Control system and control method for chemical vapor deposition film thickness of semiconductor devices

Abstract

The present invention provides a control system and a control method for the thickness of chemical vapor deposition film of semiconductor devices. The control system includes a reactor for chemical vapor deposition of wafers inside the reactor; a control device for setting the film forming speed and film forming time of the chemical vapor deposition of wafers in the reactor; an ellipsometer for measuring the film forming thickness of wafers after chemical vapor deposition; and a calculation device for obtaining the film forming thickness of the current batches of wafers measured by the ellipsometer after the reactor performs chemical vapor deposition on the current batches of wafers at the initial film forming speed and the initial film forming time, and performing statistics on the film forming thickness of the current batches of wafers and their corresponding chip density. The present invention can accurately understand the load effect of the wafer after chemical vapor deposition, thereby effectively improving the film forming quality and reliability of the wafer surface.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a control system and a control method for chemical vapor deposition film thickness of semiconductor devices. Background Art

[0002] In the field of semiconductor manufacturing technology, the number of chips (die) on the surface of a wafer is related to its surface area, and the surface area of ​​the wafer is related to the aspect ratio of multiple grooves on the surface of the wafer. When the wafer undergoes chemical vapor deposition (CVD, Chemical VaporDeposition), the film thickness on the surface of the wafer will be different due to the different surface areas, which is called the load effect. When the film thickness on the surface of the wafer does not meet the process standards, there is insufficient dielectric capacity, causing leakage of semiconductor devices, or there is excessive dielectric capacity, affecting the speed of semiconductor devices. In the existing chemical vapor deposition process, it is impossible to accurately understand the load effect of the wafer after chemical vapor deposition processing. Therefore, there is room for improvement. Summary of the invention

[0003] The present invention provides a control system and a control method for the thickness of a semiconductor device chemical vapor deposition film, so as to solve the technical problem in the prior art that the loading effect of a wafer after chemical vapor deposition processing cannot be accurately understood.

[0004] The present invention provides a control system for the thickness of a semiconductor device chemical vapor deposition film, comprising:

[0005] Chemical vapor deposition equipment, including:

[0006] A reactor for performing chemical vapor deposition on wafers therein; and

[0007] A control device for setting a film forming speed and a film forming time for chemical vapor deposition treatment of wafers in the reaction furnace;

[0008] An ellipsometer for measuring the film thickness of a wafer after chemical vapor deposition, wherein the film thickness is related to the film forming speed and the film forming time; and

[0009] A computing device, for obtaining the film thickness of the current multiple batches of wafers measured by the ellipsometer after the reactor performs chemical vapor deposition on the current multiple batches of wafers at an initial film forming speed and an initial film forming time, and for collecting statistics on the film thickness of the current multiple batches of wafers and their corresponding chip densities, and for generating a film forming data table according to the initial film forming time, the film thickness of the current multiple batches of wafers and their corresponding chip densities; wherein different wafers of the current multiple batches of wafers are preset with different chip densities;

[0010] Among them, the calculation device maintains the initial film formation speed for other batches of wafers according to the film formation data table, calculates the film formation time corresponding to the chip density of the other batches of wafers, so as to perform chemical vapor deposition processing on the other batches of wafers, so that the film thickness of the other batches of wafers is within the preset target film thickness range.

[0011] In one embodiment of the present invention, the calculation device searches the film formation data table for the current batch of wafers whose film thickness is within a preset target film thickness range, and the control device performs chemical vapor deposition on the next batch of wafers based on the initial film formation speed and the initial film formation time, wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

[0012] In one embodiment of the present invention, the calculation device searches out the current batch of wafers whose film thickness is greater than a preset target film thickness range in the film formation data table, the control device maintains the initial film formation speed, reduces the corresponding film formation time from the initial film formation time to obtain a first film formation time, and performs chemical vapor deposition on the next batch of wafers so that the film thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers;

[0013] The calculation device searches the film forming data table for the current batch of wafers whose film thickness is less than a preset target film thickness range, the control device maintains the initial film forming speed, adds a corresponding film forming time to the initial film forming time to obtain a second film forming time, and performs chemical vapor deposition on the next batch of wafers so that the film thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

[0014] In one embodiment of the present invention, after the calculation device generates the film forming data table, the film forming thickness and chip density of the current multiple batches of wafers are fitted. With the chip density Satisfy between:

[0015] ,in, It is expressed as the rate of change of the film thickness corresponding to different chip densities, , is a non-zero constant.

[0016] In one embodiment of the present invention, after the control device performs chemical vapor deposition on the next batch of wafers at the initial film-forming speed, the first film-forming time or the second film-forming time, the calculation device obtains the film thickness of the next batch of wafers measured by the ellipsometer, and fits the film thickness and chip density of the next batch of wafers. With the chip density Satisfy between:

[0017] ,in, Represented as a constant 0, It is indicated as the target film thickness range.

[0018] In one embodiment of the present invention, at the initial film forming speed and the initial film forming time, the computing device has a chip density of Wafers to be treated with chemical vapor deposition have a film thickness of Estimate the film thickness of the wafer Chip density Satisfy between:

[0019] ;

[0020] in, , They respectively represent the film thickness and chip density of one of the wafers in the current multiple batches of wafers after chemical vapor deposition processing, , They respectively represent the film thickness and the number of chips of another wafer of the current multiple batches of wafers after chemical vapor deposition. In the chip density on the current multiple batches of wafers, , and The difference between them is minimal.

