Oxidation film deposition method and device and chemical vapor deposition equipment

Abstract

The invention relates to the technical field of semiconductors, and discloses an oxidation film deposition method and device and chemical vapor deposition equipment, and the method comprises the steps: carrying out the heating treatment of a cavity when an idle stage is finished and a current batch of wafers are not loaded into the cavity; after the temperature of the chamber rises from a first temperature to a target temperature, the current batch of wafers are loaded into the chamber, a first oxidation film is deposited on the surface of the current batch of wafers, and the first temperature is the temperature of the chamber in the idle stage; when the cleaning stage is finished and the next batch of wafers are not loaded into the chamber, cooling the chamber; and after the temperature of the chamber is reduced to the target temperature from the second temperature, the next batch of wafers are loaded into the chamber, and a second oxide film is deposited on the surface of the next batch of wafers, so that the thickness of the first oxide film is consistent with that of the second oxide film, and the second temperature is the temperature of the chamber in the cleaning stage. According to the invention, the fluctuation degree of the thickness of oxide films deposited on multiple batches of wafers can be reduced, and the inter-wafer uniformity is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically to a method, apparatus, and chemical vapor deposition equipment for depositing oxide films. Background Technology

[0002] Oxide films have a wide range of applications in semiconductor devices. They can be used as the pre-metal dielectric (PMD) of metal oxide semiconductor field effect transistors (MOS transistors) and as the inter-metal dielectric (IMD) of multilayer interconnect structures.

[0003] Oxide films can be generated through chemical vapor deposition (CVD) processes. However, during the CVD process, changes in CVD process parameters (such as pressure, temperature, and time) may affect the thickness of oxide films generated on multiple batches of wafers, resulting in large fluctuations in oxide film thickness. Summary of the Invention

[0004] This invention provides a method, apparatus, and chemical vapor deposition equipment for depositing oxide films to solve the problem of large fluctuations in the thickness of oxide films generated on different wafer surfaces.

[0005] In a first aspect, the present invention provides a method for depositing an oxide film. This method is applied to a chemical vapor deposition (CVD) apparatus, which includes a chamber. The process of depositing an oxide film in the CVD apparatus includes an idle phase, a wafer fabrication phase, and a cleaning phase. The oxide film deposition method includes: heating the chamber at the end of the idle phase and before the current batch of wafers is loaded into the chamber; loading the current batch of wafers into the chamber and depositing a first oxide film on the surface of the current batch of wafers after the chamber temperature rises from a first temperature to a target temperature; cooling the chamber at the end of the cleaning phase and before the next batch of wafers is loaded into the chamber; and loading the next batch of wafers into the chamber and depositing a second oxide film on the surface of the next batch of wafers, such that the thickness of the first oxide film and the thickness of the second oxide film are consistent, wherein the second temperature is the temperature of the chamber during the cleaning phase.

[0006] The oxide film deposition method provided by this invention involves heating the chamber after the idle phase ends and before the current batch of wafers is loaded into the chamber. Only after the chamber temperature rises from a first temperature to a target temperature is a first oxide film deposited on the surface of the current batch of wafers. After the cleaning phase ends and before the next batch of wafers is loaded into the chamber, the chamber is cooled. Only after the chamber temperature drops from a second temperature to the target temperature is a second oxide film deposited on the surface of the next batch of wafers. This invention increases the chamber temperature after the idle phase and decreases the chamber temperature after the cleaning phase, ensuring a consistent chamber temperature throughout the wafer fabrication process. This negligible effect of temperature on film thickness reduces film thickness fluctuations between different batches of wafers and between different wafers within the same batch, improving inter-wafer uniformity.

[0007] In one alternative implementation, the chamber is heated by adding plasma to the chamber for a preset duration to adjust the first temperature to a target temperature.

[0008] This embodiment uses plasma to heat the chamber, which can not only regulate the temperature, but also use the high-energy particles of plasma to bombard residual impurities (such as water vapor and organic residues) on the surface of the chamber wall, causing them to decompose or be carried out of the chamber by the airflow.

[0009] In one alternative embodiment, before cooling the chamber, the oxide film deposition method further includes: determining a target cooling time based on the target film thickness configured in the wafer fabrication stage; and cooling the chamber, including: cooling the chamber according to the target cooling time.

[0010] In this embodiment, after the cleaning stage, the target cooling time is selected according to the target film thickness, and the chamber is cooled based on the target cooling time. This can avoid temperature fluctuations in the chamber during the deposition process due to different film thicknesses and ensure the consistency of the chamber temperature during wafer fabrication.

