A chamber cleaning control method and semiconductor process equipment

Abstract

This invention provides a chamber cleaning control method and semiconductor process equipment. The method includes: a cleaning step, in which, after the chamber has completed maintenance, a preset cleaning gas is introduced into the chamber to perform dry cleaning to remove residual polymers and chloride ions; wherein the preset cleaning gas includes oxygen-containing gas and hydrogen-containing gas; and a pre-cleaning step, in which, before each start of operation of the chamber, a set cleaning gas is introduced into the chamber to perform pre-cleaning to remove residual polymers and chloride ions; wherein the set cleaning gas includes oxygen-containing gas and hydrogen-containing gas. This invention can ensure that the polymer in the chamber is maintained in a balanced state, avoiding a continuous decrease in the photoresist etching rate due to excessive polymers, and eliminates the need for chamber opening for cleaning, reducing component wear and equipment failure rate. It can effectively remove residual polymers and chloride ions in the chamber, restore the photoresist etching rate, and improve product yield.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a chamber cleaning control method and semiconductor process equipment. Background Technology

[0002] In integrated circuit manufacturing, dry etching is a commonly used process in device fabrication. Dry etching allows for precise control over the morphology of the desired device, ensuring its electrical performance. Aluminum (Al) is a commonly used interconnect metal material and metal contact point for chips due to its low resistivity, low cost, and ease of etching. To ensure etching accuracy, dry etching technology is typically used to etch aluminum substrates, with photoresist used as a mask. After the aluminum substrate etching process is complete, it is crucial to quickly remove the residual corrosive products (chloride-containing photoresist and etching byproducts) from the silicon wafer surface. Otherwise, they will not only corrode the aluminum substrate but also increase defects on the silicon wafer surface, thereby compromising device performance. Therefore, timely removal of residual photoresist and etching byproducts from the aluminum substrate surface without exposure to the atmosphere, along with passivation protection treatment, is an essential process step.

[0003] However, as production continues, the polymer content within the chamber continues to increase, see, for example... Figure 1 The graph showing the relationship between the etching time of the photoresist removal chamber and the photoresist etching rate indicates that as the etching time of the aluminum photoresist removal chamber increases, the photoresist etching rate of the machine's photoresist removal chamber continuously decreases, which can easily lead to incomplete photoresist removal. When the residual photoresist on the aluminum substrate comes into contact with the atmosphere, the chloride ions in the residual photoresist will corrode the aluminum substrate, thereby greatly reducing the product yield. Periodic maintenance of the machine can only improve the photoresist etching rate in a short period of time, but cannot prevent the continuous decline in the photoresist etching rate of the machine's photoresist removal chamber.

[0004] To prevent the photoresist etching rate in the photoresist stripping chamber from continuously decreasing, related chamber cleaning techniques typically involve opening the chamber for cleaning to remove accumulated polymer, or periodically introducing a certain amount of oxygen into the aluminum stripping chamber to remove accumulated polymer. However, frequent opening for cleaning can increase component wear and thus increase the machine failure rate; while periodically introducing oxygen into the chamber can only remove some polymer, leaving a large amount of chloride ions in the chamber that corrodes the aluminum substrate, failing to effectively slow down the decrease in the photoresist etching rate and reducing product yield. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a chamber cleaning control method and semiconductor process equipment, which can ensure that the polymer in the chamber is maintained in a balanced state, avoid the continuous decline of the photoresist etching rate due to excessive polymer, and eliminate the need for chamber cleaning, thereby reducing component wear and machine failure rate. It can effectively remove residual polymer and chloride ions in the chamber, restore the photoresist etching rate, and improve product yield.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows:

[0007] In a first aspect, embodiments of the present invention provide a chamber cleaning control method, comprising:

[0008] The cleaning step involves introducing a pre-set cleaning gas into the chamber after maintenance is completed to perform dry cleaning and remove residual polymers and chloride ions from the chamber; wherein the pre-set cleaning gas includes oxygen-containing gas and hydrogen-containing gas.

[0009] The pre-cleaning step involves introducing a pre-selected cleaning gas into the chamber before each operation to remove residual polymers and chloride ions; wherein the pre-selected cleaning gas includes oxygen-containing gas and hydrogen-containing gas.

[0010] Furthermore, the present invention provides a first possible implementation of the first aspect, wherein, in the cleaning step, the preset cleaning gas is ionized, and the chamber pressure is controlled to decrease in a stepwise manner during the dry cleaning process, so that the plasma runs vertically downward.

