Atomic layer deposition apparatus and atomic layer deposition method

Abstract

To provide an atomic layer deposition apparatus and an atomic layer deposition method that allow a high-quality thin film to be obtained when film formation is performed by Atomic Layer Deposition (ALD).SOLUTION: After completing a step of reacting with a reactant at high temperature, a substrate 24 placed in a countersunk portion 9 of a susceptor 8 is moved to another position in a reaction chamber 3 by rotation of a turntable 18 and brought close to a convex portion 13 of a third stage 30, and an inert gas is supplied from below through a third stage gas nozzle 57 between the countersunk portion 9 and the convex portion 13, so as to rapidly cool the substrate 24. With this configuration, ALD film formation can be performed at high speed, in which a precursor is adsorbed at a low temperature and reacted with the reactant at a high temperature, and a high-quality thin film can be obtained.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to an atomic layer deposition apparatus and an atomic layer deposition method used in the manufacture of electronic devices such as semiconductors, flat panel displays, solar cells, and light emitting diodes. [Background technology]

[0002] Atomic layer deposition (ALD) is a technique used to form films on a wide range of electronic devices, including semiconductors, flat panel displays, solar cells, and light-emitting diodes.

[0003] In particular, in recent years, a double patterning technology has been developed that enables extremely fine pattern formation without using extremely expensive extreme ultraviolet (EUV) exposure equipment, and ALD is attracting attention as a key technology. This is a technology that forms a silicon or metal oxide film with a thickness of about 10 to 20 nm on a patterned organic resist film by a film formation method that is uniform and has good step coverage at a temperature of about 200°C or less so as not to deteriorate the patterned organic resist film.

[0004] Meanwhile, power semiconductors are indispensable for automobiles in which engines, brakes, etc. are highly electronically controlled. Electric vehicles (EVs) are being promoted worldwide, and improving the performance of power semiconductors is also essential for improving the performance of electric vehicles. As one method for improving the performance of power semiconductors, the replacement of Si substrates with SiC substrates or GaN substrates capable of handling high voltage and high current is being promoted. In power semiconductors using SiC substrates or GaN substrates, the quality of the nitride film is particularly important, so ALD is being introduced instead of CVD (chemical vapor deposition). For example, in GaN devices, by forming an aluminum nitride (AlN) layer using the ALD technology, a significant improvement in channel mobility has been achieved compared to elements without an aluminum nitride layer (see, for example, Non-Patent Document 1).

[0005] In addition, ALD technology is being used in many other processes, such as forming high-k / metal gates, forming upper and lower electrodes of DRAM capacitors using TiN or Ru, forming gate electrode sidewalls using SiN, forming barrier seeds in contacts and through-holes, forming high-k insulating films and charge trap films for NAND flash memories, etc. ALD technology is also used in forming ITO films and passivation films for flat panel displays, LEDs, and solar cells.

[0006] In conventional ALD, single-wafer and batch types (see, for example, Patent Document 1) are widely known, but the low processing speed (the number of substrates that can be processed per unit time) is often a problem, and various improvements have been made so far (see, for example, Patent Document 2). As one of the improvements, a rotary semi-batch ALD apparatus has been developed. In the rotary semi-batch ALD apparatus, a cylindrical vacuum vessel is divided into a total of four sector-shaped sub-chambers consisting of two reaction gas chambers and two purge gas chambers arranged between them, a reaction gas supply means is arranged above the center of each sub-chamber, and a gas exhaust section is installed below the two purge gas chambers. By rotating a disk-shaped table, multiple substrates to be processed on the table pass through each sub-chamber, and ALD film formation is performed (see, for example, Patent Document 3).

[0007] An improved type of rotary semi-batch ALD apparatus is a gas curtain type. In the gas curtain type rotary semi-batch ALD apparatus, a purge gas is caused to flow like a curtain between the reaction gas supply means, thereby suppressing the mixing of the reaction gases (for example, see Patent Document 4).

[0008] As a film-forming apparatus using sputtering, an apparatus that deposits a multilayer film on a disk-shaped workpiece transported by a rotating transport table and that is equipped with a cooling mechanism for cooling the disk-shaped workpiece has been disclosed (see, for example, Patent Documents 5 and 6). [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2004-6801 A [Patent Document 2] JP 2014-201804 A [Patent Document 3] U.S. Patent Publication No. 5,225,366 [Patent Document 4] U.S. Patent Publication No. 6,576,062 [Patent Document 5] JP 2005-325428 A [Patent Document 6] JP 2020-97779 A [Non-patent literature]

[0010] [Non-Patent Document 1] Kuraguchi, Kajiwara, Mukai, Toshiba Review, Vol. 75, No. 6 (2020) Summary of the Invention [Problem to be solved by the invention]

[0011] However, the ALD techniques described in Patent Documents 1 to 4, which are shown as conventional examples, have a problem in that good film quality cannot be obtained. In the step of reacting the reactant with the substrate, the substrate temperature needs to be raised to a predetermined temperature, and the step of reacting the precursor with the substrate is also carried out at a high temperature. This is thought to result in carbon generated by decomposition of the precursor being incorporated into the film, deteriorating the film quality.

[0012] Furthermore, the techniques described in Patent Documents 5 and 6, which are shown as conventional examples, relate to sputtering film formation and cannot be used for ALD film formation. Sputtering usually requires film formation at low pressures of about 1 Pa or less, where heat transfer by gas hardly occurs, so cooling is performed using a complex mechanism that raises and lowers the substrate, but this type of cooling mechanism is generally unsuitable for ALD, which forms films at pressures of several hundred Pa.

[0013] The present invention has been made in consideration of the above problems, and has an object to provide an atomic layer deposition apparatus and an atomic layer deposition method that can obtain high-quality thin films when forming films by ALD. [Means for solving the problem]

[0014] The atomic layer deposition apparatus of the first invention of the present application is an atomic layer deposition apparatus comprising: a reaction chamber; a plurality of susceptors each having a substrate mounting portion; a first position for controlling the temperature of the substrate mounted on the substrate mounting portion to a first temperature; a second position for controlling the temperature of the substrate mounted on the substrate mounting portion to a second temperature; a precursor nozzle for supplying a gas containing a precursor to the substrate mounting portion disposed at the first position; a reactant nozzle for supplying a gas containing a reactant to the substrate mounting portion disposed at the second position; and a turntable on which the plurality of susceptors are mounted so that the substrate mounting portion is horizontal and which rotates horizontally within the reaction chamber to position the substrate mounting portion at the first position and the second position, wherein the second temperature is higher than the first temperature.

[0015] In the atomic layer deposition apparatus of the first aspect of the present invention, it is preferable that the first temperature is 50 to 150°C and the second temperature is 250 to 700°C.

[0016] Preferably, the apparatus further comprises a third position for controlling the temperature of the substrate placed on the substrate placement portion to a third temperature.

[0017] More preferably, the third temperature is lower than the first temperature.

[0018] It is also preferable to provide a fourth position for exchanging the substrate placed on the substrate placement part with a substrate outside the reaction chamber.

[0019] It is also preferable that a lamp unit be provided below the second position.

[0020] It is also preferable to provide a plasma generating unit above the second position.

[0021] It is also preferable that, in the first position, the apparatus comprises a first stage adjacent to the substrate mounting portion and a temperature control mechanism that controls the first stage to a predetermined temperature, and, in the third position, a third stage adjacent to the substrate mounting portion and a temperature control mechanism that controls the third stage to a predetermined temperature.

[0022] More preferably, at the first position, a first stage gas nozzle is provided which supplies an inert gas from below the first stage between the substrate placement portion and the first stage, and at the third position, a third stage gas nozzle is provided which supplies an inert gas from below the third stage between the substrate placement portion and the third stage.

[0023] More preferably, it is desirable that the first stage and the third stage have grooves that serve as flow paths for an inert gas on their surfaces facing the substrate placement portion.