[0021] In one embodiment of the present invention, when the film thickness is In the preset target film thickness range, the control device controls the initial film forming speed and the initial film forming time according to the initial film forming speed and the initial film forming time, and controls the chip density The wafer is subjected to chemical vapor deposition processing;

[0022] When the film thickness If the target film thickness is not within the preset target film thickness range, the control device maintains the initial film forming speed, increases or decreases the corresponding film forming time based on the initial film forming time, and controls the film thickness of the chip with a certain density. Wafers are chemically vapor deposited to produce a certain chip density. The film thickness of the wafer is within the preset target film thickness range.

[0023] The present invention also provides a method for controlling the thickness of a semiconductor device chemical vapor deposition film, comprising:

[0024] Setting an initial film forming speed and an initial film forming time, and performing chemical vapor deposition processing on the current multiple batches of wafers at the initial film forming speed and the initial film forming time;

[0025] Measuring the film thickness of the current multiple batches of wafers after chemical vapor deposition, wherein different wafers of the current multiple batches of wafers are preset with different chip densities;

[0026] Based on the film thickness measured for the current multiple batches of wafers, the film thickness of the current multiple batches of wafers and the corresponding chip density are counted, and a film data table is generated according to the initial film forming time, the film thickness of the current multiple batches of wafers and the corresponding chip density;

[0027] For other batches of wafers, the initial film forming speed is maintained according to the film forming data table, and the film forming time corresponding to the chip density of the other batches of wafers is calculated to perform chemical vapor deposition on the other batches of wafers so that the film thickness of the other batches of wafers is within the preset target film thickness range.

[0028] In one embodiment of the present invention, for other batches of wafers, according to the film forming data table, the initial film forming speed is maintained, and the film forming time corresponding to the chip density of the other batches of wafers is calculated to perform chemical vapor deposition on the other batches of wafers so that the film thickness of the other batches of wafers is within a preset target film thickness range:

[0029] In the film forming data table, the current batch of wafers whose film thickness is within the preset target film thickness range is found, and the control device performs chemical vapor deposition processing on the next batch of wafers based on the initial film forming speed and the initial film forming time, wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

[0030] In one embodiment of the present invention, for other batches of wafers, according to the film forming data table, the initial film forming speed is maintained, and the film forming time corresponding to the chip density of the other batches of wafers is calculated to perform chemical vapor deposition on the other batches of wafers so that the film thickness of the other batches of wafers is within a preset target film thickness range:

[0031] In the film forming data table, find out the current batch of wafers whose film forming thickness is greater than the preset target film thickness range, maintain the initial film forming speed, reduce the corresponding film forming time from the initial film forming time to obtain the first film forming time, and perform chemical vapor deposition on the next batch of wafers so that the film forming thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers;

[0032] In the film forming data table, find out the current batch of wafers whose film thickness is less than the preset target film thickness range, maintain the initial film forming speed, add the corresponding film forming time to the initial film forming time to obtain a second film forming time, and perform chemical vapor deposition on the next batch of wafers so that the film thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

[0033] Beneficial effects of the present invention: The present invention proposes a control system and a control method for the thickness of chemical vapor deposition of semiconductor devices. The unexpected technical effect is that the present invention can analyze the difference in film thickness generated when chemical vapor deposition is performed under different chip densities on the current multiple batches of wafers by performing chemical vapor deposition at the initial film formation speed and initial film formation time, that is, the load effect that occurs. In the chemical vapor deposition preparation of the first batch of wafers of the new off-line product, the chip density on the wafer is used to calculate the estimated film thickness (that is, the film formation speed) at the initial film formation time, and based on the initial film formation time, the chip density and the corresponding film formation thickness, a film formation data table can be obtained. Therefore, when chemical vapor deposition is performed on other batches of wafers, the accurate time can be set based on the film formation data table to perform chemical vapor deposition on other batches of wafers to meet precise specification requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic structural diagram of a first film thickness formed on a wafer surface provided by an embodiment of the present invention.

[0036] Figure 2 A schematic structural diagram of a target film thickness on a wafer surface provided by an embodiment of the present invention.

[0037] Figure 3 A schematic structural diagram of a second film thickness formed on a wafer surface provided by an embodiment of the present invention.

[0038] Figure 4 An embodiment of the present invention provides Figure 2 Schematic diagram of electron microscope with target film thickness in the middle.

[0039] Figure 5 An embodiment of the present invention provides Figure 3 Schematic diagram of the structure of the second film thickness.

[0040] Figure 6 A schematic structural diagram of a control system for chemical vapor deposition film thickness of a semiconductor device provided by an embodiment of the present invention.

[0041] Figure 7 A schematic structural diagram of a control system for chemical vapor deposition film thickness of a semiconductor device provided in yet another embodiment of the present invention.

[0042] Figure 8 A schematic structural diagram of a chemical vapor deposition device provided in one embodiment of the present invention.

[0043] Fig. 9 A schematic diagram of the film thickness on the surface of a batch of wafers and the number of chips provided by an embodiment of the present invention.

[0044] Fig.10 A schematic diagram of the film thickness on the surface of a batch of wafers and the number of chips provided by another embodiment of the present invention.

[0045] Fig.11 A schematic diagram of the film thickness on the surface of a batch of wafers and the number of chips provided by another embodiment of the present invention.

[0046] Fig.12 A schematic diagram of the film thickness on the surface of a batch of wafers and the number of chips provided by another embodiment of the present invention.

[0047] Fig.13 A schematic diagram of the steps of a method for controlling the thickness of a chemical vapor deposition film formed in a semiconductor device provided by an embodiment of the present invention.

