TW200402106A - Method for detecting an end point in a dry etching process - Google Patents

Abstract

An etching end point is detected on a selected layer out of multi-layers deposited on a semiconductor substrate or on the semiconductor substrate, by making a spectrum analysis according to etching times on a light that is generated during a dry etching process on the semiconductor substrate inserted in a process chamber. The spectrum analysis is realized by mounting the substrate in the process chamber, etching the substrate using a plasma, detecting an light emitted from a view port installed on the process chamber wall during the dry etching process, and spectrumizing the light and extracting the spectrum by according to a dry etching time, to obtain intensities of more than one specific wave. Based on data obtained from the normalization, normalization plus differentiation, or operations to find interactive relations between wavelengths of the specific waves, the method enables a user of a semiconductor dry etching apparatus to easily find an etching end point on the substrate or on a selected layer on the substrate after a lapse of a predetermined etching time. The method improves reliability and yield of a semiconductor device, by reducing etching damages on the substrate or an underneath layer under the selected layer on the substrate during the dry etching process.

Description

200402106 V. Description of the invention (1) Background of the invention 1. Field of the invention The present invention relates to a method for detecting an end point during a dry etching process, and more particularly to a method for using a semiconductor dry etching device in a processing chamber during a dry etching process. A method for detecting the end point of the generated light during the dry etching process. 2. Description of related technologies In recent years, semiconductor devices have been highly integrated into 5 12 Mega D DRAM (Dynamic Random Access Memory) and 1 G i D DRAM. With the development of semiconductor technology, the importance of the etching function of making dry patterning devices with narrow line widths and micro-patterns on semiconductor substrates has also increased. A related art dry etching device allows a user to detect an etching end point during a dry etching process of a semiconductor device having a plurality of layers deposited on a semiconductor substrate and a layer selected from the plurality of layers, such as a high-density DRA M (dynamic RAM) , High-speed SR AM (static RAM), or highly integrated MR AM (magnetic RAM). This type of detection technology typically uses a filter or a monochromator. According to the detection technology described above, the semiconductor dry etching device is self-supported by detection and spectroscopy as a result of the reaction between the semiconductor substrate and the plasma. The light produced by the π lab. The semiconductor substrate consists of a lower layer and an etched layer above. However, this technique proved to be insufficient to show the user a correct etch endpoint, which determines whether to etch all multiple layers or only specific layers, because the technology is based on a processing room that uses a single wavelength to detect self-defined engraving devices. A specific wave of emitted light uses a specific wave, in other words' a specific wave does not always represent half of it in immediate mode

200402106 V. Description of the invention (2) The state in the processing chamber of the conductor dry etching device. In addition, the detection technique described above finds the intensity of a specific wave and the end point of the etching at a predetermined etching time. The specific wave is etched by the main money on the worm-etched layer and worm-etched on the lower layer. It is formed by the light beams generated by the ions or radicals that make up the plasma. Once again, if the thickness of the film deposited on the underlying layer is not constant, this technique cannot detect the end of the etch. The semiconductor dry etching device includes an observation hole in the wall of the processing chamber, and the observation hole is a window through which light generated by ions or radicals constituting the plasma passes through the window before being transmitted to the outside. When the cleaning cycle in the processing room is prolonged due to manufacturing line problems, polymers produced by repeated dry etching processes are accumulated in the observation hole. As a result, if the semiconductor dry etching device detects the light generated by the plasma from the processing room, and if the intensity of a specific wave of light is very low due to excessive polymer attached to the observation hole, the user cannot Use this dry etching device to find the end of the etch. It is generally known that the intensity of the light generated by the plasma is proportional to the remaining area of the semiconductor substrate 'considering the recent trends accompanying semiconductor devices', that is, high integration and high density, and reduced light intensity, so the reason to develop a new The method to detect the end of the etching is very urgent. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for detecting an etching end point during a dry etching process.

