High-pressure wafer processing method using dual high-pressure wafer processing equipment

Abstract

The present invention includes the steps of placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first processing chamber, which is one of high pressure oxidation, high pressure nitridation, high pressure carbon doping, and high pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module, and performing a second process on the wafer in the second processing chamber, which is another one of the high pressure oxidation, high pressure nitridation, high pressure carbon doping, and high pressure heat treatment.

Description

[Technical Field]

[0001] The present invention relates to a method for high pressure wafer processing using dual high pressure wafer processing equipment. [Background technology]

[0002] Generally, semiconductor manufacturing processes are roughly divided into front-end and back-end processes, which include oxidation, deposition, exposure, etching, ion implantation, and wiring.

[0003] An insulating film is formed on the wafer through an oxidation or deposition process. The insulating film prevents leakage current even after the circuit pattern is formed. The insulating film also acts as a protective film during subsequent etching processes. Therefore, the quality characteristics of the insulating film, such as density, must be maintained at a certain level.

[0004] However, insulating films formed by conventional deposition or oxidation processes do not have sufficient quality characteristics, a phenomenon that also occurs in other thin films other than insulating films.

[0005] Furthermore, when multiple processes, such as oxidation, nitridation, and heat treatment, are performed on a wafer, each process is performed in separate equipment. This results in a long queue time as the wafer is moved between separate equipment. During this queue time, the wafer may be exposed to the atmosphere and may be naturally oxidized. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a high-pressure wafer processing method using dual high-pressure wafer processing equipment that can improve the quality characteristics of processed wafers while suppressing natural oxidation of the wafers. [Means for solving the problem]

[0007] To achieve the above object, one aspect of the present invention provides a method for high-pressure wafer processing using dual high-pressure wafer processing equipment, including the steps of placing a wafer in a first processing chamber of a first high-pressure wafer processing module; performing a first process on the wafer in the first processing chamber, which is one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high-pressure wafer processing module; and performing a second process on the wafer in the second processing chamber, which is another of the high-voltage oxidation, high-voltage nitridation, high-pressure carbon doping, and high-pressure heat treatment, wherein the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed within a single accommodation space, the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space, and the first and second processes can be performed at a reaction pressure higher than atmospheric pressure.

[0008] Here, the reaction pressure of the high-pressure oxidation, the high-pressure nitridation, and the high-pressure carbon doping may be determined in the range of 5 ATM to 20 ATM.

[0009] Here, the reaction pressure of the high pressure heat treatment may be determined in the range of 3 ATM to 20 ATM.

[0010] Here, the reaction temperatures of the high pressure oxidation, the high pressure nitridation, and the high pressure heat treatment may be determined in the range of 400°C to 600°C.

[0011] Here, the source gas for each of the high-pressure oxidation and the high-pressure nitridation may include any one of oxygen gas, water vapor, and ammonia gas.

[0012] Here, the high pressure carbon doping is performed at a reaction temperature lower than the thermal decomposition temperature of the carbon doping source gas, so that the source gas in a molecular state chemically reacts with the insulating film of the wafer.

[0013] Here, the reaction temperature of the high pressure carbon doping may be determined within the range of 400°C to 600°C.

[0014] Here, the carbon doping source gas may include one of ethylene gas and propylene gas.

[0015] Here, the method may further include performing the high-pressure heat treatment on the wafer in situ after performing any one of the high-pressure oxidation, the high-pressure nitridation, and the high-pressure carbon doping.

[0016] Here, the method may further include a step of performing purging between any one of the high-pressure oxidation, the high-pressure nitridation, and the high-pressure carbon doping and the high-pressure heat treatment, and the purging may be performed while maintaining the reaction pressure and reaction temperature of the previous process.

[0017] Here, each of the first high-pressure wafer processing module and the second high-pressure wafer processing module may further include a protection chamber that accommodates either the first processing chamber or the second processing chamber and is maintained at a protection pressure, and the protection pressure of the protection chamber may be adjusted in conjunction with the reaction pressure so as to be higher than the reaction pressure.

[0018] Here, the pressure in the accommodation space can be maintained at a pressure higher than atmospheric pressure.

[0019] Here, the step of moving the wafer to the second processing chamber of the second high-pressure wafer processing module may include the step of unloading the wafer from the first processing chamber, eliminating a cooling process, and loading the wafer into the second processing chamber.

[0020] Here, the step of performing a second process, which is another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment, on the wafer in the second process chamber may include a step of determining process conditions taking into account a waiting time after completion of the first process.

[0021] Here, the first step is the high-pressure oxidation, and the second step is the high-pressure carbon doping, and the reaction pressure of the high-pressure oxidation and the high-pressure carbon doping may be determined in the range of 5 ATM to 20 ATM.

[0022] Here, the second process may further include the high-pressure heat treatment performed in situ after the high-pressure carbon doping, and the reaction pressure of the high-pressure heat treatment may be determined in the range of 5 ATM to 20 ATM.

[0023] Here, the first step is the high-pressure heat treatment, and the second step is the high-pressure oxidation, and the reaction pressure of the high-pressure heat treatment and the high-pressure oxidation may be determined in the range of 5 ATM to 20 ATM.

[0024] Here, the first step is the high-pressure heat treatment, and the second step is the high-pressure nitridation, and the reaction pressure of the high-pressure heat treatment and the high-pressure nitridation may be determined in the range of 5 ATM to 20 ATM.