[0048] Description of Figure Numbers

[0049] 10. Wafer; 100. Substrate; 110. First film layer; 111. Target film layer; 112. Second film layer; 20. Chemical vapor deposition equipment; 210. Reactor; 211. Outer tube; 212. Inner tube; 213. Exhaust pipe; 220. Control device; 30. Ellipsometer; 40. Calculation device. DETAILED DESCRIPTION

[0050] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0051] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0052] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. In other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail to avoid making the embodiments of the present invention difficult to understand.

[0053] See also Figures 1 to 13 The present invention proposes a control system and a control method for the thickness of a semiconductor device chemical vapor deposition film, which can be applied in the chemical vapor deposition (CVD) process of a semiconductor, and can accurately understand the load effect of the wafer 10 after the chemical vapor deposition process, thereby effectively improving the film quality and reliability of the surface of the wafer 10, so that the film layer on the surface of the wafer 10 has good conductivity and yield. The following is a detailed description through specific embodiments.

[0054] See also Figures 1 to 5 The wafer 10 may include a substrate 100. After the wafer 10 is subjected to a chemical vapor deposition (CVD) process, a film layer may be formed on the surface of the wafer 10. Figure 1 When the film thickness of the surface film layer (first film layer 110) of the wafer 10 is greater than the maximum value of the target film thickness range of the process standard, there is a phenomenon of leakage of the semiconductor device due to insufficient dielectric capacity, or a fragile structure due to insufficient strength, which affects the reliability of the semiconductor device. Figure 2 and Figure 4 In the process, when the film thickness of the surface film layer (target film layer 111) of the wafer 10 meets the process standard, a qualified semiconductor device can be formed through subsequent other process technologies. Figure 3 and Figure 5 When the film thickness of the surface film layer (second film layer 112) of the wafer 10 is less than the minimum value of the target film thickness range of the process standard, the dielectric capacity is too high to affect the speed of the semiconductor device, or there is molding misalignment and film removal residue, resulting in abnormal semiconductor structure.

[0055] See also Figure 6 and Figure 7 The present invention provides a control system for chemical vapor deposition film thickness of a semiconductor device, which may include a chemical vapor deposition device 20, an ellipsometer 30 and a computing device 40.

[0056] In the chemical vapor deposition equipment 20 , a gaseous precursor is used to perform a chemical reaction at a high temperature, thereby forming a solid film layer on the surface of the wafer 10 . The film layer may be an insulator, semiconductor or conductive material deposited by chemical vapor deposition.

[0057] Specifically, the chemical vapor deposition device 20 may include a reaction furnace 210 and a control device 220. The reaction furnace 210 may perform chemical vapor deposition on the wafer 10 placed therein. Figure 8 As shown, the reaction furnace 210 may include an outer tube 211, an inner tube 212 and an exhaust pipe 213. The wafer 10 may be arranged on a wafer boat of the reaction furnace 210, and a gas (gaseous precursor) containing the required deposition material is introduced into the outer tube 211 and the inner tube 212, so as to perform chemical vapor deposition treatment on the wafer 10.

[0058] Specifically, the control device 220 can control the process of chemical vapor deposition in the reaction furnace 210, for example, in the reaction furnace 210, the film forming speed and film forming time of the chemical vapor deposition process on the wafer 10 are set. The film forming speed refers to the reaction speed of the chemical vapor deposition process on the surface of the wafer 10, and the film forming time refers to the reaction time of the chemical vapor deposition process on the surface of the wafer 10.

[0059] Specifically, after the chemical vapor deposition process, the film thickness of the film layer = film forming speed * film forming time. The film forming speed can be analyzed by the ideal gas equation.

[0060] , is represented by the pressure in the reaction furnace 210, is represented by the volume in the reactor 210, It is expressed as the number of molecules of gaseous precursor introduced into the gas flow, is expressed as the universal gas constant, It is represented as the temperature in the reaction furnace 210 .

[0061] It can be seen that if you want to adjust the film thickness of the film layer, you can adjust the film forming speed or film forming time. Furthermore, due to the universal gas constant and the volume of the reactor 210 is a fixed size, so the pressure in the reactor 210 can be adjusted , the temperature in the reaction furnace 210 , the number of molecules of gaseous precursor introduced into the gas flow , thereby achieving the adjustment of the film forming speed.

[0062] In addition, it is worth mentioning that if the film thickness of the film layer is adjusted by changing the film forming speed, it will also affect the density, dielectric capacity and optical properties of the film layer. If the film thickness of the film layer is adjusted by changing the film forming time, it will not affect the density, dielectric capacity and optical properties of the film layer. After the wafer 10 is processed by chemical vapor deposition, if the film thickness does not meet the process standards, in order not to change the density, dielectric capacity and optical properties of the film layer, it is possible to consider adjusting the film forming speed of chemical vapor deposition, so that the film thickness of the wafer 10 can meet the process standards.

[0063] See also Figure 6 and Figure 7 Specifically, the ellipsometer 30 is an optical measuring device for detecting film thickness, optical constants and material microstructure. The ellipsometer 30 can measure the film thickness of the wafer 10 after chemical vapor deposition.

