A method and system for metal atomic layer deposition

Abstract

This application discloses a method and system for metal atomic layer deposition. The method includes: with the control valve at the outlet of the reaction chamber closed, supplying a metal source to the reaction chamber so that the metal source is adsorbed onto the surface of a substrate in the reaction chamber; controlling the control valve to be in an open state in response to the continuous supply time of the metal source to the reaction chamber being greater than or equal to a first supply time threshold; supplying purge gas to the reaction chamber in this state; supplying reactants to the reaction chamber to form a metal film on the substrate; and supplying purge gas to the reaction chamber. Thus, by keeping the control valve closed during the supply of the metal source to the reaction chamber, the metal source can be filled into the reaction chamber, increasing the residence time of the metal source in the reaction chamber, allowing the metal source to be uniformly adsorbed onto the substrate surface. Then, reactants are supplied to the reaction chamber, allowing the reactants to react with the metal source adsorbed on the substrate surface, thereby adsorbing a uniform thin film onto the substrate.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a method for metal atomic layer deposition. Background Technology

[0002] Electrodes in DRAM (Dynamic Random Access Memory) and FRAM (Ferroelectric Memory), gate electrodes of MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and seed layers of copper interconnects, coatings in filter membranes, and catalyst layers in automotive catalytic converters can be deposited using atomic layer deposition.

[0003] Currently, the reaction chambers used in atomic layer deposition mainly include spray reaction chambers and cross-flow reaction chambers. Spray reaction chambers have disadvantages such as complex structure, difficult installation, and high cost. Although cross-flow reaction chambers have a relatively simple structure and lower manufacturing and maintenance costs, the thickness uniformity of the films adsorbed on the substrate through cross-flow reaction chambers is poor. Summary of the Invention

[0004] To address the aforementioned technical problems in the prior art, this application provides a method and system for metal atomic layer deposition.

[0005] To address the aforementioned problems, this application provides a method and system for metal atomic layer deposition. The method includes: with the control valve at the outlet of the reaction chamber closed, supplying a metal source to the reaction chamber so that the metal source adsorbs onto the surface of a substrate in the reaction chamber; controlling the control valve to be in an open state in response to the continuous supply time of the metal source to the reaction chamber being greater than or equal to a first supply time threshold; supplying a purge gas into the reaction chamber to remove a portion of the metal source in the reaction chamber while the control valve is in the open state; supplying reactants into the reaction chamber so that the reactants react with the metal source on the surface of the substrate to form a metal film on the substrate; and supplying the purge gas into the reaction chamber to remove a portion of the reactants and byproducts in the reaction chamber.

[0006] In some embodiments, the step of supplying reactants to the reaction chamber to react the reactants with the metal source on the substrate surface and forming a metal film on the substrate includes: controlling the control valve to be in a closed state in response to a time for which the purge gas is supplied to the reaction chamber being greater than or equal to a second supply time threshold; and supplying the reactants to the reaction chamber while the control valve is in the closed state.

[0007] In some embodiments, after the step of delivering the reactant to the reaction chamber while the control valve is in the closed state, the method of metal atomic layer deposition includes: controlling the control valve to be in an open state in response to a time of continuous delivery of the reactant to the reaction chamber being greater than or equal to a third delivery time threshold; performing the step of purging gas to the reaction chamber while the control valve is in the open state; adjusting the substrate from a first state to a second state and returning to the step of delivering a metal source to the reaction chamber while the control valve at the outlet of the reaction chamber is in the closed state, so that the metal source is adsorbed onto the surface of the substrate in the reaction chamber until the thickness of the metal film formed on the substrate is greater than or equal to a first target thickness; wherein, in the first state, the second end of the substrate is located downstream of the first end of the substrate in the direction of metal source flow, and in the second state, the first end of the substrate is located downstream of the second end of the substrate in the direction of metal source flow.

[0008] In some embodiments, after the step of delivering purge gas into the reaction chamber to remove a portion of the metal source in the reaction chamber when the control valve is in the open state, the method of metal atomic layer deposition further includes: adjusting the substrate from a first state to a second state, and returning once the step of delivering the metal source into the reaction chamber when the control valve at the outlet of the reaction chamber is in the closed state; wherein, in the first state, the second end of the substrate is located downstream of the first end of the substrate in the direction of metal source flow, and in the second state, the first end of the substrate is located downstream of the second end of the substrate in the direction of metal source flow.

[0009] In some embodiments, the step of supplying reactants to the reaction chamber to react the reactants with the metal source on the substrate surface and form a metal film on the substrate includes: supplying the reactants to the reaction chamber while the control valve is closed; and after the step of supplying the purge gas to the reaction chamber to remove some of the reactants and byproducts from the reaction chamber, the step includes: adjusting the substrate from a second state to a first state, and returning to the step of supplying the reactants to the reaction chamber while the control valve is closed, until the thickness of the metal film adsorbed on the substrate is greater than or equal to a second target thickness.