[0024] Furthermore, preferably, a plurality of C-shaped rings, each consisting of a circular ring with a portion missing and forming an overall horseshoe shape, are arranged on the rotating table concentrically with the substrate mounting portion in the first position and the second position, and it is desirable that the upper surfaces of the plurality of C-shaped rings are close to the ceiling surface of the reaction chamber.

[0025] More preferably, a center block is provided that fills the space between the multiple C-shaped rings while leaving a gap between the center block and the multiple C-shaped rings, and it is desirable that the upper surface of the center block is close to the ceiling surface of the reaction chamber.

[0026] More preferably, the rotary table is provided with an inter-position gas exhaust port outside the center block.

[0027] It is also preferable to provide a substrate peripheral gas exhaust port between the substrate placement portion and the C-ring.

[0028] An atomic layer deposition method of a second invention of the present application is an atomic layer deposition method comprising the steps of: moving a substrate from outside the reaction chamber and placing it on a substrate placement part horizontally arranged in a reaction chamber having a first position for controlling the temperature of the substrate placed on the substrate placement part to a first temperature, and a second position for controlling the temperature of the substrate placed on the substrate placement part to a second temperature; evacuating the reaction chamber while supplying a gas containing a precursor to the substrate placement part arranged at the first position and supplying a gas containing a reactant to the substrate placement part arranged at the second position; and rotating a turntable, which places the substrate placement part at the first position and the second position, in a horizontal direction within the reaction chamber, wherein the second temperature is higher than the first temperature.

[0029] In the atomic layer deposition method of the second invention of the present application, it is preferable that the first temperature is 50 to 150°C and the second temperature is 250 to 700°C.

[0030] With this configuration, it is possible to provide an atomic layer deposition apparatus and an atomic layer deposition method that can obtain a high-quality thin film. Effect of the Invention

[0031] According to the present invention, it is possible to provide an atomic layer deposition apparatus and an atomic layer deposition method that can obtain high-quality thin films when forming films by ALD. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a plan view showing a configuration of an atomic layer deposition apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a perspective view and a cross-sectional view showing a configuration of a susceptor according to a first embodiment of the present invention. [Diagram 3] FIG. 1 is a perspective view showing a configuration of a first stage according to a first embodiment of the present invention; [Figure 4] FIG. 1 is an exploded perspective view showing a configuration of a rotary table according to a first embodiment of the present invention. [Diagram 5] FIG. 1 is a perspective view showing a configuration of a rotary table according to a first embodiment of the present invention; [Figure 6] FIG. 1 is an exploded perspective view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 7] FIG. 1 is an exploded perspective view showing a configuration of a lid according to a first embodiment of the present invention. [Figure 8] FIG. 1 is an exploded perspective view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 9] FIG. 1 is a plan view showing a configuration of a reaction chamber according to a first embodiment of the present invention; [Figure 10] FIG. 1 is a cross-sectional view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 11] FIG. 1 is a cross-sectional view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 12] FIG. 1 is a cross-sectional view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 13] FIG. 1 is a plan view showing a configuration of a rotary table according to a first embodiment of the present invention; [Figure 14] FIG. 1 is a plan view showing a configuration of a reaction chamber according to a first embodiment of the present invention; [Figure 15] FIG. 1 is a perspective view and a cross-sectional view showing a configuration of a susceptor according to a first embodiment of the present invention. [Figure 16] FIG. 1 is a cross-sectional view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 17] FIG. 1 is a cross-sectional view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 18] FIG. 1 is a cross-sectional view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 19] FIG. 1 is a cross-sectional view showing a configuration of a reaction chamber according to a first embodiment of the present invention. [Figure 20] FIG. 1 is a schematic diagram showing a film-forming reaction configuration according to a first embodiment of the present invention. [Figure 21] FIG. 1 is a schematic diagram showing a film-forming reaction configuration according to a first embodiment of the present invention. [Figure 22] FIG. 13 is a perspective view and a cross-sectional view showing a configuration of a susceptor according to a second embodiment of the present invention. [Diagram 23] FIG. 13 is a perspective view and a cross-sectional view showing a configuration of a susceptor according to a third embodiment of the present invention. [Figure 24] FIG. 13 is a cross-sectional view showing the configuration of a reaction chamber according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An atomic layer deposition apparatus and an atomic layer deposition method according to embodiments of the present invention will now be described with reference to the drawings.

[0034] (Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

[0035] FIG. 1 shows the configuration of an atomic layer deposition apparatus according to a first embodiment, and is a plan view of the entire apparatus including a transfer system.

[0036] To make the following explanation easier to understand, each figure includes a diagram showing the x, y, and z axis directions. In Figure 1, the x axis runs from left to right, the y axis runs from bottom to top, and the z axis runs from the back of the page to the front.

[0037] In FIG. 1, the spare chambers 1 and 2 and the reaction chambers 3 and 4 are connected to the robot chamber 6 via a gate 5. The robot chamber 6 is equipped with a robot 7, and transports substrates between the spare chambers 1 or 2 and the reaction chambers 3 or 4. The spare chambers 1 and 2 may be used as load lock chambers, and the reaction chambers 3 and 4 and the robot chamber 6 may be operated in a vacuum state at all times, or the spare chambers 1 and 2 and the robot chamber 6 may be always in an atmospheric state, and the reaction chambers 3 and 4 may be in an atmospheric state to load and unload substrates, and then the film may be formed in a vacuum state. Note that "vacuum" refers to a reduced pressure state, meaning a pressure lower than atmospheric pressure. The robot chamber 6 may also be equipped with a function for aligning the substrate.

[0038] 2A and 2B are a perspective view and a cross-sectional view showing a configuration of a susceptor according to the first embodiment of the present invention, in which a substrate is not placed on the susceptor. Fig. 2B is a cross-sectional view of Fig. 2A cut along a plane parallel to the yz plane including the center of the susceptor.

[0039] 2, susceptor 8 has a shape similar to that of the substrate (circular) as a whole, and includes a circular countersunk portion 9 as a substrate mounting portion. In addition, slits 10 are provided at three locations around countersunk portion 9 as substrate peripheral gas exhaust ports, and pin holes 11 are provided at three locations near the edge of countersunk portion 9 for passing lift pins therethrough during substrate transport. The slits 10 and pin holes 11 are all equally spaced in the circumferential direction. The material of susceptor 8 is preferably one that has excellent heat resistance, high thermal conductivity, and is resistant to deformation and deterioration, and silicon carbide or the like can be used.

[0040] Fig. 3 is a perspective view showing the configuration of the first stage in the first embodiment of the present invention. In Fig. 3, the first stage 12 is composed of a cylindrical protrusion 13 as a whole and a bottom portion 14 made of a cylinder with a diameter larger than that of the protrusion 13. The outer periphery of the upper surface of the protrusion 13 is cut out in three places to form step portions 15. The three step portions 15 are equally spaced in the circumferential direction. The upper surface of the protrusion 13 is provided with a groove 16 that serves as a flow path for the inert gas. A first stage gas nozzle 17 that supplies the inert gas from below is provided in the center of the first stage 12.

[0041] Fig. 4 is an exploded perspective view showing the configuration of the turntable in the first embodiment of the present invention, and Fig. 5 is a perspective view showing the configuration of the turntable in the first embodiment of the present invention, showing the state after the turntable in Fig. 4 is assembled.

[0042] 4 and 5, the rotating table 18 is provided with a shaft 19 as a rotating shaft, three susceptor holders 20 (through holes) for mounting three susceptors 8, and three inter-position gas exhaust ports 21. The three inter-position gas exhaust ports 21 are disposed at intermediate positions between two of the three susceptor holders 20. Three C-shaped rings 22, each of which is a circular ring with a missing part and has an overall horseshoe shape, are disposed concentrically with the susceptor holder 20 on the rotating table 18. The missing part of the C-shaped ring 22 is disposed so as to face the outside of the rotating table 18. A center block 23 is provided to fill the space between the three C-shaped rings while leaving a gap between two of the three C-shaped rings. The inter-position gas exhaust ports 21 are disposed on the rotating table 18 outside the center block 23.