[0025] Here, the first step is the high-pressure oxidation, the second step is the high-pressure heat treatment, the reaction pressure of the high-pressure oxidation may be determined in the range of 5 ATM to 20 ATM, and the reaction pressure of the high-pressure heat treatment may be determined in the range of 3 ATM to 20 ATM.

[0026] Here, the first process is the high-pressure nitriding, the second process is the high-pressure heat treatment, the reaction pressure of the high-pressure nitriding may be determined in the range of 5 ATM to 20 ATM, and the reaction pressure of the high-pressure heat treatment may be determined in the range of 10 ATM to 20 ATM. [Effects of the Invention]

[0027] According to the high-pressure wafer processing method using the dual high-pressure wafer processing equipment of the present invention, a first high-pressure process is performed on a wafer in a first processing chamber, and then the wafer is moved to a second processing chamber within the accommodation space to perform a second high-pressure process. This minimizes the time the wafer is exposed to the atmosphere, effectively suppressing natural oxidation of the wafer. Furthermore, because both the first and second processes are performed at high pressure, the quality characteristics of the processed wafers can be significantly improved. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a conceptual diagram of a dual high-pressure wafer processing facility used to perform a high-pressure wafer processing method according to an embodiment of the present invention; [Figure 2] FIG. 2 is a conceptual diagram showing the first high-pressure wafer processing module 100 of FIG. 1 in more detail. [Figure 3] FIG. 2 is a block diagram for explaining the control operation of the first high-pressure wafer processing module 100 of FIG. [Figure 4] 1 is a flowchart illustrating a high-pressure wafer processing method according to an embodiment of the present invention. [Figure 5] 10 is a flowchart showing a specific procedure for carrying out the second step. [Figure 6] 1 is a flowchart for explaining the mechanism of action of high-pressure carbon doping (HPCD). [Figure 7] 1 is a graph comparing step coverage of insulating films manufactured by high-pressure oxidation (HPO); [Figure 8] 1 is a graph comparing the refractive index of insulating films manufactured by high-pressure oxidation (HPO) and high-pressure carbon doping (HPCD). [Figure 9] 1 is a graph comparing the dielectric constants of insulating films manufactured by high-pressure oxidation (HPO) and high-pressure carbon doping (HPCD). [Figure 10]1 is a comparative graph showing a change in the dielectric constant of an insulating film doped by additionally performing a high pressure thermal treatment (HPA); [Figure 11] 1 is a graph comparing hydrogen concentrations of wafers sequentially subjected to high pressure thermal treatment (HPA) and high pressure oxidation (HPO); [Figure 12] 1 is a comparative graph of hydrogen concentration at the interface by high pressure heat treatment (HPA) and high pressure oxidation (HPO). [Figure 13] 1 is a graph comparing hydrogen concentrations at the interface by high pressure heat treatment (HPA) and high pressure nitriding (HPN). [Figure 14] 1 is a graph comparing wet etching rates of insulating films using high pressure oxidation (HPO) and high pressure thermal treatment (HPA). [Figure 15] 1 is a graph comparing nitrogen concentrations in hafnium oxide films formed by high-pressure nitridation (HPN). [Figure 16] 1 is a comparative graph showing the change in nitrogen concentration of a hafnium oxide film by high pressure nitridation (HPN) and high pressure annealing (HPA). DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, a preferred embodiment of a method for high-pressure wafer processing using a dual high-pressure wafer processing system according to the present invention will be described in detail with reference to the accompanying drawings. In this specification, the same or similar reference numerals are used to refer to the same or similar components in different embodiments, and the description thereof supersedes the first description.

[0030] FIG. 1 is a conceptual diagram of a dual high-pressure wafer processing facility used to perform a high-pressure wafer processing method according to one embodiment of the present invention.

[0031] Referring to this figure, the dual high-pressure wafer processing equipment includes a first high-pressure wafer processing module 100, a second high-pressure wafer processing module 200, a case 300, and a transfer robot 400.

[0032] The first high-pressure wafer processing module 100 and the second high-pressure wafer processing module 200 are devices for performing high-pressure processing on wafers (not shown). Each of the modules 100 and 200 is configured to perform high-pressure oxidation (HPO), high-pressure nitridation (HPN), high-pressure carbon doping (HPCD), and high-pressure annealing (HPA).

[0033] The case 300 is configured to form one accommodation space 350. The modules 100 and 200 are arranged in the accommodation space 350. When the wafer is moved from the first high-pressure wafer processing module 100 to the second high-pressure wafer processing module 200, the wafer is transported within the accommodation space 350. The accommodation space 350 is maintained at a pressure slightly higher than atmospheric pressure. The accommodation space 350 is filled with air filtered by a fan filter unit (FFU).

[0034] The transfer robot 400 is configured to transfer the wafer between the modules 100 and 200. For example, the transfer robot 400 can unload the wafer from the first high-pressure wafer processing module 100 and load it into the second high-pressure wafer processing module 200.

[0035] With this configuration, the wafers are not exposed to the atmosphere and remain only in the receiving space 350 during the process of loading from the first high-pressure wafer processing module 100 to the second high-pressure wafer processing module 200. Since the wafers do not need to be placed in a FOUP, they do not need to undergo a cooling process to cool them down to room temperature.

[0036] The first high pressure wafer processing module 100 will now be described with reference to FIGS.

[0037] FIG. 2 is a conceptual diagram showing the first high-pressure wafer processing module 100 of FIG. 1 in more detail.

[0038] Referring to this figure, a first high pressure wafer processing module 100 may include an inner chamber 110 , an outer chamber 120 , an air supply unit 130 , and an exhaust unit 140 .