[0064] See also Figure 6 and Figure 7 Specifically, the computing device 40 can be a personal computer (PC), a tablet computer (Pad), a mobile phone (Cell Phone) and other devices, and the computing device 40 has data computing capabilities. After the ellipsometer 30 measures the film thickness of the wafer 10 after chemical vapor deposition, the computing device 40 can obtain the film thickness measured by the ellipsometer 30 and count the film thickness and the number of chips on the surface of the wafer 10. Among them, the number of chips on the surface of the wafer 10 is known before the chemical vapor deposition process, and the computing device 40 plays a role in counting the film thickness and the number of chips on the surface of the wafer 10.

[0065] See also Figure 6 and Figure 7In one embodiment of the present invention, the film thickness of the wafer 10 after chemical vapor deposition is related to the number of chips on the wafer 10, the film forming speed of the chemical vapor deposition process, and the film forming time. In order to analyze the difference in film thickness generated when chemical vapor deposition is performed under different numbers of chips corresponding to different aspect ratios on the wafer 10, that is, the load effect, this embodiment needs to first set the parameters of the film forming speed and film forming time of the chemical vapor deposition process to reference initial values ​​for processing, please see the description below.

[0066] See also Figure 6 and Figure 7 In one embodiment of the present invention, first, at the initial film forming speed and the initial film forming time, the reactor 210 performs chemical vapor deposition on the current multiple batches of wafers 10, and the current multiple batches of wafers 10 are preset with wafers 10 of different chip densities, and the chip density refers to the number of chips on the unit wafer 10. Secondly, the ellipsometer 30 can measure the film thickness of the current multiple batches of wafers 10, and the computing device 40 can obtain the film thickness measured by the ellipsometer 30 on the current multiple batches of wafers 10, and perform statistics on the film thickness and chip density of the current multiple batches of wafers 10. The computing device 40 can generate a film forming data table according to the initial film forming time, the film thickness of the current multiple batches of wafers 10 and the corresponding chip density, as shown in Table 1. Among them, the chip density is represented by the number of chips on the unit wafer 10. It should be noted that the initial film forming speed and the initial film forming time appearing in the full text have the same meaning. For the current multiple batches of wafers 10 , generally one batch (Lot) of wafers 10 refers to 25 wafers 10 , and the current multiple batches of wafers 10 refers to a large number of wafers 10 currently available.

[0067] In the chemical vapor deposition preparation of the first batch of wafers 10 of the new off-line product, the chip density on the wafer 10 (the number of chips on a unit wafer) is used to calculate the estimated film thickness (i.e., film speed) at the initial film formation time, and based on the initial film formation time, chip density, and corresponding film thickness, a film formation data table can be obtained. Therefore, when chemical vapor deposition is performed on other batches of wafers 10, the accurate time can be set based on the film formation data table to perform chemical vapor deposition on other batches of wafers 10 to meet precise specification requirements.

[0068] Table 1. Film thickness and chip quantity on the surface of wafer 10 after chemical vapor deposition treatment

[0069]

[0070] Specifically, since the number of chips (dies) on the surface of the wafer 10 is related to its surface area, the surface area of ​​the wafer 10 is related to the aspect ratio of the plurality of grooves on the surface of the wafer 10. Figure 6 , Figure 7 As shown, the chip density (the number of chips on a unit wafer 10) on different wafers 10 in the current multiple batches of wafers 10 is different. By presetting different chip densities on the current multiple batches of wafers 10, the film thickness difference generated under different chip densities on the current multiple batches of wafers 10 can be analyzed after chemical vapor deposition processing. Different chip densities are preset on the current multiple batches of wafers 10, that is, the chip density on the current multiple batches of wafers 10 is pre-stated, and the chip density on the current multiple batches of wafers 10 is known data.

[0071] See also Figure 6 and Figure 7 In one embodiment of the present invention, the control device 220 determines whether the film thickness of the current batch of wafers 10 is equal to the preset target film thickness range of the target film layer 111 under the initial film forming speed and the initial film forming time, and the target film thickness range is a non-zero constant range. The target film layer 111 is the process standard of the chemical vapor deposition process, that is, the target film thickness range value of the target film layer 111 is used to reflect whether the film thickness meets the process standard of the chemical vapor deposition process.

[0072] See also Figure 6 and Figure 7 In one embodiment of the present invention, among the current multiple batches of wafers 10, the film thickness of some current batches of wafers 10 is within the target film thickness range, indicating that at the initial film forming speed and the initial film forming time, the chemical vapor deposition film forming treatment of some current batches of wafers 10 meets the process standard. The film thickness of other current batches of wafers 10 is not within the target film thickness range, indicating that at the initial film forming speed and the initial film forming time, the chemical vapor deposition film forming treatment of other current batches of wafers 10 does not meet the process standard. The current batch of wafers 10 refers to a batch of wafers 10 among the current multiple batches of wafers 10.

[0073] Specifically, the computing device 40 maintains the initial film forming speed for other batches of wafers 10 according to the film forming data table, calculates the film forming time corresponding to the chip density of other batches of wafers 10, and performs chemical vapor deposition processing on other batches of wafers 10, so that the film thickness of other batches of wafers 10 is within the preset target film thickness range.

[0074] Furthermore, at the initial film forming speed and initial film forming time, if the film forming thickness of the current batch of wafers 10 is not within the target film thickness range, for the wafers 10 to be processed that have the same chip density as the film forming thickness of the current batch of wafers 10, since the number of chips on the wafers 10 to be processed is pre-set, corresponding adjustments cannot be made. For the wafers 10 to be processed that have the same chip density as the film forming thickness of the current batch of wafers 10, the film forming speed and film forming time of the chemical vapor deposition process can only be adjusted to make the film forming thickness of the wafers 10 to be processed within the target film thickness range, so that the wafers 10 to be processed meet the process standards of the chemical vapor deposition process.