[0010] In some embodiments, the step of supplying a metal source to the reaction chamber while the control valve at the outlet of the reaction chamber is in a closed state includes: supplying a first carrier gas to the reaction chamber while supplying the metal source to the reaction chamber, and controlling the total flow rate of the metal source and the first carrier gas based on a first supply time threshold for supplying the metal source and the first carrier gas to the reaction chamber so that the gas pressure in the reaction chamber is less than or equal to 10 torr.

[0011] In some embodiments, the total flow rate of the metal source and the first carrier gas is 100 sccm to 1000 sccm.

[0012] In some embodiments, in the step of conveying reactants to the reaction chamber to react the reactants with the metal source on the surface of the substrate and to form a metal film on the substrate, a second carrier gas is also conveyed simultaneously with the conveying of the reactants. The flow rate of the reactants is 100 sccm to 2000 sccm, and the flow rate of the second carrier gas is 100 sccm to 1000 sccm.

[0013] In some embodiments, the step of supplying purge gas to the reaction chamber when the control valve is in the on state includes: controlling the flow rate of the purge gas to be 100 sccm to 1000 sccm and the time for supplying the purge gas to be 5 s to 20 s.

[0014] To address the aforementioned problems, this application also provides a metal atomic layer deposition system, which includes a reaction chamber and a controller, the controller being used to perform the aforementioned metal atomic layer deposition method.

[0015] Compared with the prior art, the method and system for metal atomic layer deposition of this application include: with the control valve of the gas outlet of the reaction chamber in a closed state, supplying a metal source to the reaction chamber so that the metal source is adsorbed onto the surface of the substrate of the reaction chamber; controlling the control valve to be in a conducting state in response to the continuous supply time of the metal source to the reaction chamber being greater than or equal to a first supply time threshold; supplying a purge gas to the reaction chamber in the conducting state to remove part of the metal source in the reaction chamber; supplying reactants to the reaction chamber so that the reactants react with the metal source on the surface of the substrate and form a metal film on the substrate; and supplying the purge gas to the reaction chamber to remove the part of the reactants and byproducts in the reaction chamber. Through the above implementation method, the control valve is in a closed state during the process of delivering the metal source to the reaction chamber, so that the metal source can fill the reaction chamber, thereby increasing the residence time of the metal source in the reaction chamber and making the metal source uniformly adsorbed on the substrate surface. Then, reactants are delivered to the reaction chamber, so that the reactants react with the metal source adsorbed on the substrate surface, thereby adsorbing a uniform thin film on the substrate.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a metal atomic layer deposition system according to one or more embodiments of this application;

[0019] Figure 2 This is a schematic flowchart of a method for metal atomic layer deposition according to one or more embodiments of this application;

[0020] Figure 3 yes Figure 2 A schematic flowchart of an embodiment of the method for metal atomic layer deposition after step S104;

[0021] Figure 4 This is a test diagram of the substrate surface thickness in Embodiment 1 of this application;

[0022] Figure 5 This is a test diagram of the substrate surface thickness in Embodiment 2 of this application;

[0023] Figure 6 This is a test diagram of the substrate surface thickness in Embodiment 3 of this application;

[0024] Figure 7 This is a test diagram of the substrate surface thickness in Embodiment 4 of this application;

[0025] Figure 8 This is a test diagram of the substrate surface thickness in Comparative Example 1 of this application.

[0026] Reference numerals: Reaction chamber 10; Reaction cavity 100; Air inlet channel 200; Air inlet 110; Matrix 130; Rotating component 140; Air outlet 120; Control valve 121; Controller 20. Detailed Implementation

[0027] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the application. Similarly, the following embodiments are only some, not all, embodiments of the present application, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present application.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "setting," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium. Those skilled in the art will understand the specific meanings of the above terms within the context of this application.

[0030] Electrodes in DRAM (Dynamic Random Access Memory) and FRAM (Ferroelectric RAM), gate electrodes and copper interconnect seed layers in MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), coatings in filter membranes, and catalyst layers in automotive catalytic converters can all be deposited using atomic layer deposition (ALD). Currently, the reaction chambers used in ALD mainly include spray-type and cross-flow-type reaction chambers. Spray-type reaction chambers suffer from drawbacks such as complex structure, difficult installation, and high cost. While cross-flow-type reaction chambers have a relatively simple structure and lower manufacturing and maintenance costs, the uniformity of the film thickness adsorbed on the substrate through cross-flow-type reaction chambers is poor.