[0011] Furthermore, this embodiment of the invention provides a second possible implementation of the first aspect, wherein the cleaning step includes:

[0012] In the passivation step, the chamber is controlled to be at a first preset pressure, hydrogen-containing gas is introduced into the chamber, and the radio frequency power supply is turned on to ionize the hydrogen-containing gas.

[0013] In the first cleaning step, the chamber is controlled to be at a second preset pressure, oxygen-containing gas and hydrogen-containing gas are introduced into the chamber, and the radio frequency power supply is turned on to ionize the oxygen-containing gas and hydrogen-containing gas; wherein, the second preset pressure is less than the first preset pressure, and the flow rate of the oxygen-containing gas is greater than the flow rate of the hydrogen-containing gas;

[0014] In the second cleaning step, the chamber is controlled to be at a third preset pressure, oxygen-containing gas and hydrogen-containing gas are introduced into the chamber, and the radio frequency power supply is turned on to ionize the oxygen-containing gas and hydrogen-containing gas; wherein, the third preset pressure is less than the second preset pressure;

[0015] The passivation step to the second cleaning step are repeated until the preset number of times is reached.

[0016] Furthermore, this embodiment of the invention provides a third possible implementation of the first aspect, wherein the hydrogen-containing gas is H2O gas and the oxygen-containing gas is O2;

[0017] In the passivation step, the power of the upper electrode ranges from 1500W to 2500W, the first preset pressure ranges from 3T to 6T, and the flow rate of the introduced H2O gas ranges from 1500sccm to 3000sccm.

[0018] In the first cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the second preset pressure ranges from 2T to 3T, the flow rate of the introduced H2O gas ranges from 1500sccm to 3000sccm, and the flow rate of the introduced O2 ranges from 1000sccm to 3000sccm.

[0019] In the second cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the third preset pressure ranges from 0.5T to 1T, the flow rate of the introduced H2O gas ranges from 1000sccm to 1500sccm, and the flow rate of the introduced O2 ranges from 800sccm to 1500sccm.

[0020] Furthermore, the present invention provides a fourth possible implementation of the first aspect, wherein the gas introduced in the first cleaning step further includes a nitrogen-containing gas;

[0021] The flow rate of the nitrogen-containing gas introduced ranges from 200 sccm to 500 sccm.

[0022] Furthermore, this embodiment of the invention provides a fifth possible implementation of the first aspect, wherein the pre-cleaning step includes:

[0023] During the cleaning phase above the chamber, the chamber is controlled to be at a first set pressure. During the cleaning process, the proportion of hydrogen-containing gas in the set cleaning gas is controlled to decrease in a stepwise manner, and the proportion of oxygen-containing gas in the set cleaning gas is controlled to increase in a stepwise manner.

[0024] During the cleaning phase below the chamber, the chamber is controlled at a second set pressure, and the proportion of oxygen-containing gas in the introduced cleaning gas is controlled to increase in a stepwise manner during the cleaning process; wherein, the second set pressure is less than the first set pressure.

[0025] Furthermore, this embodiment of the invention provides a sixth possible implementation of the first aspect, wherein the pre-cleaning step includes:

[0026] The first cleaning step involves controlling the chamber to a first pressure, introducing the hydrogen-containing gas into the chamber, and controlling the radio frequency power supply to turn on to ionize the hydrogen-containing gas in order to remove residual chloride ions in the chamber.

[0027] The second cleaning step involves controlling the chamber to be at a second pressure, introducing the oxygen-containing gas and the hydrogen-containing gas into the chamber, and controlling the radio frequency power supply to turn on to ionize the oxygen-containing gas and the hydrogen-containing gas in order to remove the polymer and chloride ions remaining in the chamber; wherein, the second pressure is less than the first pressure; wherein, the second pressure is less than or equal to the first pressure;

[0028] The third cleaning step involves controlling the chamber to be under a third pressure, introducing the oxygen-containing gas into the chamber, and controlling the radio frequency power supply to turn on to ionize the oxygen-containing gas in order to remove the polymer remaining in the chamber.

[0029] The fourth cleaning step involves controlling the chamber at a fourth pressure, introducing the oxygen-containing gas and the hydrogen-containing gas into the chamber, and controlling the radio frequency power supply to ionize the oxygen-containing gas and the hydrogen-containing gas to remove the polymer and chloride ions remaining in the lower part of the chamber; wherein the fourth pressure is lower than the third pressure.

[0030] The fifth cleaning step involves controlling the chamber to a fifth pressure, introducing the oxygen-containing gas and the hydrogen-containing gas into the chamber, and controlling the radio frequency power supply to ionize the oxygen-containing gas and the hydrogen-containing gas to remove the polymer remaining in the lower part of the chamber.

