CN105336641A - Weight calibration method of CMP end-point detection system - Google Patents

Weight calibration method of CMP end-point detection system Download PDF

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CN105336641A
CN105336641A CN 201410280249 CN201410280249A CN105336641A CN 105336641 A CN105336641 A CN 105336641A CN 201410280249 CN201410280249 CN 201410280249 CN 201410280249 A CN201410280249 A CN 201410280249A CN 105336641 A CN105336641 A CN 105336641A
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calibration
difference
factor
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CN105336641B (en )
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张芳余
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中芯国际集成电路制造(上海)有限公司
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Abstract

The invention provides a weight calibration method of a CMP end-point detection system. The method comprises: a predetermined grinding scheme is executed on a to-be-calibrated machine and a monitoring feature curve is obtained by an end-point detection system; the monitoring feature curve is calibrated preliminarily to obtain a preliminary calibration parameter; and one or more preliminary calibration parameters are processed by weighted calibration to obtain one or more final calibration parameters. The weighted calibration content contains increasing a machine difference calibration factor F1, wherein the F1 is obtained by dividing a machine-difference-based process thickness difference value by a preliminary-calibration-parameter-change-based process thickness changing quantity. In addition, the weighted calibration also includes increasing a grinding material difference calibration factor F2 and an additional calibration factor F3 based on experience or other causes like defects or a difference between different processes selectively.

Description

CMP终点探测系统的加权校准方法 CMP end point detection method of calibration weighting system

技术领域 FIELD

[0001] 本发明涉及化学机械研磨(CMP)工艺的终点探测技术,具体的,本发明涉及CMP终点探测系统的加权校准方法。 [0001] relates to chemical mechanical polishing (CMP) process end point detection technique of the present invention, particularly, the present invention relates to a CMP end point detection system weighting calibration method.

背景技术 Background technique

[0002] 在半导体制造工艺中,化学机械研磨(CMP)是常用的全局平坦化工艺。 [0002] In the semiconductor manufacturing process, a chemical mechanical polishing (CMP) is a common global planarization process. CMP广泛地用于平坦化硅片上的各种金属和介质材料,实现多层布线结构。 CMP widely used in various metal and silicon on the planarization dielectric material, to achieve a multilayer wiring structure. 对于一些难以被化学剂或等离子体刻蚀的金属材料,CMP是制作金属图形的重要手段,例如,在大马士革工艺中,CMP被用于研磨铜材料。 For some materials are difficult to be etched metal chemical or plasma, the CMP is an important method to prepare a metal pattern, for example, in the damascene process, the CMP is used for polishing a copper material.

[0003] CMP工艺控制的一个关键技术,是如何确定研磨终点。 [0003] A key technique CMP process control, it is how to determine the polishing end point. 需要使用恰当的终点探测(End-Point Detect1n, EPD)技术来精确地监测工艺的进程,并及时地停止研磨以减小对下方材料的过研磨。 We need to use the appropriate end point detection (End-Point Detect1n, EPD) process technology to accurately monitor the process, and the polishing is stopped in a timely manner to reduce excessive polishing material below.

[0004] 一种传统的CMP系统使用挡控片研磨速率来评估产品片的抛光时间,以此来确定CMP的终点时间。 [0004] A conventional CMP system using polishing stopper rate control wafer polishing time to evaluate the product sheet, in order to determine the end time of the CMP. 这是一种比较粗糙的控制技术。 This is a relatively coarse control. 较先进的终点检测系统通过检测表征被研磨材料层所剩厚度的信号,来确定研磨终点。 More advanced end-point detection system is the thickness of the abrasive layer remaining signal characterized by detecting, to determine the polishing end point.

[0005] 一种类型的终点检测是基于信号强度的终点检测,其原理为:获取表征被研磨层所剩厚度的监控信号,当信号强度越过阈值时,则判断达到了研磨终点。 [0005] One type of endpoint detection is endpoint detection signal intensity based on the principle of: acquiring remaining characterizing abrasive layer thickness monitoring signals, when the signal strength crosses a threshold value, it is determined to reach the polishing end point. 例如,业界使用的一种间隔扫描(iScan)方案(典型的探测曲线如图1所示),通过电磁感应原理来获得与金属层厚度相关的电信号,由此来控制研磨工艺的终点。 For example, one scan interval used in the industry (the iScan) program (typically detect curve shown in FIG. 1), to obtain an electric signal related to the thickness of the metal layer by electromagnetic induction, thereby controlling the end of the grinding process.

