A multiwafer vertical atomic layer deposition apparatus and thin film deposition method

Abstract

This invention discloses a multi-wafer vertical atomic layer deposition apparatus and a thin film deposition method, relating to the field of semiconductor thin film deposition technology. The apparatus includes a reaction chamber, a wafer carrier, a multilayer gas distribution unit, a precursor supply system, a pressure detection unit, and a control unit. The precursor supply system connects the precursor source to the multilayer gas distribution unit via a gas supply equivalent path module, ensuring that the path lengths from each branch to the corresponding wafer location or reaction zone are the same or meet preset length difference requirements. The control unit adjusts the gas flow rate of each branch based on the deviation between the real-time pressure signal fed back by the pressure detection unit and the preset target value. This invention improves the problem of insufficient downstream pressure distribution in multi-wafer deposition by combining passive path balancing and active pressure compensation, thereby enhancing the uniformity of thin film deposition between multiple wafers and increasing precursor utilization.

Description

Technical Field

[0001] This invention relates to the field of semiconductor thin film deposition equipment technology, and particularly to a multi-wafer vertical atomic layer deposition equipment and a thin film deposition method. Background Technology

[0002] Atomic layer deposition (ALD) is a thin film deposition technique based on a surface self-limiting reaction mechanism, enabling atomic-level thickness control. With increasing capacity requirements in semiconductor manufacturing, multi-wafer ALD equipment has become an important development direction. Multi-wafer systems typically arrange multiple wafers vertically along the height of the reaction chamber to achieve batch processing.

[0003] However, when the precursor gas flows vertically, the upstream wafer preferentially consumes precursor molecules, leading to a decrease in precursor concentration in the downstream region and the formation of a concentration gradient. In a typical batch processing system, the deposition thickness difference between the upper and lower wafers can reach 5% to 10%. Furthermore, due to the varying lengths of the inlet pipes and the presence of dead volumes within the pipes where gas tends to stagnate, the actual gas supply pressure varies at different locations, further exacerbating the deposition unevenness problem. Existing technologies often improve uniformity by increasing the precursor dosage or extending the exposure time, but this leads to reduced precursor utilization, increased cavity contamination, and prolonged process time.

[0004] Therefore, how to achieve a balanced supply of precursor voltage across different wafer locations in a multi-wafer ALD device has become a pressing technical challenge. Summary of the Invention

[0005] The main objective of this invention is to provide a multi-wafer vertical atomic layer deposition (ALD) apparatus and a thin film deposition method, which aims to achieve a balanced supply of precursors across different wafer locations in a multi-wafer ALD apparatus.

[0006] In this invention, the reaction zone refers to the area where gas is supplied along the height direction of the reaction chamber by the multi-layer gas distribution unit.

[0007] To achieve the above objectives, the present invention proposes a multi-plate vertical atomic layer deposition apparatus, comprising: Reaction chamber; A wafer carrier is disposed within the reaction chamber and is used to support multiple wafers at intervals along the vertical direction. A multi-layer gas distribution unit is arranged along the height direction of the reaction chamber to supply precursor gas to the corresponding wafer position; A precursor supply system includes a precursor source and a gas supply equivalent path module. The precursor source is connected to the multilayer gas distribution unit through the gas supply equivalent path module. The reaction chamber is divided into multiple reaction zones along the height direction. The gas supply equivalent path module includes multiple branch flows, each branch flow corresponding to one of the multiple reaction zones. The gas flow path length from each branch flow to the corresponding wafer position or the corresponding reaction zone is the same, or the length difference of the gas flow paths in each group is less than or equal to a preset length difference threshold. A pressure detection unit is installed on the pipeline of each of the said branch lines or at the inlet of the multi-layer gas distribution unit, and is used to detect the real-time pressure signal of the reaction zone corresponding to each of the said branch lines. The control unit is electrically connected to the pressure detection unit and the precursor supply system, and the control unit controls the regulating valves installed on each of the branch lines according to the relative pressure deviation. The gas supply flow rate of each of the aforementioned branch circuits corresponding to the reaction zones is dynamically compensated to balance the precursor pressure distribution at each wafer location; wherein, For the first The relative pressure deviation of the reaction zone corresponding to the component flow branch. For the first The real-time pressure values ​​of the reaction zones corresponding to the component flow branches. For the first The preset target precursor partial pressure value for the reaction zone corresponding to the component flow branch. The control unit is also used to number the branch flows; it is further configured to acquire the pressure change rate of the reaction zone corresponding to each branch flow. As an auxiliary judgment parameter, it distinguishes between instantaneous pressure fluctuations and persistent insufficient gas supply; among them, For the first The rate of change of pressure over time in the reaction zone corresponding to the component flow branch. For time.

