TW200418114A - Control method of critical dimension and monitoring method of the hot plate temperature and the thermal uniformity thereof - Google Patents

Abstract

The present invention discloses a control method of critical dimension. Firstly, transfer the test pattern onto the photoresist layer by a test mask. Measure the critical dimension of the photoresist pattern layer by scatterometry, and establish the database of critical dimension of the mask pattern from the critical dimension of the test mask and the corresponding measurement result. Finally, modify the pattern dimension of the product mask by the database, so as to control the critical dimension of the product. The present invention further discloses the monitoring method of the hot plate temperature and the thermal uniformity thereof. Firstly, establish the relationship between the critical dimension of photoresist and the hot plate temperature. Measure the critical dimension of the photoresist pattern layer by scatterometry after the hot plate is baked. Find the hot plate temperature corresponding to the measured result and the relationship. Finally, by detecting the hot plate temperature and comparing with the hot plate temperature and the temperature set-up for the hot plate, the hot plate temperature and the thermal uniformity thereof can be monitored simultaneously.

Description

200418114 V. Description of the invention (l) The technical field to which the invention belongs • The present invention relates to a method for controlling a key figure size (cr iti ca 1 di mem on, CD), and the temperature of a hot plate and its thermal uniformity. The working method 'uses a scatterometer (sca 11 er 〇red ^ yah) technology in combination with optical proximity effect correction (OPC) technology and hot plate temperature monitoring to effectively control the key graphic size of the product. Previous technology With key graphic factors, more and more modern light (DUV) technology has a near-effect modification to make the shape. The traditional case of the inch and the actual photomask, and the control of the key semiconductor integrated circuit accumulation size (CD), and the key pattern size control challenges, especially the lithography in addition to directly using a shorter wave 1 to improve Beyond the resolution 5 can be a positive principle in the semiconductor industry is to use the size of the pattern size exposed by the technology to effectively use the pattern transferred to the photoresistor in advance to obtain what we want, using a test mask The size of the CD-scanning electronic display graphics is used to increase the understanding. During the production of components, the lithography process, which is an important system that affects the quality of components, is facing the resolution in the technology. Long exposure light sources, such as the deep UV 'optical proximity effect correction (0PC) technology, which is widely used in optical proximity. Before optical neighbors can change the shape or size of the graphics on the mask, we can get closer to the geometry we designed. · | · Differences in order to accurately correct the key graphic size of the production. A test pattern micromirror (CD-SEM) was formed on a photoresist layer to measure the test pattern mask pattern size and its actual exposure 0503-8509TWf (Nl); TSMC2002.〇512; 20001-0511; Spln. Pid page 6 200418114 V. Description of the invention (2) The difference between the pattern sizes. However, due to the use of the electron beam to enter the electron microscope + scan #, and θ 'type electron microscope, the dose of 1r sub-beam that easily accumulates electricity on the photoresist surface also seriously affects the shrinkage of the photoresistor. t The accuracy of the measurement is reduced. However, it is limited by CD —; hitting = a broken mirror in a limited measurement time, the tracing electron does not show the full solidity of a circle. 〇 ', the results are close to the effect of correction :: size, so it also affects the optical neighbors. The above explains the problems of traditional optical proximity correction and key pattern size. The factors also include the baking process used in the photoresistance process. In the process of photomicrography, the photoresist must be baked before and after light exposure, such as soft baking and post exposure baking. Ann = Hot plate processed with real money, its temperature change is quite sensitive to the change of photoresistance = wood outline, please refer to Figure 6 & The relationship between the resistance pattern and the contour changes; the relationship diagram. Taking the photoresist to make line patterns as an example, when the soft baking temperature is exposed at 110 ° to 120t, it will decrease as the temperature rises, as shown in 51). Furthermore, in addition to increasing the difficulty in controlling the size of the key pattern, the thermal uniformity of the hot plate also indirectly affects the uniformity of the key pattern size of the photoresist pattern 'rate in each position on the wafer. Therefore, it is necessary to monitor the hot plate so that when the hot plate is abnormal, maintenance can be performed to ensure the quality of subsequent product production.

