TW474851B - Optimal slurry injecting device and method of chemical mechanical polishing - Google Patents

Abstract

The present invention is an optimal slurry injecting device and method of chemical mechanical polishing to obtain the changing tendency of polishing rate and polishing uniformity of chemical mechanical polishing in semiconductor industry and figure out the optimal injecting amount of slurry and injecting position, which includes a rotating device with upper and lower rotating speeds being programmable controlled to progress chemical mechanical polishing; an image collecting unit, which can collect the polishing image of slurry during chemical mechanical polishing and output the image data; and a data processing unit, which measures and analyzes the image data output from the image recording unit to acquire the optimal injecting amount of slurry and the injecting position.

Description

-: ---- 5. Description of the invention (!) Field of the invention The present invention relates to a grinding, cooling, and lambda field, and more particularly to a method for implementing and optimizing liquid / mainstream optimization, and a method therefor. . The implementation of the grinding fluid injection in clothing is optimized. Background of the Invention: The machine used in research and development has been briefly referred to as 2 1 ^ ^ ^, because it can provide the so-called total p ten tanization instead of the existing W "Frankization" is especially in semiconducting; :: (Spin 〇 "lass", the line width is getting smaller and smaller, again? = Surface, the wafer size is getting more and more. ^ Also multi-layer interconnect (multi level = ) 'Therefore, the requirements or requirements for flattening are becoming more and more stringent. And some local flattening (l0cai) commonly used in the past

PlanariZat, 10n) technology is no longer sufficient. According to the production conditions of the 4th semiconductor industry, the chemical mechanical polishing (CMP) process parameters can only be determined by referring to the reference data provided by the original machine manufacturer; however, many process parameters (such as wafers) Dimensions, grinding wheel speed, polishing liquid injection position, polishing liquid injection rate, > polishing liquid properties, polishing pad properties, etc.] may be changed. If it is still produced according to the reference data provided by the original machine manufacturer , It will lead to a decrease in polishing rate, an increase in non-uniformity, and an increase in the consumption of polishing liquids and polishing pads, which will affect the increase in wafer defect rate, which will cause the bottleneck of technological improvement and cost reduction. However, the chemical mechanical polishing (CMP) process The flow field involved is quite complex

PD1914-- CMP.ptd

Five explanations (2) Invented pro-food, and ^ field understanding = the industry has not much flow in the most simplified two eccentric rotating plane discs, not to mention the fluid and chemical characteristics of abrasive fluids, Wang Yi noodles open: ^ a From then on, many effects such as the surface shape of Shi Kai wafers are mixed in a mechanical polishing, CMP mechanical polishing (CMP) experiment must purchase an expensive chemical circle and not count), in addition to the preparation of valuable crystals The amount of training cover was paid. And the analysis of the grinding rate and uniformity needs to be precise. Only price: such as scanning electron microscope (SEM) and ellipsometer, it is expensive, and it is time-consuming and inconvenient to use. The inspection and vocational research is, therefore *, in view of the lack of know-how, the applicant has carefully studied the machine w9 :, a spirit of perseverance, and finally developed the "chemical and its method of this case :: injection of abrasive fluid A brief description of the optimization of the implementation of the invention. The main purpose of this case is to observe the transient changes of the different injection positions and the distribution on the second grinding mill with the visual flow, and find out the better spray material. :: Do not use the "CMP" grinding process (CMP) process required wear rate and grinding burns: the use of expensive measuring equipment can be measured! Drought and grinding uniformity trends. ^ Another purpose of this case is to provide a grinding rate in the grinding of Tr, CMP, and a. ^ Find the potential of the semiconductor industry, and then find the best change in grinding uniformity and the main point of entry, which Including: one spin PD19I4 "CMP.ptd page 5 '5. Description of the invention (3) Rotary machine, Gan chemical 掬" Γ The rotation speed of up and down rotation is programmable and used for a grinding machine ... image The trapping unit can trap the polishing liquid during the grinding process of the chemical machine grinding process Grinding image;: shirt image recording unit, which records and stores the image data captured by the scene image capturing unit, and can output the image data; and a data processing sheet Γ = analysis by the image recording unit The input image data is used for the injection volume and injection point of a slurry. According to the concept of this case, the rotary shovel 嫱 A > +, ρι self-also-also with the scale " | 7 Hongxi 乂 electric monthly bag numerical control for position control, and different gaps between the discs to make accurate adjustments. The size of the turntable is changed according to the idea of this case, and the rotation speed of the turntable can be changed up and down, and its rotation speed can also be freely adjusted by the size of the helmet section. According to the idea of this case, the image capture unit is adjusted. The image capturing device is an electronic digital camera including an image capturing device. According to the idea of the present case, the image capturing unit makes the image clearly visible, wherein the light source is enclosed by a mercury arc lamp: Conceived that the image recording unit includes Ku, 卡 # an image interface card, the image recorder is used to ~ the image data captured by the image recorder capture unit, and then the image data stored by it to the data analysis unit. M-shirt image interface card output According to the idea of the present case, the data processing unit is software for analyzing the input image of the image recording unit, including the distribution of image analysis, to facilitate data analysis of a computer device. Gray scale

