基質之電荷累積最小化之 系統及方法"。 ' I本發明之領域] ，本發明大體上係有關於電漿浸入離子植入系統之領域 ，且尤指一種改良式系統及方法，用以提供跨越由此系統 植入之基質表面的植入劑量均勻性。 [本發明之背景] 離子植入已經成爲工業界所喜用之技術，在積體電路 之大型化製造中以雜質摻雜半導體。在定義一特定植入製 程中，離子劑量係兩個植入變數的一者(另一者係爲離子能 量，其決定植入深度）。離子劑量係關於在半導體材質之既 定區域或體積中植入離子之濃度。典型地，高電流植入器( 通常大於1毫安(mA)的離子束電流)被使用於高劑量植入， 中電流植入器(通常能夠高至大約1mA的離子束電流)被使 用於較低劑量應用。 傳統之離子植入器包括三個階段或次系統：（i)用於輸 出一離子束之一離子源、（ii)包括一質量分解磁場以供質量 .分離該離子束之一束線及(iii)包含半導體晶圓或其它欲由 離子朿植入之基質的一目標室。典型而言，在離子植入器 中之離子源係產生一離子束，藉由離子化於一源室之內的 4 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁〕 I J. * VI n IB n f— 1· I 線· 459265 A7 B7 五、發明說明（）） 源氣體（其一成份係一期望之摻雜元素）並且以離子束的形 式而取出離子化之源氣體。該離子束係指向於沿著由束線 提供之一抽空的束路徑。該束內之具能量的離子係撞擊在 目標室內之基質且係植入於其內。於此植入系統重要的是 欲確保跨越基質表面之植入劑量均勻性。 電漿浸入離子植入(PI-管或PI3)係一種正出現的技術， 其中諸如在一平台上的晶圓之基質係浸入在一室之電漿中 。因此，該室係同時當作處理室及供電漿源使用。典型地 ，一電壓差係被週期地建立在室之壁部及平台之間，以將 電漿中的離子往基質吸引。足夠之電壓差將導致離子植入 至該基質之表面。如同在傳統之離子植入系統中，重要的 是欲確保跨越基質表面之植入劑·量均勻性。 是以，本發明的一個目的係提供一種系統及方法，.用 以提供跨越由電漿浸入離子植入系統所植入之基質表面的 植入劑量均勻性。 [本發明之槪要] 一種系統及方法係提供用以致能跨越基質(諸如半導體 晶圓）之表面的植入劑量均勻性，其係在電漿浸入離子植入 器的處理室內所植入。在該室內產生之電漿包括期望之摻 雜離子。植入係藉由施加一連串的負脈衝至支撐晶圓的平 台來達成。在處理晶圓之前’從電漿取出之離子電流係在 平台上複數個位置由劑量測定偵測器所判定。該複數個位 置係對應於欲作植入之晶圓表面上的位置。 複數個電磁鐵係在該室內產生一磁場。該等電磁鐵的 5 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱婧背面之注意事項再填寫本頁) • \) --------訂 ---------線· 經濟部智慧財產局員工消費合作社印製 經濟部智慧財產局貝工消費合作社印製 4 59 26友 Α7 Β7 五、發明說明（5 ) 大小、位置及電流比係被選擇以在該室內建立一磁場，其 係垂直於晶圓表面且在晶圓表面上爲均勻。該劑量測定偵 測器係在處理室內之複數個位置感測從電漿取出之離子電 流，且輸出代表其回授信號至控制器β該控制器係因應於 回授信號，且輸出控制信號至控制複數個電磁鐵中之電流 量的電源供應器。該電流係視需要而改變’以達成跨越晶 圓之'均―与劑量率。在較佳實施例中’複數個電磁鐵包括放 置在處理室之外側且限定處理室之外部的複數個環狀電磁 鐵。 [附圖之簡略說明] 圖一係·一電漿浸入離子植入系統之剖面圖，其係納入 根據本發明的主旨所架構的劑量均勻機構之一實施例； 圖二係一方塊圖，顯示用以控制流經圖一之系統中的 磁鐵之電流的一閉迴路控制系統； 圖三係在圖一之系統的處理室內所建立的磁場之剖面 圖，運用於其所顯示之磁鐵；及 圖四係跨越在圖三之室中一晶圓表面的正規化電漿密 度之表示圖，其針對流經圖一之系統中的磁鐵之不同値的 磁化電流。 [元件符號說明] 10 :電漿浸入離子植入系統 12 :處理室 14 :支撐平台 16 :室外殻 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) ------1、訂--—！！-線； 6 經濟部智慧財產局員工消費合作社印製 ^ 459265 五、發明說明（+) 17 ： 壁部 18 ： 絕緣體 19 ： 石英窗口 21 ： 入口 21A:環形通道 22 :射頻(RF)產生器 .2.3 :銷 24 :匹配網路 25 :銷組件 26 :電容器 27 :調變器 28 :天線 29 :幫浦歧管 30 ' 32 :導線 34、36、38、40 :環形磁性線圏 42、42a-42g :法拉第杯罩 43 :信號輸出 44 :第一電流源 46 :第二電流源 50 :控制器 51a、51b :輸出控制信號 [較佳實施例之詳細說明] 現在請參閱圖式，圖一係揭示一電漿浸入離子植入系 統，槪括標示爲10。該系統10包括由安裝在絕緣體18上 本紙張尺度適用十國國家標準（CNS)A4規格（210 X 297公釐） ! 1 卜f 1 -----Λ, --------訂！！！_ 線^^y (請先閱讀背面之注意事項再填寫本頁) 45926^ A7 __B7__ 五、發明說明（3 ) 之可電氣致動的晶圓支撐平台Μ所界定的一抽空處理室 I2、具有壁部17之一電氣接地室外殼16及—石英窗口 19 。當負電荷電壓被外加至平台14時，該室內產生之電號包 '含期望的雑質種類（如砷化物）之離子，其被植入—基質， 諸如位於其之一半導體晶圓W。如圖一中所顯示，該晶圓 W係由銷組件25所操作之銷23而由平台移開。以此方式 ，晶圓係可經由一載入鎮定組件（未顯示）而容易地裝設至 電漿室及自電漿室所移開。 如下所述，電漿係在處理室12中產生。一可離子化的 雜質氣體係經由入口 21而導入處理室12,且通過存在於 該室之上部邊緣的環形通道21Α。一射頻(RF)產生器22產 生一RF信號(在13.5百萬赫玆(MHz)的等級），其耦合至一 匹配網路24。該匹配網路包括電容器26，其經由導線30 及32而電容耦合該射頻信號至真有內部及外部圓形線圈之 一大致爲平板的天線28。匹配該射頻產生器22的阻抗和 負載的阻抗，藉由最小化反射回到產生器的射頻信號，以 確保天線28的最大功率輸出。一種此類的匹配網路24係 已知如”倒L”網路，其中電容器26的電容量係由伺服馬達 視操作的條件來改變。 在天線28內產生的射頻電流建立一磁場，其通過石英 窗口 19至該處理室Π內。該磁場線係如箭頭B所顯示的 方向’基於經過天線線圏的電流方向。經由石英窗口 19而 穿過處理室12的磁場係在處理室中感應一電場。該電場將 加速電子，其離子化雜質氣體，其經過環形通道21A而被 8 本紙張尺度適用中國國家標^ (CNS)A4規格<210^ 297公釐） (請先閲讀背面之注意事項再填寫本頁) -^) ---------訂-------^線 經濟部智慧財產局員工消費合作社印製 459265 A7 ____B7 _ 五、發明說明（。） 導入該室以建立電漿。該電漿包括期望雜質的正電荷離子 ，其當一合適的相反電壓由調變器27所外加至平台14時 係能夠被植入晶圓W內。因爲植入製程係在真空中發生， 該處理室12係經由幫浦歧管29以幫浦而抽真空。 在處理室中感應的電場係由集中在一環形（環狀面）之 環形場線所定義，其存在於天線28之下且平行(如在圖一 之剖面谓中之X及Y的位置）。在室U內之電漿係因而沿 著該環形場線集中。該電漿然後擴散至晶圓。視擴散速度 及室高度而定，此導致在晶圓之電漿密度從在邊環爲最大 至在中央爲最大的範圍（包括一均勻條件）。然而，該擴散 速度將視電漿條件(種類、壓力、射頻功率）而定，其被選 擇以使晶圖製程最佳化，因此僅留下該室高度當作針對均 勻性之一控制變數。對於均勻性控制而言，此係一個不方 便的變數。 本發明係藉由在位於處理室12外部加入環形磁性線圈 34、36、38及40，而解決了電漿密度均勻性控制的問題。 在較佳實施例中，赫爾姆霍茲(Helmholz)線圏（電磁鐵）係被 使用。該線圈之目的係改變處理室12中的磁場以有效地改 變電漿擴散速度，其改變跨越晶圓表面之電漿密度的徑向 分佈。 、 在較佳實施例中，該電磁線圏包括兩個分別放置在上 方和下方的較大的主要線圏34及40、兩個較小的調節線 圈36及38，其存在於較接近處理室12之附近。