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 utilizing 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, wiring, etc.

[0003] An insulating film is formed on the wafer through an oxidation or deposition process. The insulating film prevents leakage current from occurring even after the circuit pattern is formed. The insulating film also acts as a protective film in the subsequent etching process. 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] In addition, when multiple processes such as oxidation, nitridation, and heat treatment are performed on a wafer, each process is performed in a separate device. This causes the wafer to be moved between separate devices, resulting in a long queue time. During the 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 the processed wafers while suppressing natural oxidation of the wafers. [Means for solving the problem]

[0007] To achieve the above object, according to one aspect of the present invention, a high pressure wafer processing method using dual high pressure wafer processing equipment 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 the other one 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 arranged in 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, each of the source gases for 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 any 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 protective chamber that accommodates either the first processing chamber or the second processing chamber and is maintained at a protective pressure, and the protective pressure of the protective chamber may be adjusted in coordination with the reaction pressure so as to be higher than the reaction pressure.

[0018] Here, the pressure in the storage 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 processing 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 process is the high pressure oxidation, and the second process 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 process is the high pressure heat treatment, and the second process 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 nitridation, the second process is the high pressure heat treatment, the reaction pressure of the high pressure nitridation 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. Effect of the Invention

[0027] According to the high pressure wafer processing method using the dual high pressure wafer processing equipment of the present invention, after the first process is performed on the wafer in the first process chamber, the wafer is moved to the second process chamber in the accommodation space and the second process is performed there, so that there is almost no queue time for the wafer. This minimizes the time that the wafer is exposed to the atmosphere, so that natural oxidation of the wafer is strongly suppressed. In addition, the quality characteristics of the processed wafer can be greatly improved because both the first and second processes are performed at high pressure. [Brief description 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 one embodiment of the present invention. [Diagram 2] FIG. 2 is a conceptual diagram showing in more detail the first high-pressure wafer processing module 100 of FIG. [Diagram 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] 2 is a flowchart showing a high pressure wafer processing method according to an embodiment of the present invention. [Diagram 5] 11 is a flowchart showing a specific procedure for carrying out the second step. [Figure 6] 1 is a flow chart for explaining the action mechanism 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 comparative graph of the refractive index of insulating films manufactured by high pressure oxidation (HPO) and high pressure carbon doping (HPCD). [Figure 9] 1 is a comparative graph of the dielectric constant 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 heat treatment (HPA); [Figure 11] 1 is a comparative graph of hydrogen concentration in 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 an interface by high pressure heat treatment (HPA) and high pressure oxidation (HPO). [Figure 13] 1 is a comparative graph of hydrogen concentration at an 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 comparative graph of nitrogen concentration in hafnium oxide films produced by high pressure nitridation (HPN). [Figure 16] 1 is a comparative graph showing changes in nitrogen concentration in a hafnium oxide film caused by high pressure nitridation (HPN) and high pressure thermal treatment (HPA). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0030] FIG. 1 is a schematic 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] Each of the first high pressure wafer processing module 100 and the second high pressure wafer processing module 200 is an apparatus for performing high pressure processing on a wafer (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 in the first high pressure wafer processing module 100 and load the wafer into the second high pressure wafer processing module 200.

[0035] According to this configuration, the wafer is not exposed to the atmosphere and remains 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 wafer does not need to be placed in a FOUP, it does not need to go through a cooling process to cool the wafer 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 more detailed conceptual diagram of the first high pressure wafer processing module 100 of FIG.

[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 has a processing chamber 115 for processing the wafer at high pressure. The inner chamber 110 may be made of a non-metallic material, for example, 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 the wafer is inserted into the processing chamber 115 while still attached to a holder (not shown). The temperature of the processing chamber 115 may reach several hundred degrees Celsius by the operation of a heater (not shown) disposed outside the inner chamber 110. The holder may be a wafer boat in which wafers can be stacked in multiple layers. The wafer boat may also be made of a quartz material.