[0011] In one optional implementation, determining the target cooling time based on the target film thickness configured in the wafer fabrication stage includes: determining a cooling coefficient based on the target film thickness; and determining the target cooling time by multiplying the cooling coefficient by the cooling unit time.

[0012] In one optional embodiment, before depositing a first oxide film on the surface of the current batch of wafers, the oxide film deposition method further includes: obtaining the cumulative film thickness during the wafer fabrication stage, wherein the cumulative film thickness is the total thickness of the oxide film deposited in the chamber from the start time of the wafer fabrication stage to the current time; determining the actual film thickness of the first oxide film based on the cumulative film thickness and a target model, wherein the target model is used to characterize the mapping relationship between the cumulative film thickness and the actual film thickness; and optimizing the target film deposition time configured in the wafer fabrication stage based on the actual film thickness and the target film thickness configured in the wafer fabrication stage to obtain the actual film deposition time of the first oxide film.

[0013] In this embodiment, before depositing an oxide film on the wafer surface, the cumulative film thickness during the wafer fabrication stage is obtained. Based on the cumulative film thickness and the target model, the actual film thickness of the first oxide film is determined. Then, based on the actual film thickness and the target film thickness, time compensation is performed on the target film deposition time. This ensures the consistency of the oxide film thickness deposited on the wafer surface entering the chamber at different times and reduces the degree of film thickness fluctuation.

[0014] In one optional implementation, optimizing the target film deposition time configured in the wafer fabrication stage based on the actual film deposition thickness and the target film deposition thickness configured in the wafer fabrication stage includes: optimizing the target film deposition time based on the actual film deposition thickness and the target film deposition thickness using the following formula to obtain the actual film deposition time:

[0015] In the formula, Indicates the actual settling time. Indicates the target deposition time. Indicates the target film thickness. This indicates the actual thickness of the film.

[0016] In one alternative implementation, the target model is a univariate cubic function model.

[0017] In one optional embodiment, both the first oxide film and the second oxide film are silicon dioxide films made of undoped silicate glass.

[0018] Secondly, the present invention provides an oxide film deposition apparatus applied to a chemical vapor deposition (CVD) device. The CVD device includes a chamber, and the process of depositing an oxide film in the CVD device includes an idle stage, a wafer fabrication stage, and a cleaning stage. The oxide film deposition apparatus includes: a heating module for heating the chamber when the idle stage ends and the current batch of wafers has not been loaded into the chamber; a first deposition module for loading the current batch of wafers into the chamber after the chamber temperature rises from a first temperature to a target temperature, and depositing a first oxide film on the surface of the current batch of wafers, wherein the first temperature is the temperature of the chamber during the idle stage, and the target temperature is the temperature configured during the wafer fabrication stage for depositing the oxide film; a cooling module for cooling the chamber when the cleaning stage ends and the next batch of wafers has not been loaded into the chamber; and a second deposition module for loading the next batch of wafers into the chamber after the chamber temperature drops from a second temperature to the target temperature, and depositing a second oxide film on the surface of the next batch of wafers, so that the thickness of the first oxide film and the thickness of the second oxide film are consistent, wherein the second temperature is the temperature of the chamber during the cleaning stage.

[0019] Thirdly, the present invention provides a chemical vapor deposition apparatus, comprising: an oxide film deposition apparatus according to the second aspect above or any corresponding embodiment thereof. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the stages of depositing an oxide film using a chemical vapor deposition apparatus according to an embodiment of the present invention; Figure 2 This is a schematic diagram showing the film thickness trend at different stages of oxide film deposition using a chemical vapor deposition apparatus according to an embodiment of the present invention. Figure 3 This is a schematic flowchart of an oxide film deposition method according to an embodiment of the present invention; Figure 4 This is a schematic flowchart of another method for depositing an oxide film according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the stages of depositing an oxide film using a chemical vapor deposition apparatus according to an embodiment of the present invention; Figure 6 This is a structural block diagram of an oxide film deposition apparatus according to an embodiment of the present invention; Figure 7This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the invention, not the entire structure.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] The oxide film deposition method provided by the present invention relies on a chemical vapor deposition (CVD) equipment. The CVD equipment includes a chamber that contains multiple wafers and reactive gases. Under certain temperature conditions, the reactive gases in the chamber interact with the wafer surface and form an oxide film on the wafer surface.