111 ^^ •• 〇7503_85091 resources (offenders); Ding Xia: 2002-0512; 2001-0511; Ruyi 111 (1 page γ 200418114

Traditionally, a temperature sensor is used on a control chip (silicon wafer), and its front side is directly placed; several degrees and its hot objects are placed. However, this method must measure the temperature of the hot plate: to the production capacity of 1 product. In addition, the number and configuration of the hot-plate hot ghost sensors are reduced, and the uniformity of the key pattern size that is limited by the resistance pattern is difficult to grasp. ^ Stone characteristics lead to light Summary of content Control method to prevent and prevent photoresistance from entering the shape size of the monitor uniformity of the key pattern ruler uniformity according to the manufacturing method. With the lithography program, the photoresist pattern is first defined here. This method has traditionally been reduced and effectively controlled by another method. In order to be effective, the above-mentioned first, there is a complex, layered diagram of the ladder diagram. The purpose of the invention is to use a scatterometer to test the problem with CD-S EM. One of the purposes of finely controlling the product is to use it to quickly and control the product. The purpose of the present invention is to accurately measure the key by measuring the quantity. The figure provides a key figure that provides a photoresist pattern with a charge amount, a light-shaped size, and a thermal plate on-line monitoring monitor to accurately determine the key figure size. A key figure ruler that provides a key figure size plan is accumulated on the photoresist surface resist pattern. The temperature of 〇 and its thermal 岣 畺 photoresist pattern closing plate temperature and its thermal control of a key pattern size provide a substrate on which one of several test patterns is formed to form a test mask into a photoresist pattern layer. After that, the following steps are included: the size of the key figure on the base scale, which includes at least one photoresist layer. Implementation of the photoresist layer—measured by a scatterometer: Provide the bottom dimension and a south dimension; change the bottom dimension, bottom dimension, and height respectively

0503-8509TWf (Nl); TSMC2002-0512; 2001_〇511; Spin.ptd page 8 200418114 V. Description of the invention (4) _ Degrees to generate a number of trapezoidal patterns corresponding to the generation of a fixed trapezoidal pattern. From these second predetermined spectra; and comparing the photoresist pattern indefinite spectrum; measuring the second predetermined trapezoidal pattern of light of the photoresist pattern layer. Next, and its corresponding photoresist map: m, = contains a library of per-test pattern sizes to correct a product mask ‘:, and then uses the mask pattern size data in inches. The size of the pattern and the key graphic rule that controls the product are no longer binary ... the spacing is there. Be careful of the line width of the second structure. Furthermore, the scatterometer is a full-spectrum ellipsometer. According to the other method mentioned above, its thermal uniformity monitoring method. First, the shape; the correlation between the temperature of the hot plate and the key pattern size and the temperature of the hot plate: to establish-the photoresist is covered with a photoresist layer; The photoresist pattern layer 'includes a second baking process using a test shirt procedure; (c) measuring the second photoresist pattern to destroy the H resist layer for one inch; ⑷ repeating steps (a) to (c) and changing the two key The temperature of the graphic ruler 4; and (e) Repeat step (d) to obtain ^ \ (b) under the hot plate, which corresponds to the key pattern size of the photoresist pattern layer. The temperature of the hot plate is measured by a scatterometer. A first for roasting ^, Department. After that, the key pattern size of the resist pattern layer includes one of the first light after the next step. Steps · Provide a 0503-8509TWf (Nl); Page 9 L *: L Γ 200418114 V. Description of the invention (5) A predetermined trapezoidal pattern, which is at least one degree in size; change the size respectively to generate a plurality of second predetermined ladder patterns corresponding to a plurality of predetermined light and compare photoresist patterns The spectrum of the layer corresponds to the second quantity result and correlation of the spectrum of the layer, corresponding to these hot plate temperatures and respective comparison degrees, so as to monitor the temperature of the hot plate at the same time, and the first and second bakes are scattered. The instrument is all to make the above-mentioned headings of the present invention specific preferred embodiments, and the following: Including an upper bottom size, a lower bottom upper bottom size, a lower bottom size, and a shape pattern; With these second existing spectrum; The light of the photoresist pattern layer and these predetermined spectra are measured to obtain a predetermined trapezoidal pattern. Next, the plurality of hot plate temperatures. Finally, the temperature of these hot plates and their setting and their thermal uniformity are used. The roasting process is soft roasting or roasting after exposure. Spectrum expander. The special features and advantages can be more obvious. With the drawings, the size and height scales are used to determine the trapezoidal spectrum. The photoresist diagram is used to measure the temperature. The temperature is easy to understand.

The following description of the present invention will be described in conjunction with Figures 1 to 3 (CD ^ Control Method 'It is applicable to the optical center repair graphic 2 :: Bai Xian, please refer to the magic map', its edge shows the key chart I method flow chart Step S 丨 is performed to provide a substrate, such as Ding Zhiyuan 'for drawing a controi wafer, and Shi Xijing forms a photoresist layer.). Then, on the substrate Next, step S1 2 is performed.