[0075] See also Figure 6 and Figure 7 In one embodiment of the present invention, the computing device 40 searches the film forming data table for the current batch of wafers 10 whose film thickness is within the preset target film thickness range, and the control device 220 performs chemical vapor deposition on the next batch of wafers 10 according to the initial film forming speed and the initial film forming time, wherein the chip density on the next batch of wafers 10 is the same as the chip density corresponding to the current batch of wafers 10.

[0076] From the above analysis, it can be seen that if the adjustment is made by changing the film forming speed, it will also affect the density, dielectric capacity and optical properties of the film layer. For the adjustment of the film thickness of the film layer, if it is adjusted by changing the film forming time, it will not affect the density, dielectric capacity and optical properties of the film layer.

[0077] Therefore, at the initial film forming speed and the initial film forming time, if the film thickness of the current batch of wafers 10 is not within the target film thickness range, for the wafers 10 to be processed having the same chip density as the current batch of wafers 10, the ideal situation is to maintain the initial film forming speed of the chemical vapor deposition process and adjust the film forming time of the chemical vapor deposition process so that the film thickness of the next batch of wafers 10 is within the preset target film thickness range.

[0078] See also Figure 6 and Figure 7 In one embodiment of the present invention, the computing device 40 searches the film forming data table for the current batch of wafers 10 whose film forming thickness is greater than the preset target film thickness range, and the control device 220 maintains the initial film forming speed, reduces the corresponding film forming time from the initial film forming time to obtain the first film forming time, and performs chemical vapor deposition on the next batch of wafers 10 so that the film forming thickness of the next batch of wafers 10 is within the preset target film thickness range. The chip density on the next batch of wafers 10 is the same as the chip density corresponding to the current batch of wafers 10.

[0079] For example, under the initial film forming speed and the initial film forming time, based on the data in the film forming data table, it is determined whether the film forming thickness of the current batch of wafers 10 is within the target film thickness range. Afterwards, when the film forming thickness of the current batch of wafers 10 is greater than the maximum value of the target film thickness range, the control device 220 maintains the initial film forming speed, reduces the film forming time based on the initial film forming time, and performs chemical vapor deposition on the next batch of wafers 10, so that the film forming thickness of the next batch of wafers 10 is within the preset target film thickness range.

[0080] See also Figure 6 and Figure 7 In one embodiment of the present invention, the computing device 40 searches the film forming data table for the current batch of wafers 10 whose film forming thickness is less than the preset target film thickness range, and the control device 220 maintains the initial film forming speed, adds the corresponding film forming time to the initial film forming time to obtain the second film forming time, and performs chemical vapor deposition on the next batch of wafers 10 so that the film forming thickness of the next batch of wafers 10 is within the preset target film thickness range. The chip density on the next batch of wafers 10 is the same as the chip density corresponding to the current batch of wafers 10.

[0081] For example, under the initial film forming speed and the initial film forming time, based on the data in the film forming data table, it is determined whether the film forming thickness of the current batch of wafers 10 is within the target film thickness range. Afterwards, when the film forming thickness of the current batch of wafers 10 is less than the minimum value of the target film thickness range, the control device 220 maintains the initial film forming speed, increases the film forming time based on the initial film forming time, and performs chemical vapor deposition on the next batch of wafers 10, so that the film forming thickness of the next batch of wafers 10 is within the preset target film thickness range.

[0082] See also Fig. 9 and Table 1. In one embodiment of the present invention, after the computing device 40 generates the film forming data table, the film forming thickness and chip density of the current multiple batches of wafers 10 are fitted. Chip density Satisfy between:

[0083] ,in, It is expressed as the rate of change of different film thicknesses corresponding to different chip densities. , is a non-zero constant.

[0084] Specifically, in Table 1, N, C, A, G, D, I, L, M, J, F, B, E, K, and H represent a group of wafers 10 that undergo chemical vapor deposition testing. The four columns of data on the right side of the first column of "Product", the data from the second to the fifth columns, are data corresponding to the current batch of wafers 10, and the average film thickness is the average film thickness of a group of wafers 10. The two rightmost columns of data in Table 1 are data corresponding to the next batch, and the film thickness is the film thickness of the next batch of wafers 10 after chemical vapor deposition treatment after adjusting the film forming time. In Table 1, the target film thickness range can be 90 angstroms to 90.8 angstroms (Å), and 1nm=10Å.

[0085] Specifically, It can be 0.0005, Can be 93.997, film thickness Number of chips Satisfaction between , where the film thickness Number of chips In the regression analysis between The coefficient of determination is 0.6101. It measures the degree of fit between the model prediction value and the actual value. The value of 0.6101 indicates that the closer the value predicted by the model is to the actual value, the better the fitting effect of the model.

[0086] See also Fig.10 and Fig.11 In one embodiment of the present invention, after the control device 220 performs chemical vapor deposition on the next batch of wafers 10 at the initial film forming speed, the first film forming time or the second film forming time, the computing device 40 obtains the film thickness of the next batch of wafers 10 measured by the ellipsometer 30, and fits the film thickness of the next batch of wafers 10 and the chip density. Chip density Satisfy between:

[0087] ,in, Represented as a constant 0, Indicated as target film thickness range.

