1286775 A7 ------- B7__ 五、發明說明（） 發明之領域 本發明係關於用於半導體晶圓或其它工件之離子植入 的系統及方法，尤其係關於用來最佳化一被掃描的離子束 的均勻性的方法及設備。 置明背景 離子植入係用來導入傳導性警告雜質至半導體晶圓的 一項標準技術。一個所需的雜質物質在一離子源中被離子 化，接著該離子被加速形成一具有指定能量的離子束，然 後g亥離子束被導至晶圓的表面，離子束中具有能量的離子 穿入大部份半導體材料，並被嵌入半導體結晶格中，以形 成一所需傳導性的區域。 離子植入系統通常包含一離子源，用來轉換氣態或固 態物質到充分界定的離子束，該離子束被大量地分析，以 減少不必要的離子種類，然後被加速至一所需的能量並導 至一靶標平面上，該離子束藉由離子束掃描、靶標移動、 或離子束掃描和靶標移動的結合而散佈在靶標區上。一使 用離子束掃描及靶標移動之結合的離子植入器係揭示於 1990年5月1日Berrian等人的美國專利第4,922，106號 中。 在離子束掃描方法中，一離子束藉由一掃描系統而偏 移而產生離子軌道，其係自一點偏移，此點稱爲掃描原點 ，然後被掃描的離子束通過一執行對焦的離子光學元件。 該離子光學元件轉換偏移的離子軌道至平行的離子軌道， 4 ^紙張尺度適用中國國家標準（CNS)A4規格(Yi〇 x 297公爱) · 一 : (請先閱讀背面之注意事項再填寫本頁) -------訂-------- 1286775 A7 __B7__ 五、發明說明（） 用來傳送到半導體晶圓。對焦能以一角度校正器磁鐵或以 一靜電透鏡來執行。 (請先閱讀背面之注意事項再填寫本頁) 掃描系統通常包含一用來使離子束轉向的掃描板，及 一對掃描板施以掃描電壓的掃描產生器。該在掃描板上的 電壓產生電場於使離子束中的離子轉向的掃描平台之間的 區域。一掃描電壓波形通常是一鋸齒、或三角形的波形， 其與晶圓移動結合，在晶圓表面產生離子束的掃描。 在半導體晶圓表面上一致的植入離子是許多應用的重 要需求。理論上，一具固定的電壓斜率或離子束位置的掃 描波形會產生一致的離子束電流，亦即在所有位置都相同 。實際上，這從不會發生，因爲在離子束光學中的偏離、 當離子束偏移時，離子束形狀會有輕微的改變、在電壓與 離子束位置之間的非線性關係等。爲達到在晶圓表面上所 需的均勻性，在習知技術的離子植入系統採用一個均勻性 的最佳化程序。一線性掃描波形開始被施加在掃描板上， 所以掃描板能以固定的速率在一個方向上掃過離子束，被 掃描的離子束的均勻性被量測，然後掃描波形被調整至在 半導體晶圓上的離子束分佈造成變化。掃描板掃過在晶圓 表面上的離子束的速率決定離子植入的劑量。掃描的波形 通常是分段線性的，在開始時，所有的分段線性波形的片 段都有相同的斜率。掃描波形的調整包含調整界定每個掃 描波形的分段線性片段斜率的數値。一般而言，初始的線 性掃描波形可能不會產生在半導體晶圓上所需的均勻性， 而需要一非線性的掃描波形。離子束均勻性的量測和掃描 5 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） A7 1286775 ___B7 _____ 五、發明說明（） 波形的調整會一直重覆到達到所需的均勻性爲止。 典型的離子植入系統的使用者可成需要建AL在不同會§ 量及劑量之不同的離子種類的多個植入。所建立的程序通 常會重覆以用於每一組植入參數，該建立的程序通常是耗 時的且會減少離子植入器的產出量。 在一些例子中，離子植入器的建立程序被自動化，該 自動化的程序可允許均勻性的最佳化程序以一預設的次數 重覆，在其中離子束均勻性被量測、掃描波形被調整，而 離子束的均勻性再次被量測。如果所需的均勻性未在預設 的重覆次數內被達成，則該最佳化程序會被中止。因此， 一已知爲成功率的參數是與自動化的均勻性最佳化程序有 關，該程序如果在預設的重覆次數內達成所需的均勻性.， 則被視爲成功。在實務上，即使是自動化的最佳化程序也 是相當耗時的，而且會減少植入器的產出量。 因此，需要有最佳化一被掃描離子束均勻性的改良方 法和設備。 發明槪要 根據本發明的一個第一方面，提供一種用來控制一離 子植入系統的劑量均勻性之方法，該方法包含調整一初始 掃描波形，以獲得一所需的均勻性而用於一第一植入程序 ;儲存該調整過的掃描波形；取回該儲存的掃描波形，·以 及使用該取回的掃描波形於一第二植入程序。 根據本發明的另一方面，提供一種用來控制在一離子 6 ^___ ____ 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閲讀背面之注意事項再填寫本頁) 裝 •lalr ·!111111 A7 1286775 __B7 五、發明說明（） 植入系統的劑量均勻性的方法，該方法包含辨識所需的離 子束參數；根據該所需的離子束參數，取回一儲存的掃描 波形，用於均勻性調整流程；以及執行該均勻性調整流程。 根據本發明的另一方面，提供用於在離子植入系統中 控制劑量均勻性的設備，該設備包含一離子束圖形器’用 來量測一被掃描的離子束的電流分佈；以及一資料擷取和 分析單元，用於根據一所需的電流分佈與該經量測的電流 分佈，調整初始掃描波形，用在一第一植入流程、儲存該 經調整的掃描波形、取回該儲存的掃描波形、以及使用取 回的掃描波形於一第二植入流程。 圖式簡單說明 爲了更了解本發明，將參考以下圖式： 圖1是一適合用在本發明之離子植入器的示意圖； 圖2是一說明一習知技術的均勻性最佳化流程之流程 圖，； . 圖3是一根據本發明一實施例之均勻性最佳化流程的 流程圖；以及 圖4是以在晶圖平面中之位置爲橫軸的離子束電流函 數圖，並繪出在掃描波形調整之前和之後的被掃描離子束 的圖形。 ίο 離子束產生器 7 本紙張尺度適用中國國家標準（CNS)A4規格（21〇 x 297公釐） (請先閱讀背面之注意事項再填寫本頁) n I n n —.1 n ϋ^OJ· IV n n n ϋ n n 1286775 a7 _B7 五、發明說明（） 12 能量離子束 16 掃描系統 20 掃描器 24 角度校正器 26 磁力磁極片 28 電源供應器 30 掃描離子束 32 終端站 34 半導體晶圓 36 平台 40 離子束來源 42 來源過濾器 44 加減速柱 50 質量分析器 52 偶極分析磁鐵 54 遮罩 56 分辨孔徑 60 掃描原點 70 平面 80 掃描板 82 掃描產生器 90 離子束圖形器 92 箭頭 94 資料擷取及分析單元 8 (請先閱讀背面之注意事項再填寫本頁)1286775 A7 ------- B7__ V. INSTRUCTIONS () Field of the Invention The present invention relates to systems and methods for ion implantation of semiconductor wafers or other workpieces, particularly with respect to optimizing one Method and apparatus for uniformity of scanned ion beams. Clear Background Ion implantation is a standard technique used to introduce conductive warning impurities to semiconductor wafers. A desired impurity species is ionized in an ion source, which is then accelerated to form an ion beam of a specified energy, and then the ion beam is directed to the surface of the wafer, and ions having energy in the ion beam are worn. Most of the semiconductor material is incorporated into the semiconductor crystal lattice to form a region of desired conductivity. Ion implantation systems typically include an ion source for converting a gaseous or solid material to a well-defined ion beam that is extensively analyzed to reduce unwanted ion species and then accelerated to a desired energy and Leading to a target plane, the ion beam is spread over the target zone by ion beam scanning, target movement, or a combination of ion beam scanning and target movement. An ion implanter that uses a combination of ion beam scanning and target movement is disclosed in U.S. Patent No. 4,922,106, issued to Berrian et al. In the ion beam scanning method, an ion beam is deflected by a scanning system to generate an ion orbit, which is offset from a point, which is called a scanning origin, and then the scanned ion beam passes through an ion that performs focusing. Optical element. The ion optics converts the shifted ion orbit to a