WO2022028077A1 - 准确获取光刻参数的方法 - Google Patents

准确获取光刻参数的方法 Download PDF

Info

Publication number
WO2022028077A1
WO2022028077A1 PCT/CN2021/097740 CN2021097740W WO2022028077A1 WO 2022028077 A1 WO2022028077 A1 WO 2022028077A1 CN 2021097740 W CN2021097740 W CN 2021097740W WO 2022028077 A1 WO2022028077 A1 WO 2022028077A1
Authority
WO
WIPO (PCT)
Prior art keywords
pattern
target
preset
lithography
line width
Prior art date
Application number
PCT/CN2021/097740
Other languages
English (en)
French (fr)
Inventor
严勋
Original Assignee
长鑫存储技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 长鑫存储技术有限公司 filed Critical 长鑫存储技术有限公司
Priority to EP21772657.9A priority Critical patent/EP3979003B1/en
Priority to US17/391,215 priority patent/US11868053B2/en
Publication of WO2022028077A1 publication Critical patent/WO2022028077A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70483—Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
    • G03F7/70491—Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring processes
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/20—Exposure; Apparatus therefor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
    • Y02P90/30—Computing systems specially adapted for manufacturing

Definitions

  • the present application relates to the field of semiconductor manufacturing, and in particular, to a method for accurately obtaining lithography parameters in a lithography process.
  • the photolithography process window refers to the range of exposure energy and focus value that can be used for production
  • the exposure condition refers to the exposure energy and focus value set during production.
  • the technical problem to be solved by the present application is to provide a method for accurately obtaining lithography parameters, which can avoid the influence of human factors on the selection of lithography parameters, improve the stability of the semiconductor process, and can greatly save production time and improve production efficiency. .
  • the present application provides a method for accurately obtaining lithography parameters, which includes the following steps:
  • the lithography parameters corresponding to the preset line width are obtained according to the Poisson curve.
  • the mask patterns consist of the same type or different types of lithographic patterns.
  • the target carrier is a semiconductor substrate coated with a photoresist layer, and the target pattern is formed on the photoresist layer.
  • the preset lithography parameter is a combination of exposure energy and focus value.
  • the target carrier is lithography to obtain
  • the preset lithography parameters are respectively changed by using the exposure energy and the focus value as variables.
  • the step of drawing a Poisson curve using the line width of the effective pattern and its corresponding preset lithography parameters as data further includes: setting the exposure energy as a fixed value, using the line width of the effective pattern as data The width and the focus value are used to draw a Poisson curve as data, or a Poisson curve is drawn by using the focus value as a fixed value and the line width of the effective graph and the exposure energy as data.
  • the method for comparing the target graphic with the standard graphic is as follows: acquiring a scanned image of the target graphic and the standard image, and performing pixel grayscale comparison on the scanned image to obtain the The similarity between the target graphic and the standard graphic, and the similarity is the evaluation value.
  • the preset value ranges from 70% to 85%.
  • the target graphic is set as an invalid graphic if the evaluation value corresponding to the target graphic is smaller than a preset value.
  • the valid graphics or the invalid graphics are marked to distinguish valid graphics from invalid graphics.
  • the line width of the target graphic is obtained before the step of comparing the target graphic with the standard graphic.
  • the line width of the effective graphic is obtained.
  • the advantage of the present application is that the standard pattern is used to screen the target pattern, which standardizes the screening process, avoids errors caused by inconsistent manual screening standards, reduces the influence of human factors on the selection of lithography parameters, and greatly improves the stability of the semiconductor process. At the same time, since manual operation is not required, the production efficiency is greatly improved.
  • FIG. 1 is a schematic diagram of steps of an embodiment of a method for accurately obtaining lithography parameters of the present application
  • 2 and 3 are the distribution diagrams of target patterns obtained by photolithography under different preset photolithography parameters using the same mask pattern as a mask;
  • Figure 4 is a set of Poisson curves drawn with the exposure energy as a fixed value, the line width of the effective graph as the ordinate, and the focus value as the abscissa;
  • Figure 5 is a set of Poisson curves drawn with a fixed focus value, the line width of the effective graph as the ordinate, and the exposure energy as the abscissa.
  • FIG. 1 is a schematic diagram of steps of an embodiment of a method for accurately acquiring lithography parameters of the present application.
  • the method for accurately obtaining lithography parameters includes the following steps:
  • Step S10 using the same mask pattern as a mask, and under different preset lithography parameters, perform lithography on the target carrier to obtain multiple target patterns.
  • the mask patterns are composed of the same type or different types of photolithography patterns.
  • the type may refer to the density of the lithographic patterns, for example, dense patterns, semi-dense patterns, and isolated patterns.
  • the mask pattern may consist of only a single type of lithography pattern, for example, only an isolated pattern, or may consist of multiple types of lithography patterns, for example, a dense pattern and a semi-dense pattern, or a Dense graphics and island graphics, or dense graphics, semi-dense graphics and island graphics, etc.
  • the advantage of the mask pattern consisting of only a single type of lithography pattern is that the complexity of subsequent operations is simplified; the advantage of the mask pattern consisting of multiple types of lithography patterns is that the obtained light