[0006]另一种类型的终点检测是基于窗口探测的终点检测,其通过抓取监测曲线中较为明显的变化(揭示出被研磨材料层的过渡)来确定研磨终点。 [0006] Another type of end-point detection is based on detecting the end point detection window, by monitoring the gripping curve changes significantly (revealed transition material layer to be polished) to determine the polishing end point. 例如,业界使用的一种全扫描(FullScan)方案(典型的探测曲线如图2所示),通过用扫描光束对晶片表面进行扫描,同时利用传感器监测经晶片表面反射的光强度,由于金属层与阻挡层的反射率不同,因此可以根据反射强度来控制研磨工艺的终点。 For example, one full scan used in the industry (FULLSCAN) program (typically detect curve shown in Figure 2), by scanning the wafer surface with a scanning light beam, while the use of monitoring the intensity of light reflected by the surface of the sensor chip, since the metal layer with different reflectivities barrier layer, it is possible to control the end of the grinding process according to the reflection intensity. 具体来说,当金属层被研磨掉一部分,被研磨材料的厚度出现变化时,光反射信号开始发生变化,当被研磨层被研磨完后,反射信号变化趋缓。 Specifically, when a portion of the metal layer is polished away, a thickness of the abrasive material changes occur, the reflected light signal begins to change when the polishing layer is polished after being reflected signal changes to slow down. 因此,通过捕获光反射信号的两次明显变化,即可判定化学机械研磨终点。 Thus, significant changes in the light reflected by two capturing signal, a chemical mechanical polishing end point can be determined.

[0007] 现有技术对每个机台均采用标准校准方法。 [0007] The prior art method of calibration standards are used for each machine. 然而,机台间的性能总是存在差异,同时由于CMP所用研磨材料(研磨液,研磨垫等)的不同批次间的一些细微差别也会影响EPD检测系统的监控的准确性。 However, the performance differences between the machines are always present, and because some minor differences between different batches of abrasive material (polishing liquid, polishing pads, etc.) will also affect the accuracy of monitoring of CMP EPD detection system used. 另外,某些CMP工艺由于固有的一些缺陷,在探测出终点时并未完全达到预期效果,需要人为引入过研磨。 Further, some of the CMP process due to some inherent defects detected at the end does not fully achieve the desired effects, introduced artificially by grinding. 因此,需要一种更为准确高效的校准方法。 Accordingly, a need for a more accurate and efficient calibration method.

发明内容 SUMMARY

[0008] 本发明提出一种CMP机台的终点探测系统的探测方法。 [0008] The present invention provides a method of detecting a CMP end point detection system of the machine. 本发明首先对待校准机台给出的监控特征曲线进行初步校准,获得初步校准参数(可采取标准的校准流程对Ero系统进行初步校准;或可基于标准机台给出的标准特征曲线进行初步校准,以使得监控特征曲线和标准特征曲线匹配)。 The present invention first treatment machine monitor calibration characteristic curves given preliminary calibration parameters to obtain initial calibration (standard calibration procedure can be taken for preliminary calibration Ero system; standard features or based on a standard machine may be given a preliminary calibration curve , so that the characteristic curve and the standard monitor characteristic curve fitting). 然后,本发明对一个或多个初步校准参数进行加权校准。 Then, the present invention is one or more preliminary calibration parameters are weighted calibration. 在基于窗口探测的终点探测系统中,本发明对增益Gain进行加权校准。 At the end of the detection window based detection system, the present invention is weighted gain Gain calibration. 在基于信号强度的终点探测系统中,本发明对增益Gain和补偿Offset均可进行加权校准。 At the end of the detection system based on signal strength, the present invention is to compensate the Gain and Offset calibration can be weighted.

[0009] 本发明的加权校准考虑一个或多个加权因子:机台差异校准因子F1,研磨材料差异校准因子F2,基于经验或其它因素(如缺陷,不同制程间差异)的附加校准因子F3。 [0009] weighting the calibration of the present invention contemplate one or more weighting factors: the machine difference calibration factor F1, the abrasive difference calibration factor F2 of, based on empirical or other factors (e.g., defects, between different processes difference) an additional calibration factor F3. 其中,根据实际需要,校准因子F2和F3是可选项。 Wherein, according to actual needs, the calibration factor F2 and F3 are optional. 因此,根据本发明,加权校准参数=初步校准参数+F1+F2 (可选)+F3 (可选)。 Thus, according to the present invention, weighting the preliminary calibration parameters = parameter calibration + F1 + F2 (optional) + F3 (optional).

[0010] 根据本发明的一个方面,提出一种CMP机台的终点探测系统的校准方法,包括:在待校准的机台上执行预定研磨方案,并通过其终点探测系统获得监控特征曲线;初步校准所述监控特征曲线,以获得初步校准参数;以及加权校准一个或多个初步校准参数,以获得一个或多个最终校准参数,所述加权校准包括:向初步校准参数增加机台差异校准因子F1,其中F1 =(基于机台差异的工艺厚度差值)/(基于初步校准参数变化的工艺厚度变化量)Ο [0010] In accordance with one aspect of the present invention, a method of calibrating a CMP end point detection system of the machine, comprising: performing predetermined programs grinding machine table to be calibrated, and a characteristic curve obtained by monitoring its endpoint detection system; Initial calibrating the monitoring characteristic curve, to obtain a preliminary calibration parameters; and calibrating the one or more weighted preliminary calibration parameters, to obtain one or more final calibration parameters, the weighting calibration comprising: a calibration factor to increase the difference in machine preliminary calibration parameters F1, where F1 = (thickness based on a difference process machine difference) / (thickness variation process is based on the preliminary calibration parameters) o

[0011] 根据本发明的一个方面,所述加权校准还包括:向初步校准参数增加研磨材料差异校准因子F2,其中F2 =(基于研磨材料差异的工艺厚度差值)/(基于初步校准参数变化的工艺厚度变化量)。 [0011] In accordance with one aspect of the present invention, the calibration weighting further comprising: abrasive material to increase the initial difference between the calibration factor calibration parameters F2, where F2 = (thickness of the polishing process based on the difference of the difference in material) / (preliminary calibration parameters based on process thickness variation).