[0031] To address the technical problems existing in related technologies, this application provides a method and system for metal atomic layer deposition. The metal atomic layer deposition system includes a reaction chamber and a controller, which can be used to control the reaction chamber to deposit a thin film on a substrate in the reaction chamber.

[0032] Specifically, this application provides a metal atomic layer deposition system, see [link to relevant documentation]. Figure 1 , Figure 1 This is a schematic diagram of the structure of a metal atomic layer deposition system according to one or more embodiments of this application.

[0033] A metal atomic layer deposition system may include a reaction chamber 10 and a controller 20. The controller 20 controls the reaction chamber 10 to perform a metal atomic layer deposition method. The reaction chamber 10 may include a reaction cavity 100, an inlet 110, an outlet 120, an inlet channel 200, and a control valve 121. The reaction cavity 100 is used to place a substrate 130 and provides space to accommodate a metal source and reactants, as well as to allow the metal source and reactants to react, so that the substances generated by the chemical reaction of the metal source and reactants are adsorbed onto the substrate 130. The reaction cavity 100 has an inlet 110 and an outlet 120 at its two ends, respectively. The other end of the inlet 110 is connected to the inlet channel 200 to input the metal source and reactants into the reaction cavity 100. Specifically, the metal source may be a metal-organic complex. The substrate 130 is placed inside the reaction cavity 100, and the inlet 110 and outlet 120 are located at opposite ends of the substrate 130. The outlet 120 is used to discharge substances from the reaction chamber 100, and the outlet 120 is equipped with a control valve 121. The controller 20 is used to control the flow rate and time of the precursor and reactants being delivered to the reaction chamber 100, and can also control the opening degree of the control valve 121 to increase the residence time of the precursor and reactants in the reaction chamber 100, thereby improving the uniformity of the substances adsorbed on the substrate 130. The reaction chamber 100 is also equipped with a rotating component 140, and the substrate 130 is placed on the upper surface of the rotating component 140. The controller 20 can control the rotation of the rotating component 140 to drive the substrate 130 to rotate. The reaction chamber may also be equipped with a vacuum pump, which is located at the outlet 120, and is used to extract substances from the reaction chamber 100.

[0034] To address the technical problems existing in related technologies, this application provides a method for metal atomic layer deposition. This metal atomic layer deposition method can be executed by the controller described in the above embodiments. See also... Figure 2 , Figure 2 This is a schematic flowchart of a method for metal atomic layer deposition according to one or more embodiments of this application. Specifically, it includes the following steps S101 to S105:

[0035] Step S101: With the control valve at the outlet of the reaction chamber closed, a metal source is supplied to the reaction chamber so that the metal source is adsorbed onto the surface of the substrate of the reaction chamber.

[0036] A substrate is placed horizontally in the reaction chamber. The control valve at the outlet at one end of the reaction chamber is closed, allowing a metal source to be supplied. This can be understood as a continuous supply of metal source to the reaction chamber, with the control valve remaining closed throughout to prevent the metal source from being sucked out of the reaction chamber by the vacuum pump before it can be adsorbed onto the substrate surface. Closing the control valve allows the amount of metal source inside the reaction chamber to increase, thus increasing the residence time of the metal source within the chamber and ensuring sufficient and uniform contact between the metal source and the substrate surface. Ultimately, this results in the uniform adsorption of metal ions from the metal source onto the substrate surface. Furthermore, since the reaction between the metal source and the substrate requires a certain amount of time, closing the control valve increases the contact time, ensuring uniform contact and timely adsorption. After the metal source is introduced into the reaction chamber, it reacts with the substrate surface to adsorb metal ions onto the substrate surface; therefore, the metal source can refer to the metal ions adsorbed on the substrate surface. Furthermore, the closure of the control valve can be performed simultaneously with the delivery of the metal source to the reaction chamber, thereby improving the production efficiency of the process.

[0037] Step S102: In response to the time for which the metal source is delivered to the reaction chamber being greater than or equal to a first delivery time threshold, the control valve is controlled to be in the on state.

[0038] The continuous supply of a metal source to the reaction chamber for a certain period is to allow the metal source and the matrix to react, enabling the metal ions in the metal source to be adsorbed onto the matrix surface. In addition, the reaction between the metal source and the matrix will generate other byproducts. After the metal source has been supplied to the reaction chamber for a certain period, the control valve is in the open state. Opening the control valve allows other byproducts and unreacted metal source material to be discharged from the reaction chamber. Specifically, the compounds containing metal ions generated after the metal source reacts with the matrix are adsorbed onto the matrix surface, while the other substances generated are byproducts.

[0039] Step S103: When the control valve is in the open state, purge gas is supplied to the reaction chamber to remove part of the metal source in the reaction chamber.