[0040] The outer chamber 120 is configured to house the inner chamber 110. The outer chamber 120 may be made of a metal material since it is free from the problem of contamination of the wafer, unlike the inner chamber 110. 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 the 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 that is connected to a utility of a semiconductor factory. The gas supplier 131 can supply a source gas, a purge gas, and an atmosphere gas to the inner chamber 110, specifically the processing 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 atmosphere gas may include, for example, hydrogen gas, deuterium gas, tritium gas, nitrogen gas, or argon gas. The gas supplier 131 can provide, for example, nitrogen gas, argon gas, or helium gas as a protective gas to the protective chamber 125. The protective gas may be selected from the same type of gas as the purge gas. The protective gas injected into the protective chamber 125 is specifically filled in 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 high 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 with the reaction pressure.

[0043] The exhaust unit 140 is configured to exhaust the source gas, the purge gas, the atmosphere gas, and the protective gas from the chambers 110 and 120. An exhaust pipe 141 is connected to an upper portion of the inner chamber 110 in order to exhaust the source gas, the purge gas, and the atmosphere 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 and stops exhaust of the source gas, the purge gas, and the atmosphere 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. Since the exhaust pipes 141 and 145 communicate with each other, the source gas and the atmospheric gas are diluted with the protective gas and 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 gas 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 among 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 an 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 the operation of the gas supply unit 130, the inner chamber 110 is filled with the source gas, the purge gas, or the atmospheric 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 temperature of the chambers 110, 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, 120 obtained by the pressure gauge 161. By the operation of the exhaust unit 140, the source gas, the purge gas, or the atmospheric gas is exhausted 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 numbers as the corresponding components of the first high pressure wafer processing module 100.

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

[0057] FIG. 4 is a flow chart showing a high pressure wafer processing method according to one embodiment of the present invention.

[0058] Referring to this figure (and to Figures 1 to 3), a wafer is placed in the first process 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). The first process is any 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).

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

[0061] In the second processing chamber 215, a second process is performed on the wafer (S7). The second process 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 Fig. 5. Fig. 5 is a flow chart showing a specific method for carrying out the second step.

[0064] Continuing to refer to this figure, the control unit 270 grasps 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 process conditions already set for the second process are appropriate in comparison with the grasped 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 controls 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 of 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] Of the high pressure oxidation (HPO), high pressure nitridation (HPN), high pressure carbon doping (HPCD), and high pressure thermal treatment (HPA), the action mechanism of the high pressure carbon doping (HPCD) will be described with reference to Fig. 6. Fig. 6 is a flow chart for explaining the action mechanism of the high pressure carbon doping (HPCD). The high pressure carbon doping (HPCD) will be described on the basis that it is performed in the second high pressure wafer processing module 200.

[0069] Referring to this figure (and to FIGS. 2 to 3), a wafer having an insulating film is placed in the second process chamber 215. The insulating film may be, for example, a silicon oxide film (SiO) formed by the high pressure oxidation (HPO) in the first process chamber 115. An atmospheric gas is supplied to the second process chamber 215 so that the pressure in the second process chamber 215 reaches a reaction pressure. The second process chamber 215 is heated so that the temperature in the second process chamber 215 reaches 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 a molecular state in the second process chamber 215 (S21). For this purpose, the reaction temperature is maintained below the thermal decomposition temperature of the source gas. Specifically, for the ethylene gas or the propylene gas, the reaction temperature may be determined within a range of 400° C. to 600° C.

[0071] The source gas is chemically reacted 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 from 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 deeply into the insulating film due to the applied pressure (S27). The applied pressure is a force corresponding to the reaction pressure. In order to generate the applied pressure, the reaction pressure becomes the high pressure.

[0074] The first and second steps are performed in various combinations, and the details of each combination and process conditions will be described 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 comparative graph of step coverage of insulating films manufactured by high pressure oxidation (HPO).