[0031] Furthermore, this embodiment of the invention provides a seventh possible implementation of the first aspect, wherein the hydrogen-containing gas is H2O gas and the oxygen-containing gas is O2;

[0032] In the first cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the first pressure ranges from 3T to 6T, and the flow rate of the introduced H2O gas ranges from 1500sccm to 3000sccm.

[0033] In the second cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the pressure ranges from 2T to 5T, the flow rate of the introduced H2O gas ranges from 300sccm to 500sccm, and the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm.

[0034] In the third cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the first pressure ranges from 2T to 5T, and the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm.

[0035] In the fourth cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the first pressure ranges from 0.5T to 1T, the flow rate of the introduced H2O gas ranges from 300sccm to 500sccm, and the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm.

[0036] In the fifth cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the first pressure ranges from 0.5T to 1T, the flow rate of the introduced H2O gas ranges from 300sccm to 500sccm, and the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm.

[0037] Furthermore, the present invention provides an eighth possible implementation of the first aspect, wherein the gas introduced in the second cleaning step, the third cleaning step and the fourth cleaning step further includes a nitrogen-containing gas;

[0038] The flow rate of the nitrogen-containing gas introduced in the second, third, and fourth cleaning steps is in the range of 300 sccm to 500 sccm.

[0039] In a second aspect, embodiments of the present invention also provide a semiconductor process apparatus, comprising: a process chamber, an inlet assembly, an upper electrode assembly, a lower electrode assembly, and a controller, characterized in that the controller comprises at least one processor and at least one memory, the memory storing a computer program, the computer program being executed by the processor to implement the chamber cleaning control method as described in any of the first aspects.

[0040] This invention provides a chamber cleaning control method and semiconductor process equipment. The method includes: a cleaning step, in which, after the chamber has been maintained, a preset cleaning gas is introduced into the chamber to perform dry cleaning to remove residual polymers and chloride ions; wherein the preset cleaning gas includes oxygen-containing gas and hydrogen-containing gas; and a pre-cleaning step, in which, before each start of operation of the chamber, a set cleaning gas is introduced into the chamber to perform pre-cleaning to remove residual polymers and chloride ions; wherein the set cleaning gas includes oxygen-containing gas and hydrogen-containing gas. This invention adds a chamber cleaning step after periodic chamber maintenance. Using oxygen- and hydrogen-containing gases, the chamber is dry-cleaned to remove residual polymers. By pre-cleaning the chamber before each use to remove residual polymers and chloride ions, the polymer within the chamber is kept in equilibrium, preventing a continuous decrease in the photoresist etching rate due to excessive polymer. Furthermore, it eliminates the need for chamber opening for cleaning, reducing component wear and machine failure rates. It effectively removes residual polymers and chloride ions from the chamber, restoring the photoresist etching rate and improving product yield.

[0041] Other features and advantages of the embodiments of the present invention will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above in the embodiments of the present invention.

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0043] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 The graph showing the relationship between the etching time of the photoresist removal cavity and the photoresist etching rate is shown.

[0045] Figure 2 A flowchart of a chamber cleaning control method provided by an embodiment of the present invention is shown;

[0046] Figure 3 The graph showing the relationship between the etching time of the photoresist removal cavity and the photoresist etching rate provided in the embodiment of the present invention is shown. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be described below in conjunction with the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0048] Currently, in order to improve the photoresist etching rate, periodic maintenance (PM) is usually performed on the equipment to increase the photoresist etching rate in a short period of time. However, this increases the cost of using the equipment and reduces the utilization rate of the equipment.

[0049] One related chamber cleaning control technology is to remove the accumulated polymer by opening the aluminum stripping chamber of the machine to improve the photoresist etching rate. Another is to introduce a certain amount of oxygen into the aluminum stripping chamber at regular intervals to remove the accumulated polymer. For example, O2 is introduced into the aluminum stripping chamber every 10 to 15 days to react with the polymer and remove the polymer accumulated in the chamber.

[0050] However, machine downtime caused by cleaning or malfunctions can easily increase the waiting time for batch processing of products, affecting the machine's production capacity. At the same time, frequent cavity cleaning can increase component wear and tear, thereby increasing the failure rate and further increasing machine downtime. Although the photoresist etching rate is improved after the cleaned components are reinstalled, it cannot be restored to the etching rate level of new components. As the number of component cleanings increases, the photoresist etching rate is still on a downward trend overall, requiring the replacement of completely new components, which greatly increases the machine's operating costs.

[0051] While periodically introducing oxygen into the aluminum stripping chamber during mass production can remove some polymer and slow down the photoresist etching rate, the effect is not ideal. Furthermore, using only oxygen to remove polymer leaves a large amount of chloride ions in the chamber, which can corrode the aluminum substrate and reduce product yield.