[0012] 根据本发明的一个方面,所述加权校准还包括:向初步校准参数增加基于以下因素中的一项或多项的附加校准因子F3:经验;缺陷;以及不同制程间差异。 [0012] In accordance with one aspect of the present invention, the calibration weighting further comprising: based on an increase in one or more of the following factors additional calibration factor F3 of the preliminary calibration parameters: Experience; defects; and differences between different processes.

[0013] 根据本发明的一个方面,所述附加校准因子F3的取值为:0 - 2。 [0013] In accordance with one aspect of the present invention, the additional value of the calibration factor F3: 0--2.

[0014] 根据本发明的一个方面,所述附加校准因子F3引入一定量的过研磨。 [0014] In accordance with one aspect of the present invention, the additional calibration factor F3 is introduced through a certain amount of polishing.

[0015] 根据本发明的一个方面,所述终点探测系统是基于窗口探测的终点探测系统。 [0015] In accordance with one aspect of the present invention, the end-point detection system is the end of probe-based detection system window.

[0016] 根据本发明的一个方面,加权校准一个或多个初步校准参数包括:加权校准增益值。 [0016] In accordance with one aspect of the invention, one or more calibration weighting preliminary calibration parameters comprising: a weighting calibration gain value.

[0017] 根据本发明的一个方面,所述终点探测系统是基于信号强度的终点探测系统。 [0017] In accordance with one aspect of the present invention, the end-point detection system is an endpoint detection system based on signal strength.

[0018] 根据本发明的一个方面,加权校准一个或多个初步校准参数包括:加权校准增益值;以及加权校准补偿值。 [0018] In accordance with one aspect of the invention, one or more calibration weighting preliminary calibration parameters comprising: calibration gain weighting value; and a weighting calibration offset value.

[0019] 根据本发明的一个方面,初步校准所述监控特征曲线的步骤包括:基于标准的校准流程对所述监控特征曲线进行校准。 Step [0019] In accordance with one aspect of the present invention, a preliminary calibration curve of the characteristic monitor comprising: calibrating the monitoring of the characteristic curve based on a standard calibration procedure.

[0020] 根据本发明的一个方面,初步校准所述监控特征曲线的步骤包括:在标准机台上执行预定研磨方案,并通过其终点探测系统获得标准特征曲线;以及基于标准特征曲线来初步校准所述监控特征曲线,以获得初步校准参数,所述初步校准参数使所述监控特征曲线匹配所述标准特征曲线。 Step [0020] In accordance with one aspect of the present invention, a preliminary calibration curve of the characteristic monitor comprising: performing a standard grinding machine table a predetermined scheme, and obtain a standard characteristic curve which endpoint detection system; and wherein based on the standard curve preliminary calibration monitoring the characteristic curve, to obtain a preliminary calibration parameters, the preliminary calibration parameters to monitor the characteristic curve matching the standard characteristic curve.

[0021] 根据本发明的一个方面,通过以下方式获得基于初步校准参数变化的工艺厚度变化量:基于初步校准参数设置终点探测系统;在待校准的机台上执行预定研磨方案;在终点探测系统探测到终点并停止研磨后,测量第一工艺厚度;调整初步校准参数一个单位:基于调整后的初步校准参数设置终点探测系统;在待校准的机台上执行预定研磨方案;在终点探测系统探测到终点并停止研磨后,测量第二工艺厚度;比较第一工艺厚度和第二工艺厚度,获得基于初步校准参数变化的工艺厚度变化量。 [0021] In accordance with one aspect of the present invention, is obtained by the process based on the thickness change amount of the preliminary calibration parameters: a preliminary calibration parameters based on endpoint detection system; executing predetermined programs grinding machine table to be calibrated; in end point detection system stop polishing end point is detected and measured after the first process thickness; unit adjusting a preliminary calibration parameters: initial calibration setting based on the adjusted parameter endpoint detection system; performing predetermined programs grinding machine table to be calibrated; detect endpoint detection system to the end and stops after polishing, a thickness measurement second process; Comparative process a first thickness and a second thickness process to obtain the thickness variations of the process based on the preliminary calibration parameters.

[0022] 根据本发明的一个方面,所述基于机台差异的工艺厚度差值通过大宗产品的工艺厚度的统计分析获得。 [0022] In accordance with one aspect of the invention, the difference between the thickness of the process based on the difference machine through statistical process analysis of the product bulk thickness is obtained.

[0023] 根据本发明的一个方面,所述基于研磨材料差异的工艺厚度差值通过大宗产品的工艺厚度的统计分析获得。 [0023] In accordance with one aspect of the invention, the thickness difference based on a difference process by the abrasive bulk thickness statistical process analysis of the product obtained.

[0024] 本发明适用于进一步校准业界的各种终点探测系统,包括但不限于,基于窗口探测的终点探测系统(例如全扫描系统),基于信号强度的终点探测系统(例如间隔扫描系统,基于电流力矩的终点探测系统等)。 [0024] The present invention is applicable to a variety of endpoint detection system further calibrate the industry, including but not limited to, end point detection system (e.g., full scan system) based on the detection window, the end point detection system based on signal strength (e.g., interval scanning system, based on torque current end point detection systems, etc.).