[0008] Preferably, it further includes: The stage lifting and rotating mechanism is located below the reaction chamber; The stage lifting and rotating mechanism includes a stage lifting assembly and a stage rotating assembly. The stage lifting assembly drives the wafer carrier to move up and down to enter and exit the reaction chamber. The stage rotating assembly drives the wafer carrier to perform processes. Continuous rotation.

[0009] Preferably, it further includes a heating system, the heating system comprising: The first heating component is a heating tube or silicone heating strip distributed on the reaction chamber, the gas supply equivalent path module and the precursor supply system; And the second heating element is an insulating jacket wrapped around the outside of the pipe; The heating system is electrically connected to a temperature sensor and a proportional-integral-derivative temperature controller to maintain the process ambient temperature at [temperature value missing]. Within the preset range.

[0010] Preferably, the pipeline material of the gas supply equivalent path module is stainless steel, and the pipeline connection adopts a vacuum metal gasket surface sealing joint.

[0011] Preferably, a flow resistance matching unit is also provided on each of the branch lines. The flow resistance matching unit includes at least one of a flow limiting orifice, a throttle valve, or an adjustable flow resistance element, for adjusting the flow rate of the precursor material in each of the branch lines.

[0012] Preferably, the multi-layer gas distribution unit includes at least one of a porous distribution plate, an annular gas outlet structure, or a slit-type gas outlet structure; and a flow field shaping structure is also provided in the reaction chamber, the flow field shaping structure including a guide plate, a flow equalization cavity, or a buffer cavity.

[0013] Preferably, there are four branch lines, namely a first branch line, a second branch line, a third branch line, and a fourth branch line. Each branch line independently controls the precursor intake through a corresponding regulating valve. Each branch line is connected to multiple air inlets to provide precursors to multiple wafers in the reaction chamber.

[0014] Preferably, the control unit determines the relative pressure deviation based on the relative pressure deviation. The absolute value drives the stepper motor to drive the regulating valve to perform discrete opening correction; When the relative pressure deviation When the absolute value is within the first deviation range, the control unit controls the stepper motor to rotate one step angle. When the relative pressure deviation When the absolute value is within the second deviation range, the control unit controls the stepper motor to rotate a second step angle; Wherein, the second deviation range is greater than the first deviation range, and the second step angle is greater than the first step angle.

[0015] Preferably, the corrected step size of the stepper motor satisfies: When the relative pressure deviation The absolute value is At that time, the step angle is ; When the relative pressure deviation The absolute value is At that time, the step angle is ; When the relative pressure deviation The absolute value is greater than At that time, the step angle is .