[0025] like Figure 1 As shown, the process of depositing an oxide film using a chemical vapor deposition (CVD) system includes an idle phase, a wafer fabrication phase, and a chamber clean phase. The idle phase refers to the period during which the equipment operates idle, for example, 15 minutes per idle period. This idle period includes the Unload Chamber Test (UCT) phase, which verifies the chamber status and wafer unloading process after the equipment completes a batch of wafer deposition. The wafer fabrication phase is the period during which an oxide film is continuously deposited on the wafer surface. The wafer fabrication phase ends when the accumulated film thickness reaches a preset value (e.g., 230,000 Å). The chamber clean phase is the period during which the chamber is etched and cleaned according to process requirements. The chamber clean phase removes residual film layers from the chamber walls to prevent contamination of subsequent wafers.

[0026] This invention, through research, has discovered that when transitioning from the idle stage to the wafer fabrication stage, the chamber temperature is lower than the normal wafer fabrication stage temperature. During the wafer fabrication process, the film thickness on multiple wafers produced consecutively exhibits a pattern of first decreasing and then gradually increasing, i.e., as... Figure 2 As shown on the left (to the left of the dashed line O), the oxide film deposited on the wafers in the first few batches is relatively thin (thinner than the target film thickness). As production progresses, the thickness of the oxide film deposited on the wafers gradually increases and stabilizes at the target film thickness. When transitioning from the cleaning stage to the wafer fabrication stage, the chamber temperature is higher than the normal wafer fabrication stage temperature, such as... Figure 2As shown on the right, the film thickness on multiple wafers produced consecutively during the wafer fabrication process exhibits a pattern of initial thickening followed by thinning. Therefore, the oxide film thickness deposited by the CVD equipment on multiple batches of wafers fluctuates significantly, resulting in poor inter-wafer uniformity.

[0027] Figure 2 This is a graph showing the film thickness trend (THK trend) at different stages of oxide film deposition using a chemical vapor deposition (CVD) system. Figure 2 The horizontal axis represents the wafer fabrication process of the chemical vapor deposition equipment, the vertical axis represents the film thickness in Å, the range represents the film thickness fluctuation range, and WTW (Wafer-to-Wafer) represents the film thickness fluctuation between different wafers.

[0028] This invention provides a method, apparatus, and chemical vapor deposition equipment for depositing oxide films. By increasing the chamber temperature after the idle phase and decreasing the chamber temperature after the cleaning phase, the chamber temperature can be kept stable when entering the wafer fabrication phase, thereby reducing the fluctuation of oxide film thickness deposited on multiple batches of wafers and improving inter-wafer uniformity.

[0029] The oxide film in this invention can be an undoped silicate glass (USG) film, which is composed of pure silicon dioxide (SiO2) and is not doped with other impurity elements (such as boron, phosphorus, etc.). The USG film can be generated using plasma-enhanced chemical vapor deposition (PECVD), and the aforementioned CVD equipment can be a PECVD device. The PECVD process uses a microwave or radio frequency source to locally form a plasma from a gas containing the atoms that make up the film. The strong chemical activity of the plasma triggers a reaction, depositing the USG film on the wafer surface. This process has advantages such as low base temperature, fast deposition rate, and good film quality.

[0030] USG films formed by PECVD process are called PE-USG films. PE-USG films can be used in semiconductor devices that require high-quality insulation and excellent filling capability.

[0031] For example, the USG thin film can be used as a pre-metal dielectric (PMD). Specifically, after the source, drain, and gate of the transistor are formed and before the first metal layer is formed, the USG thin film can serve as an insulating dielectric to separate it from the subsequent interconnect layers and to planarize it.

[0032] For example, USG films can be used as inter-metal dielectrics (IMDs). Specifically, in multilayer interconnect structures, USG films are used to fill the spaces between different metal layers, providing electrical insulation. As manufacturing processes shrink, the gaps between metal lines become smaller and the aspect ratios become larger, making the void-free filling capability of PE-USG crucial.

[0033] For example, USG films can be used as passivation layers. Specifically, USG films can be used as part of the top protective passivation layer of a chip to protect the circuit from scratches, moisture, and ion contamination.

[0034] The following describes in detail the oxide film deposition method provided by the present invention, taking USG thin film as an example and with reference to the accompanying drawings.

[0035] This embodiment provides a method for depositing an oxide film. Figure 3 This is a schematic flowchart of an oxide film deposition method according to an embodiment of the present invention, as shown below. Figure 3 As shown, the process includes the following steps: Step S301: When the idle phase ends and the current batch of wafers has not been loaded into the chamber, the chamber is heated.