該較大主 要線圏34及40係由第一電流源44所供電，且該較小調節 9 本紙張尺度適用中國國家標準（CNS)A4規格（210 xi97公楚^ (請先閱讀背面之注意事項再填寫本頁) ---------訂---------線 經濟部智慧財產局員工消費合作社印製 A7 B7 459265 五、發明說明（1 ) 線圈36及38係由第二電流源46所供電(參閱圖二）。通常 ，第一電流値被外加至兩個較大主要線圈，且第二、較小 的電流値被外加至較小調節線圏。或者，單一電流源可以 被使用以供應電流至所有的四個線圏。 該晶圓平台Η包括諸如複數個法拉第(Faraday)電流收 集器或杯罩42的一劑量測定偵測器，其被使用以測量電漿 _電流密'度且因而提供植入劑量的指示。該等法拉第杯罩可 係以如共同所有之美國專利申請案第〇9/218,770號所示者 來架構。在較佳實施例中，七個此類的杯罩係被放置在晶 圓平台之以一半徑相同的位置。 該等法拉第杯罩42係被電氣偏壓，且包括一平行於植 入表面之電荷離子集中表面。當製程中一晶圓出現在平台 上時，該徑向最外部之法拉第杯罩可以被使用以測量電漿 電流密度，且提供一在晶圓中植入的劑量之指示的即時回 授。在處理之前，當晶圓未出現在平台上時，所有的法拉 第杯罩可以使用以提供跨越晶圓表面電漿電流之徑向分佈 的指示，其直接對應於離子劑量。 如以下將再解釋者，欲調整電漿電流密度的徑向分佈 以確保均勻的植入劑量，在處理室12內的磁場係被改變以 有效地改變該室內之電漿密度的分佈。該磁場係藉由變化 通過磁性線圏的電流來改變。 圖二係顯示用以控制經過磁性線圈之電流的控制系統 之方塊圖。七個法拉第杯罩42a-42g提供信號輸出4S至控 制器50。視該法拉第杯罩的讀數而定，控制器輸出控制信 10 紙張尺麾通用中國國釔標準（CNS)A4規格（210 X297公釐） (請先閱讀背面之注意事項再填寫本頁) ,¾ — ϋ n I · n It n ϋ <t n I - 經濟部智慧財產局貝工消費合作社印製 t ^ 459265 A7 ___ _ B7 五、發明說明（《） <請先閲讀背&之生意事項再填寫本頁) 號51a及51b以分別操作較大主要及較小調節線圏的電流 源44及46。以這種方式，一閉迴路控制系統被提供用以 控制在晶圓之電漿的分佈。 圖三係在圖一之系統的處理室內使用磁鐵34、36、38 及40所建立的磁場之剖面圖。該處理室12係槪括由室壁 部丨7的虛線來顯示。在圓三中僅係顯示沿著室中央線CL 半的室。'假設由線圏34、36、38及40所建立之磁場和 室未顯示的另一半者是幾乎完全相同。 圖三中之場線B定義由Hehnholz線圏在室內所建立 的磁場。如從這些磁場線所能夠看到者，線圈相對於室12 的位置及於其所流通的電流大小係造成在室12中跨越晶圓 W表面一高至30闻斯(Gauss)的均勻磁場。該均句磁場係 垂直於晶圓表面且均勻跨越晶圓表面。很重要的是，該場 係均勻且垂直跨越整個晶圓表面，以避免任何由於植入製 程間不均勻電子軌道之充電問題。在此例中，晶圓具有 300mm(30cm)的直徑。 經濟部智慧財產局員工消費合作社印製 如圖三中所顯示，該線圈提供一磁場，其是均勻地從 室中央線Ct放射狀地往每一方向幾乎20cm，因而提供整 個晶圓W位於其內之均勻磁場的一個區域。晶圓W之上 方該區域內的均勻磁場係直接控制跨越晶圓表面電漿的均 勻性。該電漿均勻性接著將確保跨越晶圓表面一均勻植入Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs's Consumer Cooperatives 459265 5. Description of the Invention (I) [Related Patent Applications] The following US patent applications are incorporated herein by reference, as if they had been fully filed: Serial number of patent application:, filed in __ 'with the name " System and method for improving energy purity and implant consistency and for minimizing charge accumulation of implanted substrate ". 'I Field of the Invention] The present invention generally relates to the field of plasma immersion ion implantation systems, and more particularly to an improved system and method for providing implantation across the surface of a substrate implanted by the system. Dose uniformity. [Background of the Invention] Ion implantation has become a technology favored by the industry, and semiconductors are doped with impurities in the large-scale manufacturing of integrated circuits. In defining a specific implantation process, the ion dose is one of two implantation variables (the other is ion energy, which determines the depth of implantation). Ion dose refers to the concentration of implanted ions in a given area or volume of a semiconductor material. Typically, high current implanters (typically greater than 1 milliamp (mA) ion beam current) are used for high dose implants, and medium current implanters (typically capable of ion beam currents up to about 1 mA) are used for Lower dose application. A conventional ion implanter includes three stages or sub-systems: (i) an ion source for outputting an ion beam, and (ii) a mass decomposition magnetic field for mass. Separating a beam line of the ion beam and ( iii) A target chamber containing a semiconductor wafer or other substrate to be implanted by ion plutonium. Typically, the ion source in the ion implanter generates an ion beam. The 4 paper sizes that are ionized in a source chamber apply the Chinese National Standard (CNS) A4 specification (210 X 297 mm). (Please read the notes on the back before filling this page] I J. * VI n IB nf— 1 · I line · 459265 A7 B7 V. Description of the invention ()) Source gas (one component is a desired