  • the lithography parameters are applicable to all pattern types on the wafer, improving the universality of lithography parameters.
  • the target carrier is a semiconductor substrate coated with a photoresist layer, and the target pattern is formed on the photoresist layer.
  • the semiconductor substrate is a silicon substrate, and the photoresist layer is formed on the silicon substrate.
  • a mask pattern is used as a mask, and the photoresist layer is exposed and developed under a first preset lithography parameter to form a first target pattern; the preset lithography parameter is changed to The second preset lithography parameters are used, and the same mask pattern is used as a mask, and the photoresist layer is exposed and developed under the second preset lithography parameters to form a second target pattern;
  • the preset lithography parameters are the third preset lithography parameters, and then the same mask pattern is used as a mask, and the photoresist layer is exposed and developed under the third preset lithography parameters to form The third target pattern; and so on, to obtain a plurality of target patterns, the lithography parameters corresponding to each target pattern are different.
  • the preset lithography parameter is a combination of exposure energy and focus value.
  • the exposure-energy matrix (Focus-Energy Matrix, FEM) test method is used for testing, which can be set in the lithography apparatus.
  • the preset lithography parameters are changed with the exposure energy and the focus value as variables respectively. Specifically, using the focus value as a fixed value and the exposure energy as a variable to change the preset lithography parameters, or using the exposure energy as a fixed value and the focus value as a variable to change the preset light engraving parameters.
  • the focus value is changed with a fixed step size in one direction, and the exposure energy is changed with another fixed step size in the other direction, and each condition corresponds to a pattern on a wafer (a small one in Figure 2 Grid), which is the condition for exposure and development.
  • FIG. 2 is a distribution diagram of target patterns obtained by lithography under different preset lithography parameters using the same mask pattern as a mask, wherein each row has the same exposure energy D, and each row has the same exposure energy D.
  • a column has the same focus value F, and each small cell represents a pattern, which corresponds to a combination of exposure energy D and focus value F.
  • the exposure energy D can be used as a fixed value, such as 40, and the focus value F can be changed in sequence with a fixed step size, and the same mask pattern can be used as a mask to form multiple target patterns; then the exposure energy D can be changed.
  • the focus value F can also be used as a fixed value
  • the exposure energy D can be changed in sequence with a fixed step size
  • the same mask pattern can be used as a mask to form multiple target patterns. Repeat.
  • the target carrier for example, a silicon wafer coated with photoresist
  • the target carrier is circular
  • null values in the distribution map eg, the area corresponding to an exposure energy of 40.0 and a focus value of -0.3.
  • Step S11 compare the target graphic with the standard graphic to obtain an evaluation value, and if the evaluation value corresponding to the target graphic is greater than or equal to a preset value, set the target graphic as an effective graphic.
  • the standard graph is a graph with an ideal shape, which can be a graph manufactured by simulating data, or can be an optimal graph manually selected after a series of tests.
  • the standard graphics include, but are not limited to, existing golden images and the like. It can be understood that the shape of the standard graphic is the desired shape of the target graphic.
  • standard patterns eg gold images
  • the standard pattern can be compared with the target pattern in the CD-SEM device to obtain an evaluation value, and the evaluation value can be recorded by the CD-SEM device or the processing system for subsequent use.
  • the reference value for the operation is typically stored in CD-SEM equipment.
  • the preset value is a preset numerical value, which is used as the evaluation standard of the evaluation value.
  • the preset value can be set according to the requirements for the quality of the target graphics. For example, if the requirements for the quality of the target graphics are high, the preset value can be set to a high value, and the requirements for the quality of the target graphics are not high. Appropriately set to a low value.
  • the evaluation value corresponding to the target graphic is greater than or equal to a preset value, it means that the difference between the target graphic and the standard graphic is within the allowable range, and the target graphic is set as a valid graphic ; If the evaluation value corresponding to the target graphic is less than the preset value, it means that the difference between the target graphic and the standard graphic is not within the allowable range, and the target graphic is set as an invalid graphic.
  • the processing system can automatically mark the valid graphics or the invalid graphics, so that the processing system can identify the two graphics data when processing the data. For example, the processing system marks only valid graphics, or only marks invalid graphics, or marks invalid graphics and valid graphics with different marks. For example, in one embodiment, the processing system automatically marks the invalid graphics with shadows. Specifically, in the distribution diagram shown in FIG. 2 , the cells corresponding to the invalid graphics are covered with shadows, and the cells corresponding to the valid graphics are covered with shadows. No overlay is made to distinguish valid graphics from invalid graphics. In other embodiments of the present application, other marking methods may also be used to distinguish valid graphics from invalid graphics.