[0052] To address the aforementioned issues, this invention provides a chamber cleaning control method and semiconductor process equipment. The embodiments of this invention will be described in detail below.

[0053] This embodiment provides a chamber cleaning control method, see [link to relevant documentation] Figure 2 The flowchart shown illustrates the chamber cleaning control method, which mainly includes the following steps:

[0054] Step S202, cleaning step: After the chamber is maintained, a preset cleaning gas is introduced into the chamber to perform dry cleaning to remove residual polymer and chloride ions in the chamber.

[0055] The pre-set cleaning gases include oxygen-containing and hydrogen-containing gases. Since the main component of the polymer remaining in the chamber is carbon, at a high temperature of 200-300℃, O2 combines with carbon to form carbon dioxide, which is then removed. The reaction expression is: C + O2 → CO2↑

[0056] By introducing oxygen-containing gas into the chamber during the cleaning process, the gas can react with the polymer inside the chamber and remove the resulting byproducts, thus removing the polymer from the chamber. By introducing hydrogen-containing gas into the chamber during the cleaning process, residual chloride ions inside the chamber can be removed, reducing the corrosion of aluminum caused by chloride.

[0057] The aforementioned chamber can be the aluminum photoresist removal chamber of the etching machine. The continuous operation of the machine causes a large amount of polymer (etching byproducts and photoresist) to accumulate in the aluminum photoresist removal chamber, which causes the photoresist etching rate to continuously decrease. After periodic maintenance of the aluminum photoresist removal chamber machine, dry cleaning (Clean WAC) is used to remove the residual polymer in the areas not cleaned in the chamber after periodic maintenance, so as to further remove the polymer and chloride ions that were not cleaned during maintenance.

[0058] Step S204, pre-cleaning step: Before each operation of the chamber, a set cleaning gas is introduced into the chamber to pre-clean it, so as to remove residual polymers and chloride ions in the chamber.

[0059] The cleaning gases include oxygen-containing gases and hydrogen-containing gases. By adding a pre-conditioning cleaning process (WAC) before working in the chamber (including warm-up and product processing), the combined effect of dry cleaning after maintenance and pre-cleaning before operation ensures that the polymer in the chamber remains in a balanced state, avoiding the problem of a continuous decrease in photoresist etching rate due to excessive polymer.

[0060] The chamber cleaning control method provided in this embodiment adds a chamber cleaning step after periodic chamber maintenance. This step uses oxygen-containing and hydrogen-containing gases to perform dry cleaning of the chamber, removing residual polymers from the chamber after maintenance. By pre-cleaning the chamber before each use to remove residual polymers and chloride ions, the polymers in the chamber can be kept in a balanced state, preventing the photoresist etching rate from continuously decreasing due to excessive polymers. Furthermore, it eliminates the need for chamber cleaning, reducing component wear and machine failure rate. It effectively removes residual polymers and chloride ions from the chamber, restores the photoresist etching rate, and improves product yield.

[0061] In one embodiment, the cleaning step provided in this embodiment involves ionizing a preset cleaning gas and controlling the chamber pressure to decrease in a stepwise manner during the dry cleaning process, so that the plasma runs vertically downward.

[0062] The above cleaning steps can be divided into multiple sub-steps. When executing multiple sub-steps, the chamber pressure of the next sub-step can be controlled to be lower than that of the previous sub-step, so as to gradually reduce the chamber pressure. Lower chamber pressure can increase the mean free path of the plasma, increase the anisotropy of the plasma, and make more plasma move vertically downward, which can play a better cleaning role in the chamber.

[0063] In one embodiment, the cleaning steps provided in this embodiment specifically include:

[0064] In the passivation step, the chamber is controlled at a first preset pressure, hydrogen-containing gas is introduced into the chamber, and the radio frequency power supply is turned on to ionize the hydrogen-containing gas.

[0065] In the first cleaning step, the chamber is controlled at a second preset pressure, oxygen-containing gas and hydrogen-containing gas are introduced into the chamber, and the radio frequency power supply is turned on to ionize the oxygen-containing gas and hydrogen-containing gas; wherein, the second preset pressure is less than the first preset pressure, and the flow rate of oxygen-containing gas is greater than the flow rate of hydrogen-containing gas.

[0066] In the second cleaning step, the chamber is controlled at a third preset pressure, oxygen-containing gas and hydrogen-containing gas are introduced into the chamber, and the radio frequency power supply is turned on to ionize the oxygen-containing gas and hydrogen-containing gas; wherein, the third preset pressure is less than the second preset pressure.