doping element ) And take out the ionized source gas in the form of an ion beam. The ion beam is directed along an evacuated beam path provided by the beamline. The energetic ions in the beam impinge on the substrate in the target chamber and are implanted therein. It is important in this implant system to ensure uniform implantation dose across the surface of the matrix. Plasma immersion ion implantation (PI-tube or PI3) is an emerging technology in which a substrate such as a wafer on a platform is immersed in a plasma in a chamber. Therefore, this room is used as both a processing room and a power supply. Typically, a voltage difference is periodically established between the wall of the chamber and the platform to attract ions in the plasma to the substrate. A sufficient voltage difference will result in ion implantation on the surface of the substrate. As in conventional ion implantation systems, it is important to ensure uniformity of implantation amount across the surface of the matrix. Therefore, an object of the present invention is to provide a system and method for providing uniform implantation dose across the surface of a substrate implanted by a plasma immersion ion implantation system. [Summary of the invention] A system and method for providing uniform implantation dose across a surface of a substrate such as a semiconductor wafer, which is implanted in a processing chamber of a plasma immersion ion implanter. The plasma generated in the chamber includes the desired doped ions. Implantation is achieved by applying a series of negative pulses to the platform supporting the wafer. Before the wafer is processed, the ion current extracted from the plasma is determined by the dosimetry detector at a plurality of positions on the platform. The plurality of positions correspond to positions on the surface of the wafer to be implanted. A plurality of electromagnets generate a magnetic field in the chamber. The 5 paper sizes of these electromagnets are applicable to China National Standard (CNS) A4 specifications (210 X 297 mm) (please read the precautions on the back of Jing before filling this page) • \) -------- Order --------- Line · Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs and printed by the Shelley Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 4 59 26 Friends A7 Β7 V. Description of the invention (5) Size, location and The current ratio is selected to establish a magnetic field in the chamber, which is perpendicular to the wafer surface and is uniform on the wafer surface. The dosimetry detector senses the ion current taken out from the plasma in a plurality of positions in the processing chamber, and outputs a feedback signal representing the feedback signal to the controller. The controller responds to the feedback signal and outputs a control signal to A power supply that controls the amount of current in a plurality of electromagnets. This current is changed 'as necessary to achieve the' average 'and dose rate across the wafer. In the preferred embodiment ', the plurality of electromagnets include a plurality of ring-shaped electromagnets placed outside the processing chamber and defining the outside of the processing chamber. [Brief description of the drawings] FIG. 1 is a cross-sectional view of a plasma immersion ion implantation system, which is an embodiment of a dose uniformity mechanism incorporated in accordance with the subject matter of the present invention; FIG. 2 is a block diagram showing A closed-loop control system for controlling the current flowing through the magnets in the system