[0043] FIG. 6 is an exploded perspective view showing the configuration of the reaction chamber in the first embodiment of the present invention. In FIG. 6, three substrates 24 are mounted on each of the countersunk portions on the three susceptors 8, i.e., three substrates 24 in total. The three susceptors 8 are fitted into three susceptor holders 20. That is, the three C-shaped rings 22 are arranged on the rotary table 18 concentrically with the countersunk portions as substrate placement portions at the first position, the second position, and the third position. The reaction chamber 3 has a rectangular parallelepiped outer shape, but has a cylindrical internal space. The shaft 19 is inserted into a shaft hole 26 provided in a bottom surface 25 of the reaction chamber 3. The bottom surface 25 of the reaction chamber 3 has a first position bottom hole 27, a second position bottom hole 28, and a third position bottom hole 29 equally arranged in the circumferential direction. The convex portion of the first stage 12 is inserted into the first position bottom hole 27 from below, and the convex portion of the third stage 30 is inserted into the third position bottom hole 29 from below. The third stage 30 has the same configuration as the first stage 12. A quartz glass window 31 is fitted into the second position bottom hole 28 from below. The bottom surface 25 of the reaction chamber 3 is further provided with three pin holes 32 for passing lift pins, and three lift pins 34 fixed to a lift pin holder 33 are inserted into the pin holes. In addition, three gas exhaust ports 35 are provided in the bottom surface 25 of the reaction chamber 3 at intermediate positions between two of the first position bottom hole 27, the second position bottom hole 28, and the third position bottom hole 29. A gate opening 36 for replacing the substrate 24 is provided on the side surface of the reaction chamber 3.

[0044] Fig. 7 is an exploded perspective view showing the configuration of the lid in the first embodiment of the present invention. In Fig. 7, a coil 39 is wound around a quartz tube 38 having a gas inlet 37 at the top, forming a plasma generating unit located above the second position. The bottom of the quartz tube 38 is fitted into an opening 41 provided in a position corresponding to directly above the second position of the lid 40. A gas inlet hole 42 is provided in a position corresponding to directly above the first position of the lid 40, and a gas inlet hole 43 is provided in a position corresponding to directly above the third position. Two shower plates 45 provided with a large number of shower holes 44 are fitted from below.

[0045] 8 is an exploded perspective view showing the configuration of the reaction chamber in the first embodiment of the present invention. A lid 40 into which a quartz tube 38 is fitted is fitted onto the reaction chamber 3.

[0046] 9 is a plan view showing the configuration of the reaction chamber in the first embodiment of the present invention, and is a view of reaction chamber 3 seen from above. However, for simplicity, only main components are shown.

[0047] FIG. 10 is a cross-sectional view showing the configuration of the reaction chamber in the first embodiment of the present invention, and shows a cross section taken along line AA perpendicular to the xy plane, passing through the center of the first position in FIG. 9, as viewed in the direction of arrow a.

[0048] In FIG. 10, a substrate 24 is placed on a countersunk portion 9 as a substrate placement portion on a horizontally disposed susceptor 8. In this figure, the substrate 24 is located at the first position. In the reaction chamber 3, a slit 10 as a substrate peripheral gas exhaust port is provided between the countersunk portion 9 and the C-shaped ring 22, and a pin hole 11 for passing a lift pin during substrate transfer is provided near the edge of the countersunk portion 9. The first stage 12 adjacent to the countersunk portion 9 is composed of a convex portion 13 and a bottom portion 14 having a larger diameter than the convex portion 13. The outer periphery of the upper surface of the convex portion 13 is cut out to form a step portion 15. A first stage gas nozzle 17 for supplying an inert gas from below is provided in the center of the first stage 12. The rotating table 18 is provided with a shaft 19 as a rotating axis and an inter-position gas exhaust port 21. The C-shaped ring 22 is placed on the rotating table 18, and its upper surface is adjacent to the ceiling surface of the reaction chamber 3. A center block 23 is provided with a gap 47 between it and the C-shaped ring 22, and its upper surface is close to the ceiling surface of the reaction chamber 3. The shaft 19 is inserted into a shaft hole 26 provided in the bottom surface 25 of the reaction chamber 3. A gas exhaust port 35 is provided in the bottom surface 25 of the reaction chamber 3.

[0049] A gas introduction hole 42 is provided in the lid 40, and a shower plate 45 provided with a number of shower holes 44 as precursor nozzles is fitted from below to form a gas supply manifold 46 containing the precursor. In order to prevent the precursor from liquefying, it is preferable to heat the parts that come into contact with the gas containing the precursor, and the lid 40 and the shower plate 45 may be provided with a temperature control mechanism (fluid flow path, resistance heater, etc.). In this case, it is preferable to control the temperature of the lid 40 and the shower plate 45 to about 40 to 150°C, typically 80°C.

[0050] A coolant flow path 48 is provided around the susceptor holder 20 (the through hole in which the susceptor 8 is fitted) of the rotating table 18. A coolant is supplied to the coolant flow path 48 through a coolant introduction pipe 49. For the purpose of controlling the temperature of the substrate 24 to a first temperature, a temperature control mechanism 50 that controls the first stage 12 to a predetermined temperature is provided inside the protrusion 13 of the first stage 12. The temperature control mechanism 50 may be a fluid flow path or a resistance heater.

[0051] FIG. 11 is a cross-sectional view showing the configuration of the reaction chamber in the first embodiment of the present invention, and shows a cross section taken along line BB in FIG. 9, which is perpendicular to the xy plane and passes through the center of the second position, as viewed in the direction of arrow b.

[0052] In FIG. 11, a substrate 24 is placed on a countersunk portion 9 as a substrate placement portion on a susceptor 8. In this figure, the substrate 24 is located at the second position. In the reaction chamber 3, a slit 10 is provided between the countersunk portion 9 and the C-shaped ring 22 as a substrate peripheral gas exhaust port, and a pin hole 11 is provided near the edge of the countersunk portion 9 for passing a lift pin during substrate transport. The rotating table 18 is provided with a shaft 19 as a rotating shaft and an inter-position gas exhaust port 21. The C-shaped ring 22 is placed on the rotating table 18, and its upper surface is close to the ceiling surface of the reaction chamber 3. A center block 23 is provided with a gap 47 between it and the C-shaped ring 22, and its upper surface is close to the ceiling surface of the reaction chamber 3. The shaft 19 is inserted into a shaft hole 26 provided in the bottom surface 25 of the reaction chamber 3. A gas exhaust port 35 is provided in the bottom surface 25 of the reaction chamber 3. A coolant flow path 48 is provided around the susceptor holder 20 of the rotary table 18 (the through hole in which the susceptor 8 is fitted).

[0053] A plasma generating unit consisting of a quartz tube 38 having a gas inlet 37 as a reactant nozzle at the top and a coil 39 wound around the quartz tube 38 is provided on the cover 40. The plasma generating unit is surrounded by a shield 51 to suppress the generation of electromagnetic noise.

[0054] A quartz glass window 31 is fitted from below the reaction chamber 3, and a lamp unit consisting of a lamp 52 and a reflector 53 is provided below the window. A reflector ring 54 equipped with a cooling mechanism such as a coolant passage is provided to efficiently irradiate the light from the lamp 52 to the back surface of the susceptor 8 and reduce the light irradiated to the rotary table 18. The reflector ring 54 may be provided with a through hole (not shown) so that gas can be quickly exhausted. Here, the method of controlling the temperature of the substrate is exemplified by using the lamp 52, but other methods such as a resistance heater may be used. A pin hole 32 for passing a lift pin is provided on the bottom surface 25 of the reaction chamber 3, and a lift pin 34 fixed to a lift pin holder 33 is inserted into the pin hole. The lift pin holder 33 is fixed to a bellows 55 so as to be able to rise and fall, and is stored in a case 56. A gate opening 36 for replacing the substrate 24 is provided on the side of the reaction chamber 3.