Page 10 200402106 V. Description of the invention (3) This method can easily and accurately detect the end point of etching on a semiconductor substrate or a selected layer on the substrate when the multilayer of the material is used. Exemplary embodiments are described in detail. Reference will now be made in detail to exemplary embodiments of the invention, which are illustrated in the accompanying drawings. FIG. 1 is a schematic diagram of a semiconductor dry etching device, and a semiconductor substrate is installed there, and FIG. 2 is a flowchart of processing, which illustrates a method for detecting an etching end point using the semiconductor dry etching device of FIG. Referring to FIGS. 1 and 2, the semiconductor dry etching device 5 includes a processing chamber 10, a detection section 3 2, a detector 3 4, and a main control section 36. The bottom of the processing chamber 10 is used as a foot on which the lower electrode 12 and the semiconductor substrate 16 can be installed, the upper electrode 14 is installed on the top of the chamber, and the observation hole 30 is placed in the chamber. 10 of the sidewalls. The upper and lower electrodes 12 and 14 allow a process gas (not shown) transferred into the processing chamber 10 to enter the plasma. The observation hole 30 is used as a window to guide the light generated by the reaction between the layer deposited on the semiconductor substrate 16 and the plasma to the outside of the processing chamber 10. The detection section 32 is placed at a distance from the observation hole 3 0-a predetermined distance, which detects or captures light emitted from the processing room 10. The detector 3 4 connected to the detection section 3 2 generates more than one specific wave by spectralizing the light and using the spectrum. According to the dry etching method, these specific wave systems are obtained by subdividing the spectrum into spectral traces having more than one wavelength. The lower and upper electrodes 12 and 14 are respectively supplied with electricity 2 8 and they are grounded at the same location. The method of detecting the end of the etching during the etching will now be described with reference to Figs.

Page 11 200402106 V. Description of the invention (4) In this method, the semiconductor substrate 16 is first installed on the lower electrode 1 2 (S 2) in the processing chamber 10, and the process gas is injected into the processing chamber 1 0 At the same time, power 28 is supplied to the lower and upper electrodes 12 and 14 to etch a layer formed (or deposited) on the semiconductor substrate 16 (S4). Here, the semiconductor substrate 16 is at least a single layer. On the other hand, the process gas in the processing chamber becomes a plasma of the semiconductor substrate 16 and the layer etched on the substrate 16 Is the plasma. Due to the reaction between the plasma and the layers on the semiconductor substrate 16, light is generated in the processing room 10, and this light passes through the observation hole 30 in the processing room 10, and is radiated to the outside of the processing room 10 and caused by Detection part 3 2 detection (S 6). The detection portion 32 is placed at a predetermined distance in front of the observation hole 30, and is also connected to the detector 34. During the etching process, the detected light is spectrally detected by the detector 34 in a real-time mode and stored in the semiconductor dry etching device 5 (S8). The spectrum is further divided into more than one specific wave by wavelength according to the dry etching time (S 1 0), and the specific wave is normalized by selecting the wavelength and dividing other wavelengths by the selected wavelength (S 1 2). These standardized specific waves are differentiated (S 1 4) according to the dry etching time, and the differentiation can be performed on the standardized specific waves at at least one time. The user can use these specific and then differentiated specific waves to calculate the reflex point based on the dry etching time (S 1 6). Calculating the rebate point means calculating the number of rebate points passing through the rebate band with an allowable (deviation) limit of 0 to 0.15, and the rebate point has a differential value of '0'. More specifically, calculating the rebate point includes calculating its differential value from (+) to (-), from (-) to (+), or from '0' to (+) or (-) Value of the number of inflection points, however, this