[0016] The present invention also discloses a thin film deposition method using a multi-plate vertical atomic layer deposition apparatus as described in any of the preceding claims, characterized in that it comprises: Initialization steps: Set the target precursor partial pressure value and tolerance range for each reaction zone; Intake step: Turn on the precursor supply system so that the precursor gas enters the multi-layer gas distribution unit of each reaction zone through the gas supply equivalent path module; Monitoring steps: The pressure detection unit detects the real-time pressure signal of the corresponding reaction zone of each of the branch branches in real time; Comparison step: The control unit receives the real-time pressure signal and calculates the relative pressure deviation. ;in, For the first The relative pressure deviation of the reaction zone corresponding to the component flow branch. For the first The real-time pressure values ​​of the reaction zones corresponding to the component flow branches. For the first The partial pressure of the target precursor in the reaction zone corresponding to the component flow branch. Number the branch roads; Compensation steps: If the relative pressure deviation If the absolute value exceeds the tolerance range, the control unit determines the relative pressure deviation based on the relative pressure deviation. The absolute value and sign of the value are used to calculate the adjustment value of the regulating valve opening, and to drive the stepper motor to increase or decrease the opening of the regulating valve of the corresponding reaction zone, so as to compensate for the decrease in downstream partial pressure caused by the consumption of upstream wafers along the direction of precursor gas flow; the control unit is also used to obtain the pressure change rate of the corresponding reaction zone of each of the branch branches. As an auxiliary judgment parameter, it distinguishes between instantaneous pressure fluctuations and persistent insufficient gas supply; among them, For the first The rate of change of pressure over time in the reaction zone corresponding to the component flow branch. For time.

[0017] The above technical solution has the following advantages: This invention establishes equivalent gas supply path modules with identical or preset length difference requirements, ensuring that the pressure loss and transmission delay of the precursor gas entering each reaction zone are the same or meet preset requirements. A pressure detection unit, in conjunction with a control unit, enables real-time monitoring of the pressure in each reaction zone. The control unit adjusts the pressure based on relative pressure deviations. The dynamic stepper motor adjusts the opening of the regulating valve, compensating in real time for the decrease in downstream partial pressure caused by upstream wafer consumption along the precursor gas flow direction. This dual regulation mechanism, combining active closed-loop control with passive equivalent path design, effectively reduces the concentration gradient along the cavity height. The equipment can control the deposition thickness difference between multiple wafers within a very small range, significantly improving the uniformity and process stability of thin film deposition while maintaining high throughput. Attached Figure Description

[0018] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a schematic diagram of the overall structure of a multi-plate vertical atomic layer deposition apparatus provided in an embodiment of the present invention.

[0019] Figure 2 This is a partial structural schematic diagram of the gas supply equivalent path module provided in an embodiment of the present invention.

[0020] Figure 3 The control logic flowchart of the thin film deposition method provided in the embodiment of the present invention is shown.

[0021] Figure 4 A black-and-white streamline diagram of the gas flow field inside the reaction chamber provided in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0023] Example 1 See Figures 1 to 4As shown, this embodiment addresses the technical challenges of poor deposition uniformity and significant precursor consumption gradients in multi-wafer atomic layer deposition processes in semiconductor manufacturing. It provides a multi-wafer vertical atomic layer deposition apparatus. The main structure of this apparatus includes a reaction chamber 1, which adopts a vertical design. In this embodiment, the reaction chamber 1 is made of 6061 aluminum alloy, a material known for its high strength, corrosion resistance, and excellent thermal conductivity. The reaction chamber 1 is specifically designed with a diameter of 346 mm and a height of 575 mm, accommodating wafers 3 of 8 inches and below, with a maximum of 64 wafers 3 processed in a single process.

[0024] It is worth noting that, in order to further optimize the equipment's footprint and adapt to space-constrained process environments, this embodiment integrates the electrical control system directly into the equipment body, rather than using a traditional external control cabinet. This highly integrated design significantly reduces the horizontal footprint of the equipment while maintaining high throughput and process stability.

[0025] A wafer carrier is disposed within the reaction chamber 1. This wafer carrier supports multiple wafers 3 at intervals along the vertical direction, so that the multiple wafers 3 are arranged discontinuously along the height direction of the reaction chamber 1. To accommodate multi-wafer processing requirements, the equipment also includes a stage lifting and rotating mechanism, which is located below the reaction chamber 1. The stage lifting assembly drives the wafer carrier to move up and down axially to complete the loading and unloading of the wafers 3. The stage rotating assembly drives the wafer carrier during the thin film deposition process. The continuous rotation of the precursor gas helps to distribute the precursor gas more evenly on the surface of each wafer, significantly compensating for the film thickness deviation caused by the uneven static gas flow field.