200418114 V. Description of the invention (6) The test mask performs a lithography process on the photoresist layer to transfer the test pattern to the photoresist layer to form a photoresist pattern layer. In this embodiment, these test patterns are composed of a plurality of grid-like structures having different lines of view arranged at different intervals. Among them, the line width of the grid-like structure is less than 5 # m, and the pitch thereof is in the range of 〇 〇 3 # η to 5. However, the test pattern of the present invention is not limited to the test pattern described above, and a grid-like structure or an island-like structure with the same line width or the same distance can be produced according to the requirements of the designer. Next, a key step s4 in the embodiment of the present invention is performed, and a scattermetry, such as a full-spectrum ellipsometer, is used to set a predetermined trapezoidal pattern. For example, changing only _ to determine the other two sizes each time results in a plurality of different second predetermined ladder patterns. Next, proceed to step S1 4 4 and use a computer simulation software to create a complex predetermined spectrum corresponding to the second predetermined trapezoidal pattern—spectrum ^ Caidou library. Next, step 'S 1 4 6' is performed to measure the spectrum of the photoresist pattern layer with a scatterometer. Please refer to FIG. 3, which shows a schematic diagram of a photoresist diagram measured by an ellipsometry. First, with a multi-frequency light source generator 10, according to the report, 'κ 〃, a 1 metering and walking I, and then a polarized light beam I through a rotating polar plate 12, the human shot at _ $ (spectroscopic ellipsometry) To measure the key pattern size of the photoresist pattern layer. Please sign the second figure, which shows the flow chart of the method for measuring the key figure size in step s 丨 4. First, step $ 14 is performed to provide a first predetermined trapezoidal pattern, such as an isosceles trapezoid, wherein the first predetermined ladder opening pattern has an upper dimension, a lower dimension, and a height dimension. Next, step S1 42 is performed, and the upper and lower dimensions, the lower dimensions, and the height dimensions of the first predetermined trapezoidal pattern are changed by the computer software to generate a plurality of second

200418114

The photoresist pattern layer on the body substrate 100, r_ and ywiuz. Then, the polarized light beam reflected by the photoresist pattern layer 102 passes through an analyzer 14 and enters a detector 16 to obtain the spectrum of the photoresist pattern layer 102. Finally, the step is performed. S148: Compare the spectrum of the photoresist pattern layer with these predetermined spectra in the spectral database to obtain the second predetermined open-earth pattern corresponding to the spectrum of the photoresist pattern layer. The related dimension data of the trapezoidal pattern is used as the key pattern size of the photoresist pattern layer. Next, step S16 is performed to establish a mask pattern size by testing the key pattern sizes of the test patterns on the photomask and the corresponding measurement results. Database. This database contains the size of each test pattern and its corresponding photoresist pattern layer size. Finally, step S 1 8 is performed to correct the mask pattern of a product using the mask pattern size database. Size in order to obtain the key graphic size of the product when making the product. Compared with the conventional method using CD-SEM to measure with an electron beam, 'because the present invention uses a scatterometer to optically measure This method does not cause charges to accumulate on the photoresist surface or the photoresist pattern to shrink. It can improve the accuracy and reliability of the measurement of key graphic dimensions. Furthermore, the scatterometer can measure a wide range of photoresistance. The pattern is far better than the local measurement of CD-SEM, which helps to perform key set size data 彳 _ before completeness correction of optical proximity effect _ _ completeness and accuracy, and then effectively control the key figure size of the product The following describes the hot plate, w of the second embodiment of the present invention with reference to FIGS. 4 and 5.

〇503-8509TWf (Nl); TSMC2002-0512; 2001-0511; Spin.ptd% 12 ΐ " " ----- 200418114

Method for monitoring temperature and thermal uniformity. Please refer to the hot plate temperature ^ heat map according to the second embodiment of the present invention, which shows the flow chart of the method for monitoring the homogeneity control wafer one hundred years ago, proceed to step S20 to establish a photoresistor closing plate temperature. Relevance. Please refer to FIG. 5, which shows the relationship between the pattern size and the thermal pattern size and the temperature of the hot plate. Step S2 0 0 is provided to provide a substrate, such as a silicon crystal. First, the step is performed. Next, step S202 is formed on the substrate to be used as a control film, and a photoresist layer is applied to the photoresist layer. Resistive pattern layer. The lithography process involves forming a light-baking treatment with a ^^ f, such as soft baking or post-exposure baking. The wide-resistance layer implements a step S204 performed by a snowman, a snowman, and a step-by-step method, and measures the photoresist pattern layer by using a tracing electron microscope, such as a CD_SEM, or a scatterometer, such as a full-spectrum ellipse + meter. Key graphic size. In this embodiment, if a scatterometer is used, measurement can be performed in accordance with steps s1-4 to S148 in the first embodiment. Next, step S206 is performed, and the temperature of the hot plate in step §202 is changed, and steps S200 to S204 are repeated. Finally, step S206 is repeated to obtain the corresponding relationship with the key pattern size of the photoresist pattern layer at different hot plate temperatures.