Page 12 200402106 V. Description of the invention (5) The calculation method will not start until the initial dry etching has been performed for a predetermined time. In other words, after the initial dry etching time, by using the specific wave that has been normalized and then differentiated to calculate the turning point with a differential value of '0', those times that are not reflected in the dry etching state of the selected layer of the substrate Vertices are excluded from self-counting. Therefore, the user first specifies an etching time and calculates the number of turning points after that time to obtain a desired turning point (S 1 8). Preferably, the number of calculated turning points ranges from 1 to 1, 0 0 0. In the method of detecting the etching end point, the desired turning point is the etching end point at a predetermined dry etching time. After the inflection point is calculated, the slope at the end of the etch is greater or less than the slope selected by the particular wave that has been normalized and differentiated. FIG. 3 is a cross-sectional view of the semiconductor substrate illustrated in FIG. 1, where the semiconductor substrate includes a photoresist layer and multiple layers deposited one after another, and FIG. 4 is a display corresponding to FIG. 1 is a diagram of the same and specific waves of two lights emitted from a processing chamber of the semiconductor dry etching apparatus of FIG. 1, wherein the two lights are detected during dry etching of two semiconductor substrates in the processing chamber, FIG. 5 is a diagram illustrating the normalized wave of FIG. 4 and FIG. 6 is a diagram showing a normalized specific wave different from the wave of FIG. 4 and a specific wave differentiated after the standard dagger With reference to Figures 3 to 6, a photoresist layer 26 and first to fourth layers 18, 20, 22, and 24 are sequentially deposited on a semiconductor substrate 16 to cause photoresist. A resist layer 26 is on top of the fourth layer 24. Preferably, the first to fourth layers 18, 20, 22, and 24 are insulating layers or conductive layers, it is also possible

Page 13 200402106 V. Description of the invention (6) It is an alternating layer of insulating layer and conductive layer to produce a desired pattern on the substrate 16. Based on the optical process of the related art, the opening portion 27 is formed on a predetermined region of the photoanti-I insecticide layer 26 on the substrate 16. Thereafter, the etching method is performed on the fourth layer 24 using the photoresist layer 26 as a mask and the third layer 22 as an etching buffer film. An etching method known in the related art is performed by the semiconductor dry etching apparatus 5 of FIG. 1. In this case, the third layer 22 is an insulating layer and the fourth layer 24 is a conductive layer, or vice versa. The device 5 spectra the light generated by the ions or radicals that make up the plasma, and the detector 34 generates a specific wave with only one wavelength at a known dry etching time. Described below is a method of detecting the end point of the etching in the third layer 22 when the third and fourth layers 22 and 24 are deposited on the semiconductor substrate 16. If there is a semiconductor substrate with third and fourth layers 22, 24 deposited under the same environmental processing chamber 10, FIG. 4 illustrates different specific wave-drying etching devices 5 showing that if in a cleaning cycle When the number of stacked sheets to be etched inside is different from that of the substrate. For example, one W 1 of the specific waves W 1 and W 2 is data obtained from a dry etching process performed on the 100th substrate 16, and the number of stacked wafers is known to be 9 9. In the same way, the other W 2 is the data obtained from the dry rest process performed on the 1000th substrate 16, when the number of stacked pieces is 9 9 9. It can be concluded from Figure 4 that at the same dry etching time, the intensity of the specific waves W 1 and W 2 is inversely proportional to the number of stacked sheets. This is because the polymer is often stuck to the observation hole 3 0 of the processing chamber 10 of Figure 1 In particular, when the dry etching process continues for an extended period of time, the detection section 32 cannot detect the light emitted from the processing chamber 10. In this case, the first thing the user can do is to select a W1 wavelength of the specific waves W1 and W2, and

