An apparatus for lateral plasma ald

Abstract

The application discloses a kind of transverse plasma ALD equipment, including plasma generating part, conical air inlet cavity, reaction chamber, vacuum pump, conical air inlet cavity and reaction chamber are sealed communication, and are connected with vacuum pump, and the plasma generated is introduced into chamber along transverse direction.ALD air inlet is used to introduce precursor and reaction gas into chamber, sample is placed on multilayer sample holder, and it is in and out of reaction chamber by quick opening door.Reaction chamber top is equipped with process connection window, can be connected infrared lamp tube for heating sample to realize in-situ annealing, also can be connected laser energy input device for depositing thin film auxiliary crystallization.The application is processed to multilayer sample by transverse plasma introduction, reduces its direct bombardment to sample, uses segmented temperature control, and combines in-situ annealing and laser auxiliary crystallization process, improves equipment process flexibility, is suitable for oxide semiconductor and other materials with higher degree of dependence on plasma, such as thin film deposition.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing equipment technology, and more particularly to an apparatus for lateral plasma ALD. Background Technology

[0002] Atomic layer deposition (ALD) is a thin film deposition technique based on a self-limiting surface reaction of a gaseous precursor on a substrate surface. It enables atomic-level precise control over film thickness, composition, and interface structure, and has wide applications in semiconductor devices, display devices, oxide thin-film transistors (TFTs), sensors, and the fabrication of novel functional thin films. However, with the continuous miniaturization of device dimensions and the development of new material systems (such as oxide semiconductors, amorphous or multi-component thin films), traditional thermal ALD has gradually shown limitations in terms of deposition temperature, reactivity, and film density. To address these limitations, plasma-enhanced atomic layer deposition (PEALD) technology has emerged. PEALD introduces plasma as a reaction activation source, causing the reactant gas to generate a large number of high-energy reactive free radicals and ions, thereby significantly reducing the deposition temperature, improving film quality, and expanding the range of depositable materials.

[0003] Existing top-down PEALD equipment can typically only process a small number of samples on a single substrate or in a single layer. The plasma acts on the substrate surface in a vertical direction, making it difficult to simultaneously process multiple samples under the same process conditions. The equipment has a limited sample processing capacity per unit time, which is not conducive to process development and large-scale application.

[0004] In addition, the unidirectional plasma interaction structure of existing PEALD equipment causes the plasma and the active species it generates to propagate along a fixed direction in the reaction chamber, which easily leads to spatial attenuation and reaction gradients in the transmission path. As a result, it is difficult to guarantee the consistency of film thickness, composition and performance during the deposition of multiple or large-area samples.

[0005] Meanwhile, existing equipment typically relies solely on plasma as the only means of energy enhancement. The closed structure of the reaction chamber and the single energy source make it difficult to achieve synergistic effects of multiple energy fields during the deposition process, thus limiting further control over the film structure, impurity content, and crystallization behavior.

[0006] Furthermore, existing PEALD processes mostly employ isothermal and fixed-parameter deposition modes. The equipment and control systems struggle to achieve rapid temperature or energy increases and decreases and periodic modulations during the deposition cycle, making it impossible to switch between different process modes during film growth, remove residual carbon, hydrogen, and other impurities from the precursor, or induce film structure optimization.

[0007] Furthermore, existing equipment often employs a fixed structural design with highly coupled functional modules, making it difficult to flexibly integrate additional functional modules according to different process requirements. This lack of structural scalability hinders the continuous expansion and upgrading of multi-physics coupling and multi-step in-situ processes. Additionally, the close proximity of the plasma region to the substrate, or even its direct interaction with the substrate surface, means that high-energy ions and electrons can easily cause physical and electrical damage to sensitive materials or device structures, limiting its application in low-damage, high-reliability devices. Summary of the Invention

[0008] To address the limitations and low efficiency of existing PEALD (Plasma ALD) technologies, this invention provides a transverse plasma ALD apparatus. This apparatus avoids spatial attenuation and reaction gradient changes in the plasma transport path, achieving consistency in film thickness, composition, and properties during the deposition of multiple or large-area samples. Furthermore, temperature or energy can be modulated as needed during the deposition cycle.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A transverse plasma ALD device includes a plasma generating section, a conical inlet chamber, a reaction chamber, and a vacuum pump. The conical inlet chamber and the reaction chamber are sealed and connected, and the conical inlet chamber is connected to the vacuum pump. The plasma generating part includes a plasma generating sleeve device, a plasma inlet provided on the plasma generating sleeve device, and a plasma generating power supply connected to the plasma generating sleeve device. The plasma generating sleeve device is sealed to the conical inlet cavity. It includes an ALD inlet, which is located on the conical inlet cavity and is used to introduce ALD precursor and reaction gas into the reaction chamber. Includes a process connection window, located at the top of the reaction chamber; Includes a quick-opening door, located on the side of the reaction chamber; The reaction chamber is equipped with multiple sample racks.

