Substrate processing method and substrate processing device

Abstract

The present invention provides a substrate processing method suitable for forming a thin and high-quality interfacial layer (IL). A substrate processing method according to the present invention comprises: a silicon oxide film formation step (S2) for supplying an oxidizing treatment liquid to the surface of a silicon layer formed on a substrate to form a silicon oxide film on the surface of the silicon layer; and a heating step (S4) for heating, with a flash lamp, the substrate on which the silicon oxide film is formed.

Description

Substrate processing method and substrate processing apparatus

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus.

[0002] A technique for forming a gate oxide film located between the gate and channel of a field-effect transistor (FET) is known. For example, Patent Document 1 describes a technique for forming a highly insulating oxide film on the surface of a silicon substrate. In the oxide film formation method of Patent Document 1, a first step is performed in which a gas phase or solution containing oxygen molecules is supplied to the silicon substrate to form an oxide film on the surface of the silicon substrate. After the first step, a second step is performed in which the oxide film is heated in a gas phase of inert gas. After the second step, a third step is performed in which the silicon substrate is heat-treated in a gas phase containing oxygen molecules at a temperature higher than the temperature at which the oxide film was formed. By performing the third step, the bond between the atoms constituting the substrate surface in the oxide film and oxygen is strengthened, and an oxide film thicker than the oxide film formed on the surface of the silicon substrate in the first step is formed on the surface of the silicon substrate.

[0003] Japanese Patent Publication No. 5-55197

[0004] Incidentally, in recent years, there has been a demand for higher performance in logic devices, and the size of logic devices has been miniaturized. With the miniaturization of logic devices, the interfacial layer (IL) located between the gate and channel of a field-effect transistor (FET) needs to be made even thinner and of higher quality in order to improve device performance.

[0005] One aspect of the present invention aims to provide a substrate processing method suitable for forming a thin and high-quality interfacial layer (IL).

[0006] To solve the above problems, a substrate processing method according to one aspect of the present invention includes a silicon oxide film forming step of supplying an oxidizing treatment liquid to the surface of a silicon layer formed on a substrate to form a silicon oxide film on the surface of the silicon layer, and a heating step of heating the substrate on which the silicon oxide film has been formed with a flash lamp.

[0007] To solve the above problems, a substrate processing apparatus according to one aspect of the present invention comprises a processing liquid supply unit that supplies an oxidizing processing liquid to the surface of a silicon layer formed on a substrate to form a silicon oxide film on the surface of the silicon layer, and a heating unit that heats the substrate on which the silicon oxide film is formed with a flash lamp.

[0008] According to one aspect of the present invention, a substrate processing method suitable for forming a thin and high-quality interfacial layer (IL) can be provided.

[0009] This is a schematic plan view showing the general configuration of the substrate processing apparatus. This is a schematic cross-sectional view of the substrate processing apparatus as seen from line A-A in Figure 1. This is a block diagram showing the configuration of the substrate processing apparatus. This is a flowchart showing an example of the flow of a substrate processing method performed by the substrate processing apparatus. This is a diagram showing the change in the thickness of the silicon oxide film on the substrate W before and after heat treatment by flash lamp annealing. This is a graph showing the thickness of the silicon oxide film and silicon strength after heat treatment under each heat treatment condition. This is a graph showing the thickness of the silicon oxide film and silicon strength after heat treatment under each heat treatment condition. This is a flowchart showing an example of a modified flow of the substrate processing method performed by the substrate processing apparatus.

[0010] [Embodiment 1] An embodiment of the present invention will be described in detail below. For the sake of convenience of explanation, the front-to-back direction, left-to-right direction, and up-and-down direction of the substrate processing apparatus 100 will be defined as shown in Figures 1 and 2. The up-and-down direction is based on the state in which the substrate processing apparatus 100 is installed on the floor. In addition, unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more and B or less".

[0011] [Outline Configuration of Substrate Processing Apparatus 100] An example of the configuration of the substrate processing apparatus 100 will be described with reference to Figures 1 and 2. Figure 1 is a schematic plan view showing the schematic configuration of the substrate processing apparatus 100. Figure 2 is a schematic cross-sectional view of the substrate processing apparatus 100 taken along line A-A in Figure 1.

[0012] The substrate processing apparatus 100 is an apparatus that performs various processes on a substrate W. The substrate W is a semiconductor substrate on which a silicon layer is formed, and for example, is a silicon wafer. The substrate processing apparatus 100 forms an IL (interfacial layer) located between the gate and the channel of a field effect transistor (FET). The IL is a layer that constitutes a part of the gate oxide film. In the present embodiment, the substrate processing apparatus 100 forms, for example, an IL between the Si channel and the High-K metal of the metal gate portion of a MOSFET (metal-oxide-semiconductor field-effect transistor) on the substrate W. The substrate processing apparatus 100 is a single wafer type apparatus that processes one substrate W at a time. As shown in FIG. 1, the substrate processing apparatus 100 includes a load port LP, an indexer unit 10, a processing unit 20, a fluid cabinet 30, a transfer unit 40, and a controller 50.

[0013] A plurality of load ports LP are provided on the front surface of the substrate processing apparatus 100. A transfer container P that houses a plurality of substrates W is placed on the load port LP. The transfer container P is, for example, a FOUP (front opening unified pod). Note that the transfer container P is not limited to a FOUP and may be a SMIF (Standard Mechanical Inter Face). The load port LP is preferably filled with an inert gas in order to make it difficult for a natural oxide film to be formed on the substrate W. In the present specification, the inert gas is a gas that makes it difficult for the substrate W to undergo an oxidation reaction. Examples of the inert gas include nitrogen gas (N ２ ) and argon gas (Ar).