[0036] For example, plasma can be added to the chamber for a preset duration to adjust the chamber temperature from a first temperature to a target temperature. The first temperature is the temperature of the chamber during the idle phase, the target temperature is the temperature configured during the wafer fabrication phase for depositing an oxide film, and the preset duration is determined based on the first temperature and the target temperature; for example, the preset duration can be 400 s to 600 s.

[0037] Specifically, an inert gas (such as nitrogen) is introduced into the chamber and laser plasma is applied. High-energy electrons in the plasma collide with the chamber wall to generate heat, gradually raising the temperature of the chamber from the initial temperature to the set temperature for normal wafer fabrication (such as 300℃-400℃ for PECVD), ensuring a stable temperature environment during subsequent USG deposition.

[0038] This embodiment uses plasma to heat the chamber, which not only regulates the temperature but also uses the high-energy particles of the plasma to bombard residual impurities (such as water vapor and organic residues) on the surface of the chamber wall, causing them to decompose or be carried out of the chamber by the airflow. Moreover, nitrogen can generate plasma to achieve heating and cleaning without depositing any thin film on the chamber wall, avoiding the introduction of additional film contamination. At the same time, nitrogen is low in cost and highly safe.

[0039] For example, CVD equipment typically also includes a heating device located near the chamber, which can also be used to heat the chamber from a first temperature to a target temperature.

[0040] In step S302, after the temperature of the chamber rises from the first temperature to the target temperature, the current batch of wafers is loaded into the chamber, and a first oxide film is deposited on the surface of the current batch of wafers.

[0041] The current batch of wafers consists of multiple sets of wafers that enter the chamber after the idle period ends. These multiple sets of wafers can enter the chamber in batches. The first oxide film is the oxide film formed on the current batch of wafers. The first oxide film can be a USG thin film.

[0042] Specifically, after the temperature treatment, normal wafer fabrication is performed, depositing an oxide film of the target thickness on the surface of the current batch of wafers. The target thickness is the theoretical film thickness set according to process requirements.

[0043] Step S303: After the cleaning stage is completed and before the next batch of wafers is loaded into the chamber, the chamber is cooled.

[0044] The next batch of wafers consists of multiple sets of wafers that will be processed in the chamber after the cleaning phase.

[0045] For example, after the cleaning phase, a highly thermally conductive gas (such as helium) can be sprayed downwards from the top of the chamber. The directional flow of helium carries away excess heat from the chamber, causing the chamber temperature to drop from the second temperature to the target temperature. The second temperature is the temperature of the chamber during the cleaning phase. The helium is either at room temperature or pre-cooled. The chamber is cooled through heat exchange, and the helium is discharged from the bottom of the chamber after the heat exchange.

[0046] In step S304, after the temperature of the chamber drops from the second temperature to the target temperature, the next batch of wafers is loaded into the chamber, and a second oxide film is deposited on the surface of the next batch of wafers to make the thickness of the first oxide film and the thickness of the second oxide film consistent.

[0047] The second oxide film is the oxide film formed on the wafers of the current batch, and the second oxide film can be a USG thin film. When the difference between the thickness of the first oxide film and the thickness of the second oxide film is less than or equal to a preset difference (e.g., 20 Å), the thickness of the first oxide film and the thickness of the second oxide film are considered to be the same.

[0048] Specifically, after cooling, normal wafer fabrication is performed, and an oxide film of the target thickness is deposited on the surface of the next batch of wafers. The wafer fabrication process after the cleaning stage is the same as the wafer fabrication process after the idle stage.

[0049] The oxide film deposition method provided by this invention involves heating the chamber after the idle phase ends and before the current batch of wafers is loaded into the chamber. Only after the chamber temperature rises from a first temperature to a target temperature is a first oxide film deposited on the surface of the current batch of wafers. After the cleaning phase ends and before the next batch of wafers is loaded into the chamber, the chamber is cooled. Only after the chamber temperature drops from a second temperature to the target temperature is a second oxide film deposited on the surface of the next batch of wafers. This invention increases the chamber temperature after the idle phase and decreases the chamber temperature after the cleaning phase, ensuring a consistent chamber temperature throughout the wafer fabrication process. This negligible effect of temperature on film thickness reduces film thickness fluctuations between different batches of wafers and between different wafers within the same batch, improving inter-wafer uniformity.

[0050] This embodiment also provides another method for depositing oxide films. Figure 4 This is a schematic flowchart of another oxide film deposition method according to an embodiment of the present invention, as shown below. Figure 4 As shown, the process includes the following steps: Step S401: When the idle phase ends and the current batch of wafers has not been loaded into the chamber, the chamber is heated.