附图说明 BRIEF DESCRIPTION

[0025] 为了进一步阐明本发明的各实施例的以上和其他优点和特征,将参考附图来呈现本发明的各实施例的更具体的描述。 [0025] To further clarify the above and other advantages and features of various embodiments of the present invention, with reference to the accompanying drawings presented more particular description of various embodiments of the present invention. 可以理解,这些附图只描绘本发明的典型实施例,因此将不被认为是对其范围的限制。 It is appreciated that these drawings depict only exemplary embodiments of the present invention is therefore not to be considered limiting of its scope.

[0026] 图1示出根据现有技术的基于信号强度的终点探测系统的监控特征曲线。 [0026] Figure 1 shows a monitoring system wherein the end point detection based on the signal intensity curve in accordance with the prior art.

[0027] 图2示出根据现有技术的基于窗口探测的终点探测系统的监控特征曲线。 [0027] Figure 2 shows a monitoring system wherein the end point detection window detection based on the curve according to the prior art.

[0028] 图3示出根据本发明的实施例的终点探测系统校准方法的流程图。 [0028] FIG. 3 shows a flowchart of the calibration method of endpoint detection system of the embodiment of the present invention.

[0029] 图4示出根据本发明的实施例,一种对监控特征曲线进行初步校准的方法的流程图。 [0029] FIG. 4 shows a flowchart of a method according to an embodiment of the present invention, a method of monitoring the preliminary calibration characteristic curves.

[0030] 图5示出根据本发明的实施例,对基于信号强度的终点探测系统进行加权校准的方法的流程图。 [0030] FIG. 5 shows an embodiment of the present invention, a flowchart of a method for calibrating the weighting endpoint detection system based on signal strength.

[0031] 图6示出根据本发明的实施例,对基于窗口探测的终点探测系统进行加权校准的方法的流程图。 [0031] FIG. 6 shows an embodiment of the present invention, a flowchart of a method for calibrating the weighting endpoint detection system based on the detection window.

[0032] 图7示出根据本发明的实施例,为Gain值/Offset值计算校准因子F1的方法的流程图。 [0032] FIG 7 illustrates a flowchart according to an embodiment of the present invention, the method of calculating the calibration factor F1 is the Gain / Offset value.

[0033] 图8示出根据本发明的实施例,为Gain值/Offset值计算校准因子F2的方法的流程图。 [0033] FIG. 8 illustrates a flowchart according to an embodiment of the present invention, the method of calculating the calibration factor F2 of the Gain / Offset value.

具体实施方式 detailed description

[0034] 下面的详细描述参照附图,附图以例示方式示出可实践所要求保护的主题的特定实施例。 [0034] The following detailed description with reference to the accompanying drawings that illustrate shows an embodiment in practicing the claimed subject matter to the specific embodiments. 充分详细地描述这些实施例,以使本领域技术人员将该主题投入实践。 These embodiments are described in sufficient detail to enable those skilled in the art into practice the subject matter. 要理解,可修改各公开实施例中的各个要素的位置或配置而不脱离所要求保护的主题的精神和范围。 Be understood that various modifications of the various elements of the disclosed embodiment of the position or configuration without departing from the scope of the claimed subject matter. 因此,下面的详细描述不具有限定意义,并且主题的范围仅由适当解释的所附权利要求连同这些权利要求被授权的等效物的全部范围来定义。 Therefore, the following detailed description is not in a limiting sense, and the scope of claimed subject matter is defined only by the appended claims appropriately interpreted along with the full scope of these claims is authorized to define equivalents.

