Semiconductor manufacturing apparatus, method for manufacturing semiconductor apparatus, and film deposition method

Abstract

The semiconductor manufacturing apparatus of this embodiment includes: a chamber for placing a substrate; a first gas flow path for supplying a first processing gas into the chamber; a second gas flow path for supplying a second processing gas into the chamber; a first displacement gas flow path for supplying a first displacement gas into the chamber; a displacement gas heating section for heating the first displacement gas; a second displacement gas flow path for supplying a second displacement gas into the chamber; and a displacement gas cooling section for cooling the second displacement gas.

Description

[0001] Citation of relevant applications

[0002] This application is based on and claims the benefit of priority of Japanese Patent Application No. 2021-153476, filed on September 21, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The embodiments of the present invention relate to a semiconductor manufacturing apparatus, a method for manufacturing a semiconductor apparatus, and a film forming method. Background Technology

[0004] As a method for forming films on semiconductor substrates, ALD (Atomic Layer Deposition) is known, in which a precursor gas and a reactant gas that reacts with the precursor gas are alternately supplied to the semiconductor substrate, and a layer of reaction products is deposited on the surface of the substrate to obtain a thin film. The precursor gas and reactant are independently introduced (pulsed) and removed (removed). In each pulse, precursor gas molecules and reactant molecules react autonomously with reactive sites on the surface of the semiconductor substrate. By reacting the reactive sites on the surface of the semiconductor substrate during the pulse and completely removing unreacted precursor gas molecules and reactant molecules during the removal process, a film of reaction products can be formed on the surface of the semiconductor substrate. By repeating the pulse-removal of the precursor gas and the pulse-removal of the reactant as a single cycle, precise control of the film thickness can be achieved. Furthermore, as a method for etching semiconductor substrates using the same principle, ALE (Atomic Layer Etching) is known. Summary of the Invention

[0005] Embodiments of this disclosure provide semiconductor manufacturing apparatus, semiconductor device manufacturing method, and film deposition method with improved manufacturing efficiency.

[0006] One embodiment of a semiconductor manufacturing apparatus includes a chamber for placing a substrate, a first gas flow path for supplying a first processing gas into the chamber, a second gas flow path for supplying a second processing gas into the chamber, a replacement gas flow path for supplying a replacement gas into the chamber for replacing ambient gas in the chamber, a replacement gas heating unit for heating the replacement gas, and a replacement gas cooling unit for cooling the replacement gas.

[0007] Based on the above configuration, it is possible to provide a semiconductor manufacturing apparatus, a method for manufacturing a semiconductor apparatus, and a film deposition method that improve manufacturing efficiency. Attached Figure Description

[0008] Figure 1This is a diagram that schematically illustrates the overall configuration of a semiconductor manufacturing apparatus according to one embodiment.

[0009] Figure 2 It is a cross-sectional view that roughly shows the structure of the heating mechanism.

[0010] Figure 3 It is a cross-sectional view that roughly shows the structure of the cooling mechanism.

[0011] Figure 4 This is a graph showing the change in surface energy of a substrate in a semiconductor device manufacturing method according to one embodiment.

[0012] Figure 5 This is a graph showing the temperature change on the wafer surface during a semiconductor device manufacturing method according to one embodiment.

[0013] Figure 6 This is a diagram that roughly shows the overall configuration of a modified semiconductor manufacturing apparatus. Detailed Implementation

[0014] Hereinafter, a semiconductor manufacturing apparatus and a method for manufacturing a semiconductor apparatus according to this embodiment will be specifically described with reference to the accompanying drawings. In the following description, elements having substantially the same function and structure are labeled with the same reference numeral or with reference numerals followed by letters, and will be repeated only where necessary. The embodiments shown below illustrate apparatuses and methods for embodying the technical concept of these embodiments. The technical concept of the embodiments does not specify the materials, shapes, structures, arrangements, etc., of the constituent components as described below. Various modifications can be made to the claims to embody the technical concept of the embodiments.