[0055] FIG. 12 is a cross-sectional view showing the configuration of the reaction chamber in the first embodiment of the present invention, and shows a CC cross section perpendicular to the xy plane that passes through the center of the third position in FIG. 9, as viewed in the direction of the arrow c.

[0056] In FIG. 12, a substrate 24 is placed on a countersunk portion 9 as a substrate placement portion on a susceptor 8. In this figure, the substrate 24 is located at the third position. In the reaction chamber 3, a slit 10 is provided between the countersunk portion 9 and the C-shaped ring 22 as a substrate peripheral gas exhaust port, and a pin hole 11 is provided near the edge of the countersunk portion 9 for passing a lift pin during substrate transport. The third stage 30 adjacent to the countersunk portion 9 is composed of a convex portion 13 and a bottom portion 14 having a larger diameter than the convex portion 13. The outer periphery of the upper surface of the convex portion 13 is cut out to form a step portion 15. A third stage gas nozzle 57 for supplying an inert gas from below is provided in the center of the third stage 30. The rotating table 18 is provided with a shaft 19 as a rotating shaft and an inter-position gas exhaust port 21. The C-shaped ring 22 is placed on the rotating table 18, and its upper surface is adjacent to the ceiling surface of the reaction chamber 3. A center block 23 is provided with a gap 47 between it and the C-shaped ring 22, and its upper surface is close to the ceiling surface of the reaction chamber 3. The shaft 19 is inserted into a shaft hole 26 provided in the bottom surface 25 of the reaction chamber 3. A gas exhaust port 35 is provided in the bottom surface 25 of the reaction chamber 3.

[0057] A gas introduction hole 43 is provided in the lid 40, and a shower plate 45 having a large number of shower holes 44 as purge nozzles is fitted in from below, forming a purge gas supply manifold 58.

[0058] A coolant flow path 48 is provided around the susceptor holder 20 (the through hole in which the susceptor 8 is fitted) of the turntable 18. The coolant supplied to the coolant flow path 48 is discharged through a coolant discharge pipe 59. For the purpose of controlling the temperature of the substrate 24 to a third temperature, a temperature control mechanism 60 that controls the third stage 30 to a predetermined temperature is provided inside the protrusion 13 of the third stage 30. The temperature control mechanism 60 may be a fluid flow path or a resistance heater.

[0059] FIG. 13 is a plan view showing the configuration of the turntable in the first embodiment of the present invention, and shows the DD cross section (horizontal plane) in FIG. 10. In FIG. 13, the turntable 18 is provided with three susceptor holders 20 (through holes) for mounting three susceptors 8, and three inter-position gas exhaust ports 21. A coolant flow path 48 is provided around the three susceptor holders 20. A coolant is supplied to the coolant flow path 48 through a coolant introduction pipe 49 and is discharged through a coolant discharge pipe 59. The turntable 18 is cooled in this manner in order to prevent deformation due to heat. As will be apparent from the description below, the substrate 24 and the susceptor 8 are the hottest in the reaction chamber 3, so that deformation of the turntable 18 can be effectively suppressed by cooling the periphery of the susceptor holder 20.

[0060] Fig. 14 is a plan view showing the configuration of the reaction chamber in the first embodiment of the present invention, and is a view of the reaction chamber 3 as seen from above. However, for simplicity, only the main components are shown. In Fig. 14, unlike Fig. 9, no susceptor holder is located at any of the positions corresponding to the first, second, and third positions, and only one susceptor holder is located at the fourth position. In other words, Fig. 9 shows a state in which the turntable 18 is rotated 60 degrees.

[0061] 15A and 15B are a perspective view and a cross-sectional view showing a configuration of a susceptor according to the first embodiment of the present invention, in which a substrate is not placed on the susceptor, and Fig. 15B is a cross-sectional view of Fig. 15A cut along a plane parallel to the yz plane including the center of the susceptor.

[0062] In FIG. 15, the susceptor 8 has a shape similar to that of the substrate (circular) as a whole, and includes a circular countersunk portion 9 as a substrate placement portion. In addition, slits 10 are provided at four locations around the countersunk portion 9 as substrate peripheral gas exhaust ports, and pin holes 11 are provided at four locations near the edge of the countersunk portion 9 for passing lift pins during substrate transfer. The slits 10 and pin holes 11 are all equally spaced in the circumferential direction. The susceptor 8 shown in FIG. 15 is an example in which the number and arrangement of the slits 10 and pin holes 11 are different from the susceptor 8 shown in FIG. 2. When such a susceptor 8 is used, the arrangement of the step portions 15 provided in the first stage and the third stage must also be changed to match the arrangement of the slits 10. That is, four step portions 15 are provided, and the slits 10 and the step portions 15 are arranged at the same positions vertically.

[0063] Figures 16 to 19 are cross-sectional views showing the configuration of the reaction chamber in the first embodiment of the present invention, and are views of an E-E cross section perpendicular to the xy plane passing through the center of the fourth position in Figure 14, as viewed in the direction of arrow e. Figures 16 to 19 are used to explain the procedure for substrate replacement, and will be described in detail later.

[0064] 20 and 21 are conceptual diagrams showing the configuration of a film-forming reaction in the first embodiment of the present invention, and will be described in detail later.

[0065] For simplicity, the operation will be described assuming that the spare chambers 1 and 2 are load lock chambers, and the reaction chambers 3 and 4 and the robot chamber 6 are always operated in a vacuum state. With the gate 5 between the spare chamber 1 or 2 and the robot chamber 6 open, the robot 7 takes out the substrate 24 from the spare chamber 1 or 2, and with the gate 5 between the robot chamber 6 and the reaction chamber 3 open, the substrate 24 is placed on the countersunk portion 9 in the reaction chamber 3 through the gate opening 36. That is, the substrate 24 is moved from outside the reaction chamber 3 and placed on the countersunk portion 9 as a substrate placement portion provided in the reaction chamber 3. At this time, the rotation of the turntable 18 is stopped, and one of the three susceptors 8 is positioned at the fourth position. Here, the turntable 18 is a mechanism that mounts a plurality of susceptors 8 so that the countersunk portion 9 is horizontal, and rotates horizontally in the reaction chamber 3 to place the countersunk portion 9 at the first position, the second position, the third position, and the fourth position.

[0066] Here, the procedure of substrate exchange will be described. For ease of explanation, an example will be used in which a susceptor 8 shown in FIG. 15 is used, in which slits 10 are provided as substrate peripheral gas exhaust ports at four locations around the countersunk portion 9, and pin holes 11 for passing lift pins during substrate transfer are provided at four locations near the edge of the countersunk portion 9. In FIG. 16, a substrate 24 on which film formation has been completed is placed on the countersunk portion 9 on the susceptor 8. At this time, the substrate 24 is located at a fourth position for exchanging the substrate 24 placed on the countersunk portion 9 with the substrate 24 outside the reaction chamber 3. The fourth position is the position closest to the gate opening 36. Next, as shown in FIG. 17, when the lift pin holder 33 is raised, the lift pin 32 penetrates the pin hole 11 and lifts the substrate 24 upward. Next, as shown in FIG. 18, the robot 7 is inserted from the robot chamber 6 into the reaction chamber 3 through the gate opening 36, and the tip of the robot 7 is moved below the substrate 24. At this time, since the missing portion of the circle of the C-shaped ring 22 is arranged to face the outside of the turntable 18, there is no risk of interference between the robot 7 and the C-shaped ring 22. Next, as shown in Fig. 19, the lift pin holder 33 is lowered to place the substrate 24 on the tip of the robot 7. Thereafter, the robot 7 is returned to the robot chamber 6 to remove the substrate 24 from the reaction chamber 3. When the substrate 24 is to be transported into the reaction chamber 3, the above steps are reversed.