Page 14 200402106 V. Description of the invention (7) The remaining wavelengths of W 1 and W 2 are divided by the selected wavelength of ψ 1 to standardize the specific wave, and the remaining wavelengths are here designated as the reference value. The reference value may consist of a maximum sharp # value selected by the wavelengths of the specific waves W1 and W2 or any value smaller than the maximum sharp bee value. FIG. 5 illustrates the standardized specific waves W3 and W4. Referring to FIG. 5, although the difference between the wavelength intensities of the specific waves W1 and W2 at the known dry etching time is quite large, once the standardized specific waves W3 With W 4 being used, this gap can be significantly reduced. When the third and fourth layers 22 and 24 in FIG. 3 ^ are substantially thin and micropatterns ^ are formed using the fourth layer 24, it is more necessary to normalize the specific waves 1 and ^ 2 because of using The user hopes to prevent the attack from the dry etching process at 20, and the user always wants to find the end point of the etching from W 4 regardless of the number of stacks. In fact, it is found that the intensity of the detected light without any difference in the end point of the etch may have been changed due to the deposition, the standardized specific wave W 3, and then the standardized specific wave W 3 points, which helps the user more It is easy to find the specified part of the pulp and the semi-supply light with the third and fourth layers 22 and 24, and here, the specific point W 3 of the turning point and the differential value at the turning point is 0. The state of the dry etching process performed on the processing chamber 106 is expected to be through the standardized and then differentiated stack of the semiconductor substrate 16 on the specific wave W 3 and the use of a dry etching device is felt. 5, because when the detection part 3 2 observes the polymer on the hole 30 and W4 will be changed together. And W4, the dry etching time is less than that between the electric conductor substrate during the dry etching process. Body base: Only ^, then, this turning point makes the special wave expected to add more accurately

200402106 V. Description of the invention (8) The state of the laboratory and the state of the semiconductor substrate 16 are possible. This is because it is often difficult to distinguish the designated part via a standardized specific wave after a predetermined dry etching time. Yes, but when a particular wave is normalized and then differentiated, the user can easily check the specified portion during the dry etching time. To help the user more easily check the designated portion, the standardized specific wave can again differentiate the dry etching time. Unlike Figures 4 and 5, Figure 6 illustrates the standardized, differentiated specific waves W 5 and W 6 of a specific wave (not shown) with a single wavelength, which is at an extended dry etching time Periods are obtained in immediate mode. As described above, the normalized and then differentiated specific wave W 6 shows a clearer turning point than the normalized specific wave W 5, which helps the user to more quickly check the processing room 10 and the semiconductor substrate. 1 remaining state on 6. In summary, the present invention can also be applied to a specific wave having a single wavelength, where the specific wave is standardized and then differentiated, so that a user can easily check a turning point indicating the state of the processing room 10 and identify the The turning point is the end point of the dry etching process. FIG. 7 is an explanatory diagram showing a method of detecting an etching end point and finding a dry etching time when all the specific waves are seen by dividing light emitted from the processing chamber of FIG. 1 into more than one specific wave. And FIG. 8 is a diagram showing another method for detecting the end point of etching using the remaining specific waves after a part of more than one specific wave meets the requirements of the method according to FIG. 7. Figures 9 and 10 are diagrams showing another method for detecting the end of the etching using a specific wave at a predetermined dry etching time, respectively. The specific wave system

Page 16 200402106 V. Description of the invention (9) Selected from many specific waves, these waves are monitored based on the environment of the processing room based on the method in Figure 7. Referring to FIGS. 7 to 10, contact holes or lines (not shown) are formed on the semiconductor substrate 16 of FIG. 3, and a photoresist layer 26 and first to fourth layers 18, 20, and 22 are formed. , And 24 are deposited on a semiconductor substrate 16. The formation of contact holes in the semiconductor substrate 16 is performed by opening portions 2 7 through the photoresist layer 26 using a semiconductor dry etching device 5-one after another to etch the first to fourth layers 18, 20, 22, and 24. This line can be formed by using the photoresist layer 26 as a mask to sequentially and dryly pass through the opening portion 27 to form a layer composed of the first to fourth layers 18, 20, 22, and 24. The method of detecting the end point of the etching during the dry etching process using the light generated in the processing chamber between the plasma and the substrates composed of the first to fourth layers 18, 20, 22, and 24 will now be explained. First, the light generated during the dry etching process on the first to fourth layers 18, 20, 22, and 24 is changed to more than a specific wave at the detector 34 of FIG. According to the algorithm of this method, the exposed substrate 1 is not obtained until all the intersections P1, P2, P3, P4, P5, P6, and P7 of the specific wave are seen on the index line A in Fig. 7 6 desired etching end point. Once the above requirements are met, the user or the dry etching device recognizes these points as the desired etching end point at a predetermined dry etching time. If one or more specific waves do not satisfy the algorithm, the above method informs the user through the algorithm that the dry etching process has not been completed. Furthermore, if the intensity of a particular wave is weak or low, the method can be applied after normalizing the particular wave and after normalizing and differentiating the particular wave. And this method can be used by using the selected specific wave (as