[0040] After supplying the metal source to the reaction chamber for a certain period, the control valve is kept in the open state, and purge gas is supplied to the reaction chamber. Purge gas is supplied because after the reactants and metal source are introduced into the reaction chamber and the reaction occurs, there are unadsorbed metal sources and byproducts present in the reaction chamber. Supplying purge gas removes excess metal sources and byproducts from the reaction chamber. Excess metal sources refer to metal sources located on the substrate surface that have not reacted with the substrate, as well as metal sources suspended in the reaction chamber. Supplying purge gas to the reaction chamber reduces the impact of metal sources and byproducts on subsequent steps. The purge gas can be an inert gas such as nitrogen or argon.

[0041] Step S104: The reactants are fed into the reaction chamber to react with the metal source on the substrate surface and form a metal film on the substrate.

[0042] After removing excess metal sources and byproducts from the reaction chamber, reactants are introduced into the reaction chamber. The reactants react with the metal sources adsorbed on the substrate to convert the metal ions in the metal sources into stable metal compounds, which are then adsorbed onto the surface of the substrate, thereby forming a metal film on the substrate surface.

[0043] Step S105: Purge gas is introduced into the reaction chamber to remove some reactants and byproducts from the reaction chamber.

[0044] After the reactants are introduced into the reaction chamber, the reaction between the reactants and the metal source adsorbed on the substrate produces stable metal compounds and byproducts. Therefore, introducing purge gas into the reaction chamber removes excess reactants and byproducts, reducing their impact on subsequent steps. After step S105, steps S101 to S105 can be repeated to continuously deposit a metal film on the substrate surface until a certain thickness is achieved.

[0045] Through the above implementation method, during the process of delivering the metal source to the reaction chamber, the control valve is closed, allowing the metal source to fill the reaction chamber and ensuring that the residence time of the metal source in the reaction chamber is greater than or equal to a first delivery time threshold. This results in more and more uniform contact between the metal source and the substrate surface, ensuring sufficient contact between the substrate surface and the metal source. The residence time of the metal source in the reaction chamber is increased to meet the time required for the reaction between the metal source and the substrate, ultimately allowing the metal ions in the metal source to be uniformly adsorbed onto the substrate surface. Subsequently, reactants are delivered to the reaction chamber, allowing the reactants to react with the metal source adsorbed on the substrate surface, thereby adsorbing a uniform metal film containing metal ions onto the substrate.

[0046] In some embodiments, the step of supplying reactants to the reaction chamber to react with the metal source on the substrate surface and form a metal film on the substrate (step S104) includes: controlling the control valve to be in a closed state in response to the time for which the purge gas is supplied to the reaction chamber being greater than or equal to a second supply time threshold; and supplying the reactants to the reaction chamber while the control valve is in the closed state. That is, after the step of controlling the control valve to be in the open state and supplying purge gas to the reaction chamber (step S103), the control valve is controlled to be closed after the time for which the purge gas is supplied to the reaction chamber is greater than or equal to the second supply time threshold. While the control valve is in the closed state, reactants are supplied to the reaction chamber to uniformly fill the reaction chamber with reactants, thereby allowing the reactants to react uniformly with the metal source adsorbed on the substrate, ultimately forming a uniform thin film on the substrate surface. The reactants can be supplied to the reaction chamber while the control valve is being closed, allowing the control valve closure and reactant supply to be achieved simultaneously, thereby improving production efficiency.

[0047] See Figure 3 , Figure 3 yes Figure 2 A schematic flowchart of an embodiment of the method for metal atomic layer deposition after step S104.

[0048] In one embodiment, after the step of delivering reactants to the reaction chamber (step S104) with the control valve in the closed state, the following steps are further included: steps S201 to S203.

[0049] Step 201: In response to the reaction chamber being continuously supplied with reactants for a time greater than or equal to the third supply time threshold, the control valve is turned on.

[0050] After the reactants are fed into the reaction chamber for a certain period of time, the control valve is turned on to allow sufficient reaction time for the metal source on the surface of the reactant substrate. This allows the reactants to fully react with the metal source and deposit a uniform metal film on the substrate surface. Afterward, the control valve is turned off to allow byproducts and excess reactants in the reaction chamber to be discharged.

[0051] Step S202: With the control valve in the on state, perform the step of purging the reaction chamber with the purging gas.

[0052] After the control valve is turned on, purge gas is supplied to the reaction chamber to remove excess reactants and byproducts. However, since the metal source in the reaction chamber is supplied from one end of the substrate to the other, the substrate near the inlet has a higher adsorption capacity per unit area, while the substrate near the outlet has a lower adsorption capacity per unit area. In other words, some reactive sites on the substrate near the outlet do not adsorb metal sources, resulting in uneven metal source distribution on the substrate. This prevents reactants from reacting with the substrate at sites without adsorbed metal sources, ultimately leading to uneven metal film deposition on the substrate surface. After multiple cycles, the thickness difference of the adsorbed metal film on the substrate surface will become increasingly significant. The following methods can reduce the difference in the thickness of the adsorbed metal film.