Next, step S22 is performed to measure the key pattern size of the photoresist pattern layer on a product with a scatterometer, as shown in FIG. 3. The photoresist pattern layer has been baked on a hot plate at a set temperature, for example, soft baking or post-exposure baking. The measurement method is as described above, and its description is omitted here. Next, step S24 is performed, using the measurement results and the result of step S20.

0503-8509TWf (m); TSl \ O002-0512; 2001-0Ml; Spin.ptd page 13 200418114 V. Description of the invention (9) Correspondence to create a positive m & Finally, go to the pattern layer Hot plate temperature everywhere. Corresponding to the temperature of the hot plate, it is necessary to detect these errors by the above-mentioned correlation to the heat of the above-mentioned related household boards. At the same time, check whether the temperature of the hot plate and the original setting of the hot plate are abnormal. When the range of the c management is to monitor the temperature of the hot plate, the process can be interrupted and the c is abnormal or the thermal uniformity is poor, the designed size is consistent to ensure that the key graphic size of the product is the same as that of the embodiment of the present invention. The uniformity of the hot plate temperature and the key graphic size of the hot average product can be used for on-line measurement and the uniformity of the number and configuration of large-scale sensors. At the same time, there is no need to interrupt the system to increase production capacity. The way the radiograph measures the size of the key graphics is monitored, and it accurately and accurately grasps the response. Moreover, compared with the conventional technology, the measurement of the scatter, so that the hot plate temperature and heat path can be accurately detected for offline detection without being limited by temperature, which is effective although the present invention has limited Invention, any person familiar with this god and scope, when it can be changed and when the scope of the patent application attached to the attached example is disclosed as above, but it is not for the skilled person, without departing from the refined decoration of the present invention, so the present invention The scope of protection shall prevail.

200418114 Brief Description of Drawings Figure 1 is a flowchart showing a method for controlling a key graphic size according to the first embodiment of the present invention. Fig. 2 is a flow chart showing a method for measuring the size of a key figure by the scatterometer in Fig. 1. FIG. 3 is a schematic diagram of measuring a photoresist pattern layer with an ellipsometer. Fig. 4 is a flow chart showing a method for monitoring a hot plate temperature and its thermal uniformity according to a second embodiment of the present invention. Fig. 5 is a flow chart showing a method for establishing the correlation between the key pattern size of the photoresist and the temperature of the hot plate in Fig. 3. Line 6a shows the relationship between the change in soft baking temperature and the change in the outline of the photoresist pattern. Figure 6b is a graph showing the relationship between the change in baking temperature after exposure and the change in the contour of the photoresist pattern. [Symbol description] 10 ~ light source generator; 12 ~ rotating polar plate; 14 ~ analyzer; 16 ~ detector; 100 ~ substrate; 102 ~ photoresist pattern layer; I ~ measuring beam ; I '~ reflected polarized light beam.

0503-8509TWf (Nl); TSMC2002-0512; 2001-0511; Spin.ptd page 15

Claims (1)