parallel ion orbit, 4^paper scale applies to the Chinese National Standard (CNS) A4 specification (Yi〇x 297 public) · A: (Please read the notes on the back and fill in This page) ------- order --------- 1286775 A7 __B7__ V. Invention Description () Used to transfer to semiconductor wafers. Focusing can be performed with an angle corrector magnet or with an electrostatic lens. (Please read the precautions on the back and fill out this page.) The scanning system usually includes a scanning plate for diverting the ion beam, and a scanning generator for applying a scanning voltage to a pair of scanning plates. The voltage on the scanning plate creates an electric field between the scanning platforms that steer the ions in the ion beam. A scan voltage waveform is typically a sawtooth, or triangular, waveform that combines with wafer movement to produce an ion beam scan on the wafer surface. Consistent implanting of ions on the surface of a semiconductor wafer is an important requirement for many applications. In theory, a scan waveform with a fixed voltage slope or ion beam position produces a consistent beam current, which is the same at all locations. In fact, this never happens because of the deviation in ion beam optics, when the ion beam is shifted, the ion beam shape will change slightly, the nonlinear relationship between voltage and ion beam position, and so on. In order to achieve the uniformity required on the wafer surface, a uniformity optimization procedure is employed in prior art ion implantation systems. A linear scan waveform is initially applied to the scan plate so that the scan plate can sweep the ion beam in one direction at a fixed rate, the uniformity of the scanned ion beam is measured, and then the scan waveform is adjusted to the semiconductor crystal The ion beam distribution on the circle causes a change. The rate at which the scanning plate sweeps the ion beam across the surface of the wafer determines the dose of ion implantation. The scanned waveform is usually piecewise linear, and at the beginning, all segments of the piecewise linear waveform have the same slope. The adjustment of the scan waveform involves adjusting the number of slopes that define the slope of the piecewise linear segment of each scan waveform. In general, the initial linear scan waveform may not produce the required uniformity on the semiconductor wafer, but requires a non-linear scan waveform. Measurement and scanning of ion beam uniformity 5 This paper scale applies to China National Standard (CNS) A4 specification (210 X 297 mm) A7 1286775 ___B7 _____ V. Invention description () Waveform adjustment will be repeated until the desired The uniformity is up. A typical ion implantation system user may need to implant multiple implants of different ion species at different amounts and doses. The established procedure is typically repeated for each set of implant parameters, which is typically time consuming and reduces the throughput of the ion implanter. In some examples, the ion implanter setup procedure is automated, which allows the homogenization optimization procedure to be repeated a predetermined number of times, in which the ion beam uniformity is measured, the scan waveform is Adjustment, and the uniformity of the ion beam is measured again. If the required uniformity is not achieved within the preset number of repetitions, the optimization procedure will be aborted. Therefore, a parameter known as a success rate is associated with an automated uniformity optimization procedure that is considered successful if the desired uniformity is achieved within a preset number of repetitions. In practice, even automated optimization procedures are time consuming and reduce the throughput of the implanter. Therefore, there is a need for improved methods and apparatus for optimizing the uniformity of a scanned ion beam. SUMMARY OF THE INVENTION According to a first aspect of the present invention, a method for controlling dose uniformity of an ion implantation system is provided, the method comprising adjusting an initial scan waveform to obtain a desired uniformity for use in a method a first implanting program; storing the adjusted scan waveform; retrieving the stored scan waveform, and using the retrieved scan waveform in a second implant procedure. According to another aspect of the present invention, there is provided a method for controlling