  • the processing system automatically covers the cells corresponding to the invalid graphics with a color, for example, using a yellow overlay etc., in another embodiment of the present application, the processing system automatically uses a red border to circle the invalid graphics. It can be understood that, in other embodiments of the present application, other marks that can be identified by the system may also be used. In the present application, the processing system can automatically distinguish between valid graphics and invalid graphics, avoiding manual manual differentiation, greatly improving work efficiency, saving production time, improving accuracy, and avoiding errors.
  • the present application also enumerates a method for comparing the target pattern with the standard pattern.
  • the scanned images of the target graphic and the standard graphic are acquired.
  • the scanning pattern may be a scanning image obtained by SEM scanning. and performing pixel grayscale comparison between the scanned image of the target graphic and the scanned graphic of the standard graphic to obtain the similarity between the target graphic and the standard graphic.
  • the similarity is the evaluation value. It can be understood that, in the case that the evaluation value is the similarity, the preset value is also the similarity.
  • the range of the preset value may be 70% to 85%. If the preset value is too large, there will be too few effective graphics screened out, the subsequent drawing of Poisson curves will be inaccurate, and the product yield will be reduced; if the preset value is too small, the selected effective graphics The difference from the standard graphics is too large, resulting in inaccurate subsequent Poisson plots and reducing product yield.
  • Step S12 draw a Poisson curve using the line width of the effective pattern and its corresponding preset lithography parameters as data.
  • step S12 Since the line width of the effective graph needs to be used as the data for drawing the Poisson curve in step S12, the line width of the effective graph needs to be obtained before step S12 is executed.
  • the effective graph can be directly used corresponding line width.
  • the line width of the target graphic is measured.
  • the number indicated in each small grid is the line width of the target graphic.
  • the existing equipment for measuring the line width such as CD-SEM, can be used to measure the line width of the target pattern.
  • step S11 since the comparison step (step S11 ) is not performed, that is, no valid patterns are screened, the line widths of all target patterns are measured to obtain the line widths of all target patterns. Then, in step S12, the corresponding line width data is selected as the data for drawing the Poisson curve according to the effective graph.
  • the line width of the target graphic is not obtained before the step of comparing the target graphic with the standard graphic (step S11 ), but the target graphic is compared with the standard graphic.
  • the line width of the effective graphics is obtained.
  • the effective graphics are filtered out, and only the line width of the effective graphics is measured.
  • FIG. 3 it is the distribution diagram of the target pattern obtained by lithography under different preset lithography parameters using the same mask pattern as the mask, and the number marked in the small grid of each effective pattern is is the line width of the valid graphic.
  • the existing equipment for measuring the line width such as CD-SEM, can be used to measure the line width of the effective pattern.
  • the operation of measuring the line width is performed only after the comparison step (step S11) is performed, that is, after the valid patterns are screened out. Therefore, it is not necessary to measure the line width of the invalid patterns, which saves the measurement time and improves the efficiency of the measurement.
  • Productivity In step S12, the corresponding line width data can be selected as the data for drawing the Poisson curve according to the effective graph.
  • the preset lithography parameter is a combination of exposure energy and focus value. Therefore, in the step of drawing a Poisson curve using the line width of the effective pattern and its corresponding preset lithography parameters as data Among them, it is necessary to set one of the exposure energy and the focus value as a fixed value, and the other and the line width of the effective graph as data to draw a Poisson curve (Bossung curve).
  • the Poisson curve is a change curve of line width with exposure energy and focus value.
  • each exposure energy corresponds to a Poisson curve
  • multiple exposure energies correspond to multiple Poisson curves.
  • Figure 5 is a set of Poisson curves drawn with the focus value as a fixed value, the line width of the effective graph as the ordinate and the exposure energy as the abscissa.
  • Each focus value corresponds to a Poisson curve. Values correspond to multiple Poisson curves.
  • Step S13 obtaining lithography parameters corresponding to the preset line width according to the Poisson curve.
  • the corresponding lithography parameters are selected from the Poisson curve group shown in FIG. 4 or FIG. 5. Since the Poisson curve group contains multiple Poisson curves, the The set line width corresponds to multiple lithography parameters, and the lithography parameters corresponding to the Poisson curve with a gentle trend can be selected as the lithography parameters used in actual production.
  • the present application uses the comparison of target graphics and standard graphics to screen out effective graphics.
  • This process can be directly completed in the processor without manual screening, which greatly improves the consistency of screening and avoids human factors affecting the screening of effective graphics.
  • the stability of the process is guaranteed, and the processing speed of the processor is much higher than the manual processing speed.
  • the processing speed of the processor is less than 2 minutes, which is comparable to the manual processing speed of 60-90 minutes. It greatly saves processing time and improves production efficiency.
  • the standard pattern is used to screen the target pattern, which standardizes the screening process, avoids errors caused by inconsistent manual screening standards, reduces the influence of human factors on the selection of lithography parameters, and greatly improves the stability of the semiconductor process; at the same time, Since no manual operation is required, the production efficiency is greatly improved.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