[0035] 图3示出根据本发明的根据本发明的实施例的终点探测系统校准方法的流程图。 [0035] FIG. 3 shows a flowchart of the calibration method of endpoint detection system of the embodiment of the present invention in accordance with the present invention. 本发明的方法开始于步骤301,在待校准机台(下文称第一机台)上执行预定研磨方案,并采取预定的终点探测算法,从而获得初步的监控特征曲线(此时不进行信号放大和补偿,即Offset = 0,Gain = 1)。 The method of the present invention begins at step 301, the program executed on the predetermined milling machine to be calibrated (hereinafter referred to as a first machine), and take a predetermined end point detection algorithm, thereby obtaining a preliminary monitoring of the characteristic curve (in this case signal amplification is not performed and compensation, i.e., Offset = 0, Gain = 1). 作为示例,可采用固定的研磨方案和固定的终点探测算法来研磨Ιμπι厚的铜挡控片(copper dummy) 0在本申请的各实施例中,监控特征曲线可以是,例如,直接或间接地表征出被研磨的材料层剩余厚度随时间变化的曲线。 As an example, the program can be fixed abrasive and fixed to the polishing endpoint detection algorithm Ιμπι control thick copper sheet stopper (copper dummy) 0 In the various embodiments of the present application, the characteristic curve may be monitored, for example, directly or indirectly, Characterization of the remaining layer of material to be polished thickness versus time curve. 通过厚度随时间的变化率可以确定研磨速率,研磨速率的显著变化揭示出材料层的过渡,进而揭示适当的研磨终点。 The polishing rate may be determined by the rate of change over time of the thickness, a significant change in the polishing rate transition material layer revealed, thus revealing the appropriate polishing end point. 监控特征曲线也可以是揭示出材料过渡的任何其他特征曲线。 Characteristic curve may be monitored to reveal any other material of transition characteristic curve. 例如,由于不同材料对光有不同的反射系数,可以获取表征反射光谱的特征曲线,并在反射光谱揭示出干涉现象时(由于两种材料界面处的光干涉所致),确定研磨终点。 For example, since different materials have different light reflection coefficients, the characteristic curve may be obtained characterizing the reflection spectrum, and revealed when interference phenomena (due to the interference of light caused by the material at the two interfaces) in the reflection spectrum, the polishing end point is determined. 监控特征曲线不限于光学方案。 Monitoring the characteristic curve is not limited to an optical scheme. 例如,在基于电机电流的终点探测中,监控特征曲线可以是磨头电机的电流量随时间变化的曲线。 For example, at the end of the motor current based on the detection, the monitoring current characteristic curve may be a grinding machine versus time curve. 总之,本发明适用于本领域所采用的各种用于探测研磨终点的监控特征曲线。 In summary, the present invention is applicable to a variety of monitoring a characteristic curve used in the art for detecting the polishing end point. 因此,本发明不应受到监控特征曲线的具体类型的限制。 Accordingly, the present invention should not be a particular type of monitoring limit characteristic curve.

[0036] 随后,在步骤302,对监控特征曲线进行初步校准,以获得初步校准参数。 [0036] Subsequently, at step 302, the monitoring preliminary calibration characteristic curve, to obtain a preliminary calibration parameters. 可采用多种方式来进行初步校准步骤302。 It can be performed in various ways preliminary calibration step 302. 例如,可采取业界已经使用的各种标准的校准流程来进行初步校准。 For example, you can take a variety of industry standard calibration procedure has been used to perform a preliminary calibration. 根据本发明的一种示例性初步校准方式被示于图4:在步骤401,在标准机台上执行与前述步骤301相同的预定研磨方案和终点探测算法,从而获得标准特征曲线;之后,在步骤402,基于标准特征曲线来对第一机台的监控特征曲线进行初步校准,得到初步校准的监控特征曲线,以及初步校准参数Calibrated Offset和Calibrated Gain,这两个初步校准参数可使得第一机台的监控特征曲线匹配于标准机台的标准特征曲线。 According to an exemplary embodiment of the present invention, a preliminary calibration is shown in FIG. 4: In step 401, a standard machine table 301 perform the same steps with the predetermined program and the polishing endpoint detection algorithm, thereby obtaining a standard characteristic curve; Thereafter, step 402, based on the standard characteristic curve to the first characteristic curve to monitor the machine's initial calibration, monitoring preliminary calibration characteristic curve, and the preliminary calibration parameters and calibrated Offset calibrated Gain, these two parameters can be calibrated such that the first preliminary dryer monitoring characteristic matched to a standard curve table characteristic curve of a standard machine. 例如,对于基于信号强度的终点探测系统,可通过以下算法进行初步校准: For example, for endpoint detection system based on signal strength can be made by preliminary calibration the following algorithm:

[0037] Calibrated Gain =(监控特征曲线的最大值一监控特征曲线的最小值)/ (标准特征曲线的最大值一标准特征曲线的最小值) [0037] Calibrated Gain = (MIN MAX monitoring a characteristic curve of the characteristic curve of the monitor) / (maximum value of a minimum standard characteristic curve of a standard characteristic curve)

[0038] Calibrated Offset =(监控特征曲线的最小值一标准特征曲线的最小值)^Calibrated Gain [0038] Calibrated Offset = (minimum monitoring a characteristic curve of a standard characteristic curve minimum) ^ Calibrated Gain

[0039] 可基于初步校准的Calibrated Gain和Calibrate Offset来初步调整监控特征曲线。 [0039] The initial adjustment may be based on monitoring of the characteristic curve and the preliminary calibration Calibrated Gain Calibrate Offset. 具体而言,对于初始的监控特征曲线(初始未作信号放大)应用增益CalibratedGain,从而调整信号幅值;同时,对初始的监控特征曲线(初始未作信号补偿)施加偏移量Calibrate Offset,使该曲线在坐标空间内适当上下平移以加入信号补偿量。 Specifically, the initial monitoring of the characteristic curve (not initially as signal amplification) applies a gain CalibratedGain, to adjust the signal amplitude; the same time, applying the initial offset Calibrate Offset monitor characteristic curve (not for initial compensation signal), so that the curve within a coordinate space is added to the appropriate vertical translational compensation amount signal.

[0040] 需注意,以上初步校准算法仅为示例。 [0040] It should be noted, the initial calibration algorithm above is merely exemplary. 实际上,可采用业界已经使用的任何使得监控特征曲线匹配标准特征曲线的算法。 Indeed, the industry has employed the use of any such monitoring characteristic curve matching algorithm standard characteristic curve.