Page 17 200402106 V. Description of the Invention (Figure 6) After the specific wave is normalized and after the specific wave is normalized and differentiated, it can still be applied. The algorithm in Figure 7 differs from the algorithms in Figures 4 to 6 in that the user is free to choose one of the specific waves generated or detected by the detector 34, and the user can therefore more quickly Dealing with process changes in the manufacturing line. The dry etching device 5 can etch the semiconductor substrate 16 by a detection method incorporating another algorithm different from the algorithm shown in FIG. 7. According to the algorithm, when the first to fourth layers 18, 20, 22, and 24 in FIG. 3 are etched, the monitoring method first lies in the rest of the specific waves W 8, W 9, and W1 0 in FIG. 8 The specific waves W9 and W10 are performed, and the specific wave W8 is not included. As shown in the graph of FIG. 8, the intersection points P 9 and P 1 0 of the specific wave at a predetermined dry etching time are seen on the index line B and when the specific wave is determined at another predetermined dry etching time. When the intersection point P8 of W8 is seen on the index line B ', the etching end point is designated, and a signal showing the etching end point is sent to a user or a semiconductor dry etching device. That is, the above-mentioned etching method is based on an algorithm having a requirement that the first layer 18 is not etched until the second to fourth layers 20, 22, and 24 are all removed on the first layer 18. Using this algorithm, users can form contact holes or lines on the semiconductor substrate 16. Even when the intensity of the above specific waves W 8, W 9 and W 10 is weak, this algorithm can be applied to the standardized specific waves and the standardized and differentiated specific waves. Finally, a method for detecting the end point of etching based on another algorithm will now be described. When the environment in the processing chamber of the semiconductor dry etching device 5 is changed due to a cleaning cycle, or when the environment in the processing chamber 10 is different from the previous one

Page 18 200402106 V. Description of the invention (11) This method is preferred when the dry etching method with different etching methods is performed (mainly because different process gases are injected into the processing chamber 10). FIG. 9 is a diagram showing the environment of the processing room after the change is made, and FIG. 10 is a diagram showing the environment of the processing room after being stabilized. In these cases, the semiconductor dry etching device 5 stores two specific waves. , Which respectively correspond to the two situations after the environment of the processing room 10 is changed and when the environment of the processing room 10 is stabilized by the detector 34 in FIG. 1. As shown in FIG. 9, after the environment of the processing room 10 is changed, two intersection points P 1 1 and P 1 2 of two specific waves at a predetermined dry etching time are detected on the index line C, The user then recognizes that the time when one of the intersections P 1 1 and P 1 2 is displayed is the end point of the etching. In a similar manner, as shown in FIG. 10, when the environment of the processing chamber 10 is stabilized, two crosses of two specific waves having a waveform different from the waveform of FIG. 9 at a predetermined dry etching time The points P 1 3 and P 1 4 are detected on the index line D, and then the user recognizes that the time when one of the intersections P 1 3 and P1 4 is displayed is the end point of the etching. For the environment of each of the processing chambers 10 discussed above, because of the etching state of the dry etching device 5, the user can selectively select one of two specific waves. Based on these methods, the present invention helps the user to more easily find the end of the etch process during the dry-etch process on the substrate 16 using more than one specific wave, to cope with the dry etching state on the substrate with multiple layers or Environment of the processing room. FIG. 11 is a diagram in which light emitted from a processing chamber of a semiconductor dry etching device is divided into more than one specific wave, and the emission occurs during a famous substrate etching process of a semiconductor substrate. By 4