[0067] Next, the turntable 18 is rotated, and the substrate 24 is placed on the adjacent countersunk portion 9. By repeating this operation, the substrate 24 is placed on all the countersunk portions 9 in the reaction chamber 3. The substrate exchange operation of removing the substrate 24 on which the film formation process has already been completed from the countersunk portion 9 and placing the substrate 24 on which the film formation process has already been completed on the countersunk portion 9 may be performed consecutively for each countersunk portion 9, or after removing all the substrates 24 on which the film formation process has already been completed from the countersunk portions 9 in the reaction chamber 3, the substrates 24 on which the film formation process has not yet been completed may be sequentially placed on the countersunk portions 9. During the exchange or placement operation of the substrate 24, a small amount of purge gas or inert gas is supplied from all the gas nozzles into the reaction chamber 3 so that the reaction chamber 3 is at a positive pressure relative to the robot chamber 6. This can minimize the concentration of unnecessary gas that may be mixed into the reaction chamber 3 from the robot chamber 6 by opening the gate 5.

[0068] Once the substrates 24 have been placed on all of the countersunk portions 9 within the reaction chamber 3, the gate 5 is closed and a small amount of purge gas or inert gas is supplied from all of the gas nozzles into the reaction chamber 3 for a few seconds. This makes it possible to reduce the concentration of unnecessary gas that may be mixed into the reaction chamber 3 from the robot chamber 6 due to the opening of the gate 5. Note that the purge gas or inert gas may be a rare gas such as Ar or nitrogen gas (N 2 ) can be used.

[0069] Next, the step of rotating the turntable 18 and the step of supplying various gases and operating the lamp unit and the plasma generating unit are repeated to perform the atomic layer deposition process. Hereinafter, the process flow will be described focusing on one substrate 24.

[0070] First, the substrate 24 is sent to the first position (FIG. 10). The first stage 12 is disposed directly below the position of the substrate 24 in the first position, and the protruding portion 13 of the first stage is provided with a temperature control mechanism 50 inside. The temperature of the protruding portion 13 is controlled to a temperature suitable for controlling the temperature of the substrate 24 to 50 to 150°C (particularly, 100 to 150°C when TMA is used as a precursor). Although it varies depending on the process conditions and the materials of various components constituting the apparatus, the temperature of the protruding portion 13 may be controlled to a temperature of about ±10°C with respect to the target temperature of the substrate 24. When an inert gas is supplied from the first stage gas nozzle 17 to the rear surface of the susceptor 8, the inert gas quickly spreads over the entire rear surface of the susceptor 8 through the groove 16, which is a flow path for the inert gas and is provided on the surface facing the countersunk portion 9 of the protruding portion 13, and heat transfer occurs between the rear surface of the susceptor 8 and the upper surface of the protruding portion 13, and the temperature of the substrate 24 can be stabilized at 50 to 150°C. Inert gases include rare gases such as Ar and nitrogen gas (N 2) can be used, but by using He, which has a large thermal conductivity, the temperature difference between the susceptor 8 and the protrusion 13 can be quickly minimized. Most of this inert gas is exhausted from the gas exhaust port 35 without reaching above the rotary table 18. A vacuum pump (not shown) is connected to the rear of the gas exhaust port 35. A purge gas may be simultaneously supplied from the gas introduction hole 42 so that the substrate 24 does not jump or vibrate due to the supply of inert gas from below. In order to ensure the heat transfer between the susceptor 8 and the protrusion 13, it is desirable to set the pressure in the reaction chamber 3 to 100 to 1000 Pa. If the pressure in the reaction chamber 3 is less than 100 Pa, the heat transfer between the susceptor 8 and the protrusion 13 becomes insufficient, and conversely, if the pressure exceeds 1000 Pa, it takes time to adjust the pressure to perform the precursor adsorption process performed at several hundred Pa.

[0071] When the gas containing the precursor is supplied from the gas introduction hole 42, the gas supply manifold 46 containing the precursor is quickly filled with the gas containing the precursor, and the gas containing the precursor is supplied in a shower toward the substrate 24 placed on the countersunk portion arranged at the first position. A part of the precursor reacts with the surface of the substrate 24, but the remaining gas flows from the slit 10 to the lower side of the rotary table 18, passes through the step portion 15, and is exhausted from the gas exhaust port 35. Since the slit 10 and the step portion 15 are arranged at the same position above and below, unnecessary gas is quickly exhausted. The C-shaped ring 22 and the center block 23 effectively prevent the gas containing the precursor from being mixed into the second position, the third position, and the fourth position. The gas containing the precursor that has flowed over the C-shaped ring 22 and flowed out of the first position slightly passes through the gap 47 between the C-shaped ring 22 and the center block 23 and is exhausted from the inter-position gas exhaust port 21 (the inter-position gas exhaust port 21 in FIG. 11 and the inter-position gas exhaust port 21 in FIG. 12).

[0072] The precursor can be selected appropriately according to the type of film to be formed. For example, AlN or Al 2 O 3 When forming a film, use TMA (trimethylaluminum), ZrO 2When forming a film, use TEMAZ (tetrakisethylmethylaminozirconium), TiO 2 When forming a film of methylcyclopentadienyl tris(dimethylamino)titanium, SiO 2 When forming a film of, 3DMAS (trisdimethylaminosilane) can be used. The precursor is supplied using a bubbler, vaporizer, ultrasonic vibration, injection, etc., and the supply amount is adjusted according to the process so as to be about 3 to 30 mg / time, typically 10 mg / time. Since it is difficult to supply the precursor alone to the reaction chamber 3, it is usually diluted with an inert gas such as a rare gas. Typically, it is diluted with Ar gas, and the flow rate of the dilution gas is about 10 to 1000 sccm (standard cubic centimeters per minute), typically 100 sccm. In addition, it is preferable to heat the dilution gas to prevent the precursor from liquefying. The temperature of the dilution gas is about 40 to 150°C, typically 80°C. When the substrate 24 is exposed to a gas containing the precursor, the precursor molecules are adsorbed on the surface of the substrate 24. The reaction is self-limiting, and the adsorption reaction ends when there are no more sites available for adsorption on the surface of the substrate 24. That is, a state is obtained in which precursor molecules of one atomic layer are adsorbed almost uniformly on the surface of the substrate 24. Figure 20(a) shows a schematic diagram of the reaction when TMA is used on a GaN substrate.

[0073] Next, when purge gas is supplied from gas inlet hole 42, gas supply manifold 46 containing the precursor is quickly filled with purge gas, and the purge gas is supplied in a shower toward substrate 24 placed on the countersunk portion arranged at the first position. At the same time, precursors remaining in the vicinity of the first position are exhausted from reaction chamber 3. The flow rate of the purge gas used at this time is about 10 to 1000 sccm, typically 100 sccm. This reaction is shown diagrammatically in FIG. 20(b).

[0074] Next, the turntable 18 is rotated 120 degrees in the horizontal direction, and the substrate 24 is moved to the second position (FIG. 11). When the turntable 18 is rotated, a small amount of purge gas or inert gas is supplied into the reaction chamber 3 from all the gas nozzles. A quartz glass window 31 is disposed directly below the position of the substrate 24 in the second position, and the susceptor 8 and the substrate 24 are heated by a lamp 52 disposed below the quartz glass window 31. By monitoring the temperature of the susceptor 8 or the substrate 24 with a radiation thermometer (not shown) or the like, the temperature of the substrate 24 can be controlled to 250 to 700° C. (500 to 700° C., particularly when a nitride film is formed using TMA).

[0075] When gas containing reactants is supplied from the gas inlet 37 in the direction of the arrow, the gas containing reactants is supplied toward the substrate 24 placed on the countersunk portion arranged at the second position. At this time, by supplying high-frequency power to the coil 39, an inductively coupled plasma is generated in the quartz tube 38 and diffuses near the second position. Some of the reactants and ions and radicals generated by ionization react with the surface of the substrate 24, but the remaining gas flows from the slit 10 to the bottom of the rotary table 18 and is exhausted from the gas exhaust port 35. The C-shaped ring 22 and the center block 23 effectively prevent the gas containing reactants from mixing into the first position, the third position, and the fourth position. The gas containing reactants that has flowed over the C-shaped ring 22 and flowed out of the first position in a small amount passes through the gap 47 between the C-shaped ring 22 and the center block 23 and is exhausted from the inter-position gas exhaust port 21 (the inter-position gas exhaust port 21 in FIG. 10 and the inter-position gas exhaust port 21 in FIG. 12).