[0041] 回到图3,在获得初步校准参数Calibrated Offset和Calibrated Gain后,可对一个或多个初步校准参数进行加权校准以获得最终校准参数。 [0041] Returning to Figure 3, after obtaining a preliminary calibration parameters and Calibrated Offset Calibrated Gain, calibration may be weighted for one or more calibration parameters to obtain the final preliminary calibration parameters. 加权校准的内容包括:在步骤303,对于初步校准参数,增加机台差异校准因子F1。 Calibration weight content comprises: at step 303, for the preliminary calibration parameters, increasing the machine difference calibration factor F1. 该校准因子F1校准由于第一机台的性能差异所导致的第一机台工艺厚度和目标厚度(标准机台加工厚度)的差异。 Target thickness and the thickness difference (thickness standard machine processing) of the calibration correction factor F1 since the performance difference caused by the first machine to the first machine process. F1的计算方法将稍后在图7中描述。 The method of calculation will be described later in F1 in FIG.

[0042] 可选地,加权校准的内容还包括:在步骤304,对于初步校准参数,增加研磨材料差异校准因子F2和/或附加校准因子F3。 [0042] Alternatively, the calibration weight content further comprises: at step 304, for the preliminary calibration parameters, increasing abrasive difference calibration factor F2 and / or additional calibration factor F3. 研磨材料差异校准因子F2校准由于第一机台所用的研磨材料的差异性所导致的第一机台工艺厚度和目标厚度的差异。 Differences abrasive difference F2 calibration since the first calibration factors process machines target thickness and thickness differences of the first abrasive machine used caused. F2的计算方法将稍后在图8中描述。 The method of calculation F2 will be described later in FIG. 8. 附加校准因子F3基于经验、缺陷、不同制程间差异等因素,根据生产实践中的特别需要而对监控特征曲线进一步地人为进行调整。 Additional factors based on empirical calibration factor F3, defects, differences among different processes, according to the production needs in practice, particularly for monitoring the characteristic curve is further adjusted artificially. 例如,某些现有的CMP工艺由于其固有的不足而不能很好地研磨到期望的厚度,此时通过人为加入过研磨(即调整监控特征曲线,使终点探测延后),可以对这种情况加以补偿。 For example, some conventional CMP process due to its inherent deficiencies can not be well polished to a desired thickness, this time by artificially added by grinding (i.e., adjusting the characteristic curve monitoring the endpoint detection delay), which may situation to compensate.

[0043] 根据本发明的实施例,校准因子F2和F3是可选的校准因子。 [0043] According to an embodiment of the present invention, the calibration factor F2 and F3 are optional calibration factor. 对于F2而言,如果一直使用相同批次的研磨材料,或者研磨材料的批次间差异极小,则可基本忽略材料差异性,研磨材料差异校准因子F2 = 0。 For F2, the batch to batch, if the abrasive material has been used the same batch of abrasive material, or a little difference, the difference can be substantially ignored material, abrasive difference calibration factor F2 = 0. 同样,如果CMP工艺充分满足工艺需求,则不需人为补偿,附加校准因子F3 = 0。 Similarly, if the CMP process is sufficient to meet process requirements, without human is compensated, additional calibration factor F3 = 0. 另一方面,机台间差异则几乎是不可避免的,因为多台CMP设备在使用中不可避免地会有性能差异,因此机台差异校准因子F1是本发明的必要校准项。 On the other hand, the difference between the machines is almost inevitable, because multiple CMP apparatus, in use, there is inevitably difference in performance, so the machine difference calibration factor is necessary to calibrate the F1 key to the present invention. 因此,根据本发明的实施例,加权校准参数=初步校准参数+F1+F2(可选)+F3(可选)。 Thus, according to an embodiment of the present invention, weighting the preliminary calibration parameters = parameter calibration + F1 + F2 (optional) + F3 (optional).

[0044] 如前所述,图3的步骤302中,获得了初步校准参数Calibrated Offset和Calibrated Gain。 [0044] As described above, step 302 in FIG. 3, to obtain a preliminary calibration parameters and Calibrated Offset Calibrated Gain. 但这两个初步校准参数并非都要进一步加权校准。 But two preliminary calibration parameters are not to be further weighted calibration. 对于基于信号强度的终点探测系统,增益Gain和补偿Offset都会影响终点探测系统对工艺终点的触发,因此,优选地,Calibrated Offset和Calibrated Gain这两个参数分别都要加权校准,如图5中步骤501-502-503所示。 Effects for endpoint detection system triggers the end of the process based on the signal strength of the endpoint detection system, the Gain and Offset compensation will, therefore, preferably, Calibrated Gain and Offset Calibrated these two parameters are weighted to be calibrated, in step 5 in FIG. As shown 501-502-503. 另一方面,对于基于窗口探测的终点探测系统,Offset值对于特征信号捕捉不起实际作用,起作用的是Gain值,因此,可仅对Calibrated Gain进行加权校准,如图6中步骤601-602所示。 On the other hand, for system-based endpoint detection window detection, signal acquisition Offset value for the feature can not afford practical effect, acting Gain value is, therefore, only be Calibrated weights Gain calibration steps 601-602 in FIG. 6 Fig.