PD1914-- CMP.ptd Page 6 474851 V. Description of the invention (4) According to the concept of the case, the polishing rate can be estimated by the low of the knife cloth of the stomach one wafer and the polishing pad two of the rotary table. . The amount of the polishing liquid of S, thus obtaining another object of the present case, A load / 4 + ma w- ^ au, ', a kind of chemical mechanical polishing | ι 』口 + polishing liquid optimization method, π said i One of the objectives in the grinding process of Yunzhong Chemical Machinery Research ::: == Chemical machinery and injection volume optimization method, its step σ grinding fluid injection position fluid injection parameters, (b) determine the plurality of "a plurality of grinding bodies Calculate the average gray scale and:; :: === Set the item by analyzing the soft-mechanical reaction status: = bit, the machine condition of the rotary machine is the same, and the chemical mechanical polishing (CMP) machine is the same as The eyepiece is made into a lecture hall, and the grinding fluid and soil factors are all transferred to the chemical mechanical polishing (CMP) machine; the setting of the mediation is used to perform the grinding operation; (e) the to-be-milled bundle is 122, parameters Analyze the grinding chapter. After the grinding operation is completed, the Zhaya records can be used to support the ancestral industry. Each recorded change corresponds to the grinding: the factors produced by the best grinding state "the best g majority, and (G) Apply the optimal polishing liquid injection parameters on the machine.彖 η In the case of this case, (a) Injecting a plurality of grinding fluids into the household weight 14 includes a glass disc rotation speed, a grinding pad rotation speed, a grinding fluid injection, and a grinding fluid injection amount. According to the idea of this case, the average gray level described in step (b) may be high or low.

PD1914-page 7 474851 V. Description of the invention (5) ‘Estimate the amount of polishing liquid between a wafer and the polishing pad, and then know the polishing rate. According to the idea of the present case, the step (e) includes providing a light source to make the image clearly visible, wherein the light source is preferably a mercury arc lamp. According to the idea of the present case, the method described in step (e) further includes providing an imaging device to perform a grinding observation record analysis of the wafer surface. According to the idea of the present case, the image capturing device is an electronic digital camera. According to the concept of the present case, the image capturing device captures images of the movement of the polishing liquid in multiple consecutive times. According to the idea of this case, in order to make the image data captured by the imaging device more analyzable, the image capturing device records and stores the captured image data at a high speed with an image recording unit, and then at a lower speed. Output the image data. According to the idea of this case, the output of the image data is analyzed by image analysis software. Selecting 1 basis /% structure Λ, the image analysis software system will round out the image data points, and calculate the average grayscale value and non-uniformity of the gray k points of these 48 points. Further to find the 48 cases, this case can be understood by the following cabinets-: Insufficient to implement the description of the examples, I got a deeper illustration