[0014] The indexer unit 10 loads the substrate W housed in the transfer container P placed on each load port LP into the processing unit 20, and houses the substrate W unloaded from the processing unit 20 in the transfer container P. The indexer unit 10 includes a transfer device 12 (see FIG. 2), and transfers the substrate W housed in the transfer container P by the transfer device 12 to the buffer station 43. A chemical filter for cleaning the air taken into the indexer unit 10 may be provided above the indexer unit 10.

[0015] In the processing unit 20, various devices for performing various processes on the substrate W are installed. In the processing unit 20, processes for forming an IL on the substrate W and modifying the formed IL are performed. The processing unit 20 includes a plurality of towers 21, a liquid box 22, and a FLA device 23.

[0016] The towers 21 are provided on both sides of the transport unit 40 in the left-right direction. In the following description, the tower 21 located on the right side of the transport unit 40 may be denoted as "R", and the tower 21 located on the left side of the transport unit 40 may be denoted as "L" for explanation. In each tower 21, a plurality of chambers in which various processing units are installed are stacked in the vertical direction.

[0017] Referring to FIG. 2, the processing units installed in each chamber of the tower 21L will be described. FIG. 2 shows an example of the processing units installed in each chamber of the tower 21L included in the substrate processing apparatus 100. The tower 21R has basically the same configuration as the tower 21L. Therefore, in the following description, only the parts where the configuration of the tower 21R differs from the configuration of the tower 21L will be described.

[0018] As shown in FIG. 2, in the tower 21L, four chambers are stacked in the vertical direction. The number of chambers stacked in each tower 21L is not limited to four, and for example, may be six. Also, the number of chambers stacked in each tower 21L may be different. The tower 21R has four chambers stacked in the vertical direction in the same manner as the tower 21L. The number of chambers stacked in the tower 21R may be different from the number of chambers stacked in the tower 21L.

[0019] A notch aligner (AL) 212 may be installed in the chamber located at the top of the tower 21L. The AL 212 is a processing unit that aligns the substrate W to be processed. In each of the three chambers located below the chamber in which the AL 212 is installed, a processing unit, a device (hereinafter referred to as a WET device) 211, is installed that processes the substrate W by supplying a processing liquid to the substrate W. The substrate W, which has been aligned by the AL 212, is transported to each WET device 211 by the center robot 41.

[0020] The WET apparatus 211 supplies an oxidizing treatment solution as a treatment solution to the surface of the silicon layer formed on the substrate W, thereby forming a silicon oxide film (SiO₂) on the surface of the silicon layer. ２ This is a device for forming a silicon oxide film. The silicon oxide film is formed as IL. As an oxidizing treatment solution, for example, ozonated deionized water (DIO) ３ Preferably, at least one of the following is used: ammonia hydrogen peroxide solution (SC-1), sulfuric acid hydrogen peroxide solution (SPM), and hydrochloric acid hydrogen peroxide solution (SC-2). By using the above oxidizing treatment solution, a silicon oxide film can be efficiently and sufficiently formed.

[0021] The WET apparatus 211 includes, for example, a processing liquid supply unit 211A for supplying an oxidizing processing liquid and a substrate holding unit 211B for holding the substrate W. The processing liquid supply unit 211A supplies the oxidizing processing liquid to the substrate W held by the substrate holding unit 211B. The substrate holding unit 211B may be rotatable. The centrifugal force generated by the rotation of the substrate holding unit 211B may be used to scatter the oxidizing processing liquid on the substrate W and discharge the oxidizing processing liquid to the outside of the substrate W. The WET apparatus 211 uses a well-known apparatus for supplying processing liquid to the surface of a substrate. An example of a specific configuration of the WET apparatus 211 is the apparatus described in Japanese Patent Application Publication No. 2024-33671.

[0022] As shown in Figure 1, a cooling unit (CL) 213 may be installed in the chamber located at the top of the tower 21R. The CL 213 is a unit for cooling the substrate W that has undergone heat treatment. The heat treatment is a process in which the substrate W is heated by a heating unit, which will be described later. The CL 213 may, for example, be equipped with a metal cool plate for cooling the substrate W. In the tower 21R, a WET device 211 is installed in each of the three chambers located below the chamber in which the CL 213 is installed. The CL 213 may also be installed in the chamber of tower 21L, and the AL 212 may be installed in the chamber of tower 21R.

[0023] As shown in Figure 2, a liquid box 22 is installed in the tower 21L. The liquid box 22 is provided in each tower 21L and is a box in which various devices for supplying processing liquid to each WET device 211 in the corresponding tower 21L are installed. The liquid box 22 is equipped with a processing liquid supply pipe (not shown) for supplying processing liquid supplied from a fluid cabinet 30 (described later) to the corresponding WET device 211. The liquid box 22 may also be equipped with a valve (not shown) for adjusting the flow rate of processing liquid supplied to the processing liquid supply section 211A of the corresponding WET device 211. The liquid box 22 may also be equipped with a flow sensor for measuring the flow rate of processing liquid flowing through the processing liquid supply pipe. The liquid box 22 may also be equipped with a gas supply pipe (not shown) for supplying gas supplied from a fluid cabinet 30 (described later) to the corresponding WET device 211. The gas may be supplied by the gas supply pipe to the space of the WET device 211 where the substrate W held by the substrate holding section 211B is located.