[0039] The inner chamber 110 includes a processing chamber 115 for high-pressure processing of wafers. The inner chamber 110 may be made of a non-metallic material, such as quartz, to reduce the possibility of contaminants (particles) being generated in the process environment. Although simplified in the drawing, a door (not shown) for opening the processing chamber 115 is provided at the bottom of the inner chamber 110. The processing chamber 115 is opened by lowering the door, and a wafer attached to a holder (not shown) is inserted into the processing chamber 115. The temperature of the processing chamber 115 can reach several hundred degrees Celsius by operating a heater (not shown) located outside the inner chamber 110. The holder may be a wafer boat capable of stacking multiple wafers. The wafer boat may also be made of quartz.

[0040] The outer chamber 120 is configured to house the inner chamber 110. Unlike the inner chamber 110, the outer chamber 120 is free from wafer contamination issues and may be made of metal. The outer chamber 120 has a protection chamber 125 that houses the inner chamber 110. The outer chamber 120 also has a door (not shown) at its bottom, which descends together with the door of the inner chamber 110 to open the protection chamber 125.

[0041] The gas supply unit 130 is configured to supply gas to the chambers 110 and 120. The gas supply unit 130 includes a gas supplier 131 connected to a utility system of a semiconductor factory. The gas supplier 131 can supply a source gas, a purge gas, and an ambient gas to the inner chamber 110, specifically the process chamber 115. The source gas may include, for example, oxygen gas, water vapor, ammonia gas, ethylene gas, or propylene gas. The purge gas may include, for example, nitrogen gas, argon gas, or helium gas. The ambient gas may include, for example, hydrogen gas, deuterium gas, tritium gas, nitrogen gas, or argon gas. The gas supplier 131 can supply a protective gas, such as nitrogen gas, argon gas, or helium gas, to the protective chamber 125. The protective gas may be the same gas as the purge gas. The protective gas injected into the protective chamber 125 specifically fills the area of ​​the protective chamber 125 excluding the inner chamber 110. These gases are injected into the processing chamber 115 or the protective chamber 125 via an inner gas line 133 or an outer gas line 135, respectively.

[0042] The source gas, the purge gas, and the ambient gas are supplied to the inner chamber 110 to form a reaction pressure higher than atmospheric pressure, for example, several atmospheres to several tens of atmospheres. In this specification, "high pressure" refers to a pressure higher than atmospheric pressure (1 ATM). The protective gas is supplied to the outer chamber 120 to form a protective pressure having a certain relationship to the reaction pressure. For example, the protective pressure is set to be slightly higher than the reaction pressure to prevent the source gas, the purge gas, and the ambient gas from leaking from the process chamber 115. The protective pressure is adjusted in conjunction with the reaction pressure, in accordance with its relationship to the reaction pressure.

[0043] The exhaust unit 140 is configured to exhaust the source gas, the purge gas, the ambient gas, and the protective gas from the chambers 110 and 120. An exhaust pipe 141 is connected to the upper part of the inner chamber 110 to exhaust the source gas, the purge gas, and the ambient gas from the inner chamber 110, specifically the process chamber 115. A gas exhauster 143 is installed in the exhaust pipe 141. The gas exhauster 143 may be a valve that allows or blocks the exhaust of the source gas, the purge gas, and the ambient gas.

[0044] In order to exhaust the protective gas from the outer chamber 120, specifically the protective chamber 125, an exhaust pipe 145 communicating with the outer chamber 120 and a gas exhauster 147 installed therein are provided. These exhaust pipes 141 and 145 communicate with each other, so that the source gas and the ambient gas are diluted with the protective gas and then exhausted.

[0045] The control operation of the first high-pressure wafer processing module 100 will be described with reference to Fig. 3. Fig. 3 is a block diagram for explaining the control operation of the first high-pressure wafer processing module 100 of Fig. 1.

[0046] Referring to this figure (and FIG. 2), the first high-pressure wafer processing module 100 may further include a heating unit 150, a sensing unit 160, a control unit 170, and a storage unit 180 in addition to the aforementioned air supply unit 130, etc.

[0047] The heating unit 150 includes the heater described above. The heater may be disposed in the protection chamber 125. The heater heats the source gas, the purge gas, and the ambient gas to reach a reaction temperature.

[0048] The sensing unit 160 is configured to sense the environment of the chambers 110 and 120. The sensing unit 160 may include a pressure gauge 161 and a temperature gauge 165. The pressure gauge 161 and the temperature gauge 165 may be installed in each of the chambers 110 and 120.

[0049] The control unit 170 is configured to control the air supply unit 130, the exhaust unit 140, etc. The control unit 170 can control the air supply unit 130, etc. based on the detection result of the detection unit 160.

[0050] The storage unit 180 is configured to store data, programs, etc. that the control unit 170 can refer to for control purposes. The storage unit 180 may include at least one type of storage medium selected from the group consisting of a flash memory, a hard disk, a magnetic disk, and an optical disk.

[0051] According to this configuration, the control unit 170 can control the gas supply unit 130 and the like to perform the high-pressure wafer processing method according to one embodiment of the present invention.

[0052] Specifically, the control unit 170 can control the operation of the gas supply unit 130 based on the pressures of the chambers 110 and 120 obtained by the pressure gauge 161. By operating the gas supply unit 130, the inner chamber 110 is filled with the source gas, the purge gas, or the ambient gas at the reaction pressure, and the outer chamber 120 is filled with the protective gas at the protective pressure.