the application of the Chinese National Standard (CNS) A4 specification (210 X 297 mm) on an ion 6 ^___ ____ paper scale (please read the back note first and then fill in the form) Page) 装•lalr·!111111 A7 1286775 __B7 V. INSTRUCTIONS () A method of implanting the dose uniformity of a system, the method comprising identifying the required ion beam parameters; and retrieving one according to the required ion beam parameters The stored scan waveform is used for the uniformity adjustment process; and the uniformity adjustment process is performed. According to another aspect of the present invention, there is provided an apparatus for controlling dose uniformity in an ion implantation system, the apparatus comprising an ion beam patterner for measuring a current distribution of a scanned ion beam; and a data And a sampling and analyzing unit, configured to adjust an initial scan waveform according to a required current distribution and the measured current distribution, to store the adjusted scan waveform, and retrieve the storage in a first implantation process The scan waveform and the use of the retrieved scan waveform are in a second implantation process. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, reference will be made to the following drawings: FIG. 1 is a schematic diagram of an ion implanter suitable for use in the present invention; FIG. 2 is a schematic diagram showing a uniformity optimization process of the prior art. FIG. 3 is a flow chart of a process for optimizing the uniformity according to an embodiment of the present invention; and FIG. 4 is a graph of ion beam current as a function of the horizontal axis in the plane of the crystal plane, and A pattern of scanned ion beams before and after scanning waveform adjustment. Οο Ion Beam Generator 7 This paper size applies to the Chinese National Standard (CNS) A4 specification (21〇x 297 mm) (please read the notes on the back and fill out this page) n I nn —.1 n ϋ^OJ· IV nnn ϋ nn 1286775 a7 _B7 V. Description of invention () 12 Energy ion beam 16 Scanning system 20 Scanner 24 Angle corrector 26 Magnetic pole piece 28 Power supply 30 Scanning ion beam 32 Terminal station 34 Semiconductor wafer 36 Platform 40 Ions Beam source 42 Source filter 44 Acceleration and deceleration column 50 Mass analyzer 52 Dipole analysis magnet 54 Mask 56 Resolving aperture 60 Scanning origin 70 Plane 80 Scanning plate 82 Scanning generator 90 Ion beam pattern 92 Arrow 94 Data acquisition and Analysis unit 8 (please read the notes on the back and fill out this page)
--------訂--------· ^ 本紙張尺度適用中國國家標準（CNS)A4規格（21〇χ 297公釐） A7 1286775 __ B7 — I _ ...... — I " ' * "" " " —~ ~ ·ι - 卜_ _______ _ 五、發明說明（） 詳細說明_ 在圖1顯示一個適用於本發明的離子植入器的例子的 簡化的方塊圖。一離子束產生器10產生一所需種類的離子 束、加速在該離子束中的離子到所需的能量、進行離子束 的質量/能量分析以移除能量及質量污染物、以及提供一有 低階層能量及質量污染物的能量離子束12 ; —個掃描系統 16使該離子束12偏移而產生一個有平行或近似平行的離 子軌道之掃描離子束30,該掃描系統包含一個掃描器20 和一個角度校正器24 ; —個終端站32包含一平台36，其 可支撐一半導體晶圓34或是其它在該掃描離子束30路徑 上的工作件，以致於所需種類的離子被植入該半導體晶圓 34中。該離子植入器可以包含那些熟知本技術者所知的額 外元件。舉例而言，該終端站32通常包含自動化的晶圓處 理設備，用來導入晶圓至離子植入器中，並在植入後移除 晶圓，並包含一個劑量量測系統、一個電子流槍等。必須 了解的是，整個被離子束通過的路徑在離子植入時會被清 空。 該離子束產生器10的主要元件包含一個離子束來源 40、一個來源過濾器42、一個加減速柱44 ’以及一個質重 分析器50。該來源過濾器42最好是放置在接近該離子束 來源40的地方；該加減速柱44位在該來源過濾器42及該 質量分析器50之間。該質量分析器50包含一個偶極分析 磁鐵52和一個具有分辨孔徑56的遮罩54。 該掃描器20可以是一靜電式掃描器，會使離子束12 9 _ ........... 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) ·1111111 A7 1286775 ^____B7___ 五、發明說明（） 偏移以產生一具有離子軌道的被掃描的離子束，其自一掃 描原點60偏移出來。該掃描器20可以包含分隔出來的掃 描板80，連接至一個掃描產生器82。該掃描產生器82施 予一個掃描電壓波形，諸如鋸齒狀或是三角形的波形，依 據該掃描板80之間的電場，來掃描離子束。 掃描的波形可以用數種數學的方式來描述。一個方法 是，波形是由指定電壓爲時間的函數來描述。然而，在一 較佳實施例中，波形是藉由指定離子束的位置(其與電壓完 全相同）及在那個位置離子束的掃掠率。這個公式是方便的 ，因爲當量測被掃描離子束的圖形時，離子束在一特定位 置的掃掠率與在那個位置量測的電流量有關。如果離子束 在特定位置掃得較慢，則在那個位置量測的電流會增加； 相反地，如果離子束在一特定點掃較快，在該位置的量測 電流會減少。 以位置、斜率表示的掃描波形可以被視爲以時間、電 壓表示的波形之導函數。一個從-V到+V伏特以等速率上 升的掃描波形，若以電壓對時間繪出是一傾斜上升的直線 ，但是以斜率對位置繪出則是一條在軸上一定高度的平直 線。在一個實施例中，掃描波形被表示爲一施加在掃描板 之初始的掃描電壓與一系列30數字斜率値上，每一個都代 表在該掃描中特定位置的掃描速度。在一掃描器20的實施 例中，掃描板80被+/-20千伏的高電壓放大器施予能量， 產生兩極的掃描波形。離子束被掃描波形偏移至其中一方 向，偏移角度通常是正負13.5度。 