[0015] To make the accompanying drawings clearer, the width, thickness, shape, etc., of various parts are sometimes shown schematically compared to the actual form, but this is only an example and not a limitation of the interpretation of the invention. In this specification and the various drawings, elements that have the same function as elements described with respect to previously mentioned elements are sometimes labeled with the same reference numerals and repeated descriptions are omitted.

[0016] In this specification, unless otherwise expressly stated, expressions such as "α includes A, B, or C," "α includes one of A, B, and C," or "α includes one selected from the group consisting of A, B, and C" do not preclude the possibility that α includes multiple combinations of A to C. Furthermore, these expressions do not preclude the possibility that α includes other elements.

[0017] In this specification, horizontal sometimes refers to the direction (XY direction) that is horizontal relative to the stage of the semiconductor manufacturing apparatus, and vertical sometimes refers to the direction that is substantially perpendicular to the horizontal direction (Z direction).

[0018] The following implementation methods can be combined with each other as long as they do not create technical contradictions.

[0019] In the following embodiments, a memory cell array is exemplified as a semiconductor device, but the technology disclosed herein can also be applied to semiconductor devices other than memory cell arrays (e.g., CPUs, displays, interposers, etc.).

[0020] Semiconductor Manufacturing Equipment

[0021] Figure 1 This is a diagram that schematically illustrates the overall configuration of a semiconductor manufacturing apparatus according to one embodiment. The semiconductor manufacturing apparatus 1 of this embodiment is, for example, a single-wafer-type ALD / ALE apparatus for depositing or etching a single semiconductor substrate; it can also be referred to as a film deposition apparatus. Figure 1 As shown, the semiconductor manufacturing apparatus 1 includes a chamber 10 and four gas supply passages 20, 30, 40, and 50.

[0022] The chamber 10 includes a stage 11 for fixing a substrate S. The stage 11 can hold the wafer-shaped (disk-shaped) substrate S with its main surface horizontal. Four gas supply ports 12, 13, 14, and 15 are arranged above the stage 11, penetrating the chamber 10. Four gas supply passages 20, 30, 40, and 50 are connected to the four gas supply ports 12, 13, 14, and 15, respectively. The gases supplied from the four gas supply passages 20, 30, 40, and 50 are dispersed within the chamber 10 and evenly supplied to the substrate S on the stage 11. A gas exhaust port 16 is arranged below the stage 11, penetrating the chamber 10. A gas exhaust passage 60 is connected to the gas exhaust port 16. Gas within the chamber 10 is exhausted through the gas exhaust passage 60. Furthermore, a temperature control mechanism (not shown) is provided in the chamber 10 to control the overall temperature within the chamber 10.

[0023] A gas supply device 21 for supplying raw material gas is connected to the gas supply passage (first gas flow path) 20. The gas supply device 21 supplies raw material gas to the gas supply passage 20 while adjusting the flow rate and pressure. A valve 22 is arranged between the gas supply device 21 and the gas supply port 12. When the valve 22 is opened, the raw material gas is supplied to the chamber 10 from the gas supply port 12 through the gas supply passage 20.

[0024] A gas supply device 31 for supplying reaction gas is connected to the gas supply passage (second gas flow path) 30. The gas supply device 31 supplies reaction gas to the gas supply passage 30 while adjusting the flow rate and pressure. A valve 32 is arranged between the gas supply device 31 and the gas supply port 13. When the valve 32 is opened, reaction gas is supplied to the chamber 10 from the gas supply port 13 through the gas supply passage 30.