[0024] On the rear side surface of the tower 21L located behind the apparatus, as a processing unit, a flash lamp annealing (FLA) apparatus 23 for heating the substrate W by a flash lamp is installed. The FLA apparatus 23 is an example of a heating unit. In the chamber where the FLA apparatus 23 is installed, a halogen lamp 232, a holding unit 233, and a flash lamp 234 are installed. The FLA apparatus 23 can use a well-known apparatus. As an example of the specific configuration of the FLA apparatus 23, the apparatus described in JP-A-2018-6513 can be cited.

[0025] The FLA apparatus 23 includes a plurality of halogen lamps 232, and heats the substrate W placed on the holding unit 233 from below by the halogen lamps 232.

[0026] The holding unit 233 is a portion on which the substrate W to be heat-treated is placed. The chamber of the FLA apparatus 23 is filled with, for example, an inert gas such as N ２ or oxygen (O ２ ). Therefore, the holding unit 233 is filled with an inert gas or O ２ . When the chamber where the FLA apparatus 23 is installed is filled with an inert gas, the ratio of the inert gas is preferably 80% to 100%. In the chamber where the FLA apparatus 23 is installed, an inert gas other than N ２ may be filled. Also, when the chamber where the FLA apparatus 23 is installed is filled with O ２ , the ratio of O ２ is preferably 80% to 100%.

[0027] The FLA apparatus 23 includes a plurality of flash lamps 234 that irradiate the substrate W with flash light. The flash lamps 234 include xenon flash lamps and krypton flash lamps. The flash lamps 234 heat the substrate W by irradiating the substrate W placed on the holding unit 233 with flash light from above.

[0028] Returning to Figure 1, the fluid cabinet 30 supplies processing liquid to the processing liquid supply section 211A of each WET device 211. The fluid cabinet 30 supplies processing liquid to the processing liquid supply section 211A of each WET device 211 via the processing liquid supply pipe of the liquid box 22. The fluid cabinet 30 comprises a processing liquid tank (not shown) for containing the processing liquid, processing liquid piping (not shown) connected to the processing liquid supply pipe of the liquid box 22, and a pump (not shown) for supplying the processing liquid contained in the processing liquid tank to the processing liquid piping. The fluid cabinet 30 may also be equipped with an adjustment circuit or the like for adjusting the flow rate of the processing liquid flowing through the processing liquid piping. The fluid cabinet 30 may supply the same type and the same mixing ratio of processing liquid to each processing liquid supply section 211A. Furthermore, the fluid cabinet 30 may supply a different type or a different mixing ratio of processing liquid to the processing liquid supply unit 211A of a specific WET device 211 installed in the tower 21, compared to the processing liquid supplied to the processing liquid supply unit 211A of other WET devices 211.

[0029] The fluid cabinet 30 supplies gas to the space for performing various processes on the substrate W and to the space for transporting the substrate W. The fluid cabinet 30 supplies inert gas or O to the chamber in which the FLA device 23 is installed via gas piping (not shown). ２ The fluid cabinet 30 also supplies an inert gas to the space 42 in the transport section 40 where the substrates W are transported. The fluid cabinet 30 may also supply gas to the transport space for the substrates W in the indexer section 10, and to the chambers of each tower 21 in the processing section 20 where various processes are performed on the substrates W.

[0030] The fluid cabinet 30 comprises a gas tank (not shown) for containing gas and gas piping for supplying the gas contained in the gas tank to the spaces to be supplied. The fluid cabinet 30 may also include an adjustment circuit for adjusting the flow rate of gas flowing through the gas piping, and filters for purifying the gas supplied to each space. The fluid cabinet 30 may supply gases of different types or with different mixing ratios depending on the space to be supplied. The fluid cabinet 30 may adjust the gas flow rate for each space to which gas is supplied to adjust the air pressure of the target space. The fluid cabinet 30 may be installed outside the housing that constitutes the external shape of the substrate processing apparatus 100, or it may be installed inside the housing.

[0031] The transport unit 40 transports the substrate W. The transport unit 40 is equipped with a center robot 41. The center robot 41 is a robot that can rotate. The center robot 41 is also a robot that can travel in the forward and backward direction, which is the travel direction D. The center robot 41 is equipped with one or more hands for gripping the substrate W. The center robot 41 grips the substrate W placed on the buffer station 43 with its hands, then rotates and travels in the travel direction D to transport the substrate W to each part.

[0032] The space 42 in which the central robot 41 is located is preferably filled with an inert gas. For example, the space 42 may be filled with nitrogen (N ２ It is filled with ). Note that the space 42 is N ２ It may also be filled with an inert gas other than the one specified. In space 42, the proportion of the inert gas is preferably 80% to 100%. Space 42 is the space in which the substrates W that have undergone various treatments are transported.

[0033] The controller 50 controls each part of the substrate processing apparatus 100. The configuration of the controller 50 will be described with reference to Figure 3. Figure 3 is a block diagram showing the configuration of the substrate processing apparatus 100. As shown in Figure 3, the controller 50 includes a processor 51 that performs various calculations according to a program, and a memory 52 that stores various information such as programs. The processor 51 executes various processes according to a program pre-stored in the memory 52. ​​Examples of the processor 51 include a CPU (Central Processing Unit), a DSP (Digital Signal Processor), a GPU (Graphic Processing Unit), and an MPU (Micro Processing Unit). Examples of the memory 52 include a ROM (Read Only Memory), RAM (Random Access Memory), flash memory, and an HDD (Hard Disk Drive).