[0051] Please see details Figure 3 Step S301 of the illustrated embodiment will not be described again here.

[0052] Step S402: Obtain the cumulative film thickness during the wafer fabrication stage.

[0053] The cumulative film thickness is the total thickness of the oxide film deposited in the chamber from the start of the wafer fabrication stage to the present moment.

[0054] Specifically, the deposition time from the start of the tape-out stage to the current time is recorded as the deposition time during tape-out, and the cumulative film thickness = deposition rate × deposition time during tape-out.

[0055] Step S403: Determine the actual thickness of the first oxide film based on the cumulative film thickness and the target model.

[0056] The target model is used to characterize the mapping relationship between the cumulative membrane thickness and the actual membrane thickness. For example, the target model can be a machine learning model.

[0057] Specifically, the cumulative film thickness can be input into the target model, and the actual film thickness of the first oxide film can be determined based on the output of the target model.

[0058] In some embodiments, the target model can be a univariate cubic function model, and the expression can be as shown in formula (1):

[0059] In the formula, Indicates the actual thickness of the film. This represents the cumulative film thickness, where 'a' is a third-order correction parameter. For second-order correction parameters, For third-order correction parameters, a is a constant. , and The actual film thickness on the wafer surface obtained from multiple measurements and the cumulative film thickness corresponding to each actual film thickness are fitted together.

[0060] In this embodiment, a cubic function model is used to fit the relationship between the actual film thickness and the cumulative film thickness, which can more accurately adapt to the nonlinear film thickness variation law during the deposition process.

[0061] Step S404: Based on the actual film thickness and the target film thickness configured in the wafer fabrication stage, optimize the target film deposition time configured in the wafer fabrication stage to obtain the actual film deposition time of the first oxide film.

[0062] Specifically, the wafer fabrication stage is set with a target film thickness, deposition rate, and target film deposition time corresponding to the target film thickness. Theoretically, under the same deposition rate and target film deposition time, the oxide film thickness deposited on the wafer surface entering the chamber at different times should be the same. However, the oxide film thickness deposited on the wafer surface entering the chamber at different times is not the same.

[0063] The present invention has discovered that the actual film thickness on the wafer surface is not equal to the target film thickness due to the influence of the cumulative film thickness. Therefore, the present invention quantifies the influence of the cumulative film thickness on the actual film thickness (target model) during the wafer fabrication process, and dynamically adjusts the target film deposition time during the wafer fabrication process based on the target model, so that the oxide film thickness deposited on the wafer surface entering the chamber at different times is consistent, reducing the degree of film thickness fluctuation and ensuring the stability of the film thickness during the wafer fabrication process.

[0064] For example, based on the actual film thickness and the target film thickness, the target film deposition time can be optimized using the following formula (2) to obtain the actual film deposition time:

[0065] In the formula, Indicates the actual settling time. Indicates the target deposition time. Indicates the target film thickness.

[0066] In step S405, after the temperature of the chamber rises from the first temperature to the target temperature, the current batch of wafers is loaded into the chamber, and a first oxide film is deposited on the surface of the current batch of wafers according to the actual film deposition time.

[0067] Specifically, after the wafer is chambered, an oxide film is deposited on the wafer surface according to the optimized target deposition time (i.e., the actual deposition time), so that the actual thickness of the oxide film deposited on the wafer surface is consistent with the target deposition thickness.

[0068] Step S406: Determine the target cooling time based on the target film thickness configured in the wafer fabrication stage.

[0069] The target cooling time is the cooling time corresponding to the target film thickness.

[0070] Specifically, the target film thickness affects the heat generation in the subsequent deposition process, and the cooling time needs to be matched with the heat generation to ensure that the cavity temperature remains stable at the target temperature during formal deposition under different film thicknesses. Among them, the target film thickness and the target cooling time are positively correlated; the thicker the target film, the longer the target cooling time.

[0071] For example, step S406 above may include: Step a1: Determine the cooling coefficient based on the target film thickness.

[0072] Step a2: The product of the cooling coefficient and the cooling unit time is determined as the target cooling time.

[0073] Specifically, when the target film thickness is less than or equal to the preset thickness, the oxide film deposited on the wafer surface is a thin film with a cooling coefficient of the first cooling coefficient n; when the target film thickness is greater than the preset thickness, the oxide film deposited on the wafer surface is a thick film with a cooling coefficient of the second cooling coefficient m, where m is greater than n.