[0025] A gas supply device 41 for supplying replacement gas is connected to the gas supply passage (first replacement gas flow path) 40. The replacement gas can also be called a purging gas. The gas supply device 41 supplies replacement gas to the gas supply passage 40 while adjusting the flow rate and pressure. Between the gas supply device 41 and the gas supply port 14, a pressure control mechanism 45, a valve 42, a heating mechanism (replacement gas heating unit) 43, and a valve 44 are arranged in sequence. The replacement gas supplied from the gas supply device 41 is depressurized by the pressure control mechanism 45. The pressure control mechanism 45 can be, for example, an orifice. The valve 42 is opened, allowing the depressurized replacement gas to be supplied to the heating mechanism 43. Figure 2 This is a schematic cross-sectional view showing the structure of the heating mechanism 43. The heating mechanism 43 has a gas flow path 431 and a heater 432. The heater 432 is configured to surround the gas flow path 431. The displacement gas supplied to the gas flow path 431 of the heating mechanism 43 can be heated by the heater 432. The heating mechanism 43 heats the displacement gas to a temperature higher than that of the raw material gas and the reactant gas, for example. The valve 44 is opened, thereby supplying the heated displacement gas into the chamber 10 from the gas supply port 14 via the gas supply passage 40.

[0026] A gas supply device 51 for supplying displacement gas is connected to the gas supply passage (second displacement gas flow path) 50. The gas supply device 51 supplies displacement gas to the gas supply passage 50 while adjusting the flow rate and pressure. A valve 52, a cooling mechanism (displacement gas cooling section) 53, and a valve 54 are sequentially arranged between the gas supply device 51 and the gas supply port 15. When valve 52 is opened, displacement gas is supplied to the cooling mechanism 53. Figure 3 This is a schematic cross-sectional view showing the structure of the cooling mechanism 53. The cooling mechanism 53 is a pump that expands and cools gas by rapidly changing the volume of a space, and includes a syringe 531, a piston 532, a movable part 533, and a heat-insulating material 534. The piston 532 is slidably disposed on the inner side of the syringe 531. The movable part 533 is threaded into the shaft of the piston 532. The piston 532 slides relative to the syringe 531 by rotating the movable part 533 (arrow). In addition, the heat-insulating material 534 is configured to surround the syringe 531.

[0027] The displacement gas supplied to the cooling mechanism 53 is supplied to the space surrounded by the syringe 531 and the piston 532. The space surrounded by the syringe 531 and the piston 532 can change volume by sliding the piston 532 using the movable part 533. By closing valves 52 and 54, the space surrounded by the syringe 531 and the piston 532 is rapidly expanded thermally, thereby cooling the temperature of the gas in the space. For example, by rapidly expanding the gas volume twice from a gauge pressure of 0.6 MPa to 0.3 MPa (from a gas pressure of 7 atm to 3 atm), the gas temperature is cooled by about 50°C. The cooling mechanism 53, for example, cools the temperature of the displacement gas to a temperature lower than that of the raw material gas and the reactant gas. Valve 54 is opened, thereby supplying the cooled displacement gas into the chamber 10 through the gas supply passage 50 from the gas supply port 15.

[0028] In this embodiment, the cooling mechanism 53 is shown as a pump that uses a syringe 531 and a piston 532 to expand and cool the gas. However, it is not limited to this; the cooling mechanism 53 can be a bellows or a diaphragm as long as it can rapidly change the volume of the space.

[0029] A valve 62 and an exhaust pump 63 are sequentially arranged in the gas exhaust passage 60. When the valve 62 is open, the exhaust pump 63 discharges the gas in the chamber 10 from the gas exhaust port 16 through the gas exhaust passage 60.