[0034] The controller 50 controls the WET device 211, AL 212, various devices in the liquid box 22, halogen lamp 232, and flash lamp 234 of the processing unit 20. The controller 50 also controls various devices in the fluid cabinet 30. Furthermore, the controller 50 controls the center robot 41 of the transport unit 40.

[0035] [Substrate Processing Method] An example of a substrate processing method performed by the substrate processing apparatus 100 will be described with reference to Figure 4. Figure 4 is a flowchart showing an example of the flow of a substrate processing method performed by the substrate processing apparatus 100.

[0036] In step S1, the substrate processing apparatus 100 transports the substrate W to the wetting apparatus 211. More specifically, in step S1, the controller 50 controls the center robot 41 to transport the substrate W to the wetting apparatus 211. In step S1, the controller 50 sequentially transports the substrate W to wetting apparatus 211 that are not currently being processed.

[0037] In step S2, the substrate processing apparatus 100 supplies an oxidizing treatment solution to the surface of the silicon layer formed on the substrate W to form a silicon oxide film on the surface of the silicon layer. More specifically, in step S2, the controller 50 controls the WET apparatus 211 to supply an oxidizing treatment solution from the treatment solution supply unit 211A to the surface of the silicon layer on the substrate W for a predetermined time. When the oxidizing treatment solution is supplied to the surface of the silicon layer on the substrate W, a silicon oxide film is formed on the surface of the silicon layer as a native oxide film. In step S2, the controller 50 sequentially starts the operation of each WET apparatus 211 to which the substrate W has been transported to perform the process of forming the silicon oxide film.

[0038] In step S3, the substrate processing apparatus 100 transports the substrate W on which the silicon oxide film has been formed to the FLA apparatus 23. More specifically, in step S3, the controller 50 controls the center robot 41 to transport the substrate W on which the silicon oxide film has been formed from the WET apparatus 211 to the holding section 233 of the FLA apparatus 23. The substrate W processed in the WET apparatus 211 is transported to the holding section 233 of the FLA apparatus 23 via space 42. In step S3, the controller 50 sequentially transports the substrate W processed in each WET apparatus 211 to the holding section 233.

[0039] In step S4, the substrate processing apparatus 100 heats the substrate W on which the silicon oxide film is formed using a flash lamp. More specifically, in step S4, the controller 50 controls the flash lamp 234 to irradiate the substrate W held in the holding part 233 with flash light from the flash lamp 234 for a predetermined time, thereby heating the silicon oxide film formed on the substrate W. In step S4, the controller 50 maintains the halogen lamp 232 lit and heats the substrate W from below. In step S4, the controller 50 may heat the substrate W so that its temperature reaches 600°C or higher by heating with the flash lamp 234 for 5 ms or less. In step S4, it is preferable that the controller 50 controls the flash lamp 234 so that the lower limit of the temperature of the substrate W heated by the flash lamp 234 is 600°C to 800°C.

[0040] In step S5, the substrate processing apparatus 100 transports the heated substrate W to the CL213. More specifically, in step S5, the controller 50 controls the center robot 41 to transport the heated substrate W from the holding section 233 of the FLA apparatus 23 to the CL213. The heated substrate W is cooled in the CL213 for a predetermined time.

[0041] In step S6, the substrate processing apparatus 100 transports the cooled substrate W to the WET apparatus 211. More specifically, the controller 50 controls the center robot 41 to place the substrate W on the CL 213 for a predetermined time, and then transports the substrate W from the CL 213 to the WET apparatus 211. In step S8, the controller 50 sequentially transports the cooled substrates W to the WET apparatus 211 where no processing is being performed.

[0042] In step S7, the substrate processing apparatus 100 again supplies the oxidizing treatment solution to the surface of the silicon oxide film heated by the flash lamp 234. More specifically, in step S7, the controller 50 controls the WET device 211 to supply the oxidizing treatment solution from the treatment solution supply unit 211A to the silicon oxide film of the heated substrate W for a predetermined time. In step S7, the controller 50 sequentially starts the operation of each WET device 211 to which the heated substrate W has been transported, and supplies the oxidizing treatment solution to the substrate W. After step S7 is completed, the controller 50 controls each part of the substrate processing apparatus 100 in order to place the substrate W, which has undergone various treatments, into the transport container P.

[0043] According to the above method, a silicon oxide film is first formed on the surface of the silicon layer by an oxidizing treatment solution, and then flash lamp heating is performed to improve the quality of the silicon oxide film. Therefore, a substrate processing method suitable for forming a thin, high-quality IL (Iron Integrity) between the Si channel and the High-K metal of the metal gate portion of a MOSFET can be provided. Furthermore, since the substrate W on which the silicon oxide film has been formed is heated by the flash lamp 234, the silicon oxide film can be rapidly heated in a short time, further improving the quality of the silicon oxide film.

[0044] Furthermore, according to the above method, the oxidizing treatment solution is supplied again to the heated surface of the silicon oxide film. As a result, a film terminated with OH groups is formed on the surface of the silicon oxide film. Therefore, for example, when High-K metal is laminated on this silicon oxide film, the adhesion between the silicon oxide film and the High-K metal can be improved.

[0045] Furthermore, according to the above method, the substrate W on which the silicon oxide film is formed is N ２ The silicon oxide film is transported to the FLA apparatus 23 through the space 42 filled with the material. Therefore, spontaneous oxidation of the silicon oxide film can be suppressed between the time oxidation by the oxidizing treatment solution and heating by the flash lamp 234. Thus, a higher quality silicon oxide film can be produced.