[0053] The control unit 170 can control the operation of the heating unit 150 based on the temperatures of the chambers 110 and 120 obtained by the temperature gauge 165. The operation of the heating unit 150 can allow the source gas, the purge gas, or the ambient gas to reach the reaction temperature.

[0054] The control unit 170 can also control the operation of the exhaust unit 140 based on the pressures of the chambers 110 and 120 obtained by the pressure gauge 161. The exhaust unit 140 can exhaust the source gas, the purge gas, or the ambient gas from the inner chamber 110. The protective gas can be exhausted from the outer chamber 120.

[0055] The specific configuration of the second high-pressure wafer processing module 200 is generally the same as the specific configuration of the first high-pressure wafer processing module 100. Therefore, a description of the specific configuration of the second high-pressure wafer processing module 200 will be omitted. Where necessary, specific components of the second high-pressure wafer processing module 200 may be referred to by similar reference numerals as the corresponding components of the first high-pressure wafer processing module 100.

[0056] A specific method for processing wafers using the first high-pressure wafer processing module 100 will be described with reference to FIGS.

[0057] FIG. 4 is a flowchart illustrating a high-pressure wafer processing method according to an embodiment of the present invention.

[0058] Referring to this figure (and FIGS. 1 to 3), a wafer is placed in the first processing chamber 115 of the first high-pressure wafer processing module 100 (S1). The wafer may be, for example, a silicon wafer. The wafer may have an insulating film or a metal oxide film, or may be a bare wafer.

[0059] A first process is performed on the wafer in the first process chamber 115 (S3), which is any one of the high-pressure oxidation (HPO), high-pressure nitridation (HPN), high-pressure carbon doping (HPCD), and high-pressure heat treatment (HPA).

[0060] After the first process is completed, the wafer is transferred to the second process chamber 215 of the second high-pressure wafer processing module 200 (S5). The wafer is not exposed to the atmosphere because it is transferred within the receiving space 350. The queue time for the wafer to be loaded into the second process chamber 215 is not long.

[0061] In the second processing chamber 215, a second process is performed on the wafer (S7), which is another one of the high-pressure oxidation (HPO), the high-pressure nitridation (HPN), the high-pressure carbon doping (HPCD), and the high-pressure heat treatment (HPA).

[0062] The reaction pressure in each of the first and second steps is higher than atmospheric pressure (high pressure), so that the wafer is subjected to high-pressure processing in the first and second steps in sequence.

[0063] A specific method for carrying out the second step will be described with reference to Figure 5. Figure 5 is a flow chart showing a specific method for carrying out the second step.

[0064] Referring again to this figure, the control unit 270 determines the queue time until the start of the second process after the first process is completed (S11).

[0065] The control unit 270 determines whether the pre-set process conditions of the second process are appropriate in comparison with the determined waiting time (S13). The process conditions may be, for example, a reaction pressure.

[0066] If the process conditions are appropriate, the control unit 270 confirms the process conditions, and the control unit 270 causes the second process to be performed under the confirmed process conditions (S15).

[0067] If the process conditions are not appropriate, the control unit 270 resets the process conditions for the second process to reflect the waiting time (S17). For example, if the waiting time is longer than expected, the control unit 270 may reset the reaction pressure to a value higher than the previously set value (see FIG. 10). The control unit 270 confirms the reset process conditions and causes the second process to be performed under the confirmed process conditions (S15).

[0068] Among the high-pressure oxidation (HPO), high-pressure nitridation (HPN), high-pressure carbon doping (HPCD), and high-pressure thermal treatment (HPA), the mechanism of operation of the high-pressure carbon doping (HPCD) will be described with reference to FIG. 6. FIG. 6 is a flowchart illustrating the mechanism of operation of the high-pressure carbon doping (HPCD). The high-pressure carbon doping (HPCD) will be described based on the assumption that it is performed in the second high-pressure wafer processing module 200.

[0069] Referring to this figure (and FIGS. 2 and 3), a wafer having an insulating film is placed in the second processing chamber 215. The insulating film may be, for example, a silicon oxide (SiO) film formed by high-pressure oxidation (HPO) in the first processing chamber 115. An ambient gas is supplied to the second processing chamber 215 to raise the pressure in the second processing chamber 215 to a reaction pressure. The second processing chamber 215 is heated to raise the temperature in the second processing chamber 215 to a reaction temperature.

[0070] As described above, ethylene gas or propylene gas may be used as the carbon doping source gas. The source gas maintains its molecular state in the second process chamber 215 (S21). To achieve this, the reaction temperature is maintained below the thermal decomposition temperature of the source gas. Specifically, for ethylene gas or propylene gas, the reaction temperature may be determined within a range of 400°C to 600°C.

[0071] The source gas chemically reacts with the insulating film in a molecular state (S23), which is possible because the source gas is maintained in a molecular state due to the reaction temperature.

[0072] Carbon in the source gas is absorbed into the insulating film through a chemical reaction, specifically, chemical absorption, between the source gas and the insulating film (S25).

[0073] The carbon penetrates deep into the insulating film due to the applied pressure (S27). The applied pressure corresponds to the reaction pressure. To generate the applied pressure, the reaction pressure becomes the high pressure.

[0074] The first and second steps can be performed in various combinations, and the details of each combination and process conditions will be explained below based on experimental results.

[0075] The combination of the high pressure oxidation (HPO) as the first step and the high pressure carbon doping (HPCD) as the second step will be described with reference to FIGS.

[0076] FIG. 7 is a graph comparing step coverage of insulating films fabricated by high pressure oxidation (HPO).