of FIG. 1; FIG. 3 is a cross-sectional view of a magnetic field established in the processing chamber of the system of FIG. 1 and applied to the magnets shown there; and Four are representations of normalized plasma density across a wafer surface in the chamber of FIG. 3, which are directed to different magnetizing currents flowing through the magnets in the system of FIG. [Explanation of component symbols] 10: Plasma immersion ion implantation system 12: Processing chamber 14: Support platform 16: Chamber cover The paper size is applicable to Chinese National Standard (CNS) A4 (210 X 297 mm) (Please read the back first Note for this page, please fill out this page) ------ 1, order ---! !! -Line; 6 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs ^ 459265 V. Description of the invention (+) 17: Wall 18: Insulator 19: Quartz window 21: Entrance 21A: Ring channel 22: Radio frequency (RF) generator. 2.3: Pin 24: Matching network 25: Pin assembly 26: Capacitor 27: Modulator 28: Antenna 29: Pump manifold 30 '32: Conductor 34, 36, 38, 40: Toroidal magnetic coils 42, 42a- 42g: Faraday cup cover 43: Signal output 44: First current source 46: Second current source 50: Controller 51a, 51b: Output control signal [Detailed description of the preferred embodiment] Now refer to the drawings, and the first series A plasma immersion ion implantation system is disclosed, indicated as 10. The system 10 includes a paper size installed on the insulator 18 and applicable to the ten national standards (CNS) A4 specifications (210 X 297 mm)! 1 BU f 1 ----- Λ, -------- Order! !! !! _ LINE ^^ y (Please read the notes on the back before filling this page) 45926 ^ A7 __B7__ V. Description of the invention (3) An evacuated processing chamber I2 defined by an electrically actuable wafer support platform M2, with One of the wall portions 17 is an electrical grounding chamber housing 16 and a quartz window 19. When a negative charge voltage is applied to the platform 14, the electrical package generated in the chamber contains ions of a desired species of arsenic (such as arsenide), which are implanted into a substrate, such as a semiconductor wafer W located on one of them. As shown in FIG. 1, the wafer W is removed from the platform by a pin 23 operated by a pin assembly 25. In this way, the wafer system can be easily installed in and removed from the plasma chamber via a stabilizing component (not shown). As described below, a plasma system is generated in the processing chamber 12. An ionizable impurity gas system is introduced into the processing chamber 12 through the inlet 21 and passes through an annular passage 21A existing at the upper edge of the chamber. A radio frequency (RF) generator 22 generates an RF signal (on the order of 13.5 million hertz (MHz)), which is coupled to a matching network 24. The matching network includes a capacitor 26 that capacitively couples the radio frequency signal via wires 30 and 32 to a substantially flat plate antenna 28, which has substantially internal and external circular coils. The impedance of the RF generator 22 and the impedance of the load are matched to minimize the RF signal reflected back to the generator to ensure the maximum power output of the antenna 28. One such matching network 24 is known as an "inverted L" network, in which the capacitance of the capacitor 26 is changed by the servo motor depending on the operating conditions. The radio frequency current generated in the antenna 28 creates a magnetic field, which passes through the quartz window 19 into the processing chamber Π. The direction of