[0076] The reactant can be selected appropriately. When forming an oxide film, H 2 O, H 2 O 2 , ozone, etc. can be used. When forming a nitride film, a nitriding agent such as NH 3 Alternatively, NH 3 , H 2 , N 2If the reactant is a substance that is liquid at room temperature, it can be supplied using a bubbler, vaporizer, ultrasonic vibration, injection, etc., just like the precursor. For example, NH 3 When using a reactant, the supply amount is adjusted according to the process so as to be about 1 to 100 mg / time, typically 10 mg / time. The reactant may be diluted with an inert gas such as a rare gas. Typically, it is diluted with Ar gas, and the flow rate of the dilution gas is about 10 to 1000 sccm, typically 100 sccm. The reactant is further activated by the plasma, and the reaction with the substrate 24 is promoted. A thin film of about one atomic layer is formed on the surface of the substrate 24 by the reaction between the precursor adsorbed on the surface of the substrate 24 and the reactant. For example, TMA as the precursor and NH 3 When using NH 3 reacts with the methyl group of the precursor to produce the by-product methane (CH 4 ) is generated, and methane is discharged from the gas exhaust port 35 to the outside of the reaction chamber 3, while AlN remains on the surface of the substrate 24 to form a thin film. 3 , H 2 , N 2 The reaction when using the above gas mixture is shown in Fig. 20(c). Here, the N atom on the outermost surface is terminated by two H atoms. In other words, the surface is terminated with amino groups.

[0077] Next, when purge gas is supplied from gas inlet 37, the purge gas is supplied toward substrate 24 placed on the countersunk portion arranged at the second position. At the same time, reactants remaining in the vicinity of the second position are exhausted from reaction chamber 3. This reaction is shown diagrammatically in FIG. 20(d).

[0078] Next, the turntable 18 is rotated 120 degrees horizontally to move the substrate 24 to the third position (FIG. 12). The third stage 30 is disposed directly below the position of the substrate 24 in the third position, and the convex portion 13 of the third stage has a temperature control mechanism 60 disposed therein. The temperature of the convex portion 13 is controlled to a temperature suitable for controlling the temperature of the substrate 24 to a temperature (e.g., 80° C.) lower than the target substrate temperature in the first position. Although this varies depending on the process conditions and the materials of the various components constituting the apparatus, it is sufficient to control the temperature of the convex portion 13 to a temperature within about ±10° C. of the target temperature of the substrate 24. When an inert gas is supplied to the back surface of the susceptor 8 from the third stage gas nozzle 57, the inert gas quickly spreads over the entire back surface of the susceptor 8 via the grooves 16 that serve as inert gas flow paths provided on the surface of the protrusion 13 facing the countersunk portion 9, and heat transfer occurs between the back surface of the susceptor 8 and the upper surface of the protrusion 13, making it possible to stabilize the temperature of the substrate 24 at, for example, 80° C. As the inert gas, a rare gas such as Ar or nitrogen gas (N 2 ) can be used, but by using He, which has a large thermal conductivity, the temperature difference between the susceptor 8 and the protrusion 13 can be quickly minimized. Most of this inert gas is exhausted from the gas exhaust port 35 without reaching above the rotary table 18. A vacuum pump (not shown) is connected to the rear of the gas exhaust port 35. A purge gas may be simultaneously supplied from the gas introduction hole 43 so that the substrate 24 does not jump or vibrate due to the supply of inert gas from below. In order to ensure the heat transfer between the susceptor 8 and the protrusion 13, it is desirable to set the pressure in the reaction chamber 3 to 100 to 1000 Pa. If the pressure in the reaction chamber 3 is less than 100 Pa, the heat transfer between the susceptor 8 and the protrusion 13 becomes insufficient, and conversely, if the pressure exceeds 1000 Pa, it takes time to adjust the pressure to perform the precursor adsorption process performed at several hundred Pa.

[0079] When purge gas is supplied from the gas inlet hole 43, the purge gas supply manifold 58 is quickly filled with the purge gas, and the purge gas is supplied in a shower toward the substrate 24 placed on the countersunk portion arranged at the third position. The supply of the purge gas is effective in expelling gas containing a small amount of reactant remaining near the third position from the reaction chamber 3. The gas flows from the slit 10 to the bottom of the turntable 18, passes through the step portion 15, and is exhausted from the gas exhaust port 35. Since the slit 10 and the step portion 15 are arranged at the same position vertically, the gas is quickly exhausted. The C-shaped ring 22 and the center block 23 effectively prevent the purge gas from mixing into the first position, the second position, and the fourth position. The small amount of purge gas that escapes from the third position after climbing over the C-ring 22 passes through the gap 47 between the C-ring 22 and the center block 23 and is discharged from the inter-position gas exhaust port 21 (inter-position gas exhaust port 21 in Figure 10 and inter-position gas exhaust port 21 in Figure 11).

[0080] Next, the turntable 18 is rotated 120 degrees in the horizontal direction, and the substrate 24 is moved to the first position again (FIG. 10). Thereafter, the precursor adsorption step and the reactant reaction step described above are repeatedly performed to obtain a thin film with a predetermined thickness. FIGS. 20(e)-(h) are schematic diagrams showing the film formation reaction of the second layer. In the present embodiment, while the substrate 24 is being film-formed once (while a thin film of approximately one atomic layer is formed), while the substrate 24 rotates once in the circumferential direction, each substrate 24 is exposed to various gases in the order of precursor-containing gas, purge gas, reactant-containing gas, purge gas, and purge gas only once. In order to prevent the gases from mixing as much as possible above the turntable 18, the amount of gas supplied to each position is set to be equal, so that a pressure difference between adjacent positions is unlikely to occur. Alternatively, the amount of purge gas may be set to be slightly greater than the amount of precursor-containing gas or reactant-containing gas. In this way, mixing of the precursor and reactant within the space containing each position can be effectively prevented.

[0081] In this manner, by rotating the turntable 18, a thin film of approximately one atomic layer is formed on the surface of each substrate 24. In order to repeatedly carry out this series of steps, the turntable 18 is rotated many times within the reaction chamber 3, thereby obtaining a thin film of a predetermined thickness. Here, the expression "approximately one atomic layer" is used, but since the thickness of the thin film formed in one cycle is approximately 1 to 2 angstroms when converted into a film thickness, for example, to form a thin film of 20 nm, 100 to 200 cycles of the process are required, and therefore, in this embodiment, the turntable 18 is rotated 100 to 200 times within the reaction chamber 3.

[0082] After the deposition of a film having a predetermined thickness has been completed, the substrate 24 is removed from the counterbored portion 9 through the gate opening 36 and out of the reaction chamber 3, in the opposite manner to the substrate placement step, and is stored in the spare chamber 1 or 2 by the robot 7. In this embodiment, two reaction chambers 3 and 4 are provided, and while deposition is being performed in one reaction chamber, substrate exchange can be performed in the other reaction chamber. In this manner, by simultaneously performing the processes of loading and unloading and deposition, which are all time-consuming, for a plurality of reaction chambers, an atomic layer deposition apparatus and method having high processing speed and high area productivity can be realized.

[0083] In atomic layer deposition, in order to avoid a gas phase reaction, it is necessary to suppress the mixing of the precursor and the reactant in the gas phase as much as possible. Therefore, it is desirable to always supply a purge gas at the third position when a gas containing a precursor or a gas containing a reactant is supplied. It is also desirable to always supply a purge gas or a gas containing a reactant at the second position when a gas containing a precursor is supplied at the first position. It is also desirable to always supply a purge gas or a gas containing a precursor at the first position when a gas containing a reactant is supplied at the second position. In other words, it is not desirable to supply a gas containing a precursor at the first position when a gas is not supplied at the second and third positions, and it is not desirable to supply a gas containing a reactant at the second position when a gas is not supplied at the first and third positions.