[0026] The core of the equipment's gas supply system consists of a precursor supply system and a multi-layer gas distribution unit 2. The precursor supply system is connected to the multi-layer gas distribution unit 2 via a gas supply equivalent path module. This gas supply equivalent path module is located on the side of the reaction chamber 1, and its piping material is made of stainless steel with an outer diameter of 6.35 mm. It is connected using vacuum metal gasket face-sealing joints to ensure that... It maintains reliable airtightness even in a vacuum working environment, preventing precursor leakage or condensation.

[0027] Furthermore, this gas supply equivalent path module effectively reduces the dead volume (i.e., the space where gas easily stagnates and is difficult to displace quickly) in the pipeline system through a specifically designed symmetrical distribution structure. The gas supply equivalent path module includes multiple branch flows, specifically divided into a first branch flow, a second branch flow, a third branch flow, and a fourth branch flow in this embodiment. Each branch flow independently controls the intake volume through a corresponding regulating valve 4. Crucially, the gas flow path length from each branch flow to the corresponding wafer 3 location or the corresponding reaction zone is designed to be the same, or the length difference is less than or equal to a preset length difference threshold. Through this equivalent path design, the pressure loss and transmission delay of the precursor gas entering each reaction zone are the same or meet preset requirements, thereby providing equal gas supply starting conditions for each wafer 3 location.

[0028] The multi-layer gas distribution unit 2 is partitioned along the height of the reaction chamber 1, with each branch connected to 16 gas inlets, totaling 64 gas inlets across the four branches, thus covering the entire wafer 3 area of ​​the chamber. To achieve precise control of the precursor partial pressure, pressure detection units, such as real-time pressure sensors, are installed in each branch or at the gas inlet of the multi-layer gas distribution unit 2 to monitor the real-time pressure signals of each reaction zone. These pressure signals are transmitted to the control unit.

[0029] In a multi-plate vertical reactor, when the precursor flows along the height of the cavity, the upstream wafer 3 preferentially consumes some precursor molecules due to surface self-limiting reactions. This physical phenomenon causes the precursor concentration in the downstream region to gradually decrease, forming a concentration gradient. This embodiment addresses this problem through a closed-loop control mechanism. The control unit compares the real-time pressure signal fed back by the pressure detection unit with the preset target precursor partial pressure value to calculate the relative pressure deviation. ,in, For the first The relative pressure deviation of the reaction zone corresponding to the component flow branch. For the first The real-time pressure values ​​of the reaction zones corresponding to the component flow branches. For the first The partial pressure of the target precursor in the reaction zone corresponding to the component flow branch. Number the branch circuit. If the relative pressure deviation... If the absolute value exceeds the preset tolerance range, the control unit will adjust the relative pressure deviation accordingly. The absolute value and sign of the value are used to calculate the opening correction value of the regulating valve 4, and the stepper motor is driven to drive the regulating valve 4 to perform discrete opening correction.

[0030] Specifically, the control unit uses segmented step commands for dynamic compensation. When the relative pressure deviation... The absolute value is At that time, the control unit controls the stepper motor to rotate. Angle; when the relative pressure deviation The absolute value is At that time, the step angle increases to ; and when the relative pressure deviation The absolute value is greater than At that time, the step angle is set to By using this method of zone detection and zone compensation, the equipment can increase the gas supply flow rate in the downstream area in real time, thereby offsetting the pressure reduction caused by upstream consumption and keeping the precursor pressure at position 3 of each wafer within the preset range.

[0031] In addition, the control unit can also acquire the pressure change rate of the corresponding reaction zone of each branch. ,in, For the first The rate of change of pressure over time in the reaction zone corresponding to the component flow branch. For the first The real-time pressure values ​​of the reaction zones corresponding to the component flow branches. For time, This is the branch number. The rate of pressure change serves as an auxiliary criterion, effectively helping the system distinguish between instantaneous pressure fluctuations caused by pulsed gas supply and persistent insufficient gas supply caused by changes in pipeline flow resistance or increased consumption.