[0077] Referring to this diagram, the first process, the high-pressure oxidation (HPO), was performed using a wet oxidation method. The insulating film (SiO) formed by the high-pressure oxidation (HPO) was 10 nm thick. Water vapor was supplied to the first process chamber 115 as the oxidation source gas at 20 sccm, and the reaction pressure was adjusted within the range of 1 ATM to 20 ATM. The solution used for the wet etching was a mixture of 100 parts by weight of pure water and 1 part by weight of hydrofluoric acid.

[0078] The reaction temperature of the high-pressure oxidation (HPO) is determined within the range of 400°C to 950°C. In this experiment, the reaction temperature was 500°C. Since the reaction pressure acts as a high pressure, the reaction temperature may be determined to be 600°C or less. The reaction temperature of the high-pressure oxidation (HPO) is relatively low compared to the reaction temperature of a general vacuum deposition process.

[0079] Again, attention is focused on the reaction pressure. As the reaction pressure increases from 1 ATM to 20 ATM, the step coverage of the insulating film also increases.

[0080] For example, the step coverage of the insulating film is 82% at 1 ATM and 85.4% at 2 ATM. The step coverage increases to 85.9% at 3 ATM, but the increase is slight.

[0081] However, at 5 ATM, the step coverage significantly increases to 96.7%. As the first pressure increases to 10 ATM, 15 ATM, and 20 ATM, the step coverage increases to 97.1%, 98.2%, and 98.9%.

[0082] Considering these results, the reaction pressure is preferably 5 ATM or more from the viewpoint of the step coverage. To obtain the best step coverage, the reaction pressure should be set to 20 ATM.

[0083] FIG. 8 is a graph comparing the refractive index of insulating films fabricated by high-pressure oxidation (HPO) and high-pressure carbon doping (HPCD).

[0084] Referring to this figure, the second process, high-pressure carbon doping (HPCD), was performed on the insulating film formed by the previous high-pressure oxidation (HPO) (20 ATM). Ethylene gas was supplied to the second process chamber 215 as the carbon doping source gas at 5 Ksccm, and the reaction pressure was adjusted in the range of 1 ATM to 20 ATM.

[0085] The reaction temperature of the high-pressure carbon doping (HPCD) may be determined within the range of 400°C to 950°C. In this experiment, the reaction temperature was 400°C. Since the reaction pressure acts as a high pressure, the reaction temperature can be determined to be 600°C or less.

[0086] Again, let us look at the change in reaction pressure. Compared to the insulating film that has undergone only high-pressure oxidation (HPO), the refractive index of the carbon-doped insulating film is lower even at 1 ATM. As the reaction pressure increases from 1 ATM to 20 ATM, the refractive index tends to decrease overall.

[0087] Considering this tendency, the higher the reaction pressure, the better. At 20 ATM, the refractive index reaches its lowest value of 1.31. At 5 ATM, the refractive index drops significantly. Considering this, the reaction pressure of the high-pressure carbon doping (HPCD) is preferably determined in the range of 5 ATM to 20 ATM.

[0088] FIG. 9 is a graph comparing the dielectric constant of insulating films fabricated by high pressure oxidation (HPO) and high pressure carbon doping (HPCD).

[0089] Referring to this figure, the change in the dielectric constant of the insulating film has a similar tendency to the change in the refractive index described above.

[0090] Specifically, the dielectric constant of the carbon-doped insulating film is lower than that of the insulating film subjected to only high-pressure oxidation (HPO) even at 1 ATM. As the reaction pressure increases from 1 ATM to 20 ATM, the dielectric constant also tends to decrease overall.

[0091] Considering this trend, the higher the reaction pressure, the better. At 20 ATM, the dielectric constant reaches a minimum of 3.25. At 5 ATM, the dielectric constant drops significantly. Considering this, it is once again confirmed that the reaction pressure for high-pressure carbon doping (HPCD) is preferably determined in the range of 5 ATM to 20 ATM.

[0092] FIG. 10 is a comparative graph showing the change in the dielectric constant of an insulating film doped by additionally performing a high pressure thermal treatment (HPA).

[0093] Referring further to this figure (and FIGS. 2 and 3), after the high-pressure carbon doping (HPCD) is performed in the second process chamber 215, a high-pressure thermal treatment (HPA) may be additionally performed in-situ in the second process chamber 215. The high-pressure thermal treatment (HPA) is performed on the insulating film doped by the previous high-pressure carbon doping (HPCD) (20 ATM). The high-pressure thermal treatment (HPA) is considered to be included in the second process.

[0094] To perform the HPPA in situ, a purge process is performed between the HPCD and HPA processes. The reaction temperature and pressure during the purge process can be maintained the same as those during the previous HPCD process. The control unit 270 controls the exhaust unit 240 together with the gas supply unit 230 to supply the purge gas to the second process chamber 215 and to purge and exhaust the source gas from the second process chamber 215. The time required for the purge process may be shorter than that for the HPCD process.

[0095] For the high pressure heat treatment (HPA), a heat treatment atmosphere gas, e.g., hydrogen gas, was supplied to the second process chamber 215. The reaction pressure of the atmosphere gas was adjusted in the range of 1 ATM to 20 ATM. The reaction temperature of the high pressure heat treatment (HPA) was maintained at 400°C, as in the purge process. The reaction temperature of the high pressure heat treatment (HPA) may also be determined in the range of 400°C to 950°C, and was determined to be 400°C in this experiment. Because the reaction pressure acts as a high pressure, the reaction temperature can be determined to be 600°C or less.