Page 19, 200402106 V. Description of the invention (12) The pattern formed in the opening portion of the photoresist layer to form a contact hole, and Figure 12 is a diagram illustrating the inspection by checking Figure 11 The main factors obtained from the inter-related calculations of all specific waves and other calculations about the wavelengths of specific waves, are the identifiable lines of relationship based on the dry etching time. Referring to FIGS. 11 and 12, many contact holes are formed on the semiconductor substrate of FIG. 3, and a photoresist layer 26 and first to fourth layers 18, 20, 2 2, and 24 are deposited on On the semiconductor substrate 16. The formation of contact holes on the semiconductor substrate 16 is based on the related art using photoresist 26 as a mask to dry-etch the first to fourth layers one by one 18, 20, 22, and 2. 4 are formed. The semiconductor substrate 16 is exposed through the contact hole. Here, the first to fourth layers 18, 20, 22, and 24 react with the plasma, and as a result, they obtain wavelengths different from each other and are formed in the processing room. The light inside 10 is shown in Figure 1. The light passes through an observation hole 30 installed on the wall of the processing room and is detected by the detection section 32. The light is spectralized at the detector 34 connected to the detection section 32 and is Split into more than one specific wave. According to the dry etching method, these specific wave systems are obtained by dividing the spectrum into spectral trajectories having more than one wavelength. FIG. 11 is obtained by performing spectral analysis on this light and plotting specific waves W 1 1, W 1 2, W 1 3, and W 1 4 in a semiconductor dry etching apparatus 5. However, it is often difficult for the user to read the map to find the end of the I-carve through a specific wave track at a predetermined dry I-carve time. This is because the picture is not like the pictures of FIGS. 7 to 10, which The figure does not show specific portions of specific waves W 1 1, W 1 2, W 1 3 and W1 4 during any dry etching time. Therefore, to find the end of the etch, the specific waves W1 1, W1 2 'W1 3 and W 1 4 should be standardized

Page 20 200402106 V. Description of the invention (13) Or it is standardized and then differentiated. If the specific waves W 1 1, W 1 2, W 1 3, and W 1 4 are obtained through a long dry etching process, the user must spend more time to standardize and differentiate the specific waves W 1 1, W 1 2, W 1 3 and W 1 4 and even when the user continues to change the wave through normalization and differentiation, it is not easy to analyze the specific wave that has been changed. As an attempt to solve the above problems, there are specific waves W 1 1.

W 1 2, W 1 3, and W 1 4 are another method for detecting the end point of the etching. The user does not need to perform standardization and differentiation to change the specific waves W 1 1, W 1 2, W 1 3, and W14. As illustrated in Figure 11, when the wavelengths of the specific waves Wll, W12, W13, and W14 are stored in the detector 3 4 in real-time mode according to the dry etching time, the user first specifies the wavelengths of the specific waves Wll, W12, W13, and W14. The reference value of each, and the remaining wavelengths including the specific waves W 1 1, W1 2, W 1 3, and W 1 4 are divided by the reference value to normalize the wavelength. Next, the user performs mutation and covariation operations on the standardized wavelengths to check specific waves

Interaction between W 1 2, W 1 3, and W 1 4 Here, the results of the mutation and covariation operations become elements of the mutation and covariation matrices, respectively. The eigenvalues are obtained from a matrix and using the eigenvalues, the user can obtain the eigenvectors. These eigenvectors are the main factor in arranging the interaction relationship between the wavelengths of specific waves wn, W1 2, W1 3, and ¥ 14 in the order of contribution. Finally, users replace a known equation with eigenvectors and standardized wavelengths to obtain more than one connection. Generally, the number of connections and eigenvectors is as large. The user can choose from the connected lines' of the feature vector with the most contributions and ignore other related lines. Fig. 2 illustrates a gate line W1 5 according to the dry etching time. Therefore, Guanlian W1 5 series is based on the features with the most contributions.