Abstract

一种准确获取光刻参数的方法，其包括如下步骤：采用同一掩膜图形作为掩膜，在不同的预设光刻参数下，对目标载体进行光刻，获得多个目标图形（S10）；将目标图形与标准图形进行对比，获得评估值，若目标图形所对应的评估值大于或者等于预设值，则将目标图形设定为有效图形（S11）；以有效图形的线宽及其对应的预设光刻参数为数据绘制泊松曲线（S12）；根据泊松曲线获得预设线宽对应的光刻参数（S13）。利用标准图形对目标图形进行筛选，使筛选过程标准化，避免人工筛选标准不统一而造成的误差，减少了人为因素对光刻参数选取的影响，大大提高了半导体制程的稳定性；同时，由于不需要人工手动操作，大大提高了生产效率。

Description

准确获取光刻参数的方法
相关申请的交叉引用
本申请要求在2020年08月05日提交中国专利局、申请号为202010777000.8、申请名称为“准确获取光刻参数的方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及半导体制造领域，尤其涉及一种在光刻工艺中准确获取光刻参数的方法。
背景技术
在芯片的大规模生产中，如何保证特征尺寸线宽均匀度和稳定度，对稳定产品良率具有十分重要的意义。为保证稳定的产品良率，一般通过准确确定光刻工艺窗口和曝光条件来实现。其中，光刻工艺窗口是指可用于生产的曝光能量和聚焦值范围，曝光条件是指生产时所设定的曝光能量和聚焦值。
目前，获得曝光能量、聚焦值等原始数据后，需要工程师人工对原始数据进行筛选，并根据筛选后的数据人工手动绘制曲线，以获得曝光条件。该种方法的缺点在于：需要花费大量时间，通常需要60-90min；筛选标准往往与工程师的经验相关，受人为因素的影响较大，使得筛选标准不统一，不利于制程的稳定。
因此，亟需一种准确获取光刻参数的方法，其能够避免人为因素的影响，提高半导体制程的稳定性。
发明内容
本申请所要解决的技术问题是，提供一种准确获取光刻参数的方法，其能够避免人为因素对光刻参数选取的影响，提高半导体制程的稳定性，且能够大 大节省生产时间，提高生产效率。
为了解决上述问题，本申请提供了一种准确获取光刻参数的方法，其包括如下步骤：
采用同一掩膜图形作为掩膜，在不同的预设光刻参数下，对目标载体进行光刻，获得多个目标图形；
将所述目标图形与标准图形进行对比，获得评估值，若所述目标图形所对应的评估值大于或者等于预设值，则将所述目标图形设定为有效图形；
以所述有效图形的线宽及其对应的预设光刻参数为数据绘制泊松曲线；
根据所述泊松曲线获得预设线宽对应的光刻参数。
在一些实施例中，所述掩膜图形由相同类型或者不同类型的光刻图形组成。
在一些实施例中，所述目标载体为涂覆有光刻胶层的半导体衬底，所述目标图形形成在所述光刻胶层。
在一些实施例中，所述预设光刻参数为曝光能量与聚焦值的组合，在采用同一掩膜图形作为掩膜，在不同的预设光刻参数下，对目标载体进行光刻，获得多个目标图形的步骤中，分别以所述曝光能量及所述聚焦值作为变量改变所述预设光刻参数。
在一些实施例中，以所述有效图形的线宽及其对应的预设光刻参数为数据绘制泊松曲线的步骤进一步包括：将所述曝光能量为定值，以所述有效图形的线宽及所述聚焦值为数据绘制泊松曲线，或以所述聚焦值为定值，以所述有效图形的线宽及所述曝光能量为数据绘制泊松曲线。
在一些实施例中，将所述目标图形与标准图形进行对比的方法为，获取所述目标图形与所述标准图像的扫描图像，并将所述扫描图像进行像素灰阶比对，获得所述目标图形与所述标准图形的相似度，所述相似度为所述评估值。
在一些实施例中，所述预设值的范围为70％～85％。
在一些实施例中，若所述目标图形所对应的评估值小于预设值，则将所述目标图形设定为无效图形。
在一些实施例中，对所述有效图形或者所述无效图形进行标记，以区分有 效图形与无效图形。
在一些实施例中，在将所述目标图形与标准图形进行对比的步骤之前，获取目标图形的线宽。
在一些实施例中，在将所述目标图形与标准图形进行对比的步骤之后，获取有效图形的线宽。
本申请的优点在于，利用标准图形对目标图形进行筛选，使筛选过程标准化，避免人工筛选标准不统一而造成的误差，减少了人为因素对光刻参数选取的影响，大大提高了半导体制程的稳定性；同时，由于不需要人工手动操作，大大提高了生产效率。
附图说明
图1是本申请准确获取光刻参数的方法的一实施例的步骤示意图；
图2及图3是采用同一掩膜图形为掩膜，在不同的预设光刻参数下光刻获得的目标图形的分布图；
图4是以曝光能量为定值，以有效图形的线宽为纵坐标，以聚焦值为横坐标绘制的泊松曲线组；
图5是以聚焦值为定值，以有效图形的线宽为纵坐标，以曝光能量为横坐标绘制的泊松曲线组。
具体实施方式
下面结合附图对本申请提供的准确获取光刻参数的方法的实施例做详细说明。
图1是本申请准确获取光刻参数的方法的实施例的步骤示意图。请参阅图1，所述准确获取光刻参数的方法包括如下步骤：
步骤S10，采用同一掩膜图形作为掩膜，在不同的预设光刻参数下，对目标载体进行光刻，获得多个目标图形。