[0074] The preset thickness and cooling unit time are set values. For example, the preset thickness can be 5000 Å and the cooling unit time can be 50 s.

[0075] Step S407: When the cleaning stage is over and the next batch of wafers has not been loaded into the chamber, the chamber is cooled according to the target cooling time.

[0076] Please see details Figure 3 Step S303 of the illustrated embodiment will not be described again here.

[0077] In step S408, after the temperature of the chamber drops from the second temperature to the target temperature, the next batch of wafers is loaded into the chamber, and a second oxide film is deposited on the surface of the next batch of wafers to make the thickness of the first oxide film and the thickness of the second oxide film consistent.

[0078] Please see details Figure 3 Step S304 of the illustrated embodiment will not be described again here.

[0079] In this embodiment, before depositing an oxide film on the wafer surface, the cumulative film thickness during the wafer fabrication stage is obtained. Based on the cumulative film thickness and the target model, the actual film thickness of the first oxide film is determined. Then, based on the actual film thickness and the target film thickness, time compensation is performed on the target film deposition time. This ensures the consistency of the oxide film thickness deposited on the wafer surface entering the chamber at different times, reducing the degree of film thickness fluctuation. Moreover, after the cleaning stage, a target cooling time is selected based on the target film thickness. Cooling the chamber based on the target cooling time avoids temperature fluctuations in the chamber during deposition due to different film thicknesses, ensuring the consistency of the chamber temperature during wafer fabrication. This invention can reduce film thickness fluctuations from 150 Å to 20 Å.

[0080] For example, such as Figure 5 As shown, the process of depositing an oxide film using the chemical vapor deposition equipment of the present invention includes a preheating and stabilization stage, an idle stage, a wafer fabrication stage, a cleaning stage, and a gas cooling stage, compared to... Figure 1 In order to reduce the fluctuation of film thickness on different wafers, this invention adds a preheating stabilization stage and a cooling stage, as well as a time compensation mechanism during the wafer fabrication stage.

[0081] In some embodiments, the oxide film deposition method provided by the present invention may include the following steps: S1. Preheating and stabilization steps: After the machine idle period ends, add plasma for 400s-600s. The temperature of the working chamber (cavity) after plasma treatment is consistent with the temperature during normal chip fabrication. Inert gas plasma, such as nitrogen, can be used.

[0082] S2, Chip fabrication steps, a certain number of normal wafers are fabricated; S3. Cleaning procedure for the working chamber: The cleaning procedure for the working chamber is performed after the normal wafer fabrication process is completed. S4. Post-cleaning cooling step: After obtaining the target film thickness and completing the cleaning step in the working chamber, select the target cooling time based on the target film thickness (the thicker the film, the longer the target cooling time). Perform a cooling operation on the working chamber based on the target cooling time to ensure a consistent temperature after the cleaning cycle. The target cooling time includes both thin film cooling time and thick film cooling time. Thin film cooling time = n × cooling unit time, thick film cooling time = m × cooling unit time, where m is greater than n. This cooling operation includes spraying thermally conductive helium gas downwards from the top of the working chamber, which then exits from the bottom of the working chamber after heat exchange.

[0083] The above S2 includes the following time compensation steps: S21. Obtain the cumulative film thickness during the tape-out process. Cumulative film thickness = deposition rate × deposition time during tape-out. S22. Based on the measured actual film thickness on the wafer surface, generate a curve showing the relationship between the actual film thickness and the cumulative film thickness. ), where Y is the actual film thickness and X is the cumulative film thickness; S23. Based on the relationship curve between the actual film thickness and the cumulative film thickness, and the film settling time compensation formula, the compensation time is calculated. The film settling time compensation formula is as follows:

[0084] in, This represents the cumulative film thickness of the cavity wall. The time to deposit the film after compensation is represented, and SDT represents the target time to deposit the film (obtained based on the target film thickness). Indicates the target film thickness.

[0085] The film deposition time compensation formula is used to adjust the film deposition time during the wafer fabrication process to ensure that the film thickness remains stable during the wafer fabrication process.