Page 21 200402106 V. Description of the invention (14) It is obtained from the feature vector, which represents the environment of the processing chamber 10 and the etching state on the substrate 16 during the dry etching process. Using the gate line w 1 5, the user can easily detect the end of the etching at a known dry etching time. As discussed so far, the user can detect the end point of the etch by using light generated by the ions or radicals that make up the plasma in a dry etching process on a semiconductor substrate having multiple layers. That is, the present invention is based on an algorithm for easily and accurately detecting the end point of an etching by a semiconductor dry etching device's detector to spectrally illuminate the light and form more than one specific wave under different environments in the processing room. In this way, the semiconductor dry etching device can more easily complete the etching method on the substrate or a selected layer on the substrate to ensure the reliability of the semiconductor device and to improve the production of the semiconductor device on the substrate. rate. Although the present invention has been particularly shown and described with respect to its exemplified embodiments, it will be apparent to those skilled in the art that previous and other changes in form and detail may be made without departing from the spirit and scope of the invention.

Page 22 200402106 Brief Description of Drawings Figure 1 is a schematic diagram of a semiconductor dry etching device. A semiconductor substrate is installed here. Fig. 2 is a flow chart of processing, which illustrates a method of detecting an etching end point using the semiconductor dry etching apparatus of Fig. 1. Fig. 3 is a cross-sectional view of the semiconductor substrate illustrated in Fig. 1. The semiconductor substrate includes a photoresist layer and multiple layers deposited one after the other. FIG. 4 is a diagram showing the same and specific waves corresponding to two lights emitted from the processing chamber of the semiconductor dry etching apparatus of FIG. 1, respectively, where the two lights are on two semiconductor substrates in the processing chamber. Detected during the dry I worm. FIG. 5 is a diagram illustrating the normalized wave of FIG. 4. Fig. 6 is a diagram showing a normalized specific wave different from the wave of Fig. 4 and a differentiated specific wave after normalization. FIG. 7 is an explanatory diagram showing a method for detecting an etching end point and finding a dry etching time when all the specific waves are seen by dividing the light emitted from the processing chamber of FIG. 1 into more than one specific wave. Fig. 8 is a diagram showing another method for detecting the end point of etching using the remaining specific waves after a part of more than one specific wave meets the requirements according to the method of Fig. 7. Figs. 9 and 10 are diagrams showing another method for detecting an etching end point using a specific wave at a predetermined etching time. The specific wave is selected from many specific waves. These waves are based on the method of Fig. 7 according to the processing room. Environment is monitored0

200402106 Brief Description of Drawings Figure 11 is a diagram in which the light emitted from the processing chamber of a semiconductor dry etching device is changed to more than a specific wave. This emission occurs during the etching process of a semiconductor substrate. This semiconductor substrate has many A pattern formed by the opening portion of the photoresist layer of FIG. 4 to form a contact hole. Fig. 12 is a diagram illustrating the main factors obtained by examining the correlation between all the specific waves in Fig. 11 and other calculations regarding the wavelength of the specific wave. It illustrates the identifiable relationship line based on the dry etching time. Element symbol description: 5 semiconductor dry etching device 1 0 processing chamber 1 2 lower electrode 14 upper electrode 16 semiconductor substrate 18, 20, 22, 24 first to fourth layer 2 6 photoresistive agent layer 3 0 observation hole 36 Main control part W 1-1 4 Specific wave 2 7 Opening part 2 8 Power 3 2 Detection part 3 4 Detector P 1-1 4 Crossing point A-D indicator line W1 5 Off connection

Page 24

Claims (1)