所述掩膜图形由相同类型或者不同类型的光刻图形组成。所述类型可以指 所述光刻图形的密集程度，例如，密集图形，半密集图形及孤立图形。所述掩膜图形可仅由单一类型的光刻图形组成，例如，仅由孤立图形组成，也可有由多种类型的光刻图形组成，例如，由密集图形与半密集图形组成，或者由密集图形与孤岛图形组成，或者由密集图形、半密集图形及孤岛图形组成等。
其中，所述掩膜图形仅由单一类型的光刻图形组成的优点在于，简化后续操作的复杂程度；所述掩膜图形由多种类型的光刻图形组成的优点在于，可使获得的光刻参数对晶圆上所有图形类型均适用，提高光刻参数的普遍性。
所述目标载体为涂覆有光刻胶层的半导体衬底，所述目标图形形成在所述光刻胶层。具体地说，在本实施例中，所述半导体衬底为硅衬底，所述光刻胶层形成在所述硅衬底上。
在本步骤中，采用一掩膜图形作为掩膜，在第一预设光刻参数下对所述光刻胶层进行曝光、显影，形成第一目标图形；改变所述预设光刻参数为第二预设光刻参数，再采用相同的掩膜图形作为掩膜，在所述第二预设光刻参数下对所述光刻胶层进行曝光、显影，形成第二目标图形；改变所述预设光刻参数为第三预设光刻参数，再采用相同的掩膜图形作为掩膜，在所述第三预设光刻参数下对所述光刻胶层进行曝光、显影，形成第三目标图形；依此类推，获得多个目标图形，每一个目标图形对应的光刻参数均不相同。
其中，所述预设光刻参数为曝光能量与聚焦值的组合。在本实施例中采用曝光-能量矩阵(Focus-Energy Matrix，FEM)测试方法来进行测试，其可在光刻设备内进行设置。在步骤S10中，分别以所述曝光能量及所述聚焦值作为变量改变所述预设光刻参数。具体地说，以所述聚焦值为定值，所述曝光能量为变量改变所述预设光刻参数，或者以所述曝光能量为定值，所述聚焦值为变量改变所述预设光刻参数。具体地说，曝光时，在一个方向以固定的步长改变聚焦值，另一个方向以另一个固定步长改变曝光能量，每个条件对应一片晶圆上一个图形(如图2中的一个小格)，以此为条件曝光显影。
举例说明，请参阅图2，其为采用同一掩膜图形为掩膜，在不同的预设光刻参数下光刻获得的目标图形的分布图，其中，每一行为相同的曝光能量D， 每一列为相同的聚焦值F，每一个小格代表一个图形，其对应一个曝光能量D与聚焦值F的组合。在制作目标图形时，可首先以曝光能量D为定值，例如40，以固定步长依次改变聚焦值F，采用同一个掩膜图形作为掩膜，形成多个目标图形；再改变曝光能量D为另一定值，例如38.5，以固定步长依次改变聚焦值F，采用同一个掩膜图形作为掩膜，再形成多个目标图形，依次类推，从而形成多个对应不同光刻参数的目标图形。在本申请其他实施例中，也可以以聚焦值F为定值，以固定步长依次改变曝光能量D，采用同一个掩膜图形作为掩膜，形成多个目标图形，其原理不变，不再赘述。
进一步，可以理解的是，由于目标载体(例如涂覆有光刻胶的硅片)为圆形，则在分布图中，圆形区域外的部分没有图形分布，因此，如图2所示，在分布图中存在空值(如曝光能量为40.0、聚焦值为-0.3对应的区域)。
步骤S11，将所述目标图形与标准图形进行对比，获得评估值，若所述目标图形所对应的评估值大于或者等于预设值，则将所述目标图形设定为有效图形。
所述标准图形为具有理想的形状的图形，其可为通过模拟数据制造的图形，也可为经过一系列的测试后，人工筛选出的最优图形。所述标准图形包括但不限于现有的金图像(goldenimage)等。可以理解的是，所述标准图形的形状即为所述目标图形希望得到的形状。
通常，标准图形(例如金图像)被存储在CD-SEM设备中。则在形成目标图形后，可在CD-SEM设备中将所述标准图形与所述目标图形进行对比，获得评估值，且所述评估值可被CD-SEM设备或者处理系统记录，以作为后续操作的参考值。
所述预设值为预先设置的数值，其作为所述评估值的评价标准。所述预设值可根据对目标图形质量的要求而设置，例如，对目标图形质量要求高，所述预设值可设置为高值，对目标图形质量要求不高，所述预设值可适当设置为低值。
在该步骤中，若所述目标图形所对应的评估值大于或者等于预设值，则说 明所述目标图形与所述标准图形的差别在允许范围内，则将该目标图形设定为有效图形；若所述目标图形所对应的评估值小于预设值，则说明所述目标图形与所述标准图形的差别不在允许范围内，则将该目标图形设定为无效图形。
进一步，为了区分有效图形与无效图形，处理系统可自动对有效图形或者无效图形进行标记，以使处理系统在对数据处理时，能够识别该两种图形数据。例如，处理系统仅对有效图形进行标记，或者仅对无效图形进行标记，或者对无效图形及有效图形采用不同的记号进行标记。例如，在一实施例中，处理系统自动对无效图形进行阴影标记，具体地说，在图2所示的分布图中，对无效图形对应的小格采用阴影覆盖，对有效图形对应的小格不进行覆盖，以区分有效图形与无效图形。在本申请其他实施例中，也可采用其他标记方法区分有效图形与无效图形，例如，在本申请一实施例中，处理系统自动对无效图形对应的小格采用颜色覆盖，例如，采用黄色覆盖等，在本申请另一实施例中，处理系统自动对无效图形采用红色边框圈示。可以理解的是，在本申请其他实施例中，也可采用其他能够被系统识别的标记。在本申请中，处理系统可自动区分有效图形与无效图形，避免了人工手动区分，大大提高了工作效率，节约了生产时间，且提高准确率，避免产生误差。