this magnetic field line as shown by arrow B is based on the direction of the current passing through the antenna line 圏. The magnetic field passing through the processing chamber 12 through the quartz window 19 induces an electric field in the processing chamber. This electric field will accelerate the electrons, and its ionized impurity gas, which passes through the annular channel 21A, is accepted by the Chinese paper standard ^ (CNS) A4 size < 210 ^ 297 mm) (Please read the precautions on the back before reading) (Fill in this page)-^) --------- Order ------- ^ Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 459265 A7 ____B7 _ V. Description of Invention (.) To build a plasma. The plasma includes positively charged ions of desired impurities, which can be implanted into the wafer W when a suitable opposite voltage is applied to the platform 14 by the modulator 27. Because the implantation process takes place in a vacuum, the processing chamber 12 is evacuated via a pump manifold 29 with a pump. The electric field induced in the processing chamber is defined by a ring-shaped field line concentrated on a ring (ring surface), which exists under the antenna 28 and is parallel (such as the positions of X and Y in the cross-section of Figure 1) . The plasma system in the chamber U is thus concentrated along the annular field line. The plasma then diffuses to the wafer. Depending on the diffusion speed and chamber height, this results in a range of plasma densities on the wafer from maximum at the edge ring to maximum at the center (including a uniform condition). However, the diffusion rate will depend on the plasma conditions (kind, pressure, RF power), and it was chosen to optimize the crystal map process, so leaving only the chamber height as a control variable for uniformity. This is an inconvenient variable for uniformity control. The present invention solves the problem of controlling the uniformity of the plasma density by adding annular magnetic coils 34, 36, 38, and 40 located outside the processing chamber 12. In the preferred embodiment, Helmholz coils (electromagnets) are used. The purpose of this coil is to change the magnetic field in the processing chamber 12 to effectively change the plasma diffusion speed, which changes the radial distribution of the plasma density across the wafer surface. In a preferred embodiment, the electromagnetic coil 圏 includes two larger main wires 圏 34 and 40, and two smaller adjustment coils 36 and 38, respectively, which are located closer to the processing chamber. Around 12. The larger main wires 34 and 40 are powered by the first current source 44 and the smaller adjustment 9 The paper size applies to the Chinese National Standard (CNS) A4 specification (210 xi97 Gongchu ^ (Please read the note on the back first) Please fill in this page for matters) --------- Order --------- Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs A7 B7 459265 V. Description of the invention (1) Coils 36 and 38 It is powered by the second current source 46 (see Figure 2). Generally, the first current 値 is applied to the two larger main coils, and the second and smaller current 値 is applied to the smaller adjustment line 或者. A single current source can be used to supply current to all four lines. The wafer platform includes a dosimetry detector such as a plurality of Faraday current collectors or cups 42 which are used to The plasma_current density is measured and thus provides an indication of the implant dose. The Faraday cups can be constructed as shown in commonly owned US Patent Application No. 09 / 218,770. In the preferred embodiment Of these, seven such cups are placed on the wafer platform with a radius of the same The Faraday cups 42 are electrically biased and include a charge ion concentration surface parallel to the implantation surface. When a wafer appears on the platform during the process, the radially outermost Faraday cups can Used to measure plasma current density and provide an immediate feedback of the dose implanted in the wafer. Before processing, when the wafer is not present on the platform, all Faraday cups can be used to provide The indication of the radial distribution of the plasma current across the wafer surface directly corresponds to the ion dose. As will be explained below, to adjust the radial distribution of the plasma current density to ensure a uniform implant dose, in the processing chamber 12 The internal magnetic field is changed to effectively change the plasma density distribution in the room. The magnetic field is changed by changing the current passing through the magnetic line. Figure 2 shows the control system used to control the current through the magnetic coil. Block diagram. Seven Faraday cups 42a-42g provide signal output 4S to the controller 50. Depending on the reading of the Faraday cup, the controller outputs a control letter 10 China National Yttrium Standard (CNS) A4 Specification (210 X297 mm) (Please read the notes on the back before filling this page), ¾ — ϋ n I · n It n ϋ < tn I-Intellectual Property Bureau of the Ministry of Economic Affairs Printed by Industrial and Consumer Cooperatives ^ 459265 A7 ___ _ B7 V. Description of the invention (") Please read the business matters on the back and fill in this page) No. 51a and 51b to operate the larger main and smaller adjustment lines, respectively 'S current source 44 and 46. In this manner, a closed-loop control system is provided to control the plasma distribution across the wafer. FIG. 3 is a cross-sectional view of a magnetic field created using magnets 34, 36, 38, and 40 in the processing chamber of the system of FIG. The processing chamber 12 is shown by a broken line surrounded by a wall portion 7 of the chamber. Only the chambers along the chamber center line CL are shown in circle three. 'Assume that the magnetic fields established by coils 34, 36, 38, and 40 are almost identical to the other half of the chamber not shown. The field line B in Figure 3 defines the magnetic field created by the Hehnholz line 圏 indoors. As can be seen from these magnetic field lines, the position of the coil relative to the chamber 12 and the magnitude of the current flowing through it results in a uniform magnetic field as high as 30 Gauss across the surface of the wafer W in the chamber 12. The uniform magnetic field is perpendicular to the wafer surface and uniformly spans the wafer surface. It is important that the field is uniform and perpendicular across the entire wafer surface to avoid any charging problems due to uneven electronic orbits during the implantation process. In this example, the wafer has a diameter of 300 mm (30 cm). Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs as shown in Figure 3. This coil provides a magnetic field that is evenly distributed from the center line Ct of the chamber radially to almost 20 cm in each direction. A region of a uniform magnetic field inside. The uniform magnetic field in the area above the wafer W directly controls the uniformity of the plasma across the wafer surface. This plasma uniformity will then ensure a uniform implant across the wafer surface