[0067] Repeat the passivation step to the second cleaning step until the preset number of times is reached.

[0068] The preset number of times can be set according to the polymer residue in the chamber, and the value range of the preset number of times can be, for example, 2 to 6; the hydrogen-containing gas can be a gas that can ionize to form hydrogen free radicals and carry away the chloride ions remaining in the chamber, such as H2O gas; the oxygen-containing gas can be a gas that can chemically react with carbon-containing polymers, such as any one or more of CO, CO2 and O2.

[0069] During the passivation step, the radio frequency power supply is turned on to ionize the water vapor in the chamber, forming a large number of hydrogen free radicals that carry away the residual chloride ions in the chamber, thereby reducing the corrosion of aluminum caused by chloride. The flow rate of hydrogen-containing gas introduced in the passivation step can be greater than that introduced in the first and second cleaning steps, so as to primarily remove chloride ions in the chamber during the passivation step.

[0070] By increasing the flow rate of oxygen-containing gas to greater than that of hydrogen-containing gas in the first cleaning step, the oxygen-containing gas is used as the main cleaning gas to remove the residual polymer in the chamber.

[0071] By introducing oxygen-containing and hydrogen-containing gases in the second cleaning step, while controlling the chamber pressure to continue to decrease, the mean free path of the plasma is increased, allowing more plasma to move vertically downwards to remove polymers and chloride ions below the chamber, thereby achieving a better cleaning effect.

[0072] In one embodiment, the hydrogen-containing gas provided in this embodiment is H2O gas, and the oxygen-containing gas is O2; in the passivation step, the water vapor introduced into the chamber can also react with the aluminum film layer to generate a passivation layer on the surface of the aluminum film layer.

[0073] In the passivation step, the power of the upper electrode ranges from 1500W to 2500W, the first preset pressure ranges from 3T to 6T, and the flow rate of the introduced H2O gas ranges from 1500sccm to 3000sccm.

[0074] In the first cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the second preset pressure ranges from 2T to 3T, the flow rate of the introduced H2O gas ranges from 1500sccm to 3000sccm, and the flow rate of the introduced O2 ranges from 1000sccm to 3000sccm.

[0075] In the second cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the third preset pressure ranges from 0.5T to 1T, the flow rate of the introduced H2O gas ranges from 1000sccm to 1500sccm, and the flow rate of the introduced O2 ranges from 800sccm to 1500sccm.

[0076] The process times for the passivation step, the first cleaning step, and the second cleaning step can be the same or different, and the range of process times for the passivation step, the first cleaning step, and the second cleaning step can be 200s to 400s.

[0077] Since lower chamber pressure can increase the mean free path of the plasma, by gradually reducing the chamber pressure during the passivation, first cleaning, and second cleaning steps (the chamber pressure is highest during the passivation step and lowest during the second cleaning step), the anisotropy of the plasma can be gradually increased, causing more plasma to begin moving vertically downwards. This achieves top-to-bottom cleaning of the chamber interior, avoiding inadequate cleaning at the bottom of the chamber interior and providing a better cleaning effect.

[0078] By introducing only water vapor during the passivation step, the large amount of residual chloride ions in the chamber is primarily removed, mitigating aluminum corrosion caused by chloride. In the first cleaning step, the water vapor flow rate is reduced while the oxygen flow rate is increased to primarily remove residual polymers in the chamber and to assist in removing any remaining residual chloride ions. In the second cleaning step, the oxygen flow rate is reduced while the proportion of water vapor is increased, allowing for the removal of polymers and chloride ions from the lower part of the chamber under lower chamber pressure. This prevents incomplete cleaning in the passivation and first cleaning steps, achieving comprehensive cleaning of all locations and residues within the chamber.

[0079] In one embodiment, the gas introduced in the first cleaning step of this embodiment further includes nitrogen-containing gas; the flow rate of the introduced nitrogen-containing gas ranges from 200 sccm to 500 sccm.

[0080] The nitrogen-containing gas can dilute the oxygen-containing gas that plays a cleaning role, making the cleaning process easier to control. It also helps to remove byproducts generated during the cleaning process. In addition, it can react with the aluminum film layer to form aluminum nitride, which protects the aluminum film layer.

[0081] In one embodiment, the pre-cleaning step provided in this embodiment includes:

[0082] During the cleaning phase above the chamber, the chamber is controlled at the first set pressure. During the cleaning process, the proportion of hydrogen gas in the set cleaning gas is controlled to decrease in a stepwise manner, while the proportion of oxygen gas in the set cleaning gas is controlled to increase in a stepwise manner.