[0010] Furthermore, the multi-layer sample rack is arranged inside the reaction chamber along the plasma and gas flow direction. The sample to be deposited is placed on different layers of the multi-layer sample rack, so that the plasma and reactive gas act laterally on the sample surface on the multi-layer sample rack from one side of the reaction chamber to the other, thereby realizing the synchronous processing of multi-layer samples.

[0011] Furthermore, it includes an infrared heating device and a laser energy input device, which are located inside the process connection window at the top of the reaction chamber.

[0012] Furthermore, the vacuum pump is located on the opposite side of the reaction chamber from the plasma generating sleeve device, and is used to evacuate the reaction chamber.

[0013] Furthermore, an air-cooling device is installed on one side of the plasma generating sleeve device.

[0014] Based on the above technical solutions, the present invention achieves the following technical effects: This invention relates to a transverse plasma ALD device that uses automated equipment for control, reducing manual intervention, increasing equipment utilization, simplifying the process flow, and significantly shortening the total process time.

[0015] This invention introduces plasma and reactive gas laterally along a conical inlet chamber, matching the plasma action path with the sample arrangement direction. This allows for the sequential processing of multiple layers of samples within the same process cycle, improving the sample processing capacity per unit time and facilitating process development and efficiency improvement.

[0016] This invention spatially separates the plasma generation region from the sample region, introducing plasma active species through lateral propagation. This exposes the sample surface primarily to the transported and diffused environment of active species, thereby reducing the risk of direct bombardment of the sample by high-energy ions and electrons. This design is suitable for damage-sensitive devices and material systems. Furthermore, this lateral structure creates tunable plasma interaction paths and process freedom, overcoming the unidirectional limitations of top-down devices, and lateral design facilitates the creation of multi-segment plasma regions.

[0017] This invention features a pre-installed process connection window at the top of the reaction chamber, allowing the introduction of energy fields such as infrared lamp heating, laser, or auxiliary plasma during ALD deposition. This structurally supports the synergistic process of deposition and assisted crystallization, as well as deposition and in-situ annealing. This design enables the film to undergo heat treatment during growth, promoting the complete decomposition of precursors, reducing residual carbon and hydrogen impurities, and improving the film's density and structural stability.

[0018] This invention introduces a periodic heating and rapid cooling Flashing Alternating Layer (ALD) process during deposition, enabling dynamic control of the film's chemical composition and microstructure without compromising the self-limiting characteristics of ALD. This approach facilitates the removal of residual impurities or induces structural rearrangement during film growth, offering significant advantages for material systems highly sensitive to plasma and impurities, such as IGZO.

[0019] This invention employs segmented temperature control, allowing independent adjustment of different deposition steps. Temperature settings can be flexibly adjusted to optimize process parameters and achieve more precise process control, based on the needs of different materials and applications. Furthermore, it ensures that PEALD is performed under optimal temperature conditions, achieving uniform film growth on the sample surface, minimizing side reactions, and improving film quality and performance.

[0020] This invention employs a vacuum interconnection system, maintaining a high vacuum state inside the chamber. This effectively prevents dust, moisture, and other impurities from the outside air from entering the deposition environment, resulting in deposited films with higher purity. The film surface is smooth with fewer defects, which is beneficial for improving the surface quality and performance of the film. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the transverse plasma ALD device of the present invention.

[0022] Figure 2 This is a schematic diagram of the multi-layer sample stage inside the transverse plasma ALD device of the present invention.

[0023] Figure 3 This is a schematic diagram of simultaneous plasma processing of multilayer samples using the transverse plasma ALD device of the present invention.

[0024] Figure 4 A schematic diagram of the structure of the transverse plasma ALD device of the present invention, which incorporates an infrared heating device.

[0025] Figure 5 This is a schematic diagram of the structure of the transverse plasma ALD device of the present invention, which incorporates a laser energy input device.

[0026] In the figure: 1. Conical air inlet chamber; 2. ALD air inlet; 3. Plasma generator sleeve device; 4. Plasma air inlet; 5. Plasma generator power supply; 6. Air cooling device; 7. Process connection window; 8. Reaction chamber; 9. Vacuum pump; 10. Quick-opening door; 11. Multi-layer sample rack; 12. Infrared heating device; 13. Laser energy input device. Detailed Implementation

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings. The transverse plasma ALD device described in this invention is as follows: Figure 1-5 As shown, the equipment consists of a plasma generation section, a conical cavity gas inlet section, and an ALD deposition chamber. Each part is interconnected through a vacuum sealing structure and connected to a vacuum pump 9 to achieve vacuuming and process pressure control within the reaction chamber 8.