[0053] Step S203: Adjust the substrate from the first state to the second state, and return to the step where the control valve at the outlet of the reaction chamber is closed, and deliver a metal source to the reaction chamber so that the metal source is adsorbed on the surface of the substrate in the reaction chamber until the thickness of the metal film formed on the substrate is greater than or equal to the first target thickness.

[0054] After removing excess reactants and byproducts from the reaction chamber, the substrate in the first state is adjusted to the second state. In the first state, the second end of the substrate is downstream of the first end in the direction of metal source flow; in the second state, the first end of the substrate is downstream of the second end in the direction of metal source flow. Understandably, the direction of metal source flow is from the inlet to the outlet. Adjusting the first state to the second state means moving the first end of the substrate, originally near the inlet, to the end near the outlet, and the second end, originally near the outlet, to the end near the inlet. After adjusting the substrate from the first state to the second state, the process returns to step S101. That is, it returns to the state where the control valve is closed, and then the first inert gas is supplied to the reaction chamber to allow the metal source to be adsorbed onto the reactive sites on the substrate surface that were not previously adsorbed, thus making the adsorption of the metal source on the substrate surface more uniform. After completing this step, proceed with the subsequent steps. By repeating the above steps, the thickness of the metal film adsorbed on the substrate surface reaches the required first target thickness, which can be controlled according to the number of cycles.

[0055] In some embodiments, after the step of delivering purge gas to the reaction chamber to remove some of the metal source in the reaction chamber while the control valve is in the open state, the metal atomic layer deposition method further includes: adjusting the substrate from a first state to a second state, and returning to the step of delivering the metal source to the reaction chamber while the control valve at the outlet of the reaction chamber is in the closed state. Due to the transverse structure of the reaction chamber, delivering the metal source to the reaction chamber for a certain period of time while the control valve is closed, followed by delivering purge gas for a certain period of time, will result in uneven adsorption of the metal source on the substrate surface. Therefore, by delivering the metal source while the control valve is closed, and then delivering purge gas to the reaction chamber for a certain period of time, the substrate can be adjusted from the first state to the second state. That is, by rotating the end near the outlet to the end near the inlet, and then returning to step S101, and then continuously delivering the metal source to the reaction chamber for a certain period of time, the metal source can be adsorbed on the active sites on the substrate where no metal source has been adsorbed, thereby making the adsorption of the metal source on the substrate surface more uniform. The number of times the substrate is adjusted from the first state to the second state and the number of times the process returns to step S101 can be multiple, in order to improve the uniformity of the metal source adsorbed on the substrate surface.

[0056] Furthermore, in some embodiments, after the above steps to uniformly adsorb the metal source onto the substrate surface, the process continues to the step of supplying reactants to the reaction chamber to react with the metal source on the substrate surface and form a metal film on the substrate. This step includes: supplying reactants to the reaction chamber with the control valve in a closed state; and after supplying purge gas to the reaction chamber to remove some reactants and byproducts, the process includes: adjusting the substrate from a second state to a first state, and returning to the step of supplying reactants to the reaction chamber with the control valve in a closed state until the thickness of the metal film adsorbed on the substrate is greater than or equal to a second target thickness. That is, after uniformly adsorbing the metal source onto the substrate surface and purging the reaction chamber, the control valve is closed to supply reactants to the reaction chamber, and then the control valve is opened to supply purge gas to the reaction chamber to remove excess reactants and byproducts. However, even with uniform adsorption of the metal source onto the substrate, the lateral arrangement of the reaction chamber means that the reactants may not react uniformly with the adsorbed metal source. Some metal sources adsorbed on the substrate near the outlet may not react with the reactants, thus failing to form a metal film and resulting in an uneven metal film. Therefore, after introducing reactants into the reaction chamber and purging, the substrate can be switched from the second state to the first state, and reactants can be introduced into the reaction chamber again to ensure uniform reaction with the metal source, thereby forming a uniform metal film on the substrate. The process can then return to step S101 for a cycle to ensure a uniform metal film deposited on the substrate surface and achieves the desired thickness. The steps of introducing reactants and switching the substrate between the first and second states can be repeated multiple times to ensure that the reactants react with the metal source uniformly adsorbed on the substrate surface as much as possible, ultimately resulting in a more uniform thickness of the metal film deposited on the substrate surface.