[0032] To ensure process stability, the equipment is also equipped with a comprehensive heating system. This system includes a first heating element, specifically a heating tube or silicone heating strip, distributed across the reaction chamber 1, the gas supply equivalent path module, and the precursor supply system. Additionally, an insulating jacket surrounds the piping as a second heating element. This heating system is electrically connected to a temperature sensor and a proportional-integral-derivative temperature controller, enabling precise maintenance of the entire process environment temperature. Within the set range. Through constant temperature control, it can effectively prevent the precursor gas from condensing or generating unnecessary chemical reactions in the complex equivalent path pipeline, while reducing local gas phase pressure fluctuations caused by temperature gradients.

[0033] The solution provided in this embodiment combines a passive balancing mechanism of flow resistance matching with an active adjustment mechanism of pressure closed loop, forming a dual gas supply control structure. Compared to traditional asymmetric structure devices, this embodiment can control the overall thickness deviation among 64 wafers within a certain range. This significantly improves the uniformity and repeatability of multi-layer atomic layer deposition processes.

[0034] Example 2 As a further refinement of Embodiment 1, this embodiment details the mechanical movement and thermal field control of the multi-wafer vertical atomic layer deposition apparatus. The apparatus is equipped with a stage lifting and rotating mechanism, specifically located below the reaction chamber 1. The stage lifting assembly is connected to the wafer carrier via a vertical drive device, used to remove the wafer carrier from the reaction chamber 1 for wafer 3 replacement in non-process conditions, and to precisely place the wafer carrier into the preset center position of the reaction chamber 1 before the process begins.

[0035] During the process execution, the stage rotation assembly drives the wafer carrier to move... The continuous rotation of the wafer ensures that the surface of each wafer 3 is circumferentially exposed to the precursor gas flow, thereby eliminating the near-end and far-end concentration differences caused by the side-entry port layout.

[0036] To prevent changes in the physical or chemical properties of the precursors within the complex piping system, this embodiment employs a zoned design for the heating system. The first heating assembly includes heating pipes or silicone heating strips distributed along the outer wall of the reaction chamber 1, the gas supply equivalent path module piping, and at the precursor source. These components are responsible for maintaining the process path at a preset process temperature, for example... Within this range, at each pipe connection, especially at joints sealed with vacuum metal gaskets, an additional insulating jacket serving as a secondary heating element is added to prevent precursor condensation caused by cold spots. The entire heating system forms a closed-loop temperature system via a temperature sensor and a proportional-integral-derivative temperature controller, ensuring the thermal stability of the process environment.

[0037] Example 3 This embodiment focuses on the flow resistance matching mechanism and internal flow field structure used for passive balancing and auxiliary rectification in the gas supply system. Each component branch of the gas supply equivalent path module is equipped with a flow resistance matching unit. This unit specifically includes at least one of a flow limiting orifice, a throttle valve, or an adjustable flow resistance element. During the calibration phase after equipment assembly, these flow resistance elements can be manually or pre-adjusted to compensate for minor manufacturing tolerances between the reaction zone branches, ensuring that the precursor gas has balanced fluid momentum before entering the multilayer gas distribution unit 2.

[0038] The multi-layer gas distribution unit 2 integrates a complex gas uniform distribution structure, such as a porous distribution plate, an annular gas outlet structure, or a slit-type gas outlet structure. After the precursor gas enters the inlet from the branch, it is first pressure homogenized in these distribution structures, and then injected into the reaction region through a fine array of micropores.

[0039] This embodiment uses computational fluid dynamics (CFD) to simulate the internal flow field. According to the simulation results, when the precursor gas is released through the 128-hole array, due to the extremely small cross-section of each hole, the initial peak velocity of the airflow after leaving the multilayer gas distribution unit 2 can reach [value missing]. This design of "high-speed dispersion through micropores and low-speed mixing within cavities" can break the laminar boundary layer with a localized high-momentum jet, thereby enhancing the uniformity of gas mixing.