[0028] The conical air inlet 1 is connected to one side of the reaction chamber 8. The ALD air inlet 2 is provided on the conical air inlet 1 to introduce the ALD precursor and reaction gas into the reaction chamber 8, so that they enter the deposition area along the lateral direction of the reaction chamber 8.

[0029] The plasma generating sleeve device 3 is sealed to the conical air inlet cavity 1 via a customized adapter. The plasma generating sleeve device 3 is provided with a plasma air inlet 4 and is connected to a plasma generating power supply 5 to generate plasma inside the sleeve of the plasma generating sleeve device 3, so that the generated plasma and its active species enter the reaction chamber 8 along the lateral direction with the airflow.

[0030] The reaction chamber 8 is equipped with multi-layer sample racks 11 arranged along the plasma and gas flow direction. Samples to be deposited can be placed on different layers of the multi-layer sample racks 11, allowing plasma and reactive gases to act laterally on the sample surfaces of the multi-layer sample racks 11 from one side of the reaction chamber 8 to the other, achieving simultaneous processing of multiple samples. A quick-opening door 10 is provided on the side of the reaction chamber 8 for rapid loading and unloading of samples. Of course, the sample racks used in this invention are not limited to multiple layers; they can also be single-layered. Furthermore, this invention does not impose a specific limitation on the number of layers in the sample racks.

[0031] The top of the reaction chamber 8 is reserved with at least one process connection window 7, which is used to connect an infrared heating device 12, a laser energy input device 13 or an auxiliary plasma generator according to process requirements, so as to realize in-situ heating, in-situ annealing or multi-energy field synergistic processing during ALD deposition.

[0032] The present invention also includes a wind-cooling device 6, which is set on one side of the plasma generating sleeve device 3, and the temperature of the plasma generating sleeve device 3 is adjusted by controlling the cold air delivered.

[0033] The transverse plasma ALD device of this invention employs segmented temperature control, flexibly adjusting the temperature settings according to the needs of different materials and applications to achieve uniform film growth on the sample surface. This minimizes side reactions and improves film quality and performance. The transverse plasma ALD device uses a segmented temperature control structure to achieve independent temperature regulation for different deposition steps and functional regions. Specifically, the ALD inlet 2, the conical inlet chamber 1, the reaction chamber 8, and the multi-layer sample holder 11 are each equipped with independent heating and temperature control units, which are uniformly coordinated and controlled by the control system.

[0034] In the ALD intake section, an independent heating belt is installed outside the precursor gas delivery pipeline, and its temperature is individually regulated by a temperature control system to ensure that the precursor is maintained within the set temperature range during delivery, preventing condensation or premature decomposition in the pipeline, thereby ensuring that the precursor enters the reaction chamber 8 in a stable gaseous state. In specific operation, different pipeline heating temperatures can be set for different precursor gases according to the requirements of the material system.

[0035] Insulation and heating jackets are provided on the outer walls of the conical air inlet chamber 1 and the reaction chamber 8, respectively, and are controlled by an independent temperature control circuit to maintain the air inlet chamber and the reaction chamber in a temperature range suitable for plasma transport and ALD reaction, thereby reducing adsorption, condensation and side reactions on the inner wall of the chamber.

[0036] Furthermore, each layer of the multi-layer sample holder 11 is equipped with an independent ceramic heating plate, and each ceramic heating plate is connected to a temperature control system, allowing for individual temperature adjustment of each sample layer. By independently controlling the heating temperature of samples at different layers, a temperature gradient distributed along the vertical or horizontal direction can be formed within the reaction chamber to meet the temperature requirements of different materials or different deposition stages.

[0037] The principle behind this invention is: Alternating Layer Deposition (ALD) is a thin film deposition technique based on a surface self-limiting reaction mechanism. Its basic principle involves sequentially introducing precursor gases with complementary reactivity onto a solid surface, causing them to undergo saturation adsorption and chemical reactions. A complete ALD cycle typically includes the following steps: First, precursor A is introduced into the reaction chamber and adsorbed onto active sites on the substrate surface; then, unreacted precursor A and byproducts are removed by purging with an inert carrier gas; next, precursor B is introduced, causing it to react with the adsorbed precursor A on the surface; finally, excess precursor B and reaction byproducts are removed again. By repeating this cycle, precise control of film thickness and composition can be achieved at the atomic or molecular scale.

[0038] PEALD is an improved technique based on ALD, incorporating plasma as a source of reaction energy and reactive species. Plasma contains highly reactive free radicals, ions, and excited-state particles, which can effectively promote precursor decomposition and surface reactions at relatively low substrate temperatures, thereby expanding the material system of ALD and improving film quality. In the PEALD process, film growth is still essentially controlled by surface self-limiting reactions, while the role of plasma is mainly reflected in providing reactivity, lowering the reaction energy barrier, and improving film density.

[0039] The essence of this invention is PEALD deposition technology. Both the conical inlet chamber 1 and the reaction chamber 8 are controlled by a control system to regulate the deposition temperature. During operation, the sample is placed on a multi-layer sample holder 11 and pushed into the reaction chamber 8 through a quick-opening door 10. By introducing plasma and ALD reactive gas to one side of the reaction chamber 8, the plasma and its highly reactive free radicals form a lateral gas flow path within the reaction chamber 8. Under vacuum and gas flow control conditions, the sample surface is sequentially exposed to the plasma reactive species and precursor gas environment within the same process cycle, thereby achieving plasma-enhanced atomic layer deposition (ALD) reaction.

[0040] Furthermore, by reserving a process connection window 7 at the top of the reaction chamber 8, this invention allows the introduction of external energy fields such as infrared heating, laser energy input, or auxiliary plasma during the ALD deposition process, enabling the synergistic execution of the deposition and heat treatment processes. By applying continuous or periodic energy input during deposition, the precursor reaction can be fully promoted, controlling the densification, impurity removal, and structural evolution of the film. Based on this, when a periodic heating and rapid cooling method is used, a "deposition-short-time annealing-redeposition" process principle, i.e., FlashingALD, can be formed, introducing an in-situ annealing effect during film growth without disrupting the self-limiting characteristics of atomic layer deposition. Through continuous or periodic laser energy, without significantly increasing the overall temperature of the reaction chamber, a transient high-energy input can be obtained in a localized area of ​​the film, thereby inducing structural rearrangement or crystallization growth of the film.

[0041] See appendix Figure 3-5 The method of using this invention is as follows: The conical air inlet 1 is sequentially connected to plasma A, plasma B, precursor A, precursor B, and inert gas. This invention includes a control system for overall equipment control. The plasma generator 5 is switched on and off via the control system and operates only during the time plasma is introduced into the reaction chamber 8. The control system is activated to regulate the temperature of the reaction chamber 8 and the heating plates in the multi-layer sample holder 11, maintaining the required reaction temperature.

[0042] During deposition, depending on process requirements, an infrared heating device 12, a laser energy input device 13, or an auxiliary plasma device can be introduced through the process connection window 7 reserved at the top of the reaction chamber 8. The temperature of the introduced infrared heating device 12 can be controlled by the control system to perform in-situ annealing of the sample. Alternatively, after completing several PEALD cycles, the sample temperature can be rapidly increased by controlling the infrared heating device 12 and then quickly dropped back to the PEALD deposition temperature conditions to achieve flash annealing. Then, normal deposition can continue, and the above process can be repeated to form a "deposition-short-time annealing-redeposition" Flashing ALD process. After ALD deposition is completed, the laser energy input device 13 can be controlled by the control system to introduce a laser beam through the process connection window 7 to locally irradiate the deposited thin film layer of the sample, inducing structural rearrangement or crystal growth of the film.

Claims

1. A transverse plasma ALD apparatus, characterized in that, It includes a plasma generating section, a conical air inlet chamber (1), a reaction chamber (8), and a vacuum pump (9). The conical air inlet chamber (1) and the reaction chamber (8) are sealed and connected, and connected to the vacuum pump (9). The plasma generating part includes a plasma generating sleeve device (3), a plasma inlet (4) provided on the plasma generating sleeve device (3), and a plasma generating power supply (5) connected to the plasma generating sleeve device (3). The plasma generating sleeve device (3) is sealed to the conical inlet cavity (1). It includes an ALD inlet (2), which is set on a conical inlet cavity (1) for introducing ALD precursor and reaction gas into the reaction chamber (8); Includes a process connection window (7), located at the top of the reaction chamber (8); Includes a quick-opening door (10), which is located on the side of the reaction chamber (8); The reaction chamber (8) is equipped with a multi-layer sample rack (11).

2. The transverse plasma ALD apparatus according to claim 1, characterized in that, The multi-layer sample rack (11) is set inside the reaction chamber (8) along the direction of plasma and gas flow. The sample to be deposited is placed on different layers of the multi-layer sample rack (11), so that the plasma and reactive gas act laterally on the sample surface on the multi-layer sample rack (11) from one side of the reaction chamber (8) to the other side, thereby realizing the synchronous processing of multi-layer samples.

3. The transverse plasma ALD apparatus according to claim 1, characterized in that, It includes an infrared heating device (12) and a laser energy input device (13), which are located in the process connection window (7) at the top of the reaction chamber (8).

4. The transverse plasma ALD apparatus according to claim 1, characterized in that, The vacuum pump (9) is located on the other side of the reaction chamber (8) opposite to the plasma generating sleeve device (3) and is used to evacuate the reaction chamber (8).

5. The transverse plasma ALD apparatus according to claim 1, characterized in that, It includes an air-cooling device (6), which is located on one side of the plasma generating sleeve device (3).

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