[0096] Again, let us look at the change in reaction pressure. First, the dielectric constant of the insulating film generally tends to increase with increasing waiting time. As the reaction pressure increases from 1 ATM to 20 ATM, the increase in the dielectric constant with increasing waiting time becomes smaller.

[0097] Considering this tendency, the higher the reaction pressure, the better. At 20 ATM, the dielectric constant remains almost unchanged at 3.25 even when the waiting time is changed. At 5 ATM, the change in the dielectric constant is significantly reduced. Considering this, it is preferable that the reaction pressure of the high-pressure heat treatment (HPA) be determined in the range of 5 ATM to 20 ATM.

[0098] The combination of the high pressure heat treatment (HPA) as the first step and the high pressure oxidation (HPO) as the second step will be described with reference to FIGS.

[0099] FIG. 11 is a comparative graph of hydrogen concentration in wafers that have been subjected to high pressure thermal treatment (HPA) and high pressure oxidation (HPO) in sequence.

[0100] Referring to this figure (and Figure 2), the wafer has a 5 nm thick hafnium oxide (HfO) film formed using ALD equipment under process conditions of 1 torr and 450°C.

[0101] The wafer was subjected to high pressure heat treatment (HPA) under process conditions of 20 ATM and 400° C. Hydrogen gas was supplied as the atmospheric gas at 5 Ksccm to the first processing chamber 115. Two wafers were prepared.

[0102] When only the high pressure heat treatment (HPA) was performed, both wafers showed a tendency for the hydrogen concentration to decrease from the hafnium oxide film to the silicon substrate. Specifically, the hydrogen concentration decreased in a roughly step-like manner near the surface of the hafnium oxide film and after the interface (5 nm depth) between the hafnium oxide film and the substrate.

[0103] The high-pressure oxidation (HPO) was additionally performed on both of the two wafers. The high-pressure oxidation (HPO) was performed on one of the two wafers in a chamber-to-chamber manner according to this embodiment, and on the other wafer in a tool-to-tool manner. In both methods, the high-pressure oxidation (HPO) was performed under process conditions of 20 ATM and 450°C. Water vapor was supplied as the source gas at 20 sccm into the second process chamber 215.

[0104] In the tool-to-tool case, the shape of the hydrogen concentration graph is similar to that in the case of the high-pressure thermal treatment (HPA) only, however, the hydrogen concentration in the former case is significantly lower than that in the latter case, especially in the hafnium oxide film region.

[0105] In contrast, in the chamber-to-chamber method, the hydrogen concentration increased across the interface, which is understood to be due to the hydrogen in the hafnium oxide film being transported to the interface.

[0106] FIG. 12 is a comparative graph of the hydrogen concentration at the interface by high pressure heat treatment (HPA) and high pressure oxidation (HPO).

[0107] Referring to this figure, the change in hydrogen concentration at the interface due to the reaction pressure in the chamber-to-chamber method is shown. The reaction pressure was adjusted from 1 ATM to 20 ATM.

[0108] As the reaction pressure increases from 1 ATM to 20 ATM, the hydrogen concentration at the interface generally increases. Considering this tendency, the higher the reaction pressure, the more preferable it is.

[0109] At 20 ATM, the hydrogen concentration reaches a maximum value of 2.80E+21 atom %. At 5 ATM, the hydrogen concentration increases significantly. Considering these points, it is preferable that the reaction pressure of the high-pressure oxidation (HPO) is determined within the range of 5 ATM to 20 ATM.

[0110] The combination of the high pressure heat treatment (HPA) as the first step and the high pressure nitriding (HPN) as the second step will be described with reference to Fig. 13. Fig. 13 is a graph comparing the hydrogen concentration at the interface between the high pressure heat treatment (HPA) and the high pressure nitriding (HPN).

[0111] Referring to this figure (and FIG. 2), the wafer has a 5 nm thick hafnium oxide (HfO) film, as in the previous example, and the high pressure thermal treatment (HPA) for the wafer was also performed in the first processing chamber 115 under the same process conditions as in the previous example.

[0112] In the second process, the wafer was subjected to high-pressure nitridation (HPN). Ammonia gas was supplied as a nitridation source gas at 2 Ksccm to the second process chamber 215, and the reaction pressure was adjusted in the range of 1 ATM to 20 ATM.

[0113] The reaction temperature may be determined within a range of 400°C to 950°C, and was determined to be 450°C in this experiment. Since the reaction pressure acts as a high pressure, the reaction temperature can be determined to be 600°C or less.

[0114] Again, let us look at the reaction pressure. As the reaction pressure increases from 1 ATM to 20 ATM, the hydrogen concentration at the interface generally increases. Taking this tendency into consideration, the higher the reaction pressure, the more preferable it is.

[0115] At 20 ATM, the hydrogen concentration reaches a maximum value of 8.66E+20 atom %. At 5 ATM, the hydrogen concentration increases significantly. Considering these points, it is preferable that the reaction pressure of the high-pressure nitriding (HPN) is determined within the range of 5 ATM to 20 ATM.

[0116] The combination of the high pressure oxidation (HPO) as the first process and the high pressure thermal treatment (HPA) as the second process will be described with reference to Figure 14. Figure 14 is a graph comparing the wet etching rates of insulating films by high pressure oxidation (HPO) and high pressure thermal treatment (HPA).

[0117] Referring to this figure, the first process, high pressure oxidation (HPO), was performed using wet oxidation under the same process conditions as in the previous example, and the second process, high pressure heat treatment (HPA), was also performed under the same process conditions as in the previous example.