[0030] <Methods for Manufacturing Semiconductor Devices>

[0031] The following describes a method for manufacturing a semiconductor device using the semiconductor manufacturing apparatus 1 of this embodiment. The method for manufacturing a semiconductor device according to this embodiment includes, for example, a step of forming a desired film on a semiconductor substrate using an ALD or ALE method. The ALD or ALE method includes four steps: A. adsorption of the raw material gas, B. removal of the raw material gas, C. adsorption of the reactant gas, and D. removal of the reactant gas. Figure 4 The diagram illustrates the energy variation of the surface reaction of a substrate in a semiconductor device manufacturing method according to one embodiment. Figure 4 The diagram illustrates the surface energy and activation energy before and after the reaction in each of the four basic processes: A. adsorption of the feed gas, B. desorption of the feed gas, C. adsorption of the reactant gas, and D. desorption of the reactant gas. The surface energy of the substrate differs in each basic process. Within the four-step cycle, there are steps with relatively high activation energy, higher post-reaction energy compared to pre-reaction energy, and where the so-called reverse reaction is more easily carried out. Figure 4(D. Removal of reactant gases). For example, in semiconductor substrates used to manufacture three-dimensional NAND flash memory with complex structures, steps with high activation energy and surface energy after reaction higher than before reaction become limiting processes. If the reactant gases are not completely removed, residual molecules may react with subsequent molecules to form byproducts, making it difficult to control film formation or etching. Therefore, in the semiconductor device manufacturing method using the semiconductor manufacturing apparatus 1 of this embodiment, in steps that are limiting processes, the temperature of the supplied gas is temporarily increased and then restored, thereby improving manufacturing efficiency. Figure 5 An example of temperature variation on the wafer surface during a semiconductor device manufacturing method according to one embodiment is shown. Furthermore, the overall temperature within chamber 10 in the cycle sequence is appropriately controlled by a temperature control mechanism (not shown).

[0032] First, the substrate S is placed on the stage 11 of the chamber 10. The substrate S is, for example, a semiconductor substrate used to manufacture a three-dimensional NAND flash memory with multiple memory cells stacked on top of each other.

[0033] In order to adsorb the raw material gas, valve 22 of gas supply passage 20 is opened to supply the raw material gas to chamber 10. At this time, valves 32, 42, and 52 of gas supply passages 30, 40, and 50 are closed. The raw material gas is, for example, a gas containing the elements contained in the membrane after film formation.

[0034] To remove the raw material gas (B), valves 52 and 54 of the gas supply passage 50 are opened to supply replacement gas to chamber 10, and valve 62 of the gas exhaust passage 60 is opened to discharge the gas from chamber 10. At this time, by opening valves 52 and 54, the cooling mechanism 53 is deactivated, and the replacement gas is not cooled. Meanwhile, valves 22, 32, and 52 of the gas supply passages 20, 30, and 50 are closed. The replacement gas can be, for example, nitrogen (N2) or argon (Ar).

[0035] In order to allow the reactant gas to react with and adsorb the raw material gas adsorbed on the substrate, valve 32 of gas supply passage 30 is opened to supply the reactant gas to chamber 10. At this time, valves 22, 42, and 52 of gas supply passages 20, 40, and 50 are closed. The reactant gas is, for example, a gas containing hydrogen (H), which can also be called a reducing gas.

[0036] To remove the reactant gas (D), valve 42 of gas supply passage 40 is opened to supply replacement gas to heating mechanism 43, heating the replacement gas. Valve 44 of gas supply passage 40 is then opened to supply the heated replacement gas to chamber 10. The temperature of the heated replacement gas can also be higher than the temperature of the raw material gas and the reactant gas. Additionally, valve 62 of gas exhaust passage 60 is opened to exhaust gas from chamber 10. At this time, valves 22, 32, and 52 of gas supply passages 20, 30, and 50 are closed.

[0037] In the semiconductor device manufacturing method of this embodiment, by temporarily increasing the temperature of the displacement gas, the detachment of the reactant gas from the substrate can be promoted. This shortens the time of steps in the cycle sequence that are considered limiting processes, thereby improving the manufacturing efficiency of the semiconductor device. Furthermore, it suppresses the generation of byproducts caused by residual gas, thus improving the reliability of the semiconductor device.