[0046] Furthermore, according to the above method, the substrate W is heated to a temperature of 600°C or higher by heating with a flash lamp for 5 ms or less. This makes it possible to sufficiently improve the quality of the silicon oxide film.

[0047] In the substrate processing method shown in Figure 4, steps S6 and S7 may be omitted. Also, the processing performed on the surface of the substrate W by supplying processing liquid to the substrate W by the WET device 211 (WET processing) usually takes longer than the heating process. Therefore, it is desirable that the substrate processing apparatus 100 be configured to perform WET processing in parallel using multiple WET devices 211. This improves the processing efficiency of the substrate W by the substrate processing apparatus 100.

[0048] Next, referring to Figures 5 to 8, we will describe the experimental results regarding the thickness and quality of the silicon oxide film after a heat treatment in which the substrate W on which the silicon oxide film is formed is heated by a flash lamp 234. First, referring to Figure 5, we will describe the change in the thickness of the silicon oxide film on the substrate W before and after heat treatment under each heat treatment condition. Figure 5 is a diagram showing the change in the thickness of the silicon oxide film on the substrate W before and after heat treatment by flash lamp annealing.

[0049] As shown in Figure 5, the change in the thickness of the silicon oxide film on the substrate W subjected to heat treatment under each heat treatment condition is shown by a bar graph. In the table shown in Figure 5, the vertical axis represents the thickness of the silicon oxide film, and the unit of thickness is angstroms (Å). The thickness of the silicon oxide film under each heat treatment condition is shown by two bar graphs (a plain bar graph and a shaded bar graph). The plain bar graph shows the thickness of the silicon oxide film after heat treatment. The shaded bar graph shows the increase or decrease in the thickness of the silicon oxide film before and after heat treatment, that is, the value obtained by subtracting the thickness of the silicon oxide film before heat treatment from the thickness of the silicon oxide film after heat treatment.

[0050] Figure 5 shows O ２ The changes in silicon oxide film thickness before and after heat treatment, measured by varying the heat treatment conditions for concentration and peak temperature, are shown. ２ The concentration is O in the chamber of the FLA apparatus 23 where the substrate W undergoing heat treatment is located. ２This refers to the concentration. Note that other heat treatment conditions (assist temperature, heating time, etc.) are the same, as are the conditions for the silicon oxide film formation process. ２ The concentration is the O of the chamber in which the substrate W to be heat-treated is located. ２ It is concentration. ２ The concentration is N ２ Concentration 100%, O ２ Concentration 25%, O ２ Concentration 50%, and O ２ Four conditions were set with a concentration of 100%. ２ A concentration of 100% is O ２ This means a concentration of 0%. The peak temperature is the highest temperature that the surface of the substrate W is expected to reach due to heating by the flash lamp 234, and is the target temperature for heating the surface of the substrate W. Two conditions were set for the peak temperature: 950°C and 1150°C.

[0051] As shown in the plain bar graph in Figure 5, the thickness of the silicon oxide film after heat treatment is O ２ The thickness increased as the concentration increased. That is, N ２ The silicon oxide film thickness of substrate W was thinnest when heat-treated under conditions of 100% concentration. ２ The silicon oxide film thickness on substrate W was thickest when heat-treated under 100% concentration conditions. As shown in the shaded bar graph in Figure 5, N ２ Under conditions of 100% concentration, the increase or decrease in the thickness of the silicon oxide film before and after heat treatment was negative. That is, N ２ Under conditions of 100% concentration, the thickness of the silicon oxide film after heat treatment was thinner than the thickness of the silicon oxide film before heat treatment. ２ Under heat treatment conditions ranging from 25% to 100% concentration, the increase or decrease in silicon oxide film thickness before and after heat treatment was positive in all cases, resulting in a thicker silicon oxide film after heat treatment than before. Furthermore, the silicon oxide film thickness after heat treatment was thicker when the peak temperature was 1150°C than when the peak temperature was 950°C.

[0052] From the above results, in terms of the thickness of the silicon oxide film after heat treatment, O ２ Under heat treatment conditions that reduce concentration, especially N ２ It is thought that the thickness of the silicon oxide film after heat treatment can be reduced under heat treatment conditions of 100% concentration. ２ Even when the substrate W is heat-treated under heat treatment conditions of a concentration of 25% to 100%, it is considered possible to reduce the increase in the thickness of the silicon oxide film after heat treatment by adjusting the temperature at which the substrate W is heated by at least one of the flash lamp 234 and halogen lamp 232 of the FLA apparatus 23. The experimental results shown in Figure 5 are O ２ Because the heat treatment conditions other than concentration and peak temperature are the same, O ２ Under heat treatment conditions of concentrations from 25% to 100%, the silicon oxide film thickness increased after heat treatment. However, by adjusting various heat treatment conditions (assist temperature, heating time, etc.), O ２ Even under heat treatment conditions of concentrations from 25% to 100%, the N shown in Figure 5 ２ It is possible to adjust the film thickness to be equivalent to that of a silicon oxide film under heat treatment conditions at 100% concentration.