进一步，本申请还列举了一种将所述目标图形与标准图形进行对比的方法。具体地说，获取所述目标图形与所述标准图形的扫描图像。所述扫描图形可为SEM扫描获得的扫描图像。并将所述目标图形的所述扫描图像与所述标准图形的扫描图形进行像素灰阶比对，获得所述目标图形与所述标准图形的相似度。所述相似度即为所述评估值。可以理解的是，在所述评估值为相似度的情况下，所述预设值也为相似度。
当然，本领域技术人员也可采用其他方法将所述目标图形与所述标准图形进行对比，本申请并不限于此。
进一步，所述预设值的范围可为70％～85％。若所述预设值过大，则会造成筛选出的有效图形过少，后续绘制泊松曲线不准确，降低产品良率；若所述预设值过小，则会导致筛选出的有效图形与标准图形差别过大，造成后续绘制泊 松曲线不准确，降低产品良率。
步骤S12，以所述有效图形的线宽及其对应的预设光刻参数为数据绘制泊松曲线。
由于步骤S12中需要将有效图形的线宽作为绘制泊松曲线的数据，则在执行步骤S12之前，需要先获得有效图形的线宽。
在本申请一实施例中，在将所述目标图形与标准图形进行对比的步骤(步骤S11)之前，获取目标图形的线宽，则绘制曲线的步骤(步骤S12)中，可直接使用有效图形对应的线宽。具体地说，在该实施例中，在步骤S10中制作目标图形后，测量目标图形的线宽。例如，如图2所示的分布图，每一个小格子中标示的数字即为该目标图形的线宽。其中，可采用现有的测量线宽的设备，例如CD-SEM，测量目标图形的线宽。在该实施例中，由于并未执行对比步骤(步骤S11)，即并未筛选出有效图形，因此，对所有的目标图形均进行线宽测量，获得所有目标图形的线宽。则在步骤S12中，根据有效图形而选取其对应的线宽数据作为绘制泊松曲线的数据。
而在本申请另一实施例中，并不是在将所述目标图形与标准图形进行对比的步骤(步骤S11)之前，获取目标图形的线宽，而是在将所述目标图形与标准图形进行对比的步骤(步骤S11)之后，获取有效图形的线宽。具体地说，在该实施例中，在步骤S11结束后，所述有效图形被筛选出来，则仅测量所述有效图形的线宽。例如，如图3所示，其为采用同一掩膜图形为掩膜，在不同的预设光刻参数下光刻获得的目标图形的分布图，每一个有效图形的小格子中标示的数字即为该有效图形的线宽。其中，可采用现有的测量线宽的设备，例如CD-SEM，测量有效图形的线宽。在该实施例中，在执行对比步骤(步骤S11)后，即筛选出有效图形后，才执行测量线宽的操作，因此，并不需要测量无效图形的线宽，节省了测量时间，提高了生产效率。在步骤S12中，可根据有效图形而选取其对应的线宽数据作为绘制泊松曲线的数据。
在一实施例中，所述预设光刻参数为曝光能量与聚焦值的组合，因此，在以所述有效图形的线宽及其对应的预设光刻参数为数据绘制泊松曲线的步骤 中，需要将曝光能量与聚焦值中的一个设为定值，另外一个与所述有效图形的线宽作为数据绘制泊松曲线(Bossung曲线)。所述泊松曲线为线宽随曝光能量和聚焦值的变化曲线。
举例说明，其中，每一曝光能量均对应一条泊松曲线，则多个曝光能量对应多条泊松曲线。图5是以聚焦值为定值，以有效图形的线宽为纵坐标，以曝光能量为横坐标绘制的泊松曲线组，其中，每一聚焦值均对应一条泊松曲线，则多个聚焦值对应多条泊松曲线。
步骤S13，根据所述泊松曲线获得预设线宽对应的光刻参数。
需要确定光刻参数时，根据预设线宽，在图4或者图5所示的泊松曲线组中选择其对应的光刻参数，而由于泊松曲线组包含多条泊松曲线，则预设的线宽会对应多个光刻参数，则可选择走势平缓的泊松曲线对应的光刻参数作为实际生产中采用的光刻参数。
本申请在绘制泊松曲线之前先排除无效图形，仅采用有效图形的数据绘制泊松曲线，能够减小误差，为后续的光刻参数的选择提供更准确的参考。同时，本申请利用目标图形与标准图形的对比，筛选出有效图形，该过程能够在处理器中直接完成，不需要人工筛选，大大提高了筛选的一致性，避免人为因素影响有效图形的筛选，保证了制程的稳定性，且处理器的处理速度远远高于人工处理速度，例如，在本申请一实施例中，处理器的处理速度要小于2分钟，与人工处理速度60～90分钟相比，大大节省了处理时间，提高了生产效率。
以上所述仅是本申请的优选实施方式，应当指出，对于本技术领域的普通技术人员，在不脱离本申请原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本申请的保护范围。
工业实用性：
本申请实施例中，通过采用同一掩膜图形作为掩膜，在不同的预设光刻参数下，对目标载体进行光刻，获得多个目标图形；将所述目标图形与标准图形进行对比，获得评估值，若所述目标图形所对应的评估值大于或者等于预设值， 则将所述目标图形设定为有效图形；以所述有效图形的线宽及其对应的预设光刻参数为数据绘制泊松曲线；根据所述泊松曲线获得预设线宽对应的光刻参数。这样，利用标准图形对目标图形进行筛选，使筛选过程标准化，避免人工筛选标准不统一而造成的误差，减少了人为因素对光刻参数选取的影响，大大提高了半导体制程的稳定性；同时，由于不需要人工手动操作，大大提高了生产效率。