[0077] Referring to this figure, the high pressure oxidation (HPO) in the first process was performed by wet oxidation. The insulating film (SiO) was formed to a thickness of 10 nm by the high pressure oxidation (HPO). Water vapor was supplied to the first process chamber 115 as an oxidation source gas at 20 sccm, and the reaction pressure was adjusted in 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 a 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. When 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 increases significantly 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, it is preferable that the reaction pressure is 5 ATM or more from the viewpoint of the step coverage. In order to obtain the best step coverage, the reaction pressure should be set to 20 ATM.

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

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

[0085] The reaction temperature of the high pressure carbon doping (HPCD) may be determined within a 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 been subjected to only high pressure oxidation (HPO) (HPO only), 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 is 1.31, which is the lowest value. At 5 ATM, the refractive index is significantly lower. Considering this, it is preferable that the reaction pressure of the high pressure carbon doping (HPCD) is determined in the range of 5 ATM to 20 ATM.

[0088] FIG. 9 is a comparative graph of 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 that has been 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 tendency, the higher the reaction pressure, the more preferable it is. At 20 ATM, the dielectric constant is 3.25, the lowest value. Also, at 5 ATM, the dielectric constant is significantly lower. Considering this, it is once again confirmed that the reaction pressure of the 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 dielectric constant of an insulating film doped by additionally performing a high pressure heat treatment (HPA).

[0093] 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] In order to perform the high pressure heat treatment (HPA) in situ, a purge process is performed between the high pressure carbon doping (HPCD) and the high pressure heat treatment (HPA). The reaction temperature and reaction pressure of the purge process can be maintained the same as those of the previous process, the high pressure carbon doping (HPCD). 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 the source gas and exhaust it from the second process chamber 215. The time required for the purge process may be shorter than that of the high pressure carbon doping (HPCD) process.

[0095] For the high pressure heat treatment (HPA), a heat treatment atmosphere gas, for example, hydrogen gas, was supplied to the second treatment 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., similar to 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. Since 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 the reaction pressure. First, the dielectric constant of the insulating film generally tends to increase with an increase in the waiting time. As the reaction pressure increases from 1 ATM to 20 ATM, the increase in the dielectric constant due to the increase in the waiting time becomes smaller.

[0097] Considering this tendency, the higher the reaction pressure, the more preferable. At 20 ATM, the dielectric constant remains almost unchanged at 3.25 even if the waiting time changes. 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) is 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 FIG. 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 stepwise near the surface of the hafnium oxide film and after the interface (5 nm deep) 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 manners, the high pressure oxidation (HPO) was performed under process conditions of 20 ATM and 450° C. Water vapor as the source gas was supplied to the second process chamber 215 at 20 sccm.

[0104] In the tool-to-tool case, the shape of the hydrogen concentration graph is similar to that in the case where only the high pressure thermal treatment (HPA) is performed, 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 was elevated across the interface, which is understood to be due to hydrogen in the hafnium oxide layer being transported to the interface.

[0106] FIG. 12 is a comparative graph of 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. Taking this tendency into consideration, it is preferable that the reaction pressure is as high as possible.

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

[0110] The combination of the high pressure heat treatment (HPA) as the first process and the high pressure nitriding (HPN) as the second process will be described with reference to Fig. 13. Fig. 13 is a comparative graph of 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 embodiment. The high pressure heat treatment (HPA) for the wafer was also performed in the first processing chamber 115 under the same process conditions as in the previous embodiment.

[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. Considering this tendency, it is preferable that the reaction pressure is as high as possible.

[0115] At 20 ATM, the hydrogen concentration reaches a maximum value of 8.66E+20 atom %. At 5 ATM, the hydrogen concentration is significantly higher. Considering these points, it is preferable that the reaction pressure of the high pressure nitridation (HPN) is determined in 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 Fig. 14. Fig. 14 is a comparative graph showing wet etching rates of insulating films by the high pressure oxidation (HPO) and the high pressure thermal treatment (HPA).