[0086] This embodiment also provides an oxide film deposition apparatus for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0087] This embodiment provides an oxide film deposition apparatus applied to a chemical vapor deposition (CVD) device. The CVD device includes a chamber, and the oxide film deposition process includes an idle stage, a wafer fabrication stage, and a cleaning stage. Figure 6 As shown, the oxide film deposition apparatus includes: The heating module 601 is used to heat the chamber when the idle phase ends and the current batch of wafers has not been loaded into the chamber. The first deposition module 602 is used to load the current batch of wafers into the chamber after the temperature of the chamber rises from a first temperature to a target temperature, and to deposit and form a first oxide film on the surface of the current batch of wafers. The first temperature is the temperature of the chamber during the idle stage, and the target temperature is the temperature at which the oxide film is deposited and formed during the wafer fabrication stage. Cooling module 603 is used to cool the chamber after the cleaning stage is completed and before the next batch of wafers is loaded into the chamber; The second deposition module 604 is used to load the next batch of wafers into the chamber after the temperature of the chamber drops from the second temperature to the target temperature, and to deposit a second oxide film on the surface of the next batch of wafers so that the thickness of the first oxide film and the thickness of the second oxide film are consistent, wherein the second temperature is the temperature of the chamber during the cleaning stage.

[0088] In some alternative implementations, the heating module 601 includes: The heating unit is used to add plasma to the chamber for a preset duration in order to adjust the first temperature to the target temperature.

[0089] In some alternative embodiments, the apparatus further includes: The cooling time determination module is used to determine the target cooling time based on the target film thickness configured in the tape-out stage. Cooling module 603 includes: The cooling unit is used to cool the chamber according to the target cooling time.

[0090] In some optional implementations, the cooling duration determination module includes: The coefficient determination unit is used to determine the cooling coefficient based on the target film thickness. The duration determination unit is used to determine the target cooling duration by multiplying the cooling coefficient by the cooling unit time.

[0091] In some alternative embodiments, the apparatus further includes: The thickness acquisition module is used to acquire the cumulative film thickness during the wafer fabrication stage, wherein the cumulative film thickness is the total thickness of the oxide film deposited in the chamber from the start time of the wafer fabrication stage to the current time. The actual thickness determination module is used to determine the actual thickness of the first oxide film based on the cumulative film thickness and the target model, wherein the target model is used to characterize the mapping relationship between the cumulative film thickness and the actual film thickness. The optimization module is used to optimize the target deposition time configured in the wafer fabrication stage based on the actual deposition thickness and the target deposition thickness configured in the wafer fabrication stage, so as to obtain the actual deposition time of the first oxide film.

[0092] In some alternative implementations, the optimization module includes: The optimization unit is used to optimize the target deposition time based on the actual deposition film thickness and the target deposition film thickness using the following formula to obtain the actual deposition film time:

[0093] In the formula, Indicates the actual settling time. Indicates the target deposition time. Indicates the target film thickness. This indicates the actual thickness of the film.

[0094] In some alternative implementations, the target model is a univariate cubic function model.

[0095] In some alternative embodiments, both the first oxide film and the second oxide film are silicon dioxide films of undoped silicate glass.

[0096] The oxide film deposition apparatus provided in this embodiment of the invention can perform the oxide film deposition method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for performing the method. Further functional descriptions of the various modules and units described above are the same as in the corresponding embodiments described above, and will not be repeated here.

[0097] The present invention also provides a chemical vapor deposition apparatus, including the oxide film deposition apparatus provided in any of the above embodiments.

[0098] Chemical vapor deposition equipment includes electronic equipment. Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0099] The following is a detailed reference. Figure 7 This diagram illustrates a suitable structural schematic for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 701, which can perform various appropriate actions and processes based on a program stored in read-only memory (ROM) 702 or a program loaded from memory 708 into random access memory (RAM) 703. The RAM 703 also stores various programs and data required for the operation of the electronic device. The processor 701, ROM 702, and RAM 703 are interconnected via a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704.

[0100] Typically, the following devices can be connected to I / O interface 705: input devices 706 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 707 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 708 including, for example, magnetic tapes, hard disks, etc.; and communication devices 709. Communication device 709 allows electronic devices to exchange data via wireless or wired communication with other devices. Although Figure 7 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0101] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 709, or installed from a memory 708, or installed from a ROM 702. When the computer program is executed by the processor 701, it performs the functions defined in the oxide film deposition method of the embodiments of the present invention.

[0102] Figure 7 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0103] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium after being downloaded via a network. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium may also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the oxide film deposition method shown in the above embodiments is implemented.

[0104] A portion of this invention can be applied to computer program products, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installation program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0105] The above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described above, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention.

[0106] Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention.