[0084] In this embodiment, a high quality thin film can be obtained compared to the conventional techniques, for example, the atomic layer deposition techniques described in Patent Documents 1 to 4. In the step of reacting the reactant with the substrate, the substrate temperature needs to be raised to a predetermined temperature, but in the conventional techniques, the step of reacting the precursor with the substrate is also performed at a high temperature. This is thought to result in carbon generated by decomposition of the precursor being incorporated into the film, deteriorating the film quality. Figure 21 shows a schematic diagram of the progress of the reaction at this time. In Figure 21(a), if the substrate temperature is higher than 150°C, decomposition of TMA may occur in the gas phase. The decomposition of TMA produces CH 3 , C.H. 2Radicals such as , etc. are generated, and some of the carbon atoms are incorporated into the adsorption layer. In FIG. 21(b), even when the gas is replaced with a purge gas, carbon atoms remain in the film. In FIG. 21(c), when the substrate is exposed to a gas containing a reactant, the surface of the substrate is terminated with amino groups. In FIG. 21(d), the gas is replaced again with a purge gas. FIGS. 21(e)-(h) are schematic diagrams showing the state of the film formation reaction of the second layer, and in FIG. 21(e), when the substrate is exposed again to a gas containing a precursor, some of the carbon atoms are incorporated into the adsorption layer. In this way, if the precursor adsorption step is performed with the substrate temperature higher than 150° C., unnecessary carbon is incorporated into the film, and it is presumed that the film characteristics are deteriorated. On the other hand, in the present embodiment, in the step of supplying a gas containing a precursor, decomposition of TMA does not occur in the gas phase, so that a high-quality thin film containing almost no carbon in the film can be obtained, as described with reference to FIG. 20. In the step of supplying a gas containing a precursor, the substrate temperature is preferably 50° C. or higher. If the substrate temperature is lower than 50°C, migration of the precursor on the substrate becomes difficult, making it difficult to obtain a well-ordered adsorption layer. Since the decomposition temperature differs depending on the type of precursor corresponding to the type of film to be formed (oxide film, nitride film, etc.), it is preferable to control the temperature to an appropriate level.

[0085] Generally, a dense and high-quality thin film can be obtained by increasing the substrate temperature in the step of exposing to a gas containing a reactant. Therefore, the second temperature in the step of exposing to a gas containing a reactant is preferably higher than the first temperature in the step of exposing to a gas containing a precursor. When forming an AlN thin film using TMA, the second temperature is preferably 250°C or higher. Since increasing the substrate temperature to more than 700°C would be difficult in terms of the configuration of the device, such as restricting the material of parts to avoid deformation and deterioration, the substrate temperature is preferably 250 to 700°C.

[0086] In this embodiment, unlike the conventional technology, for example, the film forming apparatus described in Patent Document 1, an inert gas is supplied to the back surface of the substrate 24 at the first position, so that the precursor is less likely to be adsorbed to the back surface of the substrate 24, and as a result, a thin film is not formed. Therefore, there is an advantage that there is no need to add a process of etching the back surface.

[0087] In this embodiment, the countersunk portion 9 and the convex portion 13 of the first or third stage are close to each other. This allows effective heat transfer between the countersunk portion 9 and the convex portion 13 of the first or third stage. To obtain such an effect, the distance between the countersunk portion 9 and the convex portion 13 of the first or third stage should be 0.5 mm or more and 2 mm or less. If the distance between the countersunk portion 9 and the convex portion 13 of the first or third stage is less than 0.5 mm, there is a risk that the countersunk portion 9 and the convex portion 13 of the first or third stage may come into contact with each other when the rotation accuracy is reduced due to aging of the device or the like. Conversely, if the distance between the countersunk portion 9 and the convex portion 13 of the first or third stage is greater than 2 mm, the efficiency of heat transfer is extremely deteriorated.

[0088] In this embodiment, the C-shaped ring 22 and the center block 23 are disposed on the rotating table 18, and the upper surfaces of the C-shaped ring 22 and the center block 23 are close to the ceiling surface of the reaction chamber 3. This effectively prevents gas from mixing between adjacent positions. A small amount of gas containing precursors that has flowed over the C-shaped ring 22 and flowed out of the first position passes through the gap 47 between the C-shaped ring 22 and the center block 23 and is discharged from the inter-position gas discharge port 21. In order to obtain such an effect, the distance between the top of the C-shaped ring 22 and the center block 23 and the ceiling surface (upper inner wall surface) of the reaction chamber 3 should be 0.5 mm or more and 10 mm or less. If the distance between the top of the C-shaped ring 22 and the center block 23 and the ceiling surface (upper inner wall surface) of the reaction chamber 3 is less than 0.5 mm, there is a risk that the top of the C-shaped ring 22 and the center block 23 will come into contact with the ceiling surface (upper inner wall surface) of the reaction chamber 3 when the rotation accuracy is reduced due to aging of the device or the like. Conversely, if the distance between the top of the C-ring 22 and center block 23 and the ceiling surface (upper inner wall surface) of the reaction chamber 3 is greater than 10 mm, there is a slight risk of the precursor-containing gas and the reactant-containing gas mixing.

[0089] (Embodiment 2) The second embodiment of the present invention will be described below with reference to FIG.

[0090] 22A and 22B are a perspective view and a cross-sectional view showing a configuration of a susceptor according to a second embodiment of the present invention, in which a substrate is not placed on the susceptor. Fig. 22B is a cross-sectional view of Fig. 22A cut along a plane parallel to the yz plane including the center of the susceptor.

[0091] 22, the susceptor 8 has a shape similar to that of the substrate (circular) as a whole, and includes a circular countersunk portion 9 as a substrate placement portion. In addition, slits 10 are provided at three locations around the countersunk portion 9 as substrate peripheral gas exhaust ports, and pin holes 11 are provided at three locations near the edge of the countersunk portion 9 for passing lift pins during substrate transfer. The slits 10 and pin holes 11 are all equally spaced in the circumferential direction. Furthermore, a large number of through holes 61 are provided over the entire surface of the countersunk portion 9. This configuration promotes heat transfer between the substrate 24 and the first stage or the third stage, and also speeds up lamp heating in the second position, enabling more productive atomic layer deposition.

[0092] (Embodiment 3) Hereinafter, the third embodiment of the present invention will be described with reference to FIG.

[0093] 23A and 23B are a perspective view and a cross-sectional view showing a configuration of a susceptor according to a third embodiment of the present invention, in which a substrate is not placed on the susceptor. Fig. 23B is a cross-sectional view of Fig. 23A cut along a plane parallel to the yz plane including the center of the susceptor.

[0094] 23, the susceptor 8 has a shape similar to that of the substrate (circular) as a whole, and includes a circular countersunk portion 9 as a substrate placement portion. In addition, slits 10 are provided at three locations around the periphery of the countersunk portion 9 as substrate peripheral gas exhaust ports, and pin holes 11 are provided at three locations near the edge of the countersunk portion 9 for passing lift pins therethrough during substrate transfer. The slits 10 and pin holes 11 are all equally spaced in the circumferential direction. In addition, one through hole 62 is provided across the entire surface of the countersunk portion 9. This configuration promotes heat transfer between the substrate 24 and the first or third stage, and also speeds up lamp heating in the second position, enabling more productive atomic layer deposition. (Embodiment 4) Hereinafter, the fourth embodiment of the present invention will be described with reference to FIG.

[0095] FIG. 24 is a cross-sectional view showing the configuration of a reaction chamber in the fourth embodiment of the present invention, and corresponds to FIG.

[0096] In FIG. 24, an inner cover 63 is provided to cover the side wall surface of the reaction chamber 3. Although various measures are taken in the present invention to suppress mixing of the precursor and the reactant, there is a possibility that a thin film may be deposited on the side wall surface of the reaction chamber 3, although it is very small, when the apparatus is operated for a long period of time. Therefore, by operating the apparatus with the side wall surface of the reaction chamber 3 protected by the inner cover 63 and periodically removing and cleaning the inner cover 63, it is possible to keep the inner surface of the reaction chamber 3 always clean. In addition, the inner cover 63 is provided with a through hole (not shown) near the fourth position, which is large enough for the substrate and the robot 7 to pass through for substrate replacement.

[0097] The above-mentioned film forming apparatus and method are merely typical examples within the scope of application of the present invention, and the present invention can be applied to various scopes other than those mentioned above.

[0098] For example, although an example having three exhaust ports has been given, the pipes may be joined at the rear of the exhaust ports to evacuate the reaction chamber 3 with one vacuum pump, or each exhaust port may be evacuated with a separate pump. Alternatively, each exhaust port may be provided with a separate pressure regulating valve to allow for fine pressure regulation. It goes without saying that the number of exhaust ports is not limited to three.

[0099] In addition, although the third position is provided to lower the temperature of the substrate 24, the function of the third position may be combined with the first position, and the third position may not be used. When the third position is used, another substrate can be cooled while the adsorption and nitridation reactions are being carried out, which has the advantage of enabling faster processing.

[0100] In addition, although the substrate replacement is performed at the fourth position, it is also possible to perform the substrate replacement at the first, second, or third position without providing the fourth position. If the substrate replacement is performed at the first or third position, it is necessary to incorporate a lift pin-related mechanism below the first stage 12 or the third stage 30, which increases design constraints. Similarly, if the substrate replacement is performed at the second position, it is necessary to incorporate a lift pin-related mechanism below the lamp unit, which makes design very difficult. Therefore, it is preferable to provide a fourth position for substrate replacement in addition to the first, second, and third positions.

[0101] In addition, although an example has been given of a case in which a plasma generating unit that generates plasma is provided in the second position, it is also possible to perform atomic layer deposition by configuring the second position in the same manner as the first position without using a plasma generating unit.

[0102] In addition, although the plasma generating unit is exemplified as generating inductively coupled plasma in the quartz tube 38 by supplying high frequency power to the coil 39, various methods may be applied as a method for generating plasma, such as a method using electrodes, a method using pulsed power, or a method using microwaves. In addition, it is preferable to provide the plasma generating unit upstream of the substrate mounting surface in the gas flow. This allows for efficient use of active particles such as ions and radicals.

[0103] Various configurations of the present invention enable various film formation processes. For example, application to the manufacture of electronic devices such as semiconductors, flat panel displays, solar cells, and light emitting diodes is effective. In particular, it is useful for forming AlN in GaN power semiconductor devices. It can also be used in many processes such as double patterning processes in semiconductor integrated circuit manufacture, High-k / Metal gate formation, DRAM capacitor upper and lower electrode formation using TiN, Ru, etc., gate electrode sidewall formation using SiN, barrier seed formation in contacts and through holes, and High-k insulating film and charge trap film formation in NAND flash memories. It can also be used in ITO film formation and passivation film formation in flat panel displays, LEDs, and solar cells. [Industrial Applicability]

[0104] As described above, the present invention can be used in the manufacture of various electronic devices, and is effectively applied to the manufacture of electronic devices such as semiconductors, flat panel displays, solar cells, and light-emitting diodes. In particular, the present invention is useful for forming AlN in GaN power semiconductor devices. The present invention can also be used in many processes, such as double patterning processes in the manufacture of semiconductor integrated circuits, high-k / metal gate formation, DRAM capacitor upper and lower electrode formation using TiN, Ru, etc., gate electrode sidewall formation using SiN, barrier seed formation in contacts and through holes, and high-k insulating film and charge trap film formation in NAND flash memories. The present invention is also useful in the formation of ITO films and passivation films in flat panel displays, LEDs, and solar cells. [Explanation of symbols]

[0105] 3. Reaction chamber 8 Susceptor 9 Counterbore 10 Slit 11 Pin hole 13 Convex 14 Bottom 15 Step 18 Rotating Table 19 Shaft 21 Gas exhaust port between positions 22 C-ring 23 Center Block 24 Substrate 26 Shaft hole 30 Third Stage 35 Gas exhaust port 40 Lid 43 Gas inlet hole 44 Shower Hole 45 Shower Plate 47 Gap 48 Coolant flow path 57 3rd stage gas nozzle 58 Purge gas supply manifold

Claims

1. A reaction chamber; A plurality of susceptors each having a substrate placement portion; a first position in which a temperature of the substrate placed on the substrate placement part is controlled to a first temperature; a second position in which the temperature of the substrate placed on the substrate placement part is controlled to a second temperature; a precursor nozzle that supplies a gas containing a precursor to the substrate placement part disposed at the first position; a reactant nozzle for supplying a gas containing a reactant to the substrate placement unit disposed at the second position; a rotation table that mounts the plurality of susceptors so that the substrate mounting portion is horizontal, and that rotates in a horizontal direction within the reaction chamber to position the substrate mounting portion at the first position and the second position; An atomic layer deposition apparatus comprising: The second temperature is higher than the first temperature. An atomic layer deposition apparatus comprising:

2. The first temperature is 50 to 150°C, and the second temperature is 250 to 700°C. The atomic layer deposition apparatus of claim 1 .

3. a third position for controlling the temperature of the substrate placed on the substrate placement part to a third temperature; The atomic layer deposition apparatus of claim 1 .

4. the third temperature is lower than the first temperature; The atomic layer deposition apparatus of claim 3 .

5. a fourth position for exchanging the substrate placed on the substrate placement part with a substrate outside the reaction chamber; The atomic layer deposition apparatus of claim 1 .

6. A lamp unit is provided below the second position. The atomic layer deposition apparatus of claim 1 .

7. A plasma generating unit is provided above the second position. The atomic layer deposition apparatus of claim 1 .

8. a first stage adjacent to the substrate placement portion at the first position; a temperature control mechanism for controlling the first stage to a predetermined temperature; a third stage adjacent to the substrate placement portion at the third position; and a temperature control mechanism for controlling the third stage to a predetermined temperature. The atomic layer deposition apparatus of claim 3 .

9. a first stage gas nozzle that supplies an inert gas from below the first stage between the substrate placement part and the first stage at the first position; a third stage gas nozzle for supplying an inert gas from below the third stage between the substrate placement part and the third stage at the third position; The atomic layer deposition apparatus of claim 8 .

10. a groove serving as a flow path for an inert gas is provided on a surface of the first stage and a surface of the third stage facing the substrate placement portion; The atomic layer deposition apparatus of claim 9.

11. a plurality of C-shaped rings each having a horseshoe shape as a whole and each being a circular ring with a portion missing are arranged on the rotary table concentrically with the substrate placement portion at the first position and the second position; The upper surfaces of the plurality of C-shaped rings are adjacent to a ceiling surface of the reaction chamber. The atomic layer deposition apparatus of claim 1 .

12. a center block that fills a space between the plurality of C-shaped rings while providing a gap between the center block and the plurality of C-shaped rings; The upper surface of the center block is close to the ceiling surface of the reaction chamber. The atomic layer deposition apparatus of claim 11.

13. The rotary table is provided with an inter-position gas exhaust port on the outside of the center block. The atomic layer deposition apparatus of claim 12.

14. A substrate peripheral gas exhaust port is provided between the substrate mounting portion and the C-shaped ring. The atomic layer deposition apparatus of claim 11.

15. a first position in which a temperature of a substrate placed on a horizontally disposed substrate placement part is controlled to a first temperature; a second position for controlling the temperature of the substrate placed on the substrate placement part to a second temperature, moving a substrate from outside the reaction chamber onto the substrate placement part; supplying a gas containing a precursor to the substrate placement part disposed at the first position and evacuating the reaction chamber while supplying a gas containing a reactant to the substrate placement part disposed at the second position; rotating a rotation table for placing the substrate placement part at the first position and the second position in a horizontal direction within the reaction chamber; 1. An atomic layer deposition method comprising: The second temperature is higher than the first temperature.

1. An atomic layer deposition method comprising:

16. The first temperature is 50 to 150°C, and the second temperature is 250 to 700°C. The atomic layer deposition method of claim 15.

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