[0118] The reaction pressure of the high pressure heat treatment (HPA) was adjusted to 1 ATM to 20 ATM. As the reaction pressure increased from 1 ATM to 20 ATM, the wet etching rate of the insulating film (SiO) (20 ATM) formed by the high pressure oxidation (HPO) tended to decrease.

[0119] When the reaction pressure is between 1 ATM and 2 ATM, the wet etching rate is greater than 1 Å / sec. To obtain a wet etching rate lower than 1 Å / sec, the reaction pressure must be set to 3 ATM or higher. Specifically, at 3 ATM, the wet etching rate is 0.972 Å / sec, which is within the desired range.

[0120] Furthermore, as the reaction pressure increases to 5 ATM, 10 ATM, 15 ATM, and 20 ATM, the wet etching rate becomes 0.906 angstroms / sec, 0.886 angstroms / sec, 0.866 angstroms / sec, and 0.826 angstroms / sec.

[0121] Considering these results, it is preferable that the reaction pressure of the high pressure heat treatment (HPA) is 3 ATM or more from the viewpoint of the wet etching rate. To obtain the highest wet etching rate, the reaction pressure can be set to 20 ATM.

[0122] The combination of the high pressure nitriding (HPN) as the first step and the high pressure heat treatment (HPA) as the second step will be described with reference to FIGS.

[0123] FIG. 15 is a comparative graph of nitrogen concentration in hafnium oxide films formed by high pressure nitridation (HPN).

[0124] Referring to this figure, the first process, high pressure nitridation (HPN), was performed under the same process conditions as in the previous example to form a hafnium oxide film, where the reaction pressure was adjusted from 1 ATM to 20 ATM.

[0125] As the reaction pressure increases from 1 ATM to 20 ATM, the nitrogen concentration of the hafnium oxide film generally increases, where the nitrogen concentration is the average concentration within the thickness range of the hafnium oxide film.

[0126] Considering this tendency, the higher the reaction pressure, the better. At 20 ATM, the nitrogen concentration reaches a maximum value of 1.12E+21 atom%. At 5 ATM, the nitrogen concentration increases significantly. Considering this, it is preferable that the reaction pressure of the high-pressure nitriding (HPN) be determined in the range of 5 ATM to 20 ATM.

[0127] FIG. 16 is a comparative graph showing the change in nitrogen concentration in hafnium oxide films by high pressure nitridation (HPN) and high pressure annealing (HPA).

[0128] Referring to this figure, the high pressure heat treatment (HPA) as the second step was also carried out under the same process conditions as in the previous example, and the reaction pressure of the high pressure heat treatment (HPA) was adjusted from 1 ATM to 20 ATM.

[0129] First, it can be seen that the nitrogen concentration of the hafnium oxide film generally decreases with increasing waiting time. As the reaction pressure increases from 1 ATM to 20 ATM, the decrease in the nitrogen concentration due to the increase in waiting time decreases. Considering this tendency, a higher reaction pressure is preferable.

[0130] At 20 ATM, the decrease in the nitrogen concentration is smallest even when the waiting time is changed. Also, at 10 ATM, the decrease in the nitrogen concentration is significantly small. Considering these points, it is preferable that the reaction pressure of the high-pressure heat treatment (HPA) is determined in the range of 10 ATM to 20 ATM.

[0131] The high-pressure wafer processing method using the dual high-pressure wafer processing equipment is not limited to the configurations and operation methods of the above-described embodiments, and various modifications can be made by selectively combining all or part of each embodiment. [Industrial Applicability]

[0132] The present invention has industrial applicability in the field of high-pressure wafer processing using dual high-pressure wafer processing equipment.

Claims

1. placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first process chamber, the first process being one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module; and performing a second process on the wafer in the second process chamber, the second process being another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment; the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed in a single accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; the first step and the second step are carried out at a reaction pressure higher than atmospheric pressure; The first high-pressure wafer processing module and the second high-pressure wafer processing module each include: a protection chamber that houses one of the first treatment chamber and the second treatment chamber and is maintained at a protection pressure; The protective pressure of the protective chamber is adjusted in conjunction with the reaction pressure to have a higher relationship than the reaction pressure; A method for high-pressure wafer processing using dual high-pressure wafer processing equipment.

2. The reaction pressures of the high-pressure oxidation, the high-pressure nitridation, and the high-pressure carbon doping are:

2. The method for high-pressure wafer processing using the dual high-pressure wafer processing equipment according to claim 1, wherein the pressure is determined in the range of 5 ATM to 20 ATM.

3. The reaction pressure of the high-pressure heat treatment is 2. The method for high-pressure wafer processing using the dual high-pressure wafer processing equipment according to claim 1, wherein the pressure is determined in the range of 3 ATM to 20 ATM.

4. The reaction temperatures of the high-pressure oxidation, the high-pressure nitriding, and the high-pressure heat treatment are:

2. The method for high-pressure wafer processing using the dual high-pressure wafer processing equipment according to claim 1, wherein the temperature is determined in the range of 400 to 600 degrees Celsius.

5. The source gases for the high pressure oxidation and the high pressure nitridation are 2. The method for high-pressure wafer processing using dual high-pressure wafer processing equipment according to claim 1, wherein the gas used is any one of oxygen gas, water vapor, and ammonia gas.

6. placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first process chamber, the first process being one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module; and performing a second process on the wafer in the second process chamber, the second process being another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment; the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed in a single accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; the first step and the second step are carried out at a reaction pressure higher than atmospheric pressure; The high-pressure carbon dope is The carbon doping source gas is subjected to a reaction temperature lower than the thermal decomposition temperature of the carbon doping source gas, and the carbon doping source gas is allowed to chemically react with the insulating film of the wafer in a molecular state. A method for high-pressure wafer processing using dual high-pressure wafer processing equipment.