[0038] Before proceeding to the next cycle, valve 52 of gas supply passage 50 is opened to supply replacement gas to cooling mechanism 53. By closing valves 52 and 54, the space surrounded by syringe 531 and piston 532 undergoes rapid thermal expansion, thereby cooling the temperature of the replacement gas. Valve 54 of gas supply passage 50 is opened to supply the cooled replacement gas to chamber 10. The temperature of the cooled replacement gas can also be lower than the temperature of the raw material gas and the reactant gas. Additionally, valve 62 of gas exhaust passage 60 is opened to exhaust gas from chamber 10. At this time, valves 22, 32, and 42 of gas supply passages 20, 30, and 40 are closed. The replacement gas can be, for example, nitrogen (N2) or argon (Ar).

[0039] In the semiconductor device manufacturing method of this embodiment, by restoring (lowering) the temperature of the displacement gas, the reaction temperature for subsequent cycles can be optimized. This shortens the time of steps in the cycle sequence and improves the manufacturing efficiency of the semiconductor device.

[0040] The semiconductor device manufacturing method using the semiconductor manufacturing apparatus 1 of this embodiment can accelerate the steps that become limiting processes by increasing the temperature of the supplied gas and then restoring it. This shortens the time of the limiting process steps in the cycle sequence, thereby improving the manufacturing efficiency of the semiconductor device. Furthermore, it suppresses the generation of byproducts caused by residual gas, thus improving the reliability of the semiconductor device.

[0041] <Variation Example>

[0042] The configuration of this modified semiconductor manufacturing apparatus is the same as that of the semiconductor manufacturing apparatus in one embodiment, except that it is a batch-type apparatus that processes multiple substrates simultaneously. The manufacturing method of this modified semiconductor apparatus is the same as that of the semiconductor manufacturing apparatus in one embodiment. Descriptions identical to those in the embodiment are omitted; instead, the parts that differ from the configuration of the semiconductor manufacturing apparatus in the embodiment will be described.

[0043] Semiconductor Manufacturing Equipment

[0044] Figure 6 This is a diagram that schematically illustrates the overall configuration of a modified semiconductor manufacturing apparatus. The modified semiconductor manufacturing apparatus 1a is, for example, a batch-type ALD / ALE apparatus for depositing or etching multiple semiconductor substrates. Figure 6 As shown, the semiconductor manufacturing apparatus 1a includes a chamber 10a and four gas supply passages 20a, 30a, 40a and 50a.

[0045] The chamber 10a includes a worktable 11a for fixing substrates S. The worktable 11a can arrange multiple substrates S in rows at predetermined intervals with their main surfaces horizontal. For example, up to about 200 substrates S can be accommodated in one chamber 10a. Four gas supply ports 12a, 13a, 14a, and 15a are arranged next to the worktable 11a, penetrating the chamber 10a. The four gas supply ports 12a, 13a, 14a, and 15a are respectively connected to four gas supply passages 20a, 30a, 40a, and 50a. Gases supplied from the four gas supply passages 20a, 30a, 40a, and 50a are supplied into the chamber 10a through the four gas supply ports 12a, 13a, 14a, and 15a via gas supply pipes 121a, 131a, 141a, and 151a. Gas supply pipes 121a, 131a, 141a, and 151a extend along multiple substrates S in a row-like arrangement (vertical direction).

[0046] Gas supply pipes 121a, 131a, 141a, and 151a have multiple gas outlets on their sides in a vertical direction where the multiple substrates S are arranged in rows. Preferably, the gas outlets are located between the multiple substrates S. Gas discharged from the gas outlets is supplied equally to the multiple substrates S. A gas exhaust port 16a is disposed below the worktable 11a, penetrating the chamber 10a. A gas exhaust passage 60a is connected to the gas exhaust port 16a. Gas within the chamber 10a is discharged through the gas exhaust passage 60a. Additionally, a temperature control mechanism (not shown) is provided in the chamber 10a to control the overall temperature within the chamber 10a. Alternatively, the gas supply pipes 121a, 131a, 141a, and 151a may not have multiple outlets on their sides, but may have outlets at their ends. Figure 6 In the figure, the height of the ends of the gas supply pipes 121a, 131a, 141a, and 151a is shown in such a way that they are near the upper section of the multiple substrates S, but their height is not specifically defined.