[0040] To mitigate the direct impact of high-speed airflow on the surface of wafer 3 and optimize concentration distribution, a flow-shaping structure is incorporated within reaction chamber 1. This structure includes guide plates, flow equalization chambers, buffer chambers, or flow channels. Upon entering the chamber, the high-speed airflow rapidly disperses and merges under the guidance of these shaping structures, with the velocity magnitude smoothly decreasing from its peak. Within the cylindrical reaction region, streamlines form smooth spiral or wavy trajectories and converge orderly towards the exhaust port. Vortices, backflows, and stagnation zones in the flow field are reduced, resulting in excellent flow stability and directionality. This design not only improves the mixing uniformity of the precursor gas but also avoids particulate contamination caused by macroscopic high-speed airflow.

[0041] Example 4 This embodiment provides a thin film deposition method using the aforementioned equipment, achieving highly consistent film thickness control through closed-loop compensation of reaction zone pressure. The method first performs an initialization step, where the control unit loads the process formulation and sets the target precursor partial pressure values ​​and corresponding tolerance ranges for each reaction zone's corresponding branch. Subsequently, the gas intake step begins, activating the precursor supply system. The precursor gas simultaneously enters the multilayer gas distribution unit 2 via the component flow branches of the equivalent path.

[0042] During process execution, the monitoring step operates continuously. Pressure detection units located at each branch or inlet capture real-time pressure signals from each reaction zone and feed the data back to the control unit. In the comparison step, the control unit calculates the relative pressure deviation between the fed-back real-time pressure value and the preset target value. ,in, For the first The relative pressure deviation of the reaction zone corresponding to the component flow branch. For the first The real-time pressure values ​​of the reaction zones corresponding to the component flow branches. For the first The partial pressure of the target precursor in the reaction zone corresponding to the component flow branch. Number the branch circuit. After entering the compensation step, if the relative pressure deviation... If the absolute value exceeds the tolerance range, the control unit determines that insufficient downstream voltage distribution is caused by the consumption of upstream wafer 3. At this time, the control unit determines the relative pressure deviation based on the above. The absolute value and sign are used to calculate the corresponding correction step size, which drives the stepper motors of each branch to adjust the opening of the regulating valve 4. For example, when the relative pressure deviation... The absolute value reaches When the motor rotates This compensates for the gas supply. Through this dynamic reaction zone flow compensation, the surface of wafer 3 at different heights can be maintained or nearly maintained within the partial pressure range of saturated adsorption.

[0043] To further enhance the system's anti-interference capability, the control unit will also acquire the pressure change rate during the compensation process. Parameters, where, For the first The rate of change of pressure over time in the reaction zone corresponding to the component flow branch. For the first The real-time pressure values ​​of the reaction zones corresponding to the component flow branches. For time, The branch circuit is numbered. By analyzing this rate, the system can intelligently identify instantaneous pulse fluctuations caused by the action of the upstream valve, thereby avoiding unnecessary adjustment actions.

[0044] In a comparative experiment involving 64 wafers (3), the experimental conditions were set as follows: trimethylaluminum and water were used as precursors, the chamber pressure was approximately 26.7 Pa, and the wafer (3) temperature was... 1200 atomic layer deposition cycles were performed. The experimental group using this method exhibited high uniformity, with consistent film thickness across all reaction zones (zones 1 to 4), and the overall film thickness showed a decreasing trend of only [missing information]. Overall thickness deviation controlled within Around 100 mm. In contrast, the control group, which did not employ zoned pressure closed-loop compensation, exhibited a thickness deviation as high as 100 mm. Furthermore, due to upstream consumption, the downstream film thickness decreased significantly (from zone 1 to zone 4, the thickness decreased by a significant amount). ).

[0045] In other variations of the present invention, each technical module may have the following alternatives: I. Changes in gas distribution structure: The multi-layer gas distribution unit 2 can adopt a porous gas distribution plate structure, through which multiple gas nozzles are set on the plate to make the precursor form a more uniform distribution.

[0046] II. Changes in gas supply method: The precursor supply system may include multiple independent precursor supply branches, each corresponding to a gas distribution unit 2, and each equipped with a micro mass flow controller (MFC) to achieve digital and more precise independent control.