[0117] Referring to this figure, the high pressure oxidation (HPO) as the first process was performed by wet oxidation under the same process conditions as in the previous example, and the high pressure heat treatment (HPA) as the second process 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 increases from 1 ATM to 20 ATM, the wet etching rate of the insulating film (SiO) (20 ATM) formed by the high pressure oxidation (HPO) tends 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 less than 1 Å / sec, the reaction pressure must be set to 3 ATM or greater. 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 rates become 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. 15 and 16. FIG.

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

[0124] 1, the first process, the high pressure nitridation (HPN), was performed under the same process conditions as in the previous example to produce 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 an average concentration within the thickness range of the hafnium oxide film.

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

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

[0128] Referring to this figure, the high pressure heat treatment (HPA) as the second process 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, the higher the reaction pressure, the more preferable it is.

[0130] At 20 ATM, the decrease in the nitrogen concentration is smallest even if the waiting time is changed. Also, at 10 ATM, the decrease in the nitrogen concentration is significantly small. Considering this, 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-mentioned embodiments, and the above-mentioned embodiments may be configured to be variously modified 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 process 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 process 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 one accommodation space, and the wafer is moved from the first processing chamber to the second processing chamber within the accommodation space; The first and second steps are performed at a reaction pressure higher than atmospheric pressure.

2. The reaction pressures of the high pressure oxidation, the high pressure nitridation, and the high pressure carbon doping are 2. The method of claim 1, wherein the pressure range is determined to be between 5 ATM and 20 ATM.

3. The reaction pressure of the high pressure heat treatment is 2. The method of claim 1, wherein the pressure range is determined to be between 3 ATM and 20 ATM.

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

2. The method of claim 1, wherein the temperature is determined in the range of 400° C. to 600° C. by using the dual high pressure wafer processing equipment.

5. The source gases for the high pressure oxidation and the high pressure nitridation are 2. The method of claim 1, further comprising the step of: providing a gas mixture containing at least one of oxygen gas, water vapor, and ammonia gas.

6. The high pressure carbon dope is 2. The method of claim 1, wherein the method is performed at a reaction temperature lower than the thermal decomposition temperature of a carbon doping source gas, and the source gas is chemically reacted with the insulating film of the wafer in a molecular state.

7. The reaction temperature of the high pressure carbon dope is 7. The method of 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 of claim 6, further comprising the step of: providing a gas supply to the dual high pressure wafer processing facility;

9. 2. The method of claim 1, 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.

10. The method further includes a step of 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; 10. The method of claim 9, wherein the purging is performed while maintaining the reaction pressure and reaction temperature of the previous process.

11. Each of the first high pressure wafer processing module and the second high pressure wafer processing module comprises: a protection chamber that contains 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 2. The method of claim 1, wherein the pressure is adjusted in conjunction with the reaction pressure to have a higher relationship with the reaction pressure.

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

13. 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.

14. 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; 2. The method of claim 1, further comprising determining process conditions by taking into consideration a waiting time after completion of the first process.

15. 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 2. The method of claim 1, wherein the pressure range is determined to be between 5 ATM and 20 ATM.

16. The second step comprises: The method further includes the high pressure heat treatment performed in situ after the high pressure carbon doping, The reaction pressure of the high pressure heat treatment is 16. The method of claim 15, wherein the pressure range is determined to be between 5 ATM and 20 ATM.

17. the first step is the high pressure heat treatment, and the second step is the high pressure oxidation; The reaction pressure of the high pressure heat treatment and the high pressure oxidation is 2. The method of claim 1, wherein the pressure range is determined to be between 5 ATM and 20 ATM.

18. 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 nitridation is 2. The method of claim 1, wherein the pressure range is determined to be between 5 ATM and 20 ATM.

19. 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 of claim 1, wherein the pressure range is determined to be between 3 ATM and 20 ATM.

20. 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 nitridation 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 of claim 1, wherein the pressure is determined in the range of 10 ATM to 20 ATM.

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