Q 圖四係對於流經磁鐵之不同値的電流，在圖三之室中 跨越一晶圓表面之正規化電漿密度的表示圖。圖四的圖形 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 經濟部智慧財產局員工消費今作社印製 4 59 26ί Α7 Β7 五、發明說明（q ) 係由一操作在200瓦(watt)之射頻源所激發之氬電漿。天線 28之磁場葉部(圖三中之位置X及Y)係分開20cm(中央線 CL之每側l〇cm)。圖例中從6安培(amp)至16.9安培的電 流値係代表流經較大主要線圈34及40的電流。流經較小 調節線圏36及38的電流是主要線圏電流的0.33(33%)，其 • 經由實驗已經發現是合適的比率》 ' '圖四中所示之正規化電漿電子密度由已知方法(例如由 一移動的朗格膠爾(Langmuir)探棒)在晶圓表面上方2cm所 測量。該Langmuir探棒沿著晶圓的平面重複地移動，以測 定各種磁場電流之電漿密度。另外，法拉第杯罩42可被使 用以測量在晶圓表面之電漿密度。 使用移動之Langmuir探棒或法拉第杯罩陣列，跨越晶 圓表面的電漿密度係被測定。然後，控制器50能夠由調整 磁鐵34、36、38及40中的電流而改變磁場，直到獲得期 望的均勻磁場電漿密度。假如法拉第杯罩被使用，爲了達 到側向電漿密度的均勻性，法拉第杯罩之輸出信號可使用 ..當作閉迴路系統中的回授(參考圖二)以改變磁場電流。 如圖四中所顯示，電漿之兩種穩定的模式係被獲得。 在第一種模式中，在較低的主要磁場電流(6-8安培），電漿 密度集中在沿著室中央線。在第二種模式，在較高的主 要磁場電流（12-17安培），電漿密度集中在兩側（距離中央 線CL +l〇cm及_i〇cm)，符合天線28之磁場葉部的位置。 在中間的電流(9-11安培），係達到跨越晶圓表面更均勻的 電漿密度。然而，這是一個不穩定的區域且該電漿密度顯 12 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 丨丨 ------ 丨 1 i — — — — — — 訂· (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 4 59 266 A7 B7 五、發明說明（ί。> 示一種朝向以上兩種較穩定的模式之一移動的傾向。 存在該兩種不同的電漿模式之原因，可以由電漿遠離 電場源(其係由天線28之下的環形面來代表)之不同的擴散 速度乘解釋。由磁鐵34、36、.38及40所建立低的磁場’ 電漿側向擴散速率是高的，而環形面的中央開始被電漿充 滿且逐漸在中央線達到高峰。由磁鐵34、36、38及40 所建立高的磁場，電槳側向擴散速率是低的，且電漿維持 環形。 ' 因此，本發明預期以兩種方法達到跨越晶圓W表面均 勻電漿密度。使用法拉第杯罩陣列或移動的Langmuir探棒 ，流經主要線圈34及40的精確電流可以被測定，其將導 •致跨越晶圓W表面之均勻電漿密度。該晶圓然後可以使用 單一植入製程步驟來植入。 或者是，因爲以上的方法均涉及電漿不穩定的區域， 雨個步驟的植入可以被執行。使用法拉第杯罩陣列或移動 的Langmuir探棒，第一次植入使用第一種電漿密度模式來 執行，且第二次植入使用第二種電漿密度模式來執行。相 對於單一步驟的方法，該兩步驟方法提供每種模式中更穩 定的電漿，儘管兩步驟分離植入製程步驟將必定需要更多 的時間。 是以，用以提供跨越基質表面植入劑量均勻性之一種 .方法及系統的較佳實施例已經被描述。使用本發明，跨越 300mm晶圓之表面小於2%變化的劑量均勻性已經被達成 。然而，吾人可以瞭解前述之描述僅是由實例的方式來說 13 (請先閱讀背面之注意事項再填窝本頁) 襄 本紙張尺度適用申國國家標準（CNS)A4規格(210 X 297公釐） 459266 ____ 五、發明說明（μ ) 明，本發明不侷限於本文所描述之特定實施例，舉凡各種 變化的安排、修改及替代可以關於前述描述而實施，均不 脫離本發明由以下之申請專利範圍及其等效者所界定者。 (請先閱讀背面之注意事項再填寫本頁) ----訂---------線1/ 經濟部智慧財產局員工消費合作社印製 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）Q Figure 4 is a representation of the normalized plasma density across the surface of a wafer in the chamber of Figure 3 for different currents flowing through the magnet. The figure in Figure 4 is based on the Chinese National Standard (CNS) A4 specification (210 X 297 mm). Printed by Jinsakusha, employee of the Intellectual Property Bureau of the Ministry of Economic Affairs 4 59 26ί Α7 Β7 V. Description of the invention (q) Operate an argon plasma excited by a 200 watt RF source. The magnetic field leaves of the antenna 28 (positions X and Y in FIG. 3) are separated by 20 cm (10 cm on each side of the center line CL). The current system from 6 amps to 16.9 amps in the legend represents the current flowing through the larger main coils 34 and 40. The current flowing through the smaller adjustment lines 及 36 and 38 is 0.33 (33%) of the main line current, which has been found to be a suitable ratio through experiments. "" The normalized plasma electron density shown in Figure 4 is given by A known method (for example, by a moving Langmuir probe) is measured 2 cm above the wafer surface. The Langmuir probe is repeatedly moved along the plane of the wafer to measure the plasma density of various magnetic field currents. In addition, the Faraday cup cover 42 can be used to measure the plasma density on the wafer surface. Using a moving Langmuir probe or Faraday cup array, the plasma density across the wafer surface is measured. The controller 50 can then change the magnetic field by adjusting the current in the magnets 34, 36, 38, and 40 until the desired uniform magnetic field plasma density is obtained. If a Faraday cup is used, in order to achieve the uniformity of the lateral plasma density, the output signal of the Faraday cup can be used as a feedback in a