[0083] During the cleaning phase below the chamber, the chamber is controlled at a second set pressure, and the proportion of oxygen-containing gas in the introduced cleaning gas increases in a stepwise manner during the cleaning process; wherein, the second set pressure is lower than the first set pressure.

[0084] By controlling the chamber at different pressures during the chamber pre-cleaning process, the chamber pre-cleaning step is divided into an upper chamber cleaning stage and a lower chamber cleaning stage to thoroughly clean residual polymers and chloride ions in various locations within the chamber, thereby improving the etching rate of the photoresist in subsequent processes.

[0085] In one embodiment, the pre-cleaning step provided in this embodiment includes:

[0086] The first cleaning step involves controlling the chamber to a first pressure, introducing hydrogen-containing gas into the chamber, and controlling the radio frequency power supply to ionize the hydrogen-containing gas in order to remove residual chloride ions in the chamber.

[0087] The hydrogen-containing gas can be a gas that can ionize to form hydrogen free radicals and carry away the residual chloride ions in the chamber, such as H2O gas;

[0088] Under certain pressure, by ionizing the hydrogen-containing gas in the chamber, a large number of hydrogen free radicals are formed, which carry away the residual chloride ions in the chamber, thus mitigating the corrosion of aluminum caused by chloride. The reaction expression is as follows:

[0089] H2O—2H+O

[0090] H+Cl→HCl↑

[0091] The second cleaning step involves controlling the chamber at a second pressure, introducing oxygen-containing gas and hydrogen-containing gas into the chamber, and controlling the radio frequency power supply to ionize the oxygen-containing gas and hydrogen-containing gas to remove residual polymers and chloride ions in the chamber; wherein the second pressure is less than the first pressure; wherein the second pressure is less than or equal to the first pressure;

[0092] The oxygen-containing gas mentioned above can be a gas capable of chemically reacting with carbon-containing polymers, such as any one or more of CO, CO2, and O2.

[0093] In this cleaning step, oxygen-containing gas is the main cleaning gas. The main component of the polymer remaining in the chamber is carbon. In an environment of 200-300℃, the oxygen-containing gas combines with carbon to generate carbon dioxide, which is then removed, thus reducing the accumulation of polymer in the chamber. Since the chloride ions remaining in the chamber need to be removed through multiple cycles of cleaning, a small amount of hydrogen-containing gas can be used in this cleaning step to remove the chloride ions remaining in the chamber.

[0094] The third cleaning step involves controlling the chamber to be at a third pressure, introducing oxygen-containing gas into the chamber, and controlling the radio frequency power supply to ionize the oxygen-containing gas in order to remove the residual polymer in the chamber.

[0095] The third pressure can be equal to the second pressure. By removing hydrogen-containing gas in this cleaning step and using only oxygen-containing gas, the dilution of oxygen-containing gas is reduced, the removal rate of polymer in the chamber is increased, and the pre-cleaning rate of the chamber is improved.

[0096] The fourth cleaning step involves controlling the chamber at a fourth pressure, introducing oxygen-containing gas and hydrogen-containing gas into the chamber, and controlling the radio frequency power supply to ionize the oxygen-containing gas and hydrogen-containing gas to remove residual polymers and chloride ions at the bottom of the chamber; wherein, the fourth pressure is lower than the third pressure.

[0097] Because a large amount of polymer will accumulate at the bottom of the chamber during the etching process, the pressure in the chamber is controlled to be reduced in the fourth cleaning step. The lower chamber pressure can increase the mean free path of the plasma and increase the anisotropy of the plasma, so that more plasma moves vertically downward. The free radicals generated by oxygen-containing gas are more likely to react with the polymers remaining at the bottom of the chamber and be removed. The hydrogen free radicals in hydrogen-containing gas are more likely to carry away the chloride ions remaining at the bottom of the chamber, reducing the corrosion of aluminum.

[0098] The fifth cleaning step involves controlling the chamber to a fifth pressure, introducing oxygen-containing gas and hydrogen-containing gas into the chamber, and controlling the radio frequency power supply to ionize the oxygen-containing gas and hydrogen-containing gas in order to remove the residual polymer at the bottom of the chamber.

[0099] The fifth pressure mentioned above can be equal to the fourth pressure mentioned above.

[0100] When there are a lot of residual chloride ions and polymers in the chamber, the first to fifth cleaning steps can be repeated to remove the residual chloride ions and polymers in the upper and lower positions inside the chamber.

[0101] In one embodiment, in the first cleaning step provided in this embodiment, the hydrogen-containing gas is H2O gas and the oxygen-containing gas is O2;

[0102] In the first cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the first pressure ranges from 3T to 6T, and the flow rate of the introduced H2O gas ranges from 1500sccm to 3000sccm.