7. The reaction temperature of the high-pressure carbon doping is 7. The method for high-pressure wafer processing using dual high-pressure wafer processing equipment according to claim 6, wherein the temperature is determined within a range of 400°C to 600°C.

8. The carbon doping source gas is 7. The method for high-pressure wafer processing using dual high-pressure wafer processing equipment according to claim 6, wherein the gas used is one of ethylene gas and propylene gas.

9. The method of claim 8, further comprising: placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first process chamber, the first process being one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module; and performing a second process on the wafer in the second process chamber, the second process being another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment; the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed in a single accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; the first step and the second step are carried out at a reaction pressure higher than atmospheric pressure; and further comprising performing the high-pressure heat treatment on the wafer in situ after performing any one of the high-pressure oxidation, the high-pressure nitridation, and the high-pressure carbon doping. A method for high-pressure wafer processing using dual high-pressure wafer processing equipment.

10. The method further includes performing a purge between any one of the high-pressure oxidation, the high-pressure nitridation, and the high-pressure carbon doping and the high-pressure heat treatment; 10. The method of claim 9, wherein the purging is performed while maintaining the reaction pressure and reaction temperature of the previous process.

11. The pressure in the storage space is 10. A method for high pressure wafer processing using the dual high pressure wafer processing equipment of claim 1, wherein the equipment is maintained at a pressure higher than atmospheric pressure.

12. moving the wafer to a second process chamber of the second high pressure wafer processing module, 2. The method of claim 1, further comprising the step of unloading the wafer from the first processing chamber and then loading the wafer into the second processing chamber without a cooling process.

13. The step of placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first process chamber, the first process being one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module; and performing a second process on the wafer in the second process chamber, the second process being another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment; the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed in a single accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; the first step and the second step are carried out at a reaction pressure higher than atmospheric pressure; performing a second process, which is another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment, on the wafer in the second process chamber; determining process conditions in consideration of a waiting time after completion of the first process; A method for high-pressure wafer processing using dual high-pressure wafer processing equipment.

14. The step of placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first process chamber, the first process being one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module; and performing a second process on the wafer in the second process chamber, the second process being another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment; the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed in a single accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; the first step and the second step are carried out at a reaction pressure higher than atmospheric pressure; the first step is the high-pressure oxidation, and the second step is the high-pressure carbon doping; The reaction pressure of the high-pressure oxidation and the high-pressure carbon doping is Determined in the range of 5 ATM to 20 ATM, A method for high-pressure wafer processing using dual high-pressure wafer processing equipment.

15. The second step comprises: The method further includes the high-pressure heat treatment being performed in situ after the high-pressure carbon doping, The reaction pressure of the high-pressure heat treatment is 15. The method for high-pressure wafer processing using dual high-pressure wafer processing equipment according to claim 14, wherein the pressure is determined in the range of 5 ATM to 20 ATM.

16. The step of placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first process chamber, the first process being one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module; and performing a second process on the wafer in the second process chamber, the second process being another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment; the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed in a single accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; the first step and the second step are carried out at a reaction pressure higher than atmospheric pressure; the first step is the high-pressure heat treatment, and the second step is the high-pressure oxidation; The reaction pressures of the high-pressure heat treatment and the high-pressure oxidation are: Determined in the range of 5 ATM to 20 ATM, A method for high-pressure wafer processing using dual high-pressure wafer processing equipment.

17. The step of placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first process chamber, the first process being one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module; and performing a second process on the wafer in the second process chamber, the second process being another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment; the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed in a single accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; the first step and the second step are carried out at a reaction pressure higher than atmospheric pressure; the first step is the high-pressure heat treatment, and the second step is the high-pressure nitriding; The reaction pressure of the high-pressure heat treatment and the high-pressure nitriding is Determined in the range of 5 ATM to 20 ATM, A method for high-pressure wafer processing using dual high-pressure wafer processing equipment.

18. the first step is the high-pressure oxidation, and the second step is the high-pressure heat treatment; The reaction pressure of the high-pressure oxidation is It is determined in the range of 5 ATM to 20 ATM, The reaction pressure of the high-pressure heat treatment is 2. The method for high-pressure wafer processing using the dual high-pressure wafer processing equipment according to claim 1, wherein the pressure is determined in the range of 3 ATM to 20 ATM.

19. The step of placing a wafer in a first processing chamber of a first high pressure wafer processing module; performing a first process on the wafer in the first process chamber, the first process being one of high-pressure oxidation, high-pressure nitridation, high-pressure carbon doping, and high-pressure heat treatment; moving the wafer to a second processing chamber of a second high pressure wafer processing module; and performing a second process on the wafer in the second process chamber, the second process being another one of the high-pressure oxidation, the high-pressure nitridation, the high-pressure carbon doping, and the high-pressure heat treatment; the first high-pressure wafer processing module and the second high-pressure wafer processing module are disposed in a single accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; the first step and the second step are carried out at a reaction pressure higher than atmospheric pressure; the first step is the high-pressure nitriding, and the second step is the high-pressure heat treatment, The reaction pressure of the high-pressure nitriding is It is determined in the range of 5 ATM to 20 ATM, The reaction pressure of the high-pressure heat treatment is Determined in the range of 10 ATM to 20 ATM, A method for high-pressure wafer processing using dual high-pressure wafer processing equipment.

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