[0088] Specifically, Fig.10 As shown, the film thickness value of the current batch of wafers 10 is not within the target film thickness value, and when the gap between the film thickness of the current batch of wafers 10 and the target film thickness is large, the film forming time of the chemical vapor deposition treatment of the wafers 10 to be processed corresponding to the same number of chips as the film thickness needs to be adjusted. Fig.11As shown in Table 1, after adjusting the film forming time, the film thickness of the next batch of wafers 10 is within the target film thickness range, and it can be considered that the chemical vapor deposition process of the next batch of wafers 10 meets the process standard.

[0089] See also Fig.12 In one embodiment of the present invention, at the initial film forming speed and initial film forming time, the computing device 40 calculates the chip density The thickness of the film to be formed by chemical vapor deposition treatment is It is estimated that the film thickness of the wafer 10 Chip density Satisfy between:

[0090] ;

[0091] in, , They respectively represent the film thickness and chip density of one of the wafers 10 in the current multiple batches of wafers 10 after chemical vapor deposition processing, , They respectively represent the film thickness and the number of chips of another wafer 10 of the current multiple batches of wafers 10 after chemical vapor deposition processing, and the chip density on the current multiple batches of wafers 10. , and The difference between them is minimal.

[0092] Specifically, Fig.12 As shown, for a chip density Wafer 10, a certain chip density Different from the chip density on the current batch of wafers 10, since there is no corresponding chemical vapor deposition processing data for reference, in order to predict the relationship between film thickness and chip density at the initial film formation speed and initial film formation time, an estimated calculation can be performed using known data.

[0093] Specifically, at the initial film forming speed and a certain film forming time, for a chip with a certain density The thickness of the film to be formed by chemical vapor deposition treatment is Number of chips Then, when the film thickness Within the preset target film thickness range, the control device 220 controls the number of chips having a certain number of chips according to the initial film forming speed and the initial film forming time. The wafer 10 is subjected to chemical vapor deposition processing.

[0094] When film thickness If the target film thickness is not within the preset target film thickness range, the control device 220 maintains the initial film forming speed, adjusts (increases or decreases) the film forming time based on the initial film forming time, and The wafer 10 is subjected to chemical vapor deposition processing to make it have a certain chip density The film thickness of the wafer 10 is within a preset target film thickness range.

[0095] See also Fig.13 As shown, the present invention proposes a method for controlling the thickness of a chemical vapor deposition film of a semiconductor device, comprising the following steps.

[0096] Step S10 , setting an initial film forming speed and an initial film forming time, and performing chemical vapor deposition processing on the current multiple batches of wafers under the initial film forming speed and the initial film forming time.

[0097] Step S20 , measuring the film thickness of the current batches of wafers after chemical vapor deposition, wherein different wafers in the current batches of wafers are preset with different chip densities.

[0098] Step S30, based on the measured film thickness of the current multiple batches of wafers, the film thickness of the current multiple batches of wafers and the corresponding chip density are counted, and a film data table is generated according to the initial film time, the film thickness of the current multiple batches of wafers and the corresponding chip density.

[0099] Step S40, for other batches of wafers, maintain the initial film forming speed according to the film forming data table, calculate the film forming time corresponding to the chip density of other batches of wafers, and perform chemical vapor deposition on other batches of wafers so that the film thickness of other batches of wafers is within the preset target film thickness range.

[0100] The above steps are analyzed in detail below through specific examples.

[0101] Step S10 , setting an initial film forming speed and an initial film forming time, and performing chemical vapor deposition processing on the current multiple batches of wafers under the initial film forming speed and the initial film forming time.

[0102] In one embodiment of the present invention, the film thickness of the wafer 10 after chemical vapor deposition is related to the number of chips on the wafer 10, the film forming speed of the chemical vapor deposition process, and the film forming time. In order to analyze the difference in film thickness generated when chemical vapor deposition is performed under different numbers of chips corresponding to different aspect ratios on the wafer 10, that is, the load effect, this embodiment needs to first set the parameters of the film forming speed and film forming time of the chemical vapor deposition process to reference initial values ​​for processing.

[0103] Step S20 , measuring the film thickness of the current batches of wafers after chemical vapor deposition, wherein different wafers in the current batches of wafers are preset with different chip densities.

[0104] In one embodiment of the present invention, Figure 6 , Figure 7 As shown, the chip density (the number of chips on a unit wafer 10) on different wafers 10 in the current multiple batches of wafers 10 is different. By presetting different chip densities on the current multiple batches of wafers 10, the film thickness difference generated under different chip densities on the current multiple batches of wafers 10 can be analyzed after chemical vapor deposition processing. Different chip densities are preset on the current multiple batches of wafers 10, that is, the chip density on the current multiple batches of wafers 10 is pre-stated, and the chip density on the current multiple batches of wafers 10 is known data.

[0105] Step S30, based on the measured film thickness of the current multiple batches of wafers, the film thickness of the current multiple batches of wafers and the corresponding chip density are counted, and a film data table is generated according to the initial film time, the film thickness of the current multiple batches of wafers and the corresponding chip density.

[0106] In one embodiment of the present invention, a film forming data table can be generated according to the initial film forming time, the film forming thickness of the current multiple batches of wafers 10 and their corresponding chip density, as shown in Table 1. The chip density is represented by the number of chips on the unit wafer 10. It should be noted that the initial film forming speed and the initial film forming time appearing in the full text have the same meaning. For the current multiple batches of wafers 10, usually a batch (Lot) of wafers 10 refers to 25 wafers 10, and the current multiple batches of wafers 10 refer to a large number of wafers 10 currently.