200402106 VI. Scope of patent application 1. A method for detecting the end point of a money engraving process in a dry process. The method includes the steps of: performing a plasma on a semiconductor substrate inserted into a processing chamber: the free process (or Dry etching process); detecting more than one specific wave generated during the plasma etching process; using a reference value to normalize each specific wave; differentiating each normalized specific wave; calculating the normalized and then differentiated The number of retrace points with '0' differential values in a particular wave; and checking an etch endpoint based on the calculated number of retrace points. 2. The method according to item 1 of the scope of patent application, wherein the step of detecting more than one specific wave includes sub-steps: spectroscopy light emitted from the processing chamber during the dry etching process in an instant mode; The spectrum is a spectral trace with more than one wavelength. 3. The method according to item 1 of the scope of patent application, wherein the reference value is a maximum spike of the specific wave or any value smaller than the maximum spike. 4. The method according to item 1 of the scope of patent application, wherein the calculation of the rebate point is characterized by the calculation of a rebate band including a previously determined ± permitted (allowable) limit and a rebate with a '0' differential value The number of points. 5. The method according to item 1 of the scope of patent application, wherein the feature of calculating the rebate point is to calculate the number of rebate points with a '0' differential value and the consecutive rebates that have not been refolded after being refolded once. The number of points. Page 25 200402106 6. Scope of patent application 6. The method according to item 4 of the scope of patent application, wherein the permissible limit ranges from 0 to 0 · 15. 7. The method according to item 1 of the patent application range, wherein the number of calculated rebates ranges from 0 to 1, 0 0 0. 8. The method according to item 1 of the scope of patent application, wherein the number of retrace points having a '0' differential value in the standardized and differentiated specific wave is calculated after a predetermined time has elapsed. 9. A method according to item 1 of the patent application, wherein the standardized specific wave is differentiated at least once. 10. The method according to item 1 of the scope of patent application, wherein after the rebate point is calculated, the end point of the moment is at a value greater than or less than one of the standardized and differentiated specific waves obtained from more than one The point of the selected slope value is checked. 11. The method according to item 1 of the patent application range, wherein the etching end point is inspected at a predetermined dry etching time by detecting a specific wave with a single wavelength from the light. 12. The method according to item 1 of the scope of patent application, wherein the inspection of the etching end point can be achieved by the specific wave formed from light and then looking for a dry time with a predetermined time when one of the requirements for all the specific waves is seen. 13. The method according to item 1 of the patent application scope, wherein checking the etch end point can be achieved by one of the specific wave obtained from light and then selecting the specific wave at a predetermined dry etching time. 14. The method according to item 1 of the scope of patent application, wherein the inspection of the etching end point can be seen by the inspection tool when a specific wave other than a specific wave is viewed. Page 26 200402106 VI. Scope of patent application After one of the pre-determined dry etching times, check another predetermined dry etching time when the one particular wave is seen. 15. The method according to item 1 of the scope of patent application, wherein checking the end point of the etching can be doubled to see the specific wave after the environment in the processing chamber is changed and after the environment in the processing chamber is stabilized, And it is achieved using a specific wave selected from one of the specific waves according to the environment of the processing room. 16. —A method for detecting an etching end point during a dry etching process, the method comprising the steps of: performing a plasma etching process (or dry etching process) on a semiconductor substrate inserted into a processing chamber; detecting the electrical More than one specific wave generated during the process of making rice meal; using a reference value to standardize each specific wave; forming a mutation and co-variation matrix for the individual wavelengths of the standardized specific wave; obtaining the variation and co-variation matrix Eigenvalues; use the eigenvalues to obtain eigenvectors; select more than one major factor from the eigenvectors; substitute a known equation with more than one major factor and the wavelength of the specific wave to obtain the connection; and use the connection One checks an etch endpoint at a predetermined dry etch time. 17. The method according to item 16 of the scope of patent application, wherein the step of detecting more than one specific wave includes sub-steps: Page 27 200402106 VI. Scope of patent application In a real-time mode, the light emitted from the processing chamber during the dry etching process is spectrumd; and according to the dry etching process, the spectrum is subdivided into spectral traces with more than one wavelength. 18. The method according to item 16 of the scope of patent application, wherein the main factor is an ordered feature vector based on the contribution of the interaction relationship between specific waves. 19. The method according to item 16 of the scope of patent application, wherein the etching end point is checked at a predetermined dry etching time by using one of the relations obtained from a feature vector having the largest contribution to the interaction. Page 28