[0047] The configuration of the four gas supply passages 20a, 30a, 40a, and 50a, and the manufacturing method of the semiconductor device are the same as those of the semiconductor device in one embodiment, so they are omitted here.

[0048] The semiconductor manufacturing method using the semiconductor manufacturing apparatus 1a of this modification can accelerate the steps that become limiting processes by increasing the temperature of the supplied gas and then restoring it. This shortens the time of the limiting process steps in the cycle sequence, thereby improving the manufacturing efficiency of the semiconductor device. Furthermore, it suppresses the generation of byproducts caused by residual gas, thus improving the reliability of the semiconductor device.

Claims

1. A method for manufacturing a semiconductor device using the ALD or ALE method, comprising repeatedly performing the following steps, Each of the steps has the following characteristics: The first step is to supply raw material gas into the chamber where the substrate is placed and to adsorb the raw material gas onto the substrate. Following the first step, a second step is performed to supply a second displacement gas at a first temperature into the chamber and to remove the raw material gas. In the third step, after the second step, a reaction gas is supplied into the chamber, so that the reaction gas reacts with the raw material gas and is adsorbed onto the substrate. Following the third step, a fourth step involves supplying a first displacement gas at a temperature higher than the first temperature, the temperature of the raw material gas, and the temperature of the reactant gas into the chamber, thereby removing the reactant gas; and Following the fourth step, a fifth step involves supplying the chamber with a second displacement gas at a temperature lower than the first temperature, the temperature of the raw material gas, and the temperature of the reactant gas. The activation energy of the fourth step is higher than that of the first, second, and third steps, and it is the step that limits the process.

2. The method for manufacturing a semiconductor device according to claim 1, The displacement gas cooling unit, which cools the second displacement gas, includes a pump that expands the second displacement gas. The pump has: syringe; A piston is slidably disposed on the inner surface of the syringe; The movable part, threadedly engaged with the piston shaft; and Thermal insulation material is configured to surround the syringe. The piston slides relative to the syringe by rotating the movable part.

3. The method for manufacturing a semiconductor device according to claim 2, The pump expands the second displacement gas to more than twice its original volume.

4. The method for manufacturing a semiconductor device according to claim 1, The second replacement gas contains either nitrogen (N2) or argon (Ar).

5. A method for forming a film in a semiconductor device using the ALD or ALE method, comprising repeatedly performing the following steps: Each of the steps has the following characteristics: The first step is to supply raw material gas into the chamber where the substrate is placed and to adsorb the raw material gas onto the substrate. Following the first step, a second step is performed to supply a second displacement gas at a first temperature into the chamber and to remove the raw material gas. In the third step, after the second step, a reaction gas is supplied into the chamber, so that the reaction gas reacts with the raw material gas and is adsorbed onto the substrate. Following the third step, a fourth step involves supplying a first displacement gas at a temperature higher than the first temperature, the temperature of the raw material gas, and the temperature of the reactant gas into the chamber, thereby removing the reactant gas; and Following the fourth step, a fifth step involves supplying the chamber with a second displacement gas at a temperature lower than the first temperature, the temperature of the raw material gas, and the temperature of the reactant gas. The activation energy of the fourth step is higher than that of the first, second, and third steps, and therefore it is the limiting step in the process. The displacement gas cooling unit, which cools the second displacement gas, includes a pump that expands the second displacement gas. The pump has the following features: syringe; A piston is slidably disposed on the inner surface of the syringe; The movable part, threadedly engaged with the piston shaft; and Thermal insulation material is configured to surround the syringe. The piston slides relative to the syringe due to the rotation of the movable part. The pump expands the second displacement gas to more than twice its volume. The second replacement gas contains either nitrogen (N2) or argon (Ar).

Images