Claims (11)

  1. 一种准确获取光刻参数的方法，包括如下步骤：
    采用同一掩膜图形作为掩膜，在不同的预设光刻参数下，对目标载体进行光刻，获得多个目标图形；
    将所述目标图形与标准图形进行对比，获得评估值，若所述目标图形所对应的评估值大于或者等于预设值，则将所述目标图形设定为有效图形；
    以所述有效图形的线宽及其对应的预设光刻参数为数据绘制泊松曲线；
    根据所述泊松曲线获得预设线宽对应的光刻参数。
  2. 根据权利要求1所述的准确获取光刻参数的方法，其中，所述掩膜图形由相同类型或者不同类型的光刻图形组成。
  3. 根据权利要求1所述的准确获取光刻参数的方法，其中，所述目标载体为涂覆有光刻胶层的半导体衬底，所述目标图形形成在所述光刻胶层。
  4. 根据权利要求1所述的准确获取光刻参数的方法，其中，所述预设光刻参数为曝光能量与聚焦值的组合，在采用同一掩膜图形作为掩膜，在不同的预设光刻参数下，对目标载体进行光刻，获得多个目标图形的步骤中，分别以所述曝光能量及所述聚焦值作为变量改变所述预设光刻参数。
  5. 根据权利要求4所述的准确获取光刻参数的方法，其中，以所述有效图形的线宽及其对应的预设光刻参数为数据绘制泊松曲线的步骤进一步包括：将所述曝光能量设为定值，以所述有效图形的线宽及所述聚焦值为数据绘制泊松曲线，或以所述聚焦值为定值，以所述有效图形的线宽及所述曝光能量为数据绘制泊松曲线。
  6. 根据权利要求1所述的准确获取光刻参数的方法，其中，将所述目标图形与标准图形进行对比的方法为，获取所述目标图形与所述标准图像的扫描图像，并将所述扫描图像进行像素灰阶比对，获得所述目标图形与所述标准图形的相似度，所述相似度为所述评估值。
  7. 根据权利要求6所述的准确获取光刻参数的方法，其中，所述预设值的 范围为70％～85％。
  8. 根据权利要求1所述的准确获取光刻参数的方法，其中，若所述目标图形所对应的评估值小于预设值，则将所述目标图形设定为无效图形。
  9. 根据权利要求8所述的准确获取光刻参数的方法，其中，对所述有效图形或者所述无效图形进行标记，以区分有效图形与无效图形。
  10. 根据权利要求1所述的准确获取光刻参数的方法，其中，在将所述目标图形与标准图形进行对比的步骤之前，获取目标图形的线宽。
  11. 根据权利要求1所述的准确获取光刻参数的方法，其中，在将所述目标图形与标准图形进行对比的步骤之后，获取有效图形的线宽。
PCT/CN2021/097740 2020-08-05 2021-06-01 准确获取光刻参数的方法 WO2022028077A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP21772657.9A EP3979003B1 (en) 2020-08-05 2021-06-01 Method for accurately acquiring lithographic parameter
US17/391,215 US11868053B2 (en) 2020-08-05 2021-08-02 Method for accurately obtaining photolithography parameter

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010777000.8A CN114063392B (zh) 2020-08-05 2020-08-05 准确获取光刻参数的方法
CN202010777000.8 2020-08-05

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US17/391,215 Continuation US11868053B2 (en) 2020-08-05 2021-08-02 Method for accurately obtaining photolithography parameter

Publications (1)

Publication Number Publication Date
WO2022028077A1 true WO2022028077A1 (zh) 2022-02-10

Family

ID=78820598

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/097740 WO2022028077A1 (zh) 2020-08-05 2021-06-01 准确获取光刻参数的方法

Country Status (2)