[0107] In the chemical vapor deposition preparation of the first batch of wafers 10 of the new off-line product, the chip density on the wafer 10 (the number of chips on a unit wafer) is used to calculate the estimated film thickness (i.e., film speed) at the initial film formation time, and based on the initial film formation time, chip density, and corresponding film thickness, a film formation data table can be obtained. Therefore, when chemical vapor deposition is performed on other batches of wafers 10, the accurate time can be set based on the film formation data table to perform chemical vapor deposition on other batches of wafers 10 to meet precise specification requirements.

[0108] Step S40, for other batches of wafers, maintain the initial film forming speed according to the film forming data table, calculate the film forming time corresponding to the chip density of other batches of wafers, and perform chemical vapor deposition on other batches of wafers so that the film thickness of other batches of wafers is within the preset target film thickness range.

[0109] In one embodiment of the present invention, in the corresponding film forming data table of the current multiple batches of wafers 10, the film thickness of some current batches of wafers 10 is within the target film thickness range, indicating that at the initial film forming speed and the initial film forming time, the chemical vapor deposition film forming treatment of some current batches of wafers 10 meets the process standard. The film thickness of other current batches of wafers 10 is not within the target film thickness range, indicating that at the initial film forming speed and the initial film forming time, the chemical vapor deposition film forming treatment of other current batches of wafers 10 does not meet the process standard. The current batch of wafers 10 refers to a batch of wafers 10 among the current multiple batches of wafers 10.

[0110] Specifically, the computing device 40 maintains the initial film forming speed for other batches of wafers 10 according to the film forming data table, calculates the film forming time corresponding to the chip density of other batches of wafers 10, and performs chemical vapor deposition processing on other batches of wafers 10, so that the film thickness of other batches of wafers 10 is within the preset target film thickness range.

[0111] See also Fig.13 In one embodiment of the present invention, in step S40, for other batches of wafers, according to the film forming data table, the initial film forming speed is maintained, and the film forming time corresponding to the chip density of other batches of wafers is calculated to perform chemical vapor deposition on other batches of wafers, so that the film thickness of other batches of wafers is within a preset target film thickness range:

[0112] In the film forming data table, find out the current batch of wafers whose film thickness is within the preset target film thickness range, and perform chemical vapor deposition on the next batch of wafers based on the initial film forming speed and the initial film forming time, wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

[0113] See also Fig.13 In one embodiment of the present invention, in step S40, for other batches of wafers, according to the film forming data table, the initial film forming speed is maintained, and the film forming time corresponding to the chip density of other batches of wafers is calculated to perform chemical vapor deposition on other batches of wafers, so that the film thickness of other batches of wafers is within a preset target film thickness range:

[0114] In the film forming data table, find out the current batch of wafers whose film forming thickness is greater than the preset target film thickness range, maintain the initial film forming speed, reduce the corresponding film forming time from the initial film forming time to obtain the first film forming time, and perform chemical vapor deposition on the next batch of wafers so that the film forming thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers;

[0115] In the film forming data table, find out the current batch of wafers whose film thickness is less than the preset target film thickness range, control the device to maintain the initial film forming speed, add the corresponding film forming time to the initial film forming time to obtain the second film forming time, and perform chemical vapor deposition on the next batch of wafers so that the film thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

[0116] In summary, the present invention proposes a control system and control method for the thickness of chemical vapor deposition of semiconductor devices. The unexpected technical effect is: the present invention can analyze the difference in film thickness generated when chemical vapor deposition is performed under different chip densities on the current multiple batches of wafers, that is, the load effect, by performing chemical vapor deposition processing on the current multiple batches of wafers at the initial film forming speed and initial film forming time. In the chemical vapor deposition preparation of the first batch of wafers of the new off-line product, the chip density on the wafer is used to calculate the estimated film thickness (that is, the film forming speed) at the initial film forming time, and based on the initial film forming time, the chip density and the corresponding film forming thickness, a film forming data table can be obtained. Therefore, when chemical vapor deposition is performed on other batches of wafers, the accurate time can be set based on the film forming data table to perform chemical vapor deposition on other batches of wafers to meet the precise specification requirements.

[0117] The flow chart and block diagram in the accompanying drawings illustrate the possible implementation architecture, function and operation of the method and computer program product according to various embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

Claims

1. A control system for the thickness of a semiconductor device chemical vapor deposition film, characterized in that: include: Chemical vapor deposition equipment, including: A reactor for performing chemical vapor deposition on wafers therein; and A control device for setting a film forming speed and a film forming time for chemical vapor deposition treatment of wafers in the reaction furnace; An ellipsometer for measuring the film thickness of a wafer after chemical vapor deposition, wherein the film thickness is related to the film forming speed and the film forming time; and A computing device, for obtaining the film thickness of the current multiple batches of wafers measured by the ellipsometer after the reactor performs chemical vapor deposition on the current multiple batches of wafers at an initial film forming speed and an initial film forming time, and for collecting statistics on the film thickness of the current multiple batches of wafers and their corresponding chip densities, and for generating a film forming data table according to the initial film forming time, the film thickness of the current multiple batches of wafers and their corresponding chip densities; wherein different wafers of the current multiple batches of wafers are preset with different chip densities; Among them, the calculation device maintains the initial film formation speed for other batches of wafers according to the film formation data table, calculates the film formation time corresponding to the chip density of the other batches of wafers, so as to perform chemical vapor deposition processing on the other batches of wafers, so that the film thickness of the other batches of wafers is within the preset target film thickness range.