Claims

1. A method for depositing an oxide film, characterized in that, The oxide film deposition method is applied to a chemical vapor deposition (CVD) apparatus, which includes a chamber. The process of depositing the oxide film using the CVD apparatus includes an idle stage, a wafer fabrication stage, and a cleaning stage. The oxide film deposition method includes: When the idle phase ends and the current batch of wafers has not been loaded into the chamber, the chamber is heated. After the temperature of the chamber rises from a first temperature to a target temperature, the current batch of wafers is loaded into the chamber, and a first oxide film is deposited on the surface of the current batch of wafers. The first temperature is the temperature of the chamber during the idle phase, and the target temperature is the temperature at which the oxide film is deposited during the wafer fabrication phase. When the cleaning phase is completed and the next batch of wafers has not been loaded into the chamber, the chamber is cooled. After the temperature of the chamber drops from the second temperature to the target temperature, the next batch of wafers is loaded into the chamber, and a second oxide film is deposited on the surface of the next batch of wafers to make the thickness of the first oxide film and the thickness of the second oxide film consistent, wherein the second temperature is the temperature of the chamber during the cleaning stage.

2. The method for depositing an oxide film according to claim 1, characterized in that, The heating process of the chamber includes: Plasma is added to the chamber for a preset duration to adjust the first temperature to the target temperature.

3. The method for depositing an oxide film according to claim 1, characterized in that, The method for depositing the oxide film prior to cooling the chamber further includes: The target cooling time is determined based on the target film thickness configured in the wafer fabrication stage; The cooling process for the chamber includes: The chamber is cooled according to the target cooling duration.

4. The method for depositing an oxide film according to claim 3, characterized in that, Determining the target cooling time based on the target film thickness configured in the wafer fabrication stage includes: The cooling coefficient is determined based on the target film thickness; The product of the cooling coefficient and the cooling unit time is determined as the target cooling time.

5. The method for depositing an oxide film according to any one of claims 1 to 4, characterized in that, Prior to the deposition of the first oxide film on the surface of the current batch of wafers, the method for depositing the oxide film further includes: The cumulative film thickness during the wafer fabrication stage is obtained, wherein the cumulative film thickness is the total thickness of the oxide film deposited in the chamber from the start time of the wafer fabrication stage to the current time. Based on the cumulative film thickness and the target model, the actual film thickness of the first oxide film is determined, wherein the target model is used to characterize the mapping relationship between the cumulative film thickness and the actual film thickness. Based on the actual film thickness and the target film thickness configured in the wafer fabrication stage, the target film deposition time configured in the wafer fabrication stage is optimized to obtain the actual film deposition time of the first oxide film.

6. The method for depositing an oxide film according to claim 5, characterized in that, The step of optimizing the target deposition time configured in the wafer fabrication stage based on the actual deposition thickness and the target deposition thickness configured in the wafer fabrication stage includes: Based on the actual film deposition thickness and the target film deposition thickness, the target film deposition time is optimized using the following formula to obtain the actual film deposition time: In the formula, This indicates the actual film settling time. This indicates the target deposition time. This indicates the thickness of the target film. This indicates the actual thickness of the film.

7. The method for depositing an oxide film according to claim 5, characterized in that, The target model is a cubic function model.

8. The method for depositing an oxide film according to any one of claims 1 to 4, characterized in that, Both the first oxide film and the second oxide film are silicon dioxide films of undoped silicate glass.

9. An apparatus for depositing an oxide film, characterized in that, An apparatus for chemical vapor deposition (CVD) is used, the CVD apparatus including a chamber, the CVD process for depositing an oxide film including an idle stage, a wafer fabrication stage, and a cleaning stage, and the oxide film deposition device including: A heating module is used to heat the chamber when the idle phase ends and the current batch of wafers has not been loaded into the chamber; A first deposition module is configured to load the current batch of wafers into the chamber after the temperature of the chamber rises from a first temperature to a target temperature, and to deposit a first oxide film on the surface of the current batch of wafers, wherein the first temperature is the temperature of the chamber during the idle phase, and the target temperature is the temperature at which the oxide film is deposited during the wafer fabrication phase; A cooling module is used to cool the chamber when the cleaning stage is completed and the next batch of wafers has not been loaded into the chamber. The second deposition module is used to load the next batch of wafers into the chamber after the temperature of the chamber drops from the second temperature to the target temperature, and to deposit a second oxide film on the surface of the next batch of wafers so that the thickness of the first oxide film and the thickness of the second oxide film are consistent, wherein the second temperature is the temperature of the chamber during the cleaning stage.

10. A chemical vapor deposition apparatus, characterized in that, The apparatus includes the oxide film deposition apparatus of claim 9.

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