10 _______________________ 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)--------Book ---·· ^ This paper scale applies to China National Standard (CNS) A4 specification (21〇χ 297 mm) A7 1286775 __ B7 — I _ .... .. — I " ' * """" —~ ~ ·ι - _ _______ _ V. Description of the invention () Detailed description _ shows an ion implanter suitable for use in the present invention A simplified block diagram of the example. An ion beam generator 10 produces a desired type of ion beam, accelerates ions in the ion beam to a desired energy, performs ion beam mass/energy analysis to remove energy and mass contaminants, and provides Energy ion beam 12 of low level energy and mass contaminants; a scanning system 16 shifts the ion beam 12 to produce a scanned ion beam 30 having parallel or nearly parallel ion orbits, the scanning system comprising a scanner 20 And an angle corrector 24; an end station 32 includes a platform 36 that can support a semiconductor wafer 34 or other workpiece on the path of the scanned ion beam 30 such that the desired species of ions are implanted In the semiconductor wafer 34. The ion implanter can comprise additional components known to those skilled in the art. For example, the terminal station 32 typically includes automated wafer processing equipment for introducing wafers into the ion implanter and removing the wafer after implantation, and includes a dose measurement system, a flow of electrons Guns, etc. It must be understood that the entire path through which the ion beam passes is cleared during ion implantation. The main components of the ion beam generator 10 include an ion beam source 40, a source filter 42, an acceleration and deceleration column 44', and a mass analyzer 50. The source filter 42 is preferably placed adjacent to the ion beam source 40; the acceleration and deceleration column 44 is positioned between the source filter 42 and the mass analyzer 50. The mass analyzer 50 includes a dipole analysis magnet 52 and a mask 54 having a resolution aperture 56. The scanner 20 can be an electrostatic scanner that will make the ion beam 12 9 _ ........... The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) ( Please read the notes on the back and fill out this page.) 1111111 A7 1286775 ^____B7___ V. Description of the invention () Offset to produce a scanned ion beam with ion orbits that is offset from a scanning origin 60. The scanner 20 can include a spaced apart scanning plate 80 coupled to a scanning generator 82. The scan generator 82 applies a scan voltage waveform, such as a sawtooth or triangular waveform, to scan the ion beam based on the electric field between the scan plates 80. The scanned waveform can be described in several mathematical ways. One method is that the waveform is described by a function of the specified voltage as a function of time. However, in a preferred embodiment, the waveform is by specifying the position of the ion beam (which is exactly the same as the voltage) and the sweep rate of the ion beam at that location. This formula is convenient because when the pattern of the ion beam is scanned, the sweep rate of the ion beam at a particular location is related to the amount of current measured at that location. If the ion beam sweeps more slowly at a particular location, the current measured at that location will increase; conversely, if the ion beam sweeps faster at a particular point, the measured current at that location will decrease. The scan waveform expressed in terms of position and slope can be regarded as a derivative function of the waveform expressed in time and voltage. A sweep waveform that rises from -V to +V volts at an equal rate, if plotted against voltage versus time, is a straight line that rises obliquely, but is plotted as a straight line at a certain height on the axis. In one embodiment, the scan waveform is represented as an initial scan voltage applied to the scan panel and a series of 30 digital slopes, each representing a scan speed at a particular location in the scan. In an embodiment of a scanner 20, the scan board 80 is energized by a high voltage amplifier of +/- 20 kV to produce a scan waveform of the two poles. The ion beam is shifted to one of the scanned waveforms, and the offset angle is usually plus or minus 13.5 degrees. 10 _______________________ This paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (please read the notes on the back and fill out this page)