[0057] In some embodiments, the step (S101) of supplying a first inert gas containing a metal source to the reaction chamber while the control valve at the outlet of the reaction chamber is closed includes: supplying a first carrier gas simultaneously with the metal source to the reaction chamber; and controlling the flow rate of the first carrier gas supplied to the reaction chamber based on a first supply time threshold for supplying the metal source and the first carrier gas to the reaction chamber, so that the gas pressure in the reaction chamber is less than or equal to 10 torr. Supplying the metal source and the first carrier gas simultaneously, or supplying a mixture of the metal source and the first carrier gas, is to provide an inert environment to prevent other side reactions. When the metal source and the first carrier gas are supplied to the reaction chamber, the control valve is closed. The continuous supply of the metal source and the first carrier gas will cause the gas pressure in the reaction chamber to continuously increase. However, excessive gas pressure can damage the structure of the substrate and the metal source already adsorbed on the substrate surface. Therefore, it is particularly important to control the gas pressure in the reaction chamber by adjusting the flow rate of the first inert gas based on the first supply time threshold. Controlling the gas pressure in the reaction chamber to within 10 torr allows the metal source to be adsorbed onto the substrate surface better and more uniformly.

[0058] In some embodiments, the total flow rate of the metal source and the first carrier gas is 100 sccm to 1000 sccm. Since the flow rates of the metal source and the first carrier gas are set based on a first delivery time threshold, and this threshold may change, the flow rates of the metal source and the first carrier gas also change accordingly. Having a total flow rate of 100 sccm to 1000 sccm allows for better control of the gas pressure within the reaction chamber. Because the metal source has a latency period for adsorption onto the substrate, meaning it requires a certain amount of time, the first delivery time threshold can be 1 s to 5 s, preferably 1 s to 3 s. Within this range, the first delivery time threshold allows sufficient time for the metal source to adsorb onto the substrate.

[0059] The total flow rate of the metal source and the first inert gas can be 100 sccm, 200 sccm, 500 sccm, 700 sccm, 1000 sccm, or any range of any two of the above values, such as 100 sccm to 500 sccm, 500 sccm to 700 sccm, or 700 sccm to 1000 sccm. The first delivery time threshold can be 1 s, 2 s, 3 s, 4 s, 5 s, or any range of any two of the above values, such as 1 s to 3 s or 3 s to 5 s.

[0060] In some embodiments, with the control valve in the open state, during the step of conveying reactants to the reaction chamber to react with the metal source on the substrate surface and form a metal film on the substrate, a second carrier gas is also conveyed simultaneously with the reactants. The flow rate of the reactants is 100 sccm to 2000 sccm, and the flow rate of the second carrier gas is 100 sccm to 1000 sccm. The reactant flow rate is within the range of 100 sccm to 2000 sccm, and the reactant flow rate can be greater than the second carrier gas flow rate, thereby maximizing the reaction between the metal source adsorbed on the substrate surface and the reactants, resulting in a more uniform adsorption of the metal source on the substrate surface after multiple cycles. Furthermore, the control valve is closed during this process, thus providing a certain pressure in the reaction chamber, which promotes the reaction rate between the metal source and the reaction, and increases the adsorption rate. The time for conveying the reactants and the second carrier gas can be 1 s to 5 s.

[0061] The flow rate of the reactants can be 100 sccm, 500 sccm, 1000 sccm, 1500 sccm, 2000 sccm, or any range of two of the above values, such as 100 sccm to 500 sccm, 500 sccm to 1500 sccm, or 1500 sccm to 2000 sccm. The flow rate of the second carrier gas can be 100 sccm, 200 sccm, 500 sccm, 700 sccm, 1000 sccm, or any range of two of the above values, such as 100 sccm to 500 sccm, 500 sccm to 700 sccm, or 700 sccm to 1000 sccm.

[0062] In one embodiment, the step of supplying purge gas to the reaction chamber with the control valve in the open state includes: controlling the flow rate of the purge gas to be 100 sccm to 1000 sccm and the supply time of the purge gas to be 5 s to 20 s. After the metal source is supplied to the reaction chamber, the control valve is opened, and purge gas is supplied to the reaction chamber to remove excess metal source and byproducts from the reaction chamber. A purge gas flow rate within the above range is beneficial for the purge gas to carry the metal source and byproducts out of the reaction chamber. A purge gas supply time within the above range can remove excess metal source and byproducts from the reaction chamber as much as possible, thereby reducing the impact on the subsequent reaction between the metal source and the reactants. After the reactants and the second carrier gas are supplied to the reaction chamber, the flow rate and time of the supplied purge gas can also be 100 sccm to 1000 sccm and 5 s to 20 s, respectively. The flow rate of the purge gas can be the same as that of the first and second carrier gases, and can be at least one of argon or nitrogen.