[0047] III. Changes in Pressure Detection Method: The pressure detection unit can be located not only near the multi-layer gas distribution unit 2, but also in the precursor delivery pipeline, inside the reaction chamber 1, or at the gas exhaust end. Optionally, the system can adopt a multi-point pressure monitoring method, whereby the control unit calculates the complete pressure distribution within the reaction chamber 1 based on multi-point signals.

[0048] IV. Changes in wafer carrier structure: Depending on the process space requirements, wafer carriers can be rotary carriers, lifting carriers, or ring carriers to allow the wafer 3 to be positioned during the deposition process, further improving the uniformity of the thin film.

[0049] V. Changes in the flow resistance matching unit: The flow resistance matching unit can be selected from a combination of adjustable throttle valve, fixed orifice flow limiter or miniature mass flow controller, depending on the control strategy.

[0050] VI. Changes in the structure of reaction chamber 1: The geometry of reaction chamber 1 is not limited to a cylindrical shape. It can also be a square reaction chamber 1 or a multi-segment reaction chamber 1, depending on the shape of wafer 3.

[0051] All of the above-mentioned hardware variants can apply the gas partial pressure equalization control strategy described in this invention to achieve the technical objectives of improving process uniformity, increasing precursor utilization, and reducing gas waste.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-plate vertical atomic layer deposition apparatus, characterized in that, include: Reaction chamber; A wafer carrier, disposed within the reaction chamber, is used to support multiple wafers at intervals along a vertical direction; A multi-layer gas distribution unit is arranged along the height direction of the reaction chamber to supply precursor gas to the corresponding wafer position; A precursor supply system includes a precursor source and a gas supply equivalent path module. The precursor source is connected to the multilayer gas distribution unit through the gas supply equivalent path module. The reaction chamber is divided into multiple reaction zones along the height direction. The gas supply equivalent path module includes multiple branch flows, each branch flow corresponding to one of the multiple reaction zones. The gas flow path length from each branch flow to the corresponding wafer position or the corresponding reaction zone is the same, or the length difference of the gas flow paths in each group is less than or equal to a preset length difference threshold. A pressure detection unit is installed on the pipeline of each of the said branch lines or at the inlet of the multi-layer gas distribution unit, and is used to detect the real-time pressure signal of the reaction zone corresponding to each of the said branch lines. The control unit is electrically connected to the pressure detection unit and the precursor supply system, and the control unit controls the regulating valves installed on each of the branch lines according to the relative pressure deviation. Dynamically compensate the gas supply flow rate of each of the aforementioned branch circuits corresponding to the reaction zones to balance the precursor pressure distribution at each wafer location; wherein, For the first The relative pressure deviation of the reaction zone corresponding to the component flow branch. For the first The real-time pressure values ​​of the reaction zones corresponding to the component flow branches. For the first The preset target precursor partial pressure value for the reaction zone corresponding to the component flow branch. The control unit is also used to number the branch flows; it is further configured to acquire the pressure change rate of the reaction zone corresponding to each branch flow. As an auxiliary judgment parameter, it distinguishes between instantaneous pressure fluctuations and persistent insufficient gas supply; among them, For the first The rate of change of pressure over time in the reaction zone corresponding to the component flow branch. For time.

2. The multi-plate vertical atomic layer deposition apparatus according to claim 1, characterized in that, Also includes: The stage lifting and rotating mechanism is located below the reaction chamber; The stage lifting and rotating mechanism includes a stage lifting assembly and a stage rotating assembly. The stage lifting assembly drives the wafer carrier to move up and down to enter and exit the reaction chamber. The stage rotating assembly drives the wafer carrier to perform processes. Continuous rotation.

3. The multi-plate vertical atomic layer deposition apparatus according to claim 1, characterized in that, It also includes a heating system, which comprises: The first heating component is a heating tube or silicone heating strip distributed on the reaction chamber, the gas supply equivalent path module and the precursor supply system; And a second heating element, which is an insulating jacket wrapped around the outside of the pipes; The heating system is electrically connected to a temperature sensor and a proportional-integral-derivative temperature controller to maintain the process ambient temperature at [temperature value missing]. Within the preset range.