n ϋ n n n n I^dJ« n I I I n I I I mm尺度適用 1286775 A7 _ B7 五、發明說明（） 角度校正器24被設計用來偏移在被掃描離子束中的離 子，來產生有平行的離子軌道的被掃描離子束30，因而聚 焦了該被掃描離子束。特別是，角度校正器24可以包含磁 性磁極片26，其被間隔以界定一間隙及一磁性線圈（未顯 示出來），其連結到一電源供應器28上。被掃描的離子束 通過磁極片26的之間的間隙，並依據在間隙中的磁場而偏 移，該磁場可以由改變通過該磁性線圈的電流而調整。離 子束掃描及離子束對焦在一選定的平面上進行，例如一水 平面上。 該離子植入器更進一步包含一 Faraday離子束圖形器 9〇，其位在或是接近晶圓34的一平面70上。離子束圖形 器90在晶圓34的平面70中被轉換，如同箭頭92所指示 的。該被掃描的離子束30的均勻性是由轉換在晶圓平面上 的離子束圖形器90以及監測離子束電流而決定的。在晶圓 平面上離子束電流的分佈是藉由改變掃描波形的形狀而調 整。從離子束圖形器的輸出電流被提供給一資料擺取及分 析單元94。 在一個實施例中，該資料擷取及分析單元94是以一般 用途的電腦來使用，其被程式化來控制離子植入器的建立 及ί采作。特別是，該資料擷取及分析單元94可以被程式化 來執行底下所述之均勻性的調整流程。在其它的實施例中 ’該資料擷取及分析單元94可能是一個特殊用途的控制器 或是現場控制器，其爲部分或是全部用於掃描控制。 該資料擷取及分析單元94可能包含一個記憶體，用來 11 國國家標準（CNS)A4規格（210 X 297公t ) (請先閱讀背面之注意事項再填寫本頁) --------訂-------- A7 1286775 ___B7____ 五、發明說明（） 儲存一個或更多的植入方法，其指定用來摻雜一批晶圓的 參數。舉例而言，植入的方法可以識別一摻質種類、一能 量，以及施加在晶圓的劑量，每一個參數可以指定爲一最 小値、一最大値、一範圍內的値、或一目標値。一個植入 方法有一個名稱，其可允許識別該方法。該資料擷取及分 析單元94可以包含一個操作員介面，其允許根據該方法的 識別名稱，來搜尋及選擇一特定植入方法。更進一步地， 該資料擷取及分析單元94可以根據被選擇的植入方法，存 取一初始掃描波形。 圖2所示爲根據習知技術用來最佳化一被掃描離子波 形之均勻性的流程的流程圖。在步驟100中，一線性的掃 描波形被施加在該掃描板80上；在步驟102中，離子束的 均勻性被量測；在步驟104中，決定了均勻性是否合乎規 定。如果在步驟104中所決定的均勻性合於規定，則在步 驟106中執行植入動作；如果均勻性不合乎規定，則在步 驟108中調整掃描波形以達成所需的均勻性，且在步驟 110中將該掃描波形施加在掃描板80上。特別是，掃描波 形被調整，以致於離子束更快地被掃描，以減少離子束電 流，或是更慢地被掃描，以增加離子束電流。此流程接著 回到步驟102，重覆均勻性的量測。此流程可能需要許多 例行性的重覆，包含均勻性的量測及掃描波形的調整，來 達到所需的均勻性。 在圖2所說明的流程和以上所描述的可能是相當耗時 的’尤其是需要許多重覆以達成所需的均勻性。在典型的 12 |_________ 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)n ϋ nnnn I^dJ« n III n III mm scale applies to 1286775 A7 _ B7 V. INSTRUCTION DESCRIPTION () Angle corrector 24 is designed to offset ions in the scanned ion beam to produce parallel ion orbitals The scanned ion beam 30 is thus focused on the scanned ion beam. In particular, the angle corrector 24 can include magnetic pole pieces 26 that are spaced to define a gap and a magnetic coil (not shown) that is coupled to a power supply 28. The scanned ion beam passes through the gap between the pole pieces 26 and is deflected in accordance with the magnetic field in the gap, which can be adjusted by varying the current through the magnetic coil. The ion beam scan and ion beam focusing are performed on a selected plane, such as a horizontal plane. The ion implanter further includes a Faraday ion beam pattern 9 位 located on or near a plane 70 of the wafer 34. Ion beam patterner 90 is converted in plane 70 of wafer 34 as indicated by arrow 92. The uniformity of the scanned ion beam 30 is determined by the ion beam patterner 90 that is converted on the wafer plane and by monitoring the ion beam current. The distribution of the ion beam current on the wafer plane is adjusted by changing the shape of the scanning waveform. The output current from the ion beam pattern is supplied to a data acquisition and analysis unit 94. In one embodiment, the data capture and analysis unit 94 is used in a general purpose computer that is programmed to control the establishment and fabrication of the ion implanter. In particular, the data capture and analysis unit 94 can be programmed to perform the adjustment process for uniformity as described below. In other embodiments, the data capture and analysis unit 94 may be a special purpose controller or a field controller that is used in part or in whole for scan control. The data acquisition and analysis unit 94 may contain a memory for the National Standards (CNS) A4 specification (210 X 297 metric tons) (please read the notes on the back and fill out this page) ----- --- Order --------- A7 1286775 ___B7____ V. Description of the invention () Store one or more implant methods that specify parameters for doping a batch of wafers. For example, the method of implantation can identify a dopant species, an energy, and a dose applied to the wafer, each parameter can be designated as a minimum 値, a maximum 値, a range of 値, or a target 値. An implant method has a name that allows the method to be identified. The data capture and analysis unit 94 can include an operator interface that allows for the search and selection of a particular implant method based on the identified name of the method. Further, the data acquisition and analysis unit 94 can retrieve an initial scan waveform according to the selected implantation method. Figure 2 is a flow chart showing the flow of a technique for optimizing the uniformity of a scanned ion waveform in accordance with conventional techniques. In step 100, a linear scan waveform is applied to the scan plate 80; in step 102, the uniformity of the ion beam is measured; in step 104, it is determined whether the uniformity is satisfactory. If the uniformity determined in step 104 is stipulated, then the implanting action is performed in step 106; if the uniformity is not compliant, the scan waveform is adjusted in step 108 to achieve the desired uniformity, and in the step