I

The main input table optimizes the schematic diagram of the equipment. , Dead picture: It is the top view on the disc rotating machine. The third figure: the relationship between non-uniformity and wafer rotation speed. Description of drawing number 11: Rotary table I 1 2: Polishing pad II 4: Positioning control platform 1 2 2: Imaging device 1 4: Polishing liquid supply barrel 111: Servo motor 11 3: Glass break disc 1 2 1: Light source 1 3: Computer control system 1 41: Description of the implementation list of polishing liquid ° Monthly "See the figure. In the chemical mechanical polishing process of the preferred embodiment of this case, the schematic diagram of the equipment for optimizing the grinding liquid injection is implemented. It can be seen from the first figure that the optimization implementation equipment of this case includes a rotating machine π, an image capturing unit (121, 2 2), an image recording unit, and a data processing unit for obtaining a semiconductor industry chemical machinery. The changing trend of the polishing rate and polishing uniformity during the polishing process, and then find the optimal injection volume and injection point of the polishing liquid. The rotating machine 11 includes a servo motor 丨 丨 i, a polishing pad J 丨 2, a glass tablet disc 113, and a positioning control platform 114. The size of the upper and lower shifts of the glass disc n3 can be changed freely, and its rotation speed can also be adjusted from the SI system by stepless speed change. = Position control is performed by using a servo motor and electric fine numerical control, and a precision light 474851 V. Description of the invention (7) The school scale monitors the position of the Z-axis' to accurately adjust the different gaps between the rotary tables and the rotary tables. The image capturing unit (1 2 1, 1 2 2) includes a light source 1 2 1 and an image capturing device 1 2 2. The light source 1 2 1 is a 1.5 amp mercury arc lamp used to make the image clearly visible. The image capturing device 12 is an electronic digital camera 'for capturing an image of the entire wafer surface. The image recording unit is used to record and store image data captured by the electronic digital camera and can output the image data. The image recording unit includes an image recorder and an image interface card. The image recorder is used to record and store the image data. The image data obtained by the image capturing unit is used to output the image data to the data analysis unit through the image interface card. The data processing unit includes an image analysis software Op ti mas 'for analyzing the distribution of the gray level of the image data input by the image recording unit, so that a computer device 13 can analyze the input image data' to obtain the best The amount of polishing liquid and the injection point. The amount of polishing liquid between the wafer and the polishing pad 112 of the rotating machine 丨 I can be estimated by the distribution of the gray level, and the polishing rate can be obtained. The steps of the polishing liquid injection optimization method in the chemical mechanical polishing (CMP) process of this case are as follows. First, select a plurality of polishing liquid injection parameters and then determine the variation range of the plurality of polishing liquid injection parameters, and within the range of the injection parameter changes, the analysis software 0 state and count] = and non-uniformity, using the average gray scale Estimation of the value of the value = said = the amount of the grinding liquid between the grinding machine 112, and then speed up: the breaking disk 113 is placed on the rotary machine " , And according to the multiple settings of grinding, night, and main entry age, grinding 祚 祚 π π W and main entry parameters. During the grinding operation, use this 1.5 amps

4/4851 V. Description of the invention (8): The arc lamp 1 21 illuminates the surface of the electronic digital camera ^ 22 ^ disc 11 3 so that the image is clearly visible. The image of the polishing liquid is moved to extract the image data of the glass disc for several times. The high-speed recording unit of the Haishan image records and strays it. An image analysis software, Jiang Yulx, outputs the image data at a lower speed. After 48 points of grayscale value, who ^ selects 48 points from the image data and calculates the uniformity. Sex. According to the record 铮 11 = the average gray scale value and the non-uniformity of the optimal grinding state of the 48 points :: select the number of the grinding state data corresponding to the variable. And inject the best grinding solution of the best research group into the parameters of the straightforward Xifu /: / and apply the parameters on the target machine. Rotating speed of polishing pad, one grinding hemp, ± rotation speed of Ma Poli disc, one main position of grinding liquid, and one injection amount of grinding liquid. The μ CMP mechanical polishing (CMP) device is in a Korean-like manner, and it can be used for μ L々 =: grinding pad η2 and the polishing liquid is commercially available and can be attached to each machine, ... view, two wafers for glass discs: The 5th position of the "God of Confucius", and the injection position is as shown in the second picture

^ 丄 5 position. And use the charge coupling device 122 (CCD ": located on the entire wafer surface) 'and cooperate with the image capture unit to send the === inspection image to the camp light curtain for monitoring, so that the experiment can be carried out. Quick and correct grasp, and with this image processing unit

Observation of the flow field. The σ JT condition setting of the chemical mechanical polishing (CMP) device is the same as the shape of the target chemical mechanical polishing (CMp) machine = the same heart, and the polishing liquid 141, polishing pad 112, and environmental factors used by it are compared. Spot target chemical mechanical polishing (CMP) machine has the same actual application status. White "474851 V. Description of the invention (9) In order to obtain a semi-quantitative result from the image of the charge coupling device 22 (CCD), a gray scale (Gray