4. The multi-plate vertical atomic layer deposition apparatus according to claim 1, characterized in that, The gas supply equivalent path module has stainless steel piping, and the pipe connections use vacuum metal gaskets for surface sealing.

5. The multi-plate vertical atomic layer deposition apparatus according to claim 1, characterized in that, Each of the aforementioned branch lines is further provided with a flow resistance matching unit, which includes at least one of a flow limiting orifice, a throttle valve, or an adjustable flow resistance element, for adjusting the flow rate of the precursor material in each of the aforementioned branch lines.

6. The multi-plate vertical atomic layer deposition apparatus according to claim 1, characterized in that, The multi-layer gas distribution unit includes at least one of a porous distribution plate, an annular gas outlet structure, or a slit-type gas outlet structure; and a flow field shaping structure is also provided in the reaction chamber, the flow field shaping structure including a guide plate, a flow equalization cavity, or a buffer cavity.

7. The multi-plate vertical atomic layer deposition apparatus according to claim 1, characterized in that, The number of the branch lines is four, namely the first branch line, the second branch line, the third branch line and the fourth branch line. Each branch line independently controls the amount of precursor air intake through a corresponding regulating valve. Each branch line is connected to multiple air inlets to provide precursor to multiple wafers in the reaction chamber.

8. The multi-plate vertical atomic layer deposition apparatus according to claim 1, characterized in that, The control unit is based on the relative pressure deviation. The absolute value drives the stepper motor to drive the regulating valve to perform discrete opening correction; When the relative pressure deviation When the absolute value is within the first deviation range, the control unit controls the stepper motor to rotate one step angle. When the relative pressure deviation When the absolute value is within the second deviation range, the control unit controls the stepper motor to rotate a second step angle; Wherein, the second deviation range is greater than the first deviation range, and the second step angle is greater than the first step angle.

9. The multi-plate vertical atomic layer deposition apparatus according to claim 8, characterized in that, The corrected step size of the stepper motor satisfies: When the relative pressure deviation The absolute value is At that time, the step angle is ; When the relative pressure deviation The absolute value is At that time, the step angle is ; When the relative pressure deviation The absolute value is greater than At that time, the step angle is .

10. A thin film deposition method using a multi-plate vertical atomic layer deposition apparatus as described in any one of claims 1 to 9, characterized in that, include: Initialization steps: Set the target precursor partial pressure value and tolerance range for each reaction zone; Intake step: Turn on the precursor supply system so that the precursor gas enters the multi-layer gas distribution unit of each reaction zone through the gas supply equivalent path module; Monitoring steps: The pressure detection unit detects the real-time pressure signal of the corresponding reaction zone of each of the branch branches in real time; Comparison step: The control unit receives the real-time pressure signal and calculates the relative pressure deviation. in, For the first The relative pressure deviation of the reaction zone corresponding to the component flow branch. For the first The real-time pressure values ​​of the reaction zones corresponding to the component flow branches. For the first The partial pressure of the target precursor in the reaction zone corresponding to the component flow branch. Number the branch roads; Compensation steps: If the relative pressure deviation If the absolute value exceeds the tolerance range, the control unit determines the relative pressure deviation based on the relative pressure deviation. The absolute value and sign of the value are used to calculate the adjustment value of the regulating valve opening, and to drive the stepper motor to increase or decrease the opening of the regulating valve of the corresponding reaction zone, so as to compensate for the decrease in downstream partial pressure caused by the consumption of upstream wafers along the direction of precursor gas flow; the control unit is also used to obtain the pressure change rate of the corresponding reaction zone of each of the branch branches. As an auxiliary judgment parameter, it distinguishes between instantaneous pressure fluctuations and persistent insufficient gas supply; among them, For the first The rate of change of pressure over time in the reaction zone corresponding to the component flow branch. For time.

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