closed loop system (refer to Figure 2) to change the magnetic field current. As shown in Figure 4, two stable modes of plasma were obtained. In the first mode, at lower main magnetic field currents (6-8 amps), the plasma density is concentrated along the centerline of the chamber. In the second mode, at a higher main magnetic field current (12-17 amps), the plasma density is concentrated on both sides (from the central line CL + 10cm and _i〇cm), which corresponds to the magnetic field leaves of the antenna 28 s position. The current in the middle (9-11 amps) achieves a more uniform plasma density across the wafer surface. However, this is an unstable area and the plasma density is 12 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) 丨 丨 ------ 丨 1 i — — — — — — Order · (Please read the notes on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 4 59 266 A7 B7 V. Description of the invention (ί. ≫ The tendency of one of the modes to move. The reason for the existence of these two different plasma modes can be explained by the different diffusion speeds of the plasma away from the electric field source (which is represented by the annular surface under the antenna 28). It is explained by the magnet The low magnetic fields established by 34, 36, .38, and 40 'plasma lateral diffusion rate is high, while the center of the toroidal surface begins to be filled with plasma and gradually peaks at the central line. Magnets 34, 36, 38, and 40 With the high magnetic field established, the lateral diffusion rate of the propeller is low, and the plasma maintains a toroidal shape. 'Therefore, the present invention contemplates two methods to achieve a uniform plasma density across the surface of the wafer W. Using a Faraday cup array or Mobile Langmuir probe, The precise current through the main coils 34 and 40 can be determined, which will result in a uniform plasma density across the surface of the wafer W. The wafer can then be implanted using a single implantation process step. Or, because of the above The methods all involve areas where the plasma is unstable, and a single step of implantation can be performed. Using a Faraday cup array or a moving Langmuir probe, the first implantation is performed using the first plasma density mode, and the first Secondary implants are performed using a second plasma density mode. This two-step method provides a more stable plasma in each mode compared to a single step method, although two-step separation implantation process steps will necessarily require more Therefore, a preferred method and system for implant dose uniformity across the surface of the substrate has been described. Using the present invention, dose uniformity of less than 2% change across the surface of a 300 mm wafer Has been reached. However, I can understand that the foregoing description is only by way of example. 13 (Please read the precautions on the back before filling this page) Applicable National Standard (CNS) A4 (210 X 297 mm) 459266 ____ V. Description of the Invention (μ) The invention is not limited to the specific embodiments described herein. For example, various arrangements, modifications and Substitutions can be implemented with regard to the foregoing description, without departing from the scope of the present invention as defined by the following patent application scopes and their equivalents. (Please read the notes on the back before filling out this page) ---- Order ---- ----- Line 1 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs This paper is sized for China National Standard (CNS) A4 (210 X 297 mm)