[0063] The flow rate of the purge gas can be 100 sccm, 200 sccm, 500 sccm, 700 sccm, 1000 sccm, or any range of two of the above values, such as 100 sccm to 500 sccm, 500 sccm to 700 sccm, or 700 sccm to 1000 sccm. The duration of purge gas delivery can be 5 s, 7 s, 11 s, 17 s, 20 s, or any range of two of the above values, such as 5 s to 11 s, 11 s to 17 s, or 17 s to 20 s.

[0064] Example 1

[0065] (1) Argon gas is used to carry the platinum metal source into the reaction chamber, so that the platinum metal source is adsorbed on the surface of the wafer (substrate). The argon gas flow rate can be controlled at 500 sccm (standard cubic centimeters per minute), and the pulse duration can be controlled at 2s.

[0066] (2) Use argon gas to purge the wafer surface to remove excess platinum metal source. The argon flow rate can be controlled at 500 sccm and the pulse duration can be controlled at 10 s.

[0067] (3) A mixture of oxygen and argon is introduced into the reaction chamber, allowing the oxygen to react with the platinum metal source adsorbed on the wafer surface. The oxygen flow rate is 1000 sccm, the argon flow rate is 500 sccm, and the pulse duration can be controlled to 2 s.

[0068] (4) Argon gas is used to purge the wafer surface to remove byproducts and other gases. The flow rate of argon gas can be controlled at 500 sccm, and the pulse duration can be controlled at 10 s.

[0069] (5) Repeat (1) to (4) until a platinum oxide film of the target thickness is formed.

[0070] In step (1) above, the opening degree of the control valve is 0%, and in steps (1) to (4) the opening degree of the control valve is 100%, and it goes through 120 cycles.

[0071] Example 2

[0072] The difference from Example 1 is that the opening degree of the control valve in step (3) is 20%. Everything else is the same as in Example 1.

[0073] Example 3

[0074] The difference from Example 1 is that the opening degree of the control valve in step (3) is 0%. Everything else is the same as in Example 1.

[0075] Example 4

[0076] The difference from Example 1 is that the metal source is a ruthenium metal source, the number of cycles is 150, and the opening degree of the control valve in step (3) is 0%. Everything else is the same as in Example 1.

[0077] Comparative Example 1

[0078] The difference from Example 1 is that the opening degree of the control valve in step (1) is 100%. Everything else is the same as in Example 1.

[0079] like Figures 4 to 6 As shown, Figures 4 to 6 The figures are test diagrams of the substrate thickness for Examples 1 to 3, respectively. Figure 4 The test diagram of the thickness of the substrate is obtained when the opening degree of the control valve in step (1) is 0% and the opening degree of the control valve in the remaining steps is 100%. Figure 5 The opening degree of the control valve in step (1) is 0%, the opening degree of the control valve in step (3) is 20%, and the opening degree of the control valve in the remaining steps is 100%. Figure 6The control valve opening is 0% in step (1), 0% in step (3), and 100% in the remaining steps. Figure 8 As shown, Figure 8 This is a test diagram of the substrate surface thickness in Comparative Example 1 of this application. In Comparative Example 1, the opening degree of the control valves in steps (1) to (4) is 100%. From Figures 4 to 6 and Figure 8 The comparison shows that in Example 1, only the control valve in step (1) is closed, and the difference in thickness between the first and second ends of the substrate surface is... In Example 2, in addition to controlling the valve to close in step (1), the opening degree of the control valve in step (3) is also controlled to be 20%, and the thickness difference between the first and second ends of the substrate surface is... In Example 1, the opening degree of the control valve is 0% in both steps (1) and (3), and the difference in thickness between the first and second ends of the substrate surface is... In Comparative Example 1, the opening degree of the control valve in steps (1) to (4) is 100%, and the difference in thickness between the first and second ends of the substrate surface is... Therefore, it can be seen that closing the control valve during steps (1) and (3) significantly improves the uniformity of the film deposited on the substrate surface. For example... Figure 7 As shown, Figure 7 This is a test diagram of the substrate surface thickness in Example 4 of this application. The only difference between Example 4 and Comparative Example 1 is that the platinum metal source was replaced with a ruthenium metal source, and the number of cycles was increased. The difference in thickness between the first and second ends of the substrate surface is... Therefore, this method is also applicable to deposition with more cycles, and the thickness difference of the substrate surface will not be large due to the number of cycles.