[0053] Next, with reference to Figures 6 to 8, the silicon strength of the silicon oxide film on the substrate W after heat treatment will be explained. Figures 6 to 8 are graphs showing the film thickness and silicon strength of the silicon oxide film after heat treatment under each heat treatment condition. In the graphs shown in Figures 6 to 8, the horizontal axis represents the film thickness (Å) of the silicon oxide film after heat treatment, and the vertical axis represents the silicon strength after heat treatment. The silicon strength was measured by measuring the amount of silicon (Si4+) present on the surface of the silicon oxide film using X-ray photoelectron spectroscopy (XPS).

[0054] Figure 6 shows N ２This graph shows the relationship between the thickness of the silicon oxide film and the silicon strength under heat treatment conditions at a concentration of 100%. Reference line R1 in Figure 6 shows the relationship between the thickness of the silicon oxide film and the silicon strength in the untreated state. Plot A1 shows the thickness of the silicon oxide film and the silicon strength in the untreated state. Plot A2 shows N ２ This plot shows the thickness of the silicon oxide film and the silicon strength when heat-treated at a concentration of 100% and a peak temperature of 1150°C. Plot A3 is N ２ This plot shows the film thickness and silicon strength of the silicon oxide film after heat treatment at a concentration of 100% and a peak temperature of 950°C.

[0055] As shown in plots A2 and A3, N ２ The silicon oxide film subjected to heat treatment under conditions of 100% concentration showed a decrease in film thickness and an increase in silicon strength compared to before heat treatment. In other words, by performing heat treatment after forming a silicon oxide film on the substrate W, a silicon oxide film with a thin film thickness and high film quality was formed on the substrate W. The other heat treatment conditions in plots A2 and A3 were assist temperature: 700°C, heating time: 1.4 ms, and atmospheric pressure: 100 kPa. The assist temperature is the maximum temperature that the lower surface of the substrate W is expected to reach by heating with the halogen lamp of the PLA apparatus, and is the target temperature for heating the lower surface of the substrate W. The heating time is the time for heating by the flash lamp 234 of the FLA apparatus 23. The atmospheric pressure is the pressure inside the chamber of the FLA apparatus 23 where the substrate W being heat-treated is located.

[0056] Next, referring to Figure 7, O ２ Concentration 25% and O ２This graph shows the relationship between the thickness of the silicon oxide film and the silicon strength under heat treatment conditions at a concentration of 100%. The reference line R2 shown in Figure 7 is the line showing the relationship between the thickness of the silicon oxide film and the silicon strength in the state without heat treatment. Plots B1 and B2 shown in Figure 7 show the thickness of the silicon oxide film and the silicon strength in the state without heat treatment. In plot B1, the time for supplying the oxidizing treatment solution to the substrate W (hereinafter referred to as the supply time of the oxidizing treatment solution) is 20 s (seconds), and in plot B2, the supply time of the oxidizing treatment solution is 60 s (seconds).

[0057] Plots B3 to B7 in Figure 7 show the relationship between the thickness of the silicon oxide film and the silicon strength under the following heat treatment conditions. Plot B8 is shown as a comparative example, and N ２ This shows the relationship between the thickness of the silicon oxide film and the silicon strength under 100% concentration heat treatment conditions. In plots B3 to B8, the supply time of the oxidizing treatment solution was set to 20 s, and a silicon oxide film was formed on the substrate W. B3: Assist temperature 700°C, peak temperature 950°C, heating time 1.4 ms, atmospheric pressure 100 kPa, O ２ Concentration 100% B4: Assist temperature 700°C, peak temperature 950°C, heating time 1.4 ms, atmospheric pressure 100 kPa, O ２ Concentration 25% B5: Assist temperature 550°C, peak temperature 950°C, heating time 1.4 ms, atmospheric pressure 100 kPa, O ２ Concentration 100% B6: Assist temperature 550°C, peak temperature 950°C, heating time 1.4 ms, atmospheric pressure 100 kPa, O ２ Concentration 25% B7: Assist temperature 550°C, peak temperature 950°C, heating time 1.4 ms, atmospheric pressure 5 kPa, O ２ Concentration 25%

[0058] As shown in plots B3 to B7 of Figure 7, the strength of the silicon oxide film increased after heat treatment, i.e., the quality of the silicon oxide film improved. As shown in plots B3 to B6, the thickness of the silicon oxide film increased after heat treatment compared to the thickness of the silicon oxide film without heat treatment. From these results, O ２Even under heat treatment conditions of 25% and 100% concentrations, the quality of the silicon oxide film is high. Therefore, it was found that by performing the etch-back treatment shown in the modified example described later after the heat treatment, it is possible to improve the quality of the silicon oxide film while reducing its thickness.

[0059] Also, as shown in plot B7, O ２ Even under heat treatment conditions of a concentration of 25%, by setting the air pressure inside the chamber of the FLA apparatus 23 where the substrate W is located to 5 kPa, N ２ It was found that the same results could be obtained as under heat treatment conditions at a concentration of 100%. That is, O ２ Even under heat treatment conditions of a concentration of 25%, O ２ It was found that the thickness of the silicon oxide film and the silicon strength can be adjusted by adjusting the heat treatment conditions other than the concentration.

[0060] Next, referring to Figure 8, the relationship between the film thickness and silicon strength of the silicon oxide film after a process in which the oxidizing treatment solution is supplied again to the surface of the heat-treated silicon oxide film will be explained. The reference line R3 shown in Figure 8 is a line that shows the relationship between the film thickness and silicon strength of the silicon oxide film in the state before heat treatment. Plots C1 and C2 show the film thickness and silicon strength of the silicon oxide film in the state before heat treatment, and the supply time of the oxidizing treatment solution is different between plot C1 and plot C2.