200418114 Scope of patent application: A method for controlling the size of a key pattern, which is suitable for optical proximity effect correction, includes the following steps: for a substrate with a / photoresist layer formed on it; by using a / test mask with a plurality of test patterns Carry out a U-heart private sequence on the photoresist layer to form a photoresist pattern layer; measure the key pattern size of the photoresist pattern layer with a scatterometer side; and use the key pattern sizes of the test patterns and their corresponding The measurement results establish a mask pattern size database, which includes each of the test pattern sizes and the corresponding photoresist pattern layer size; and the mask pattern size database is used to correct the pattern ruler of a product mask. Inch to control the key graphic size of the product. 2 · The method for controlling the key figure size as described in item i of the patent application scope, where the 3 · as the application method, where the structure depends on different spacing 4. as the application method, where the 5. as the application method, where the area. 6. If the method is applied, which 7. If the application is based on a silicon wafer. The test pattern such as the key figure ^ ruler / control described in the first item of the patent scope is composed of different lines ... several grid-like junctions. d 4 The size of the key pattern size of the rewind j is equal to the grid width of the grid-like structure No. 3 i: The shape-size control of the patent scope No. 3 is also the range of the grid-like structure from 3 to 5 ^ The control of the key figure size between @ I 1 and the profit range of the 1st circle meter. The scatterometer is a full light ^ control of the key figure size. 0503-8509TWf (Nl); TSMC2002-0512; 2001-0511; Spin.ptd Page 16 200418114 Six 'Patent Application Method' Steps: Provide-the bottom size is changed to generate a plurality of numbers. Photoresist pattern ^ 8 · Rushen method 'Where. Measuring the photoresist pattern layer with the scatterometer includes the following steps: a first predetermined trapezoidal pattern, which includes at least an upper base size, a height size, and a height size; changing the upper base size, the lower base size, and the height size to Two predetermined trapezoidal patterns; waiting for the second predetermined trapezoidal pattern to generate a plurality of predetermined spectra; a spectrum of the photoresist pattern layer; and a spectrum of the photoresist pattern layer and the predetermined spectra to obtain the second predetermined trapezoid corresponding to the spectrum pattern. '' Please control the key graphic size as described in item 7 of the patent scope. These predetermined spectra are produced by a computer simulation software software. Steps are set up: _ Monitoring of the temperature and thermal uniformity of a first hot plate The method includes the correlation between the key pattern size of the photoresist and the temperature of the hot plate; the scatterometer measures the key pattern size of the light beam and the pattern layer after a first baking process is performed through a hot plate; and the result of using the remaining amount and the Correspondence corresponds to a plurality of hot plate temperatures; by detecting the temperature of the hot plates and comparing the temperatures of the hot plates with the temperatures set by the ... plates, at the same time p 彳 the temperature of the hot plates and their Hot uniform ten-year Q "now i 〇 · The temperature of the hot plate and its heat average as described in item 9 of the scope of patent application 200418114 Uniformity monitoring method, Gan + u) Provide _ A bottom to establish the correlation includes the following steps: α ί bottom, which is covered with-photoresist layer. Physical; hot plate performs a second baking on the photoresist layer (C) measure the temperature of the (d) repeated step plate; and the key pattern sizes (a) to (c) of the two photoresist pattern layers and change the step (d), repeat the step (d) In order to obtain the corresponding relationship between the different 埶 ^ and the key pattern size of the photoresist pattern layer, the method of monitoring the uniformity of the hot plate as described in item No. 丨 0 of the patent application scope, The No.-baking place, Dian Du, and "," ,, Bake. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, A Temperature and temperature control method, in which the first: photoresistance, the key pattern size of the layer of Figure 1 are measured by a scatterometer. 13. The temperature of the hot plate and its thermal uniformity as described in item 12 of the scope of patent application The monitoring method, wherein the scatterometer is a full-spectrum ellipsometer. 14_ As described in item 10 of the scope of patent application The temperature of the hot plate and its thermal average sentence I " Control method of birth " wherein the key pattern size of the second photoresist pattern layer is measured by a scanning electron microscope. 1 5. As described in item 9 of the scope of patent application Method for monitoring the temperature of a hot plate and its thermal uniformity, wherein measuring the photoresist pattern layer with the scatterer includes the following steps: Page 200418114 6. The scope of Shenqing's patent provides a first predetermined trapezoidal pattern, which includes at least an upper base size, a lower base size, and a height size; respectively, changing the upper base size, the lower base size, and the height size To generate a plurality of second predetermined trapezoidal patterns; to generate a plurality of predetermined spectra corresponding to the second predetermined trapezoidal patterns; to measure the spectrum of the test pattern of the photoresist pattern layer; and to compare the spectrum of the test pattern with the predetermined patterns Spectrum to obtain the second predetermined trapezoidal pattern corresponding to the test pattern. 16. The method for monitoring the temperature and thermal uniformity of the hot plate & as described in item 15 of the scope of patent application, wherein the predetermined spectra are generated by a computer simulation software. 1 7 · As for the method of monitoring the latitude and thermal uniformity of the hot plate as described in item g of the scope of patent application, the scatterometer in # is a full-spectrum ellipsometer. 18. The method for monitoring the temperature of the hot plate and its thermal uniformity as described in item 9 of the scope of the patent application, wherein the first baking treatment is soft baking or baking after exposure.