[0080] In the description of this application, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0081] Furthermore, 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 at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0082] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0083] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (which may be a personal computer, server, network device, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0084] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for metal atomic layer deposition, characterized in that, The method for depositing metal atomic layers includes: With the control valve at the outlet of the reaction chamber closed, a metal source is supplied to the reaction chamber so that the metal source is adsorbed onto the surface of the substrate of the reaction chamber. In response to the continuous delivery time of the metal source to the reaction chamber being greater than or equal to a first delivery time threshold, the control valve is controlled to be in the on state; With the control valve in the open state, purge gas is supplied to the reaction chamber to remove some of the metal source from the reaction chamber; Reactants are fed into the reaction chamber to react with the metal source on the surface of the substrate, and a metal film is formed on the substrate; The purge gas is supplied to the reaction chamber to remove some of the reactants and byproducts from the reaction chamber.

2. The method for metal atomic layer deposition according to claim 1, characterized in that, The step of supplying reactants to the reaction chamber to react the reactants with the metal source on the surface of the substrate, and forming a metal film on the substrate, includes: In response to the time for which the purge gas is delivered to the reaction chamber being greater than or equal to a second delivery time threshold, the control valve is controlled to be in a closed state. With the control valve in the closed state, the reactants are supplied to the reaction chamber.

3. The method for metal atomic layer deposition according to claim 2, characterized in that, After the step of supplying the reactants to the reaction chamber with the control valve in the closed state, the method for metal atomic layer deposition includes: In response to the reaction chamber being continuously supplied with the reactant for a time greater than or equal to a third supply time threshold, the control valve is controlled to be in the on state; With the control valve in the open state, the step of supplying the purge gas to the reaction chamber is performed; The substrate is adjusted from the first state to the second state, and the process returns to the step where the control valve at the outlet of the reaction chamber is closed. A metal source is then supplied to the reaction chamber so that the metal source is adsorbed onto the surface of the substrate in the reaction chamber until the thickness of the metal film formed on the substrate is greater than or equal to the first target thickness. In the first state, the second end of the substrate is located downstream of the first end of the substrate in the direction of the metal source flow, and in the second state, the first end of the substrate is located downstream of the second end of the substrate in the direction of the metal source.

4. The method for metal atomic layer deposition according to claim 1, characterized in that, After the step of supplying purge gas into the reaction chamber to remove some of the metal source in the reaction chamber while the control valve is in the open state, the metal atomic layer deposition method further includes: The substrate is adjusted from the first state to the second state, and the process of supplying a metal source to the reaction chamber is repeated once, with the control valve at the outlet of the reaction chamber in the closed state. In the first state, the second end of the substrate is located downstream of the first end of the substrate in the direction of metal source flow, and in the second state, the first end of the substrate is located downstream of the second end of the substrate in the direction of metal source flow.

5. The method for metal atomic layer deposition according to claim 4, characterized in that, The step of supplying reactants to the reaction chamber to react the reactants with the metal source on the surface of the substrate and forming a metal film on the substrate includes: With the control valve in the closed state, the reactants are supplied to the reaction chamber; Following the step of supplying the purge gas to the reaction chamber to remove some of the reactants and byproducts from the reaction chamber, the following is included: The substrate is adjusted from the second state to the first state, and the process returns to the step where the control valve is closed, to deliver the reactant into the reaction chamber until the thickness of the metal film adsorbed on the substrate is greater than or equal to the second target thickness.

6. The method for metal atomic layer deposition according to any one of claims 1 to 5, characterized in that, The step of supplying a metal source to the reaction chamber with the control valve at the outlet of the reaction chamber in the closed state includes: The metal source is supplied to the reaction chamber simultaneously with the first carrier gas. Based on a first supply time threshold for supplying the metal source and the first carrier gas to the reaction chamber, the flow rates of the metal source and the first carrier gas are controlled so that the gas pressure in the reaction chamber is less than or equal to 10 torr.

7. The method for metal atomic layer deposition according to claim 6, characterized in that, The total flow rate of the metal source and the first carrier gas is 100 sccm to 1000 sccm.

8. The method for metal atomic layer deposition according to any one of claims 1 to 5, characterized in that, In the step of conveying reactants to the reaction chamber to react the reactants with the metal source on the surface of the substrate and to form a metal film on the substrate, a second carrier gas is also conveyed simultaneously with the conveying of the reactants. The flow rate of the reactants is 100 sccm to 2000 sccm, and the flow rate of the second carrier gas is 100 sccm to 1000 sccm.

9. The method for metal atomic layer deposition according to any one of claims 1 to 5, characterized in that, The step of supplying purge gas to the reaction chamber when the control valve is in the open state includes: controlling the flow rate of the purge gas to be 100 sccm to 1000 sccm and the time for supplying the purge gas to be 5 s to 20 s.

10. A metal atomic layer deposition system, characterized in that, The metal atomic layer deposition system includes a reaction chamber and a controller, the controller being used to perform the metal atomic layer deposition method as described in any one of claims 1 to 9.

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