[0061] Plot C3 is a comparative example, N ２ This plot shows the relationship between the thickness of the silicon oxide film and the silicon strength after heat treatment under 100% concentration heat treatment conditions, i.e., the relationship between the thickness of the silicon oxide film and the silicon strength when no further oxidizing treatment solution is supplied after heat treatment. In plots C4 and C5, the type of oxidizing treatment solution supplied again to the substrate after heat treatment is different. In plot C4, ozone (O) is used as the oxidizing treatment solution supplied again. ３ A mixture of ) and SC-1 is used. In plot C5, ozone (O) is used as the oxidizing treatment solution supplied again. ３ Only ) is used. Note that in plots C3 to C5, N２ The concentration is 100%, and all other heat treatment conditions are the same.

[0062] As shown in plot C4 of Figure 8, ozone (O) is present on the surface of the heat-treated silicon oxide film. ３ When a mixture of ) and SC-1 is supplied, the silicon oxide film is shown in plot C3. ２ Under the heat treatment conditions of 100% concentration, the thickness of the silicon oxide film was thinner than that of the silicon oxide film that had only been heat-treated, and the silicon strength was also almost the same. As shown in plot C5, ozone (O) was applied to the surface of the heat-treated silicon oxide film. ３ When only ) was supplied, the silicon oxide film was thicker than the silicon oxide film thickness shown in plot C3.

[0063] From the above results, when heating with the flash lamp 234 is performed in an FLA apparatus 23 filled with inert gas, the quality of the silicon oxide film can be improved without increasing the thickness of the silicon oxide film formed by the oxidizing treatment solution. Therefore, a thinner silicon oxide film can be formed. Furthermore, when heating with the flash lamp 234 is performed in an FLA apparatus 23 filled with oxygen, the quality of the silicon oxide film can be improved.

[0064] [Modification] A modification of the substrate processing method performed by the substrate processing apparatus 100 will be described with reference to Figure 9. Figure 9 is a flowchart showing an example of the flow of a modification of the substrate processing method performed by the substrate processing apparatus 100. For the sake of explanation, the same reference numerals are used for components that have the same function as those described in the above embodiment, and their descriptions will not be repeated.

[0065] In the substrate processing method shown in Figure 9, after heat treatment is performed on the substrate W, etch-back is performed using a silicon oxide film removal treatment solution. In this modified example, for example, the WET device 211 installed in the tower 21 located at the rear of the apparatus operates as an etch-back device. Etch-back is a process in which a silicon oxide film removal treatment solution is supplied as a treatment solution to the surface of the silicon oxide film formed on the substrate W to remove a portion of the silicon oxide film formed on the substrate W. In this modified example, the treatment solution supply unit 211A of the WET device 211 installed in the tower 21 at the rear of the apparatus supplies the silicon oxide film removal treatment solution. Examples of silicon oxide film removal treatment solutions include dilute hydrofluoric acid (DHF), hydrofluoric acid hydrogen peroxide mixture (FPM), and buffered hydrofluoric acid (BHF). In this modified example, the WET device 211 located at the front of the apparatus operates as a device that supplies an oxidizing treatment solution to the surface of the silicon layer formed on the substrate W. In this modified example, the holding unit 233 of the FLA device 23 contains N ２ Even if it is filled, O ２ It is preferable that it is filled with [something].

[0066] Steps S11 to S16 included in the substrate processing method shown in Figure 9 are the same as steps S1 to S6 included in the substrate processing method shown in Figure 4, unless otherwise specified below, so their explanation will be omitted.

[0067] In step S17, the substrate processing apparatus 100 supplies silicon oxide removal processing liquid to the surface of the silicon oxide film after heating with the flash lamp 234. More specifically, in step S17, the controller 50 controls the WET device 211 in the tower 21 at the rear of the apparatus to supply silicon oxide removal processing liquid from the processing liquid supply unit 211A to the silicon oxide film of the heated substrate W for a predetermined time. In step S17, the controller 50 sequentially starts the operation of each WET device 211 in the tower 21 at the rear of the apparatus, to which the substrate W has been transported, and supplies silicon oxide removal processing liquid to the substrate W.

[0068] In step S18, the substrate processing apparatus 100 transports the substrate W after etch-back to a WET apparatus 211 that supplies an oxidizing treatment solution. More specifically, in step S18, the controller 50 controls the center robot 41 to transport the substrate W from the WET apparatus 211 in the tower 21 at the rear of the apparatus to the WET apparatus 211 in the tower 21 at the front of the apparatus.

[0069] In step S19, the substrate processing apparatus 100 again supplies the oxidizing treatment solution to the surface of the silicon oxide film heated by the flash lamp. More specifically, in step S19, the controller 50 controls the WET device 211 in the tower 21 at the front of the apparatus to supply the oxidizing treatment solution from the treatment solution supply unit 211A to the silicon oxide film of the heated substrate W for a predetermined time. In step S19, the controller 50 sequentially starts the operation of each WET device 211 to which the substrate W has been transported, and supplies the oxidizing treatment solution to the substrate W. After step S21 is completed, the controller 50 controls each part of the substrate processing apparatus 100 in order to place the substrate W, which has undergone various treatments, into the transport container P. In the substrate processing method shown in Figure 9, steps S18 and S19 may be omitted.

[0070] According to the substrate processing method of this modified example, the thickness of the silicon oxide film, which has increased in thickness, can be reduced by heating in an oxygen-filled space. Therefore, a high-quality and thin silicon oxide film can be produced.