[0045] 图7示出根据本发明的实施例,为Gain值/Offset值计算机台差异校准因子F1的流程图。 [0045] FIG. 7 shows an embodiment of the present invention, a flowchart of a computer station difference calibration factor F1 is the Gain / Offset value. 方法开始于701,计算基于第一机台的机台差异所致的工艺厚度差异值al。 The method begins at 701, the process calculates the difference in thickness of the first difference value al machines due to machine based. al可通过对大宗产品的工艺厚度进行统计分析来获得。 al statistical analysis may be performed on the process to obtain the thickness of the bulk product. 这样的统计分析可采用工艺服务软件(例如odyssey)来获得,也可以由人工或计算机系统统计获得。 Such processes may employ statistical analysis software and services (e.g. Odyssey) obtained may be manually or computer system statistics obtained. 然后,在步骤702,使Calibrated Gain值(Calibrated Offset值)增加一个单位(即数值+1)。 Then, at step 702, so Calibrated Gain value (Calibrated Offset value) increased by one unit (i.e., the value +1). 之后,在步骤703,基于调整后的Calibrated Gain值(Calibrated Offset值),运行一次CMP工艺,获得工艺厚度的增量bl。 Thereafter, in step 703, based on the adjusted value Calibrated Gain (Calibrated Offset value), run a CMP process, the thickness of the process to increment by bl. 最后,在步骤704,计算校准因子F1,F1 = al/bl。 Finally, at step 704, calculate the calibration factor F1, F1 = al / bl.

[0046] 图8示出根据本发明的实施例,为Gain值/Offset值计算机台差异校准因子F2的流程图。 [0046] FIG. 8 shows an embodiment of the present invention, the value of Gain / Offset value flowchart computer station difference calibration factor F2. 方法开始于801,计算基于第一机台的研磨材料差异所致的工艺厚度差异值a2。 The method begins at 801, the difference value calculation process a2 thickness difference abrasive machine based on the first induced. a2同样可通过对大宗产品的工艺厚度进行统计分析来获得。 a2 likewise be analyzed by statistical process to obtain the thickness of the bulk product. 然后,在步骤802,使Cal ibratedGain值(Calibrated Offset值)增加一个单位(即数值+1)。 Then, at step 802, so Cal ibratedGain value (Calibrated Offset value) increased by one unit (i.e., the value +1). 之后,在步骤803,基于调整后的Calibrated Gain值(Calibrated Offset值),运行一次CMP工艺,获得工艺厚度的增量b2。 Thereafter, in step 803, based on the adjusted value Calibrated Gain (Calibrated Offset value), a CMP process is running, the process increments to obtain a thickness b2. 最后,在步骤804,计算校准因子F2,F2 = a2/b2。 Finally, at step 804, calculate the calibration factor F2, F2 = a2 / b2.

[0047] 以上描述了本发明的若干实施例。 [0047] The above described several embodiments of the present invention. 然而,本发明可具体化为其它具体形式而不背离其精神或本质特征。 However, the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. 所描述的实施例在所有方面都应被认为仅是说明性而非限制性的。 The described embodiments are to be considered in all respects only as illustrative and not restrictive. 例如,在图7的步骤702中,为Gain值增加一个单位,但本领域技术人员当可理解,Gain值可增加任意值,只要在获得工艺厚度增量bl后,再除以这个任意值即可。 For example, in step 702 of FIG. 7, a unit increase in value as Gain, as those skilled in the art will be appreciated, the Gain can be increased to any value, as long as the thickness increase process for obtaining BL, i.e., divided by the arbitrary value can. 因此,本发明的范围由所附权利要求书而非前述描述限定。 Accordingly, the scope of the invention being indicated by the appended claims rather than the foregoing description define. 落入权利要求书的等效方案的含义和范围内的所有改变被权利要求书的范围所涵盖。 All changes which come within the scope of the claims fall within the meaning and range of equivalency of the claims are covered.

Claims (14)

  1. 1.一种CMP机台的终点探测系统的校准方法,包括: 在待校准的机台上执行预定研磨方案,并通过其终点探测系统获得监控特征曲线; 初步校准所述监控特征曲线,以获得初步校准参数;以及加权校准一个或多个初步校准参数,以获得一个或多个最终校准参数, 所述加权校准包括:向初步校准参数增加机台差异校准因子F1, 其中Fl =(基于机台差异的工艺厚度差值)/(基于初步校准参数变化的工艺厚度变化量)。 CLAIMS 1. A method of calibrating a CMP end point detection system of the machine, comprising: performing calibration to be placed on the table a predetermined polishing scheme, and a characteristic curve obtained by monitoring its endpoint detection system; wherein the monitoring a preliminary calibration curve to obtain preliminary calibration parameters; and calibrating the one or more weighted preliminary calibration parameters, to obtain one or more final calibration parameters, the weighting calibration comprises: increasing the machine difference calibration factor F1 to preliminary calibration parameters, wherein Fl = (based machine process difference in thickness difference) / (thickness variation amount of process parameters based on preliminary calibration).
  2. 2.如权利要求1所述的校准方法,其特征在于,所述加权校准还包括:向初步校准参数增加研磨材料差异校准因子F2,其中F2 =(基于研磨材料差异的工艺厚度差值)/(基于初步校准参数变化的工艺厚度变化量)。 2. The calibration method according to claim 1, wherein said calibration weighting further comprising: abrasive material to increase the initial difference between the calibration factor calibration parameters F2, where F2 = (thickness of the polishing process based on the difference of the difference in material) / (process based on the thickness change amount of the preliminary calibration parameters).
  3. 3.如权利要求1或2所述的方法,其特征在于,所述加权校准还包括:向初步校准参数增加基于以下因素中的一项或多项的附加校准因子F3: 经验; 缺陷;以及不同制程间差异。 3. The method according to claim 1, wherein said calibration weighting further comprising: based on an increase in one or more of the following factors additional calibration factor F3 of the preliminary calibration parameters: Experience; defects; and differences between different processes.
  4. 4.如权利要求3所述的方法,其特征在于,所述附加校准因子F3的取值为:0 - 2。 4. The method according to claim 3, characterized in that the additional value of the calibration factor F3: 0--2.
  5. 5.如权利要求3所述的方法,其特征在于,所述附加校准因子F3引入一定量的过研磨。 5. The method according to claim 3, characterized in that, after the polishing introducing an amount of the additional calibration factor F3.
  6. 6.如权利要求1所述的方法,其特征在于,所述终点探测系统是基于窗口探测的终点探测系统。 6. The method according to claim 1, wherein the endpoint detection system is an endpoint detection system based on the detection window.
  7. 7.如权利要求6所述的方法,其特征在于,加权校准一个或多个初步校准参数包括:力口权校准增益值。 7. The method according to claim 6, wherein the one or more calibration weighting preliminary calibration parameters comprising: a power calibration gain value of the right port.
  8. 8.如权利要求1所述的方法,其特征在于,所述终点探测系统是基于信号强度的终点探测系统。 8. The method according to claim 1, wherein the endpoint detection system is an endpoint detection system based on signal strength.
  9. 9.如权利要求8所述的方法,其特征在于,加权校准一个或多个初步校准参数包括: 加权校准增益值;以及加权校准补偿值。 9. The method according to claim 8, wherein the one or more calibration weighting preliminary calibration parameters comprising: calibration gain weighting value; and a weighting calibration offset value.
  10. 10.如权利要求1所述的方法,其特征在于,初步校准所述监控特征曲线的步骤包括: 基于标准的校准流程对所述监控特征曲线进行校准。 10. The method according to claim 1, wherein the step of preliminary calibration of the characteristic curve of the monitor comprising: calibrating the monitoring of the characteristic curve based on a standard calibration procedure.
  11. 11.如权利要求1所述的方法,其特征在于,初步校准所述监控特征曲线的步骤包括: 在标准机台上执行预定研磨方案,并通过其终点探测系统获得标准特征曲线;以及基于标准特征曲线来初步校准所述监控特征曲线,以获得初步校准参数,所述初步校准参数使所述监控特征曲线匹配所述标准特征曲线。 11. The method according to claim 1, wherein the step of preliminary calibration of the characteristic curve of the monitor comprising: performing predetermined programs in a standard milling machine table, and obtain a standard characteristic curve which endpoint detection system; and based on criteria wherein a preliminary calibration curve of the characteristic curve monitor, to obtain a preliminary calibration parameters, the preliminary calibration parameters to monitor the characteristic curve matching the standard characteristic curve.
  12. 12.如权利要求1所述的方法,其特征在于,通过以下方式获得基于初步校准参数变化的工艺厚度变化量: 基于初步校准参数设置终点探测系统; 在待校准的机台上执行预定研磨方案; 在终点探测系统探测到终点并停止研磨后,测量第一工艺厚度; 调整初步校准参数一个单位: 基于调整后的初步校准参数设置终点探测系统; 在待校准的机台上执行预定研磨方案; 在终点探测系统探测到终点并停止研磨后,测量第二工艺厚度; 比较第一工艺厚度和第二工艺厚度,获得基于初步校准参数变化的工艺厚度变化量。 12. The method according to claim 1, characterized in that, in the following manner based on the obtained thickness variations of the preliminary calibration parameters of the process: Based on the preliminary calibration parameters endpoint detection system; executing predetermined programs grinding machine table to be calibrated ; after the endpoint detection system to detect the end of polishing and stopped, measuring the thickness of the first process; adjust a preliminary calibration parameters unit: endpoint detection system is provided based on the preliminary calibration parameters adjusted; performing predetermined programs grinding machine table to be calibrated; after the endpoint detection system to detect the end of polishing and stopped, measuring the thickness of the second process; Comparative process a first thickness and a second thickness process to obtain the thickness variations of the process based on the preliminary calibration parameters.
  13. 13.如权利要求1所述的方法,其特征在于,所述基于机台差异的工艺厚度差值通过大宗产品的工艺厚度的统计分析获得。 13. The method according to claim 1, characterized in that the thickness of the process based on a difference machine difference obtained by statistical analysis of the process the thickness of the bulk product.
  14. 14.如权利要求2所述的方法,其特征在于,所述基于研磨材料差异的工艺厚度差值通过大宗产品的工艺厚度的统计分析获得。 14. The method according to claim 2, wherein said statistical process based on the thickness of the material thickness of the polishing process difference difference obtained by the bulk analysis of the product.
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