[0103] In the second cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the second pressure ranges from 2T to 5T, the flow rate of the introduced H2O gas ranges from 300sccm to 500sccm, and the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm.

[0104] In the third cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the first pressure ranges from 2T to 5T, the flow rate of the introduced H2O gas ranges from 300sccm to 500sccm, and the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm.

[0105] In the fourth cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the first pressure ranges from 0.5T to 1T, the flow rate of the introduced H2O gas ranges from 300sccm to 500sccm, and the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm.

[0106] In the fifth cleaning step, the power of the upper electrode ranges from 1500W to 2500W, the first pressure ranges from 0.5T to 1T, the flow rate of the introduced H2O gas ranges from 300sccm to 500sccm, and the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm.

[0107] By gradually reducing the chamber pressure during the first to fifth cleaning steps, and maintaining a relatively low chamber pressure in the fourth and fifth cleaning steps, the anisotropy of the plasma can be gradually increased, causing more plasma to begin moving vertically downwards. This allows the first to third cleaning steps to primarily clean chloride ions and polymers in the upper part of the chamber, while the fourth and fifth cleaning steps primarily clean chloride ions and polymers in the lower part of the chamber, avoiding cleaning dead zones and achieving comprehensive pre-cleaning of the chamber.

[0108] By introducing only water vapor in the first cleaning step, the large amount of residual chloride ions in the chamber are mainly removed, thus reducing aluminum corrosion caused by chloride.

[0109] In the second cleaning step, a large amount of oxygen and a small amount of water vapor are introduced to primarily clean most of the polymer above the interior of the chamber, and to remove chloride ions that were not completely removed in the first cleaning step, thereby thoroughly removing chloride ions above the interior of the chamber. In the third cleaning step, water vapor is removed and a large amount of oxygen is introduced to reduce the dilution of oxygen by water vapor and increase the removal rate of polymer above the interior of the chamber, thereby achieving thorough cleaning of the area above the interior of the chamber.

[0110] In the fourth cleaning step, a large amount of oxygen and a small amount of water vapor are introduced to primarily clean most of the polymer in the lower part of the chamber and remove chloride ions that were not completely removed in the first cleaning step, thereby removing residual chloride ions in the lower part of the chamber. In the fifth cleaning step, nitrogen gas is introduced to increase the flow ratio of oxygen and water vapor, thoroughly cleaning the residual chloride ions and polymer in the lower part of the chamber, improving the removal rate of polymer and chloride ions in the lower part of the chamber, and improving the cleaning efficiency in the lower part of the chamber.

[0111] In one embodiment, the gas introduced in the second, third, and fourth cleaning steps provided in this embodiment further includes nitrogen-containing gas;

[0112] The flow rate of nitrogen-containing gas introduced in the second, third, and fourth cleaning steps is in the range of 300 sccm to 500 sccm.

[0113] The nitrogen-containing gas mentioned above can be, for example, N2. The nitrogen-containing gas can dilute the cleaning gas, making the cleaning process easier to control, and at the same time, it is beneficial to remove the by-products generated during the cleaning process. By removing the nitrogen-containing gas in the fifth cleaning step above and only introducing oxygen-containing and hydrogen-containing gases, the ratio of oxygen-containing and hydrogen-containing gases is increased, thereby increasing the removal rate of polymers and chloride ions below the chamber.

[0114] The chamber cleaning control method provided in this embodiment removes residual polymer in areas not cleaned after periodic maintenance by adding dry cleaning after periodic maintenance, and adds a chamber pre-cleaning process before chamber operation. This dual action ensures that the polymer in the chamber is maintained in a balanced state, preventing the problem of a continuous decrease in photoresist etching rate due to excessive polymer. By using dry etching cleaning process instead of ordinary open-chamber cleaning, the photoresist etching rate can be restored without opening the chamber, reducing component wear and machine failure rate, which helps to reduce machine operating costs and increase machine utilization. At the same time, the cleaning process does not change the chamber environment, avoiding the problem of yield reduction due to changes in the chamber environment, and improving product yield.

[0115] Based on the foregoing embodiments, this embodiment provides an example of using the aforementioned chamber cleaning control method to solve the problem of continuously decreasing photoresist etching rate in aluminum resist removal chambers. The specific steps are as follows:

[0116] Step 1, Cleaning Step: After each maintenance of the chamber, a cleaning step is performed. The cleaning step mainly includes 3 steps. The temperature of the electrostatic chuck during the process is 200-300℃. The chamber pressure, upper electrode power, gas flow rate configuration, and process time are as follows:

[0117] In the passivation step, the upper electrode power is 1500W to 2500W, the chamber pressure is 3T to 6T, the flow rate of the introduced H2O gas is 1500sccm to 3000sccm, and the process time is 200s to 400s.