The scan waveform is applied to the scan board 80 in 110. In particular, the scan waveform is adjusted such that the ion beam is scanned faster to reduce ion beam current or to be scanned more slowly to increase ion beam current. The flow then returns to step 102 to repeat the measurement of uniformity. This process may require many routine repetitions, including uniformity measurements and sweep waveform adjustments to achieve the desired uniformity. The process illustrated in Figure 2 and described above may be quite time consuming' in particular requiring many repetitions to achieve the desired uniformity. In the typical 12 |_________ paper scale, the Chinese National Standard (CNS) A4 specification (210 X 297 mm) is applied (please read the notes on the back and fill out this page)
A7 1286775 ____B7_ 五、發明說明（） 系統中，只要離子束的調校過程是自動化的，在圖2中所 顯示的均勻性最佳化流程其可被執行的重覆次數上便有一 預設的上限。舉例而言，該預設的上限可能重覆高達1〇次 或更多，或是低達1次或零次。當預設的重覆次數已被執 行而且均勻性不合乎規定，則程序終止，且需要操作員的 介入。在這種情況中，離子束調校過程便被延遲了。 在習知技術的系統中，在圖2中顯示的均勻性最佳化 過程重覆用於每一新的離子束參數組，亦即重覆用於每次 方法之改變。因此每一新的離子束參數組會產生均勻性最 佳化時間爲。每當均勻性最佳化流程執行時，線性的掃描 波形便被用作初始波形。 在圖2中所顯示的均勻性最佳化流程常常導致相似的 掃描波形是已經決定的，特別是在離子束參數相似時。這 樣的特性被用在提供一個改良的均勻性最佳化流程。特別 是該最佳化掃描波形在一成功的均勻性最佳化流程後被儲 存，該被儲存的掃描波形被用在後績的離子束設定中，通 常一倂減少了均勻性最佳化的需要。 圖3所顯示的是根據本發明的一個實施例的一個均勻 性最佳化流程的流程圖。必須認知的是，在以下所描述的 均勻性最佳化流程未必導致一個具有理想的或是完全最佳 化特性的掃描波形。反而，掃描波形的最佳化可能包含調 整掃描波形以達到所需的掃描波形或是一符合已建立規定 的掃描波形。在步驟200中，決定了一最佳化的掃描波形 是否被儲存。該系統可以被規劃成儲存最佳化掃描波形’ 13 ____________— 本纸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) --------訂-------- 1286775 A7 ——_ B7 ____ 五、發明說明（） 以用於每一離子束方法。如果一適當的最佳化掃描波形被 儲存，則在步驟202中，最佳化掃描波形被存取，並且在 步驟204中被施加在掃描板80上。接著在步驟206中，使 用離子束圖形器90來量測均勻性。該離子束圖形器90可 以量測離子束電流，舉例而言，在晶圓平面70上的每一毫 米或是每幾毫米量測，以決定離子束的均勻性。如果在步 驟200中決定了適當的最佳化掃描波形沒被儲存，則在步 驟208中，將一線性的掃描波形施加在掃描板80上，然後 在步驟206中量測離子束均勻性。 在步驟210中，決定了均勻性是否合乎規定。如果均 勻性不合乎規定，則在步驟212中調整掃描波形。根據在 步驟206中離子束電流的量測結果，掃描波形被調整，以 減少或增加在掃描時一個或多個特定點的電流。特別是在 掃描中一點的離子束電流會藉由降低掃描波形的斜率而增 加，因而在那點較慢地掃描離子束，或是離子束電流會藉 由增加掃描波形的斜率而減少，因而在那點較快地掃描離 子束。流程接著回到步驟206，然後重覆離子束均勻性的 量測。如果在步驟210中決定了均勻性合乎規定，則在步 驟214中儲存相對應的最佳化掃描波形，而在步驟216中 執行植入。該儲存的最佳化掃描波形可用一特定的方法在 記憶體中產生關連’用來執行植入。舉例而言，一最佳化 掃描波形可以與一特定的方法名稱相關連，以致於一被儲 存的最佳化掃描波形可以根據一個特定方法的名字被搜尋 及選擇。更進一步地’被儲存的最佳化掃描波形最好被正 14 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)A7 1286775 ____B7_ V. INSTRUCTIONS () In the system, as long as the adjustment process of the ion beam is automated, the uniformity optimization process shown in Figure 2 has a preset number of repetitions that can be performed. Upper limit. For example, the preset upper limit may be repeated up to 1 or more times, or as low as 1 or 0 times. When the preset number of repetitions has been performed and the uniformity is not specified, the program is terminated and the operator's intervention is required. In this case, the ion beam tuning process is delayed. In a prior art system, the uniformity optimization process shown in Figure 2 is repeated for each new ion beam parameter set, i.e., repeated for each method change. Therefore, each new ion beam parameter set will produce a uniformity optimum time. A linear sweep waveform is used as the initial waveform whenever the uniformity optimization process is performed. The uniformity optimization process shown in Figure 2 often results in similar scan waveforms that have been determined, especially when the ion beam parameters are similar. Such characteristics are used to provide an improved uniformity optimization process. In particular, the optimized scan waveform is stored after a successful uniformity optimization process, which is used in subsequent ion beam settings, typically reducing uniformity optimization. need. Figure 3 is a flow diagram of a uniformity optimization process in accordance with one embodiment of the present invention. It must be recognized that the uniformity optimization process described below does not necessarily result in a scan waveform having ideal or fully optimized characteristics. Instead, the optimization of the scan waveform may include adjusting the scan waveform to achieve the desired scan waveform or a scan waveform that meets the established specifications. In step 200, it is determined whether an optimized scan waveform is stored. The system can be programmed to store optimized scan waveforms ' 13 ____________ — This paper scale applies to the Chinese National Standard (CNS) A4 specification (210 x 297 mm) (please read the notes on the back and fill out this page) - ------- Order -------- 1286775 A7 —— _ B7 ____ V. Description of the invention () for each ion beam method. If a suitable optimized scan waveform is stored, then in step 202, the optimized scan waveform is accessed and applied to scan board 80 in step 204. Next, in step 206, the ion beam patterner 90 is used to measure the uniformity. The ion beam patterner 90 can measure the beam current, for example, every millimeter or every few millimeters on the wafer plane 70 to determine the uniformity of the ion beam. If it is determined in step 200 that the appropriate optimized scan waveform is not stored, then in step 208 a linear scan waveform is applied to scan pad 80 and ion beam uniformity is then measured in step 206. In step 210, it is determined whether the uniformity is compliant. If the uniformity is not as specified, the scan waveform is adjusted in step 212. Based on the measurement of the ion beam current in step 206, the scan waveform is adjusted to reduce or increase the current at one or more particular points during the scan. In particular, the ion beam current at a point in the scan is increased by decreasing the slope of the scan waveform, so that the ion beam is scanned slowly at that point, or the beam current is reduced by increasing the slope of the scan waveform, thus That point scans the ion beam faster. The flow then returns to step 206 and the measurement of ion beam uniformity is repeated. If it is determined in step 210 that the uniformity is compliant, then the corresponding optimized scan waveform is stored in step 214 and the implant is performed in step 216. The stored optimized scan waveform can be correlated in the memory by a particular method' used to perform the implant. For example, an optimized scan waveform can be associated with a particular method name such that a stored optimized scan waveform can be searched and selected based on the name of a particular method. Further, the optimized scan waveform that is stored is preferably applied to the Chinese National Standard (CNS) A4 specification (210 x 297 mm) on the paper scale (please read the notes on the back and fill out this page)
ϋ n 一：OJI ϋ i^i H ϋ n n n I 1286775 A7 _____B7___ 五、發明說明（） 規化，如以下所討論的。在一個實施例中，最佳化的掃描 波形被儲存爲一系列30數値，該等界定了沿著掃描的不同 點，掃描波形的斜率。該儲存的數値一倂界定掃描波形。 由圖3的流程將了解於一第一均勻性最佳化期間使用 一線性的掃描波形作爲初始掃描波形。最佳化掃描波形被 儲存，用作後續的均勻性最佳化流程，或是在沒有均勻性 最佳化的植入流程。如果一最佳化掃描波形已經被儲存， 以用於一特定方法，則先前的波形可以被更近的最佳化掃 描波形所取代。藉由使用一儲存的最佳化掃描波形於後續 的均勻性最佳化流程，需要重覆的均勻性量測及波形調整 例行工作便較少，且離子束調校時間會減少。更進一步來 說，因爲需要較少重覆的均勻性量測及波形調整例行工作 ，較不可能達到重覆次數的預設上限，而成功率因而增加 。必須注意的是，在某些情況中，沒有執行任何重覆，以 致於儲存的最佳化掃描波形，在沒有後續的均勻性最佳化 流程的情況下，被用在一植入程序中。舉例而言，如果用 於一特定方法之已儲存的最佳化掃描波形通常會產生一符 合規定的離子束均勻性，一個操作員可以指定沒有任何重 覆需要執行，因此就不需要調整。 當一離子束第一次被調校，它會在該晶圓平面70上的 每一點以相同的時間均等地被掃描，這與施加一線性的掃 描波形在掃描板上相符。該線性掃描波形包含一組固定的 斜率。離子束圖形器90行經晶圓平面，且每隔幾毫米便量 測離子束電流。根據離子束電流曲線圖的形狀，回饋訊號 15 本紙張尺度適用中國國家標準（CiMS)A4規格（210 X 297公釐） --------------------訂----- (請先閱讀背面之注意事項再填寫本頁) 1286775 Δ7 Ά/ ____ Β7_____ 五、發明說明（） (請先閱讀背面之注意事項再填寫本頁) 係送到在該掃描產生器82中的掃描放大器，以減少或增加 在晶圓平面上一個或多個特定位置之電流。這是藉由在這 些位置掃描離子束比預設値快或慢而達成的。掃描波形是 與離子束電流曲線圖形上的每一點相關的一組掃掠率。 在本發明的一個實施例中，使用了一個正規化的例行 程序。在該正規化的例行程序中，用於已調整掃描波形的 掃描斜率資料被初始線性掃描波形的斜率所分割，其爲一 固定値。正規化的例行程序去除了最佳化掃描波形在離子 束能量上的依賴。更高的離子束能量需要一施予掃描板80 更高的電壓，以使離子束偏向一設定的角度。因此，正規 化例行程序正規化了施加在該掃描板80上的電壓，結果正 規化了掃描板80之間電場的強度。 正規化例行程序的一個優點是，非正規化的波形包含 在晶圓平面上掃描離子束要多遠及多快的資訊，而正規化 的波形只保留與相對掃描速率及距離有關的資訊。掃描速 率及距離兩者與離子束量成線性比例關係，因此，如果非 正規化波形被儲存，然後用來建立具有不同能量的離子束 的新方法，則可能無法以正確的距離或正確速率來掃描離 子束。在消除最佳化掃描波形於離子束能量上的依賴中， 正規化例行程序產生了對能量改變一目瞭然的一種方法。 圖4是在晶圓平面中離子束電流的位置函數圖，顯示出 在波形校正之前和之後的被掃描離子束曲線圖；虛線代表晶 圓邊緣，曲線300代表未校正的離子束曲線圖’而曲線302 代表在均勻性最佳化之後的一校正過的離子束曲線圖。 16 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 1286775 A7 _B7__五、發明說明（）在此已詳細說明了本發明之較佳實施例，熟悉本技術 者皆應明瞭，在不背離本發明申請專利範圍所界定之的範 圍前提下，可以進行不同的改變及修正。 (請先閱讀背面之注意事項再填寫本頁)ϋ n One: OJI ϋ i^i H ϋ n n n I 1286775 A7 _____B7___ V. Description of invention () Specification, as discussed below. In one embodiment, the optimized scan waveform is stored as a series of 30 numbers, which define the slope of the scan waveform along different points of the scan. The stored number of scans defines the scan waveform. It will be understood from the flow of Fig. 3 that a linear scan waveform is used as the initial scan waveform during a first uniformity optimization. The optimized scan waveform is stored for use as a subsequent uniformity optimization process or in an implant process where uniformity is not optimized. If an optimized scan waveform