Country Link
CN (1) CN114063392B (zh)
WO (1) WO2022028077A1 (zh)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101061568A (zh) * 2004-11-16 2007-10-24 东京毅力科创株式会社 曝光条件设定方法、衬底处理装置和计算机程序
CN103995439A (zh) * 2014-06-12 2014-08-20 上海华力微电子有限公司 一种在线确定光刻工艺窗口的方法
US20170160648A1 (en) * 2014-07-21 2017-06-08 Asml Netherlands B.V. Method for determining a process window for a lithographic process, associated apparatuses and a computer program
EP3339957A1 (en) * 2016-12-20 2018-06-27 GenISys GmbH Process dose and process bias determination for beam lithography
CN110544640A (zh) * 2018-05-28 2019-12-06 长鑫存储技术有限公司 半导体基片的检测方法及检测装置
CN110632827A (zh) * 2019-09-26 2019-12-31 上海华力集成电路制造有限公司 确定光刻工艺窗口的方法
CN111289261A (zh) * 2020-01-20 2020-06-16 成都主导科技有限责任公司 一种库内车底部件检测方法
CN111311582A (zh) * 2020-02-20 2020-06-19 上海华力集成电路制造有限公司 Opc数据采集方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4157330B2 (ja) * 2002-06-27 2008-10-01 株式会社東芝 リソグラフィ条件の最適化方法
AU2003303356A1 (en) * 2002-12-30 2004-07-22 Koninklijke Philips Electronics N.V. Determining lithographic parameters to optimise a process window
US8741511B1 (en) * 2012-12-19 2014-06-03 Globalfoundries Singapore Pte. Ltd. Determination of lithography tool process condition
CN103488060B (zh) * 2013-09-30 2015-09-09 上海华力微电子有限公司 确定光刻曝光离焦量的方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101061568A (zh) * 2004-11-16 2007-10-24 东京毅力科创株式会社 曝光条件设定方法、衬底处理装置和计算机程序
CN103995439A (zh) * 2014-06-12 2014-08-20 上海华力微电子有限公司 一种在线确定光刻工艺窗口的方法
US20170160648A1 (en) * 2014-07-21 2017-06-08 Asml Netherlands B.V. Method for determining a process window for a lithographic process, associated apparatuses and a computer program
EP3339957A1 (en) * 2016-12-20 2018-06-27 GenISys GmbH Process dose and process bias determination for beam lithography
CN110544640A (zh) * 2018-05-28 2019-12-06 长鑫存储技术有限公司 半导体基片的检测方法及检测装置
CN110632827A (zh) * 2019-09-26 2019-12-31 上海华力集成电路制造有限公司 确定光刻工艺窗口的方法
CN111289261A (zh) * 2020-01-20 2020-06-16 成都主导科技有限责任公司 一种库内车底部件检测方法
CN111311582A (zh) * 2020-02-20 2020-06-19 上海华力集成电路制造有限公司 Opc数据采集方法

Also Published As

Publication number Publication date
CN114063392B (zh) 2023-06-09
CN114063392A (zh) 2022-02-18

Similar Documents

Publication Publication Date Title
CN109828440B (zh) 基于衍射的套刻标识以及套刻误差测量方法
CN113359386B (zh) 掩模板的参数分析方法及装置
US8090192B2 (en) Pattern misalignment measurement method, program, and semiconductor device manufacturing method
CN103792785B (zh) 一种对具有低图像对比度的图形进行光学邻近修正的方法
US5633173A (en) Method for detecting wafer defects
US7932004B1 (en) Feature identification for metrological analysis
WO2022160677A1 (zh) 确定焦点边界、判断晶圆是否需要返工的方法
CN102955378B (zh) 光刻胶形貌表征方法
TW202205370A (zh) 程序控制之晶粒內度量衡方法及系統
CN102436149A (zh) 确定光刻工艺窗口的方法
WO2022028077A1 (zh) 准确获取光刻参数的方法
CN102566322B (zh) 一种多台光刻设备校正方法
CN111128829B (zh) 对准方法及校准方法
CN107045259B (zh) 包含有监测图形的掩膜版以及监测方法
CN111426701B (zh) 一种晶圆缺陷检测方法及其装置
EP3979003B1 (en) Method for accurately acquiring lithographic parameter
US20220236196A1 (en) Methods for determining focus spot window and judging whether wafer needs to be reworked
CN112331574B (zh) 半导体器件高度分布的检测方法
CN107748484A (zh) 一种最小曝光能量的测量方法
CN107221507B (zh) 一种自适应定义缺陷扫描方程式扫描区域的方法
US7987057B1 (en) Intelligent stitching boundary defect inspection
CN114296325B (zh) 表征套刻精度量测方法准确性的方法
Yang et al. New OPC verification method using die-to-database inspection
CN117666297B (zh) 光刻图形量测检测方法及其系统
CN216248762U (zh) 一种光刻机的载片台平坦度的检测系统及光刻机

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2021772657

Country of ref document: EP

Effective date: 20210927

ENP Entry into the national phase

Ref document number: 2021772657

Country of ref document: EP

Effective date: 20210927

NENP Non-entry into the national phase

Ref country code: DE