Scale) method, that is, the image of the charge coupling device 122 (CCD) is processed by the image capturing software Opt imas, and the graphics can be gray-scaled to calculate the polishing liquid 141 on the polishing pad 112 and the wafer. The distribution map of the gray level in the gap, and then calculate the average value. Because the grinding fluid 141 contains particles processed by the image capture software Opt imas, the particles can be regarded as fluid f points, and the fluid particles can be collected to reflect the gray level. Can be estimated as the amount of polishing liquid entering between the wafer and the polishing pad. Since the polishing liquid contains abrasive particles, the amount of polishing liquid entering between the wafer and the polishing pad is related to the polishing rate. The gray level is related to the grinding rate, which indicates the non-uniformity of the grinding results. The chemical mechanical polishing (CMP) device analyzed in this paper has four different input factors: polishing pad rotation speed (PS), polishing liquid injection position (1?), Wafer rotation speed (ws), and polishing volume flow rate (M F). The so-called gray-scale method is digital image processing (Dlgital Image Pjoccessing). The digital image processing is through the imaging device 1 2 2 (charge): flat (CCD)) 'to transfer the image image to the image interface card. The video " face card will then digitize the images taken according to the difference in lightness and darkness = the digitized image is composed of many bright points of different lightness and darkness, and each pixel has a pixel Its fixed coordinate position is Gray scale. The higher the resolution of the pixels on the same day, the higher the resolution. 8-bit Gray (8-bit Gray) image The range of the luminance value is 0 to 25 5 ’〇 means the darkest, 2 5 5 means the brightest, total

PD1914-- CMP.ptd Page 12 474851 V. Description of the invention (10) 2 5 6 kinds of brightness values representing different shades. Finally, the digitized image data is sent to a computer for processing, analysis, calculation, and processing by the image acquisition software Op t mas. The digitized image can be obtained by the image capture software 〇pt imas according to the lightness and darkness of its pixels to make a brightness analysis statistical image (Image Histogram), and analyze the gray scale (brightness) on the statistical image, and then select the entire crystal The surface of the round surface, ^ order range (Thresh〇ld) 'makes the entire wafer surface image and its background show a strong contrast, and then select the point on the wafer to analyze the position for further analysis, calculation and processing. Please refer to the third figure, which is a specific example of the relationship between the wafer rotation speed and the non-uniformity obtained according to the method 1 described above. Based on the above illustrations and explanations, “I can find that this case uses a low-cost flow field simulation experimental device” to simulate the physical characteristics of chemical mechanical polishing (CMp) and then provide an optimal method for chemical mechanical polishing (CMp) polishing solution injection and The equipment is an unprecedented creation and is therefore novel. In addition, the technical features of the equipment proposed in this case are to observe the changes in the distribution of the grinding fluid using visual flow, and use the image processing technology to truly reflect the characteristics of the removal rate and non-uniformity of the grinding, to find the better injection location and injection volume. Can improve the research = rate: uniform taste, is therefore progressive. In this case, the method proposed in this case can be used for polishing semiconductor wafers, and is therefore an industry leader. ♦ Conform to the specific decision ‘Issue an application according to law’ and I would like to ask the Bureau to approve it. Any person familiar with the art can use this case as a matter of course. ·, ', = Body and practice

PD1914-- CMP.ptd Page 13

Claims (1)

474851 ------ Application for patent scope 1 'Chemical mechanical polishing (c μ p) process implements equipment 1 to obtain-body' Industrialization: Grinding fluid injection to optimize the grinding rate and uniformity of grinding "Trend :: Injection amount and injection point in the mechanical grinding process, including. Finding the best grinding, 'a rotary machine, the speed of up and down rotation is to perform a chemical machine only I ^ L h, In order to control the program, the machine of the chemical grinding process is used; an image capturing unit can be used to capture the grinding image of the grinding liquid during the grinding process of the chemical mechanical grinding process; D is an image recording unit. It is used to record and store the image data captured by the image capture unit and output the image data; and a data processing unit is used to measure and analyze the image data input by the image capture unit to obtain An optimal amount of abrasive liquid injection and injection point. 2 · The equipment described in item 1 of the scope of the patent application, where the positioning mechanism of the rotary machine is using-servo motor with an axis control system to control the position with computer numerical control, and an optical ruler to monitor the position of the Z axis In order to accurately adjust the different gaps between the size of the rotary table and the turntable. 3. The equipment as described in item 1 of the scope of patent application, in which the size of the turntable of the rotating machine can be changed freely, and its rotation speed can also be adjusted freely by stepless speed change. The device described in the scope item 丨 wherein the image capturing unit includes an image capturing device. 5. As described in the scope of the patent application No. 4, the image capturing device is an electronic digital camera. PD1914-- CMP.ptd Page 14 VI. Patent application scope where the image is included in the order > which makes the light source _ where S Xuan image recorder is used for this image recorder 6. If the patent application model also includes- The equipment described in the light source enclosure, 7. As shown in Shen Xing Patent X, the mercury arc lamp is clearly visible. & The equipment described in item 6 & = The scope of the patent application includes a video recorder, a video file, and a video recorder which is recorded and stored. ~ The video interface card is used for the video recorder. Pass the video interface card: = Single? The captured image data, and then; 9. If the patent application file is known to the edge data analysis unit. The system includes-image analysis? f is described as 'ready', in which the gray scale of the image processing unit into the image data is used to analyze the image recording unit. Knife cloth to facilitate—the data points of the computer device i. If the distribution level of the ninth patent application range can be estimated—that is, 5 is prepared, and t is obtained by the amount of the gray-scale grinding liquid, and then It is known that the grinding between the grinding pads on the rotating machine table and the grinding machine in the mechanical grinding process is used to obtain-semiconducting juice and liquid solution. The main optimization method is: Grinding liquid injection of the mechanical grinding machine table The steps in the process of targeting include: optimizing the main input amount (a) selecting a plurality of polishing liquid injection parameters; a plurality of grinding: note the change range of the parameters, and then generate a polishing liquid Change of injection parameters Fan Ligu's average gray level and non-uniformity; — Calculate the flat (C) from the analysis software. — Place the glass-breaking disc on a chemical mechanical grinding rotary machine. 6. Scope of patent application ' ~ • In the positioning, the mechanical reaction status of the rotary machine is set to be the same as that of the target chemical mechanical polishing (CMP) machine, and the grinding dryness, grinding fluid, and environmental factors used by it are the same as The target chemical mechanical polishing (CMP) machine Actual users; (d) Rotate the chemical mechanical polishing (CMP) machine and perform the polishing operation according to the setting of the injection parameters of the polishing liquid; (e) Observe and record and analyze the polishing operation when the polishing operation ends; ( 〇 According to the recorded grinding state data corresponding to each variable, select the optimum grinding state injection parameter for the optimum grinding state variable group; and (g) inject the optimal grinding fluid injection parameter in The target machine is applied. 1 2. The method according to item 丨 丨 in the scope of patent application, wherein the plurality of polishing liquid injection parameters described in step (a) include a glass disc rotation speed, a polishing pad rotation speed, A polishing liquid injection position and a polishing liquid injection amount. 1 3. The method according to item 丨 丨 in the scope of the patent application, wherein the average gray level described in step (b) can estimate a wafer and The amount of polishing liquid between the polishing pads, and thus the polishing rate. 1 4 · The method as described in item 11 of the patent application range, wherein step (e) includes providing a light source to make the image clearly visible. 1 5.If applying for a patent The method according to item 14, wherein the light source is a mercury arc lamp. 1 6. The method according to item 11 of the scope of patent application, wherein the method according to step (e) further includes providing an image pickup device f Carry out polishing observation and record analysis of the wafer surface. 474851 Among the image capturing devices, among which the image capturing devices, in order to make the image capturing, the image capturing devices further use-6. Patent application scope 17. The method described in item 16 of the patent application scope is an electronic digital camera. 1 8 · The method described in item 16 of the scope of patent application is to capture the image of the abrasive liquid moving multiple times in a row. 19 · The image data obtained by the method and device in the scope of patent application 18 The more analyzable image recording unit records and stores the captured image data at high speed, and then outputs the image data at a lower speed. The output described therein calculates these 48 points 20. The method described in item 19 of the scope of patent application is used to analyze the image data by image analysis software 2. 1. As the second scope of patent application scope The method analysis software described in item 0 selects the grayscale value of 48 points in the output image data, and then obtains the average grayscale value and non-uniformity of the 48 points. PD1914-- CMP.ptd Page 17