[0118] The first cleaning step (Strip-1 step) has an upper electrode power of 1500W to 2500W, a chamber pressure range of 2T to 3T, a flow rate of H2O gas of 1500sccm to 3000sccm, a flow rate of O2 of 1000sccm to 3000sccm, a flow rate of N2 of 200sccm to 500sccm, and a process time of 200s to 400s.

[0119] The second cleaning step (Strip-2 step) has an upper electrode power of 1500W to 2500W, a chamber pressure of 0.5T to 1T, an H2O gas flow rate of 1000sccm to 1500sccm, an O2 flow rate of 800sccm to 1500sccm, and a process time of 200s to 400s.

[0120] Repeat the above passivation step, first cleaning step and second cleaning step 3 to 4 times;

[0121] Step 2, Pre-cleaning step: Before each operation of the chamber, a pre-cleaning step is performed. The pre-cleaning step includes 5 steps. The temperature of the electrostatic chuck in the process is 200-300℃. The chamber pressure, upper electrode power, gas flow rate configuration, and process time are as follows:

[0122] The first cleaning step involves an upper electrode power of 1500W to 2500W, a chamber pressure of 3T to 6T, an H2O gas flow rate of 1500sccm to 3000sccm, and a process time of 50s to 100s.

[0123] Under certain pressure, the water vapor in the chamber is ionized to form a large number of hydrogen free radicals, which carry away the residual chloride ions in the chamber, thus mitigating the corrosion of aluminum caused by chloride. The reaction expression is as follows:

[0124] H2O—2H+O

[0125] H+Cl→HCl↑

[0126] The second cleaning step involves an upper electrode power of 1500W to 2500W, a chamber pressure of 2T to 5T, a flow rate of H2O gas of 300sccm to 500sccm, a flow rate of O2 of 3000sccm to 5000sccm, a flow rate of N2 of 300sccm to 500sccm, and a process time of 50s to 100s.

[0127] During the cleaning process, O2 is the main cleaning gas. The main component of the polymer remaining in the chamber is carbon. At an temperature of 200-300℃, O2 combines with carbon to form carbon dioxide, which is then removed, reducing the accumulation of polymer in the chamber. N2 can dilute the oxygen-containing gas that plays a cleaning role, making the cleaning process easier to control and facilitating the removal of byproducts generated during the cleaning process. Since the chloride ions remaining in the chamber need to be removed through multiple cycles of cleaning, a small amount of water vapor can be used in this cleaning step to remove the chloride ions remaining in the chamber.

[0128] C + O₂ → CO₂↑

[0129] The third cleaning step involves an upper electrode power of 1500W to 2500W, a chamber pressure of 2T to 5T, an O2 flow rate of 3000sccm to 5000sccm, an N2 flow rate of 300sccm to 500sccm, and a process time of 80s to 180s.

[0130] This cleaning step uses only O2 and N2, without water vapor, to reduce the dilution of O2 gas and remove residual polymer in the chamber more quickly.

[0131] The fourth cleaning step involves the following parameters: the upper electrode power ranges from 1500W to 2500W; the chamber pressure ranges from 0.5T to 1T; the flow rate of the introduced H2O gas ranges from 300sccm to 500sccm; the flow rate of the introduced O2 ranges from 3000sccm to 5000sccm; the flow rate of the introduced N2 ranges from 300sccm to 500sccm; and the process time is from 50s to 100s.

[0132] Since a large amount of polymer will accumulate at the bottom of the chamber during the etching process, lower chamber pressure can increase the mean free path of the plasma, increase plasma anisotropy, and allow more plasma to move vertically downward. Free radicals generated by O2 are more likely to react with the polymers remaining at the bottom of the chamber and be removed. Hydrogen free radicals in water vapor are more likely to carry away the chloride ions remaining at the bottom of the chamber, thus reducing the corrosion of aluminum.

[0133] The fifth cleaning step involves setting the upper electrode power to 1500W–2500W, the chamber pressure to 0.5T–1T, the flow rate of the introduced H2O gas to 300sccm–500sccm, the flow rate of the introduced O2 to 3000sccm–5000sccm, and the process time to 50s–100s.

[0134] For example, after cleaning the aluminum descaling chamber using the chamber cleaning control method provided in this embodiment, see as follows: Figure 3 The graph showing the relationship between the etching time of the photoresist removal chamber and the photoresist etching rate provided in this embodiment demonstrates that by using the chamber cleaning control method provided in the above embodiment to clean the aluminum photoresist removal chