A hot gas supplying type of a processing system

Abstract

This invention relates to a high-temperature gas supply type process system. The high-temperature gas supply type process system includes: a spray head (12) facing an electrostatic chuck (13); a baffle (14) formed along the edge portion of the spray head (12); a drive unit (16a, 16b) that moves an edge ring (15) up and down to move a substrate (W) up and down; and a high-temperature gas supply module (GS) that supplies high-temperature gas to the underside of the spray head (12).

Description

Technical Field

[0001] This research was funded by the Korean government (Ministry of Science and ICT and Ministry of Trade, Industry and Energy) and supported by the Next Generation Smart Semiconductor Business Group (RS-2024-00407627, Development of a high-productivity and low-damage hybrid atomic layer etching equipment for deep trench silicon below 10nm).

[0002] This invention relates to a high-temperature gas supply process system, specifically, to a high-temperature gas supply process system that introduces high-temperature gas during the etching process of atomic layers, enabling the etching process in the ALE process to be carried out effectively. Prior Technology

[0003] The semiconductor industry has long pursued miniaturization to improve performance, increase integration density, and reduce costs. However, with the advent of ultra-fine processes below 10nm, various physical and technological limitations have emerged. As the spacing between transistors shrinks to the nanometer level, leakage current increases dramatically, and heat dissipation intensifies, leading to signal interference and wiring delays that degrade device performance. Due to the limitations of this two-dimensional planar structure, it is difficult to further increase integration density, and attempts to integrate more devices on the same area actually increase process complexity, contributing to higher defect rates. Furthermore, as chips evolve towards higher performance, power consumption also increases, negatively impacting performance and stability due to heat generation. Moreover, failure to address this heat generation issue will hinder the ability to meet the demands of high-performance computing and data centers. To address these challenges, semiconductor manufacturing processes are attempting a shift towards 3D structures. 3D structures can improve integration density, maximize performance, and shorten signal paths through vertical stacking, thereby improving power efficiency and processing speed. In particular, DRAM and NAND memory offer greater capacity on the same area by employing a stacked structure of dozens of cell layers. However, 3D NAND with high aspect ratio requires a precision etching technique capable of uniformly etching each layer. Furthermore, 3D packaging based on through-silicon vias (TSVs) vertically stacks various devices, achieving both high performance and miniaturization, and offering advantages such as reduced data transfer latency and power consumption in multi-chip modules like CPUs, GPUs, or HBMs. However, 3D processes are significantly more complex than existing 2D processes, especially requiring uniform etching of each layer. When using existing plasma-based etching processes, the use of high-energy ions carries the risk of substrate damage and over-etching. In contrast, Thermal ALE, utilizing thermal energy, can significantly reduce this risk. Thermal atomic layer etching (ALE) allows for precise, atomic-level control of etching, maintaining high precision even in 3D devices with high aspect ratios. Furthermore, by using thermal energy instead of plasma to induce chemical reactions, substrate damage is minimized. Additionally, it offers advantages in material compatibility due to its applicability to the fabrication of cutting-edge devices using high-dielectric-constant materials or novel materials such as metal oxides. However, ALE suffers from longer processing times due to limitations in heat transfer rates, potentially leading to reduced production efficiency. Regarding ALE etching, Patent Publication No. 10-2023-0030615 discloses a method and apparatus for processing semiconductor substrates. Furthermore, Patent Publication No. 10-2022-0016002 discloses a system and method for planarizing substrate surfaces.These existing technologies do not disclose techniques for shortening process time during the ALE process by improving heat transfer efficiency.

[0004] The present invention aims to solve the problems of the prior art and has the following objectives.

[0005] [Existing Technical Documents]

[0006] [Patent Literature]

[0007] (Patent Document 1) Prior Art 1: Patent Publication No. 10-2023-0030615 (Lam Research Corporation, published on March 6, 2023) uses ALE and selective deposition to etch the substrate.

[0008] (Patent Document 2) Prior Art 2: Patent Publication No. 10-2022-0016002 (Tokyo Electron Co., Ltd., published on 2022.02.08) System and Method for Improving Flatness Using Selective Atomic Layer Etching (ALE) Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] The purpose of this invention is to provide a high-temperature gas supply type process system that can reduce process time by improving the heat transfer efficiency to the substrate during the ALE process.

[0011] (II) Technical Solution

[0012] According to a preferred embodiment of the present invention, a high-temperature gas supply type process system includes: a spray head disposed facing an electrostatic chuck (ESC); a baffle formed along the edge portion of the spray head; a drive unit that moves the edge ring up and down to move the substrate up and down; and a high-temperature gas supply module that supplies high-temperature gas to the lower side of the spray head.

[0013] According to another preferred embodiment of the present invention, the high-temperature gas supply module includes a hot gun for generating high-temperature gas and a mass flow controller.

[0014] According to another preferred embodiment of the present invention, the high-temperature gas supply type process system further includes: a gas pipeline extending from the high-temperature gas supply module to the interior of the chamber, and the high-temperature gas supplied along the gas pipeline is sprayed from the lower side of the spray head onto the upper side of the substrate.

[0015] According to another preferred embodiment of the present invention, the high-temperature gas supply type process system further includes: a guide path formed on the lower side portion of the spray head, which guides the high-temperature gas to a first spray path and a second spray path formed on the central or edge portion of the lower side portion of the spray head.

[0016] According to another preferred embodiment of the present invention, the high-temperature gas supply type process system further includes: one or more injection holes formed on a first injection path and a second injection path.

[0017] According to another preferred embodiment of the present invention, the high-temperature gas is nitrogen, helium, argon or clean dry air.

[0018] According to another preferred embodiment of the present invention, the high-temperature gas supply type process system further includes: a pressure gauge for measuring the pressure of the process space formed by the spray head and the substrate, and for adjusting the flow rate of the high-temperature gas based on the pressure measured by the pressure gauge.

[0019] (III) Beneficial Effects

[0020] Atomic Layer Etching (ALE) is a technique that adsorbs reactive gases onto the surface to be etched and removes the adsorbed reactive gases using ionic or thermal energy. This removes atoms bound to the etched layer, resulting in a physically smooth surface. ALE utilizes a sequential self-limiting reaction to remove thin layers of material and is considered one of the most promising technologies for achieving atomically low process variability. The first step of this ALE process involves flowing etching gas into a chamber, where it adsorbs onto the thin film to be etched and reacts. In this step, to increase the adsorption rate, the etching gas often uses free radicals dissociated in a plasma state. In the first step, once the etching gas has sufficiently adsorbed onto the monolayer surface, no further adsorption reaction occurs due to self-limitation. The second step of the ALE process is to remove all residual gases except for the etching gas adsorbed onto the film surface. The third step involves heating the substrate on which the adsorbed layer is formed to remove the reactive surface layer containing the adsorbed etching gases. In this step, even if the thermal energy is sufficient to remove the chemically modified layer, if it is insufficient to etch the bulk material, only the reaction surface layer is removed due to self-limitation. Additionally, the fourth step of the ALE process is the removal of etching by-products from the chamber. These four steps form a cycle, and this cycle needs to be repeated to achieve the desired thickness or depth. In this ALE process, argon (Ar) gas takes time to reach the reaction space via the remote plasma source (RPS) and the shower head, and a relatively large amount of gas is required for sufficient heat transfer. Furthermore, since room-temperature Ar gas is used, the temperature rise of Ar itself requires additional thermal energy, potentially reducing heat transfer efficiency. The high-temperature gas supply process system according to the invention provides efficient gas flow and heat transfer. The process system according to the invention forms a dedicated gas supply channel on the lower part of the shower head, which can supply gas to the process space formed by the shower head, edge ring, and wafer, thereby optimizing gas flow. Furthermore, by injecting preheated gas via high-temperature gas injection, the heat transfer effect is improved. This method solves the problem of the low initial temperature of Ar gas, thus achieving rapid and efficient heat transfer. Additionally, the substrate etching method in the ALE process according to the present invention effectively shortens the process time by removing process steps, thereby improving production efficiency. Specifically, by supplying high-temperature gas, heat is transferred to the substrate efficiently through conduction, convection, and thermal radiation. The process system according to the present invention can be applied to various forms of ALE processes, but the present invention is not limited thereto. Simple Explanation of the Diagram

[0021] Figure 1 illustrates an embodiment of the high-temperature gas supply type process system according to the present invention.

[0022] Figure 2 illustrates an embodiment of the supply path of high-temperature gas in the process system according to the present invention.

[0023] Figure 3 illustrates another embodiment of the supply path of high-temperature gas in the process system according to the present invention.

[0024] Figure 4 illustrates an embodiment of the atomic layer etching method according to the present invention, achieved by supplying high-temperature gas. Implementation

[0025] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, the embodiments are only for clear understanding of the present invention, and the present invention is not limited thereto. In the following description, components with the same reference numerals in different drawings have similar functions, and therefore will not be described again unless required for understanding the present invention. Although conventional components are described briefly or omitted, this should not be construed as excluding them from the embodiments of the present invention.

[0026] Figure 1 illustrates an embodiment of the high-temperature gas supply type process system according to the present invention.

[0027] Referring to Figure 1, the high-temperature gas supply type process system includes: a spray head 12, which is disposed facing an electrostatic chuck (ESC) 13; a baffle 14 formed along the edge portion of the spray head 12; drive units 16a and 16b that move the edge ring 15 up and down to move the substrate W up and down; and a high-temperature gas supply module GS that supplies high-temperature gas to the lower side of the spray head 12.

[0028] The spray head 12 can be disposed on the upper side of the chamber 11, and can be made of materials such as aluminum. It has an internal heater capable of heating to a temperature up to 500°C. The chamber 11 can have a sealed structure and maintain a vacuum state during the ALE process. The ALE process can include the following steps: (i) adsorbing reactive gases onto a substrate W such as a wafer; (ii) removing unadsorbed residual gases; (iii) etching the adsorbed reactive surface layer; and (iv) removing etching byproducts from the interior of the chamber 11. The upper portion of the chamber 11 can be sealed by a cover LID, and plasma generated from a distal plasma source RPS disposed outside the cover LID can flow into the upper side of the spray head 12 through an inlet formed on the cover LID. The plasma flowing into the chamber 11 can be uniformly dispersed inside the spray head 12. The spray head 12 can have a structure that allows ions and free radicals to flow uniformly, and multiple circular holes can be formed in the central and edge portions of the spray head 12. The size and structure of the spray head 12 can vary depending on the process being performed, and the present invention is not limited thereto. In the adsorption step of the ALE process, a substrate W, such as a wafer, can be fixed to the upper side of an electrostatic chuck 13. For the reaction to occur, the required gas can flow into the upper side of the spray head 12, which is positioned above the chamber 11, via a remote plasma source (RPS). The gas used to react with the plasma is then dispersed through the spray head 12 onto the upper side of the substrate W fixed to the electrostatic chuck 13 and adsorbed to form a deposition layer. After adsorption is completed through self-limiting, residual gas can be discharged. After the residual gas is discharged, lifting components LM1 and LM2 rise via the operation of a pair of drive units 16a and 16b, allowing the substrate W to move upward toward the spray head 12. The upper ends of the lifting components LM1 and LM2 contact the lower portion of the edge ring 15, and the lifting components LM1 and LM2 can move downward or upward via the operation of drive units 16a and 16b, such as motors. When the substrate W moves upward and forms a narrow space with the spray head 12, baffle 14, and substrate W, the removal step of the ALE process can be performed. The baffle 14 can be shaped to extend downward at an angle from the circular edge of the spray head 12, and can form multiple flow holes or flow slits to allow gas to flow laterally. The narrow space formed by the spray head 12, baffle 14, and substrate W can be the etching process space, and the spray head 12 can be heated by an internal heater to provide thermal energy for removing the atomic layer. According to one embodiment of the invention, during the atomic layer removal process, a gas supply module GS can be provided for supplying high-temperature gas, and through the gas supply module GS, high-temperature gas can be supplied to the lower portion of the spray head 12 and sprayed onto the substrate W.The high-temperature gas supply module GS can be located outside the chamber 11 and can include a high-temperature gun 17 for heating the gas to a high temperature and a mass flow controller (MFC) for controlling the amount of fluid supplied. A gas line 18 can extend from the gas supply module GS into the interior of the chamber 11 and can be connected to a guide path formed on the lower portion of the spray head 12. The guide path can be formed on the lower portion of the spray head 12 so that the gas supplied through the gas line 18 flows along the lower portion of the spray head 12. For example, the gas supplied by the high-temperature gun 17 can be nitrogen, helium, argon, or clean dry air (CDA), but is not limited to these. The gas supplied by the high-temperature gun 17 can be heated to a high temperature by the high-temperature gun 17 and flow along the gas line 18. The gas line 18 can be made of a material with high thermal conductivity, such as stainless steel (SUS), so it can maintain a temperature similar to that of the spray head 12 when heated to a high temperature, thus eliminating the need for a separate device for heating the gas line 18. Gas flowing along gas line 18 can be guided to the central and edge portions by following a guide path formed on the underside of spray head 12. The high-temperature gas flowing along the guide path in the central and edge portions on the underside of spray head 12 can be sprayed onto the substrate W located on the underside of spray head 12 through spray holes 19_1 to 19_K. The pressure of the confined space can be measured by a manometer MN located outside chamber 11, and a measuring line can extend from the manometer MN located on the upper side of cover LID through cover LID and spray head 12 into the interior of the confined space. The internal temperature of the confined space can be measured by a non-contact temperature measuring thermometer TM located on the upper side of cover LID, and a sensing line can extend from cover LID and spray head 12 into the interior of the confined space, with a measuring hole formed at the end of the sensing line sealed with a material such as quartz. Based on the pressure measured by manometer MN, mass flow controller MFC can control the amount of high-temperature gas supplied through gas line 18. Furthermore, based on the temperature measured by the thermometer TM, the temperature of the high-temperature gas to be heated by the high-temperature gun 17 can be set. During the removal step of the ALE process, the high-temperature gas can be sprayed from the underside of the spray head 12, and on the upper side of the substrate W, the cooled gas can be discharged to the side along with byproducts from the removal process through the baffle 14. As described above, through the high-temperature gas, heat is transferred to the upper side of the substrate W in the form of conduction, convection, and radiation, thereby improving process efficiency while reducing etching process time. Specifically, the high-temperature gas supplied through the gas line 18 is directly sprayed into a narrow space, making the high-temperature gas act as a heat medium, thereby transferring the heat energy of the spray head 12 to the substrate W.In this process, the removal process can be effectively carried out without loss of heat energy through the supply of high-temperature gas. Furthermore, byproducts and heat-depleted gases generated during the removal process are discharged through baffle 14, and new high-temperature gas is continuously filled into the narrow space, thereby shortening the etching process time. Additionally, the flow rate of gas flowing into the narrow space can be accurately regulated by a mass flow controller (MFC). Through this process, when the removal process is completed, etching byproducts are discharged through the pumping duct (PD), thus completing one cycle of the ALE process. While the etching byproducts can be discharged through the pumping duct (PD), the invention is not limited to this.

[0029] Figure 2 illustrates an embodiment of the supply path of high-temperature gas in the process system according to the present invention.

[0030] Referring to Figure 2, the lower portion of the spray head 12 can be generally disc-shaped, and a plurality of central holes 21_1 to 21_L can be formed in the central portion. Additionally, a plurality of edge holes 22_1 to 22_M can be formed on the edge portion of the spray head 12. The central holes 21_1 to 21_L or the edge holes 22_1 to 22_M can be circular with reference to the center of the circular lower surface of the spray head 12, and can be arranged along one or more circles. The central holes 21_1 to 21_L or the edge holes 22_1 to 22_M can serve to uniformly disperse the plasma containing the reactive gas on the upper side of the substrate W. The gas pipeline 18 extending from the high-temperature gas supply module GS located outside the chamber 11 to the inside of the chamber 11 can be connected to the guide path 23 formed on the lower portion of the spray head 12. High-temperature gas supplied along gas line 18 can flow along guide path 23, and guide path 23 can be formed to extend from the edge of spray head 12 away from the center holes 21_1 to 21_L or edge holes 22_1 to 22_M toward the center. Spray path 23a can be formed around the center of spray head 12, and one or more spray holes 19_1 to 19_K can be formed along spray path 23a. Spray path 23a can be formed as a circle with reference to the center of spray head 12. High-temperature gas flowing along guide path 23 can flow along spray path 23a and be sprayed toward the lower side of spray head 12 through spray holes 19_1 to 19_K. Thus, the heat of spray head 12 can be effectively transferred to the upper part of substrate W, thereby effectively performing the removal process. As described above, when high-temperature gas is supplied to the central part of spray head 12 and fills the central part of the narrow space, etching byproducts generated during the etching process are pushed toward the edge, and can be discharged to the outside of the narrow space through baffle 14. The injection path 23a can be formed in various structures, but the present invention is not limited thereto.

[0031] Figure 3 illustrates another embodiment of the supply path of high-temperature gas in the process system according to the present invention.

[0032] Referring to FIG3, the lower portion of the spray head 12 can be disc-shaped, and a circular first spray path 23a can be formed in the center portion based on the center of the disc shape. Additionally, a second spray path 23b can be formed in the edge portion based on the center of the lower portion of the spray head 12. Furthermore, a first set of spray holes 19_1 to 19_K and a second set of spray holes 19a_1 to 19a_K can be formed on the first spray path 23a and the second spray path 23b, respectively. High-temperature gas flowing along the guide path 23 can flow to the first spray path 23a and the second spray path 23b, and be sprayed onto the lower side of the spray head 12 through the first set of spray holes 19_1 to 19_K and the second set of spray holes 19a_1 to 19a_K. As described above, by supplying high-temperature gas to the center and edge portions, the temperature conversion of the substrate W can be performed quickly and rapidly. The spray paths 23a, 23b or the first and second sets of spray holes 19_1 to 19a_K can be formed in various forms, and the present invention is not limited thereto.

[0033] Figure 4 illustrates an embodiment of the atomic layer etching method according to the present invention, achieved by supplying high-temperature gas.

[0034] Referring to Figure 4, the atomic layer etching method achieved by high-temperature gas supply includes the following steps: plasma containing reactive gas is flowed into the interior of a process chamber, causing the reactive gas to be adsorbed onto the upper surface of a substrate such as a wafer (P41); after adsorption is complete, residual gas is removed, and the substrate is raised, thereby forming a narrow space corresponding to the etching process space by the spray head, baffle, and substrate (P42); high-temperature gas is supplied to the lower portion of the spray head, and high-temperature gas is sprayed from the spray head onto the substrate, thereby performing the atomic layer removal process (P43); and after the removal process is completed, etching byproducts are removed (P44). To perform the removal process in the narrow space, the spray head can be heated by an internal heater, and the high-temperature gas can be heated to a temperature corresponding to the spray head. The high-temperature gas can be supplied from outside the narrow space to the lower portion of the spray head through appropriate gas lines, and sprayed from the lower portion of the spray head onto the upper surface of the substrate, so that the heat energy of the spray head is effectively transferred to the substrate. The high-temperature gas can be supplied to the spray head in various ways, and the present invention is not limited thereto.

[0035] The present invention has been described in detail above with reference to the illustrated embodiments. However, those skilled in the art can make various modifications and variations to the illustrated embodiments without departing from the technical spirit of the present invention. The present invention is not limited to such modifications and variations, but is defined by the scope of the claims.

[0036] 11: Chamber 12: Spray head 13:ESC 14: Baffle 15: Edge ring 16a, 16b: Drive units 17: High-Temperature Gun 18: Gas pipeline 19_1 to 19_K, 19a_1 to 19a_K: Injection holes 21_1 to 21_L: Center hole 22_1 to 22_M: Edge holes 23: Boot path 23a: First injection path 23b: Second injection path W: substrate GS: High-Temperature Gas Supply Module LID: Cover RPS: Plasma source LM1, LM2: Lifting components MFC: Mass Flow Controller MN: Pressure gauge TM: Thermometer PD: Discharge tube Pages 41-44: Steps

Claims

1. A high-temperature gas supply type process system, comprising: The spray head (12) is positioned facing the electrostatic chuck (13); A baffle (14) is formed along the edge portion of the spray head (12); a drive unit (16a, 16b) moves the edge ring (15) up and down to move the substrate (W) up and down; And a high-temperature gas supply module (GS) supplies high-temperature gas to the lower side of the spray head (12). The spray head (12) includes: a plurality of holes (21_1 to 21_L and 22_1 to 22_M) for supplying reactive gas via a remote plasma source (RPS) before the substrate (W) rises, so that the reactive gas is uniformly dispersed on the upper side of the substrate (W) to perform the adsorption step of the ALE process; And multiple spray holes (19_1 to 19_K) are used to supply high-temperature gas to the narrow space formed by the spray head (12), the baffle (14) and the substrate (W) after the substrate (W) is raised, and the high-temperature gas is discharged laterally to the outside of the narrow space through the baffle (14) to perform the removal step of the ALE process.

2. The high-temperature gas supply type process system according to claim 1, wherein, The high-temperature gas supply module (GS) includes a high-temperature gun (17) for generating high-temperature gas and a mass flow controller (MFC).

3. The high-temperature gas supply type process system according to claim 1, wherein, Further includes: a gas line (18) extending from the high-temperature gas supply module (GS) into the interior of the chamber (11), wherein high-temperature gas supplied along the gas line (18) is sprayed from the lower side of the spray head (12) onto the upper side of the substrate (W).

4. The high-temperature gas supply type process system according to claim 1, further comprising: A guide path (23) is formed on the lower part of the spray head (12) to guide the high-temperature gas to the first spray path (23a) and the second spray path (23b) formed on the center or edge part of the lower side of the spray head (12).

5. The high-temperature gas supply type process system according to claim 1, wherein, The high-temperature gas is nitrogen, helium, argon, or dry air.

6. The high-temperature gas supply type process system according to claim 1, wherein, Further includes: a pressure gauge (MN) for measuring pressure in a confined space, and adjusting the flow rate of high-temperature gas based on the pressure measured by the pressure gauge (MN).

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