has been stored for a particular method, the previous waveform can be replaced by a more recent optimized scan waveform. By using a stored optimized scan waveform for subsequent uniformity optimization processes, repeated uniformity measurements and waveform adjustments require less routine work and ion beam tuning time is reduced. Furthermore, since less repeating uniformity measurement and waveform adjustment routine work is required, it is less likely to reach the preset upper limit of the number of repetitions, and the success rate is increased. It must be noted that in some cases, no repetition is performed so that the stored optimized scan waveform is used in an implant procedure without subsequent uniformity optimization procedures. For example, if a stored optimized scan waveform for a particular method typically produces a defined ion beam uniformity, an operator can specify that no repeats need to be performed, so no adjustment is required. When an ion beam is first calibrated, it is equally scanned at each point on the wafer plane 70 at the same time, which coincides with the application of a linear scan waveform on the scanning plate. The linear scan waveform contains a fixed set of slopes. The ion beam patternr 90 travels through the wafer plane and measures the beam current every few millimeters. According to the shape of the ion beam current graph, the feedback signal 15 is applicable to the Chinese National Standard (CiMS) A4 specification (210 X 297 mm) ------------------- -Book----- (Please read the note on the back and fill out this page) 1286775 Δ7 Ά/ ____ Β7_____ V. Invention description () (Please read the note on the back and then fill out this page) The scan amplifiers in scan generator 82 are used to reduce or increase the current at one or more particular locations on the wafer plane. This is achieved by scanning the ion beam at these locations faster or slower than the preset 値. The scan waveform is a set of sweep rates associated with each point on the ion beam current curve graph. In one embodiment of the invention, a normalized routine is used. In this normalized routine, the scan slope data for the adjusted scan waveform is divided by the slope of the initial linear scan waveform, which is a fixed chirp. The normalized routine removes the dependence of the optimized scan waveform on the ion beam energy. Higher ion beam energy requires a higher voltage applied to the scanning plate 80 to bias the ion beam toward a set angle. Therefore, the normalization routine normalizes the voltage applied to the scanning plate 80, and as a result, the intensity of the electric field between the scanning plates 80 is normalized. One advantage of the normalization routine is that the unnormalized waveform contains information on how far and how fast the ion beam is scanned on the wafer plane, while the normalized waveform retains only information related to the relative scan rate and distance. Both the scan rate and the distance are linearly proportional to the amount of ion beam. Therefore, if the denormalized waveform is stored and then used to create a new method of ion beam with different energies, it may not be at the correct distance or at the correct rate. Scan the ion beam. In eliminating the dependence of the optimized scan waveform on the energy of the ion beam, the normalization routine produces a way to see the energy changes at a glance. Figure 4 is a plot of positional force of the beam current in the plane of the wafer showing the scanned ion beam profile before and after waveform correction; the dashed line represents the edge of the wafer and the curve 300 represents the uncorrected ion beam profile' Curve 302 represents a corrected ion beam profile after homogenization optimization. 16 The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm). 1286775 A7 _B7__ V. Description of the Invention () The preferred embodiment of the present invention has been described in detail herein, and those skilled in the art should It is apparent that various changes and modifications can be made without departing from the scope of the invention as defined by the scope of the invention. (Please read the notes on the back and fill out this page)
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17 本紙張尺度適用中國國家標準（CNS)A4規格mo X 297公釐）17 The paper size applies to the Chinese National Standard (CNS) A4 specification mo X 297 mm)