2. The control system for semiconductor device chemical vapor deposition film thickness according to claim 1, characterized in that: The calculation device searches the film formation data table for the current batch of wafers whose film thickness is within the preset target film thickness range, and the control device performs chemical vapor deposition on the next batch of wafers based on the initial film formation speed and the initial film formation time, wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

3. The control system for semiconductor device chemical vapor deposition film thickness according to claim 1, characterized in that: The calculation device searches out the current batch of wafers whose film thickness is greater than the preset target film thickness range in the film formation data table, the control device maintains the initial film formation speed, reduces the corresponding film formation time from the initial film formation time to obtain the first film formation time, and performs chemical vapor deposition on the next batch of wafers so that the film thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers; The calculation device searches the film forming data table for the current batch of wafers whose film thickness is less than a preset target film thickness range, the control device maintains the initial film forming speed, adds a corresponding film forming time to the initial film forming time to obtain a second film forming time, and performs chemical vapor deposition on the next batch of wafers so that the film thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

4. The control system for semiconductor device chemical vapor deposition film thickness according to claim 3, characterized in that: After the calculation device generates the film forming data table, the film forming thickness and chip density of the current multiple batches of wafers are fitted. With the chip density Satisfy between: ,in, It is expressed as the rate of change of the film thickness corresponding to different chip densities, , is a non-zero constant.

5. The control system for semiconductor device chemical vapor deposition film thickness according to claim 4, characterized in that: After the control device performs chemical vapor deposition on the next batch of wafers at the initial film forming speed, the first film forming time or the second film forming time, the calculation device obtains the film thickness of the next batch of wafers measured by the ellipsometer, and fits the film thickness and chip density of the next batch of wafers. With the chip density Satisfy between: ,in, Represented as a constant 0, It is indicated as the target film thickness range.

6. The control system for semiconductor device chemical vapor deposition film thickness according to claim 4, characterized in that: At the initial film forming speed and the initial film forming time, the computing device has a chip density Wafers to be treated with chemical vapor deposition have a film thickness of Estimate the film thickness of the wafer Chip density Satisfy between: ； in, , They respectively represent the film thickness and chip density of one of the wafers in the current multiple batches of wafers after chemical vapor deposition processing, , They respectively represent the film thickness and the number of chips of another wafer of the current multiple batches of wafers after chemical vapor deposition. In the chip density on the current multiple batches of wafers, , and The difference between them is minimal.

7. The control system for semiconductor device chemical vapor deposition film thickness according to claim 6, characterized in that: When the film thickness In the preset target film thickness range, the control device controls the initial film forming speed and the initial film forming time according to the initial film forming speed and the initial film forming time, and controls the chip density The wafer is subjected to chemical vapor deposition processing; When the film thickness If the target film thickness is not within the preset target film thickness range, the control device maintains the initial film forming speed, increases or decreases the corresponding film forming time based on the initial film forming time, and controls the film thickness of the chip with a certain density. Wafers are chemically vapor deposited to produce a certain chip density. The film thickness of the wafer is within the preset target film thickness range.

8. A method for controlling the thickness of a film formed by chemical vapor deposition of a semiconductor device, characterized in that: include: Setting an initial film forming speed and an initial film forming time, and performing chemical vapor deposition processing on the current multiple batches of wafers at the initial film forming speed and the initial film forming time; Measuring the film thickness of the current multiple batches of wafers after chemical vapor deposition, wherein different wafers of the current multiple batches of wafers are preset with different chip densities; Based on the film thickness measured for the current multiple batches of wafers, the film thickness of the current multiple batches of wafers and the corresponding chip density are counted, and a film data table is generated according to the initial film forming time, the film thickness of the current multiple batches of wafers and the corresponding chip density; For other batches of wafers, the initial film forming speed is maintained according to the film forming data table, and the film forming time corresponding to the chip density of the other batches of wafers is calculated to perform chemical vapor deposition on the other batches of wafers so that the film thickness of the other batches of wafers is within the preset target film thickness range.

9. The method for controlling the thickness of a chemical vapor deposition film of a semiconductor device according to claim 8, characterized in that: In the step of maintaining the initial film forming speed and calculating the film forming time corresponding to the chip density of the other batches of wafers according to the film forming data table, so as to perform chemical vapor deposition on the other batches of wafers so that the film forming thickness of the other batches of wafers is within a preset target film thickness range: In the film forming data table, find out the current batch of wafers whose film thickness is within the preset target film thickness range, and perform chemical vapor deposition on the next batch of wafers according to the initial film forming speed and the initial film forming time, wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

10. The method for controlling the thickness of a chemical vapor deposition film of a semiconductor device according to claim 8, characterized in that: In the step of maintaining the initial film forming speed and calculating the film forming time corresponding to the chip density of the other batches of wafers according to the film forming data table, so as to perform chemical vapor deposition on the other batches of wafers so that the film forming thickness of the other batches of wafers is within a preset target film thickness range: In the film forming data table, find out the current batch of wafers whose film forming thickness is greater than the preset target film thickness range, maintain the initial film forming speed, reduce the corresponding film forming time from the initial film forming time to obtain the first film forming time, and perform chemical vapor deposition on the next batch of wafers so that the film forming thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers; In the film forming data table, find out the current batch of wafers whose film thickness is less than the preset target film thickness range, maintain the initial film forming speed, add the corresponding film forming time to the initial film forming time to obtain a second film forming time, and perform chemical vapor deposition on the next batch of wafers so that the film thickness of the next batch of wafers is within the preset target film thickness range; wherein the chip density on the next batch of wafers is the same as the chip density corresponding to the current batch of wafers.

Images