[0071] [Other Embodiments] In the embodiments described above, the substrate processing apparatus 100 was configured to have four towers 21, but it is not limited to this configuration. The substrate processing apparatus 100 may have one or more towers. Alternatively, the substrate processing apparatus 100 may have a configuration in which the WET device 211 and the FLA device 23 are installed in one tower.

[0072] In the embodiment described above, AL212 and CL213 are installed in the uppermost chamber of the tower 21, but the configuration is not limited to this. AL212 and CL213 may be installed in chambers other than the uppermost chamber of the tower 21. Alternatively, AL212 and CL213 may be installed in the chamber of the tower in which the FLA device 23 is installed.

[0073] Furthermore, in the substrate processing method shown in Figures 4 and 9, the substrate processing apparatus 100 may perform substrate W alignment in the AL212 before steps S1 and S11. Specifically, the controller 50 controls the center robot 41 to transport the substrate W placed on the buffer station 43 by the transport device 12 to the AL212. The controller 50 controls the AL212 to perform substrate W alignment. In this case, in steps S1 and S11, the controller 50 transports the aligned substrate W to the WET device 211.

[0074] In the embodiment described above, the substrate processing apparatus 100 is equipped with a fluid cabinet 30 for supplying processing liquid and gas, but it is not limited to this configuration. The substrate processing apparatus 100 may be equipped with a processing liquid cabinet for supplying only processing liquid, or with a gas cabinet for supplying only gas.

[0075] [Summary] A substrate processing method according to one aspect of the present invention includes a silicon oxide film formation step of supplying an oxidizing treatment liquid to the surface of a silicon layer formed on a substrate to form a silicon oxide film on the surface of the silicon layer, and a heating step of heating the substrate on which the silicon oxide film has been formed with a flash lamp.

[0076] Furthermore, in a substrate processing method according to one aspect of the present invention, an oxidizing treatment solution supply step may be further included, in which the oxidizing treatment solution is supplied again to the surface of the silicon oxide film heated by the flash lamp.

[0077] Furthermore, in a substrate processing method according to one aspect of the present invention, a transport step may be further included in which, after forming the silicon oxide film on the surface of the silicon layer, the substrate is transported through a space filled with inert gas to a place where it is heated by a flash lamp.

[0078] Furthermore, in a substrate processing method according to one aspect of the present invention, the heating step may be carried out in a space filled with an inert gas.

[0079] Furthermore, in a substrate processing method according to one aspect of the present invention, the heating step may be carried out in a space filled with oxygen.

[0080] Furthermore, in a substrate processing method according to one aspect of the present invention, a removal solution supply step may be further included in which a silicon oxide film removal treatment solution is supplied to the surface of the silicon oxide film after the heating step.

[0081] Furthermore, in a substrate processing method according to one aspect of the present invention, the oxidizing treatment solution may be at least one of ozonated deionized water, a mixture of ammonia and hydrogen peroxide, a mixture of sulfuric acid and hydrogen peroxide, and a mixture of hydrochloric acid and hydrogen peroxide.

[0082] Furthermore, in a substrate processing method according to one aspect of the present invention, in the heating step, the temperature of the substrate may be raised to 600°C or higher by heating with the flash lamp for 5 ms or less.

[0083] A substrate processing apparatus according to one aspect of the present invention comprises a processing liquid supply unit that supplies an oxidizing processing liquid to the surface of a silicon layer formed on a substrate to form a silicon oxide film on the surface of the silicon layer, and a heating unit that heats the substrate on which the silicon oxide film is formed with a flash lamp.

[0084] 100 Substrate processing device 211 Wet device 211A Processing liquid supply unit 23 FLA device (heating unit) 232 Halogen lamp 234 Flash lamp

Claims

1. A substrate processing method comprising: a silicon oxide film formation step of supplying an oxidizing treatment solution to the surface of a silicon layer formed on a substrate to form a silicon oxide film on the surface of the silicon layer; and a heating step of heating the substrate on which the silicon oxide film has been formed with a flash lamp.

2. The substrate processing method according to claim 1, further comprising an oxidizing treatment solution supply step of supplying an oxidizing treatment solution again to the surface of the silicon oxide film heated by the flash lamp.

3. The substrate processing method according to claim 1, further comprising a transport step of transporting the substrate through a space filled with inert gas to a place where it is heated by a flash lamp, after forming the silicon oxide film on the surface of the silicon layer.

4. The substrate processing method according to claim 1, wherein the heating step is carried out in a space filled with an inert gas.

5. The substrate processing method according to claim 1, wherein the heating step is carried out in a space filled with oxygen.

6. The substrate processing method according to claim 5, further comprising a removal liquid supply step of supplying a silicon oxide film removal treatment liquid to the surface of the silicon oxide film after the heating step.

7. The substrate treatment method according to claim 1, wherein the oxidizing treatment solution is at least one of ozonated deionized water, a mixture of ammonia and hydrogen peroxide, a mixture of sulfuric acid and hydrogen peroxide, and a mixture of hydrochloric acid and hydrogen peroxide.

8. The substrate processing method according to claim 1, wherein in the heating step, the temperature of the substrate becomes 600°C or higher by heating with the flash lamp for 5 ms or less.

9. A substrate processing apparatus comprising: a processing liquid supply unit that supplies an oxidizing processing liquid to the surface of a silicon layer formed on a substrate to form a silicon oxide film on the surface of the silicon layer; and a heating unit that heats the substrate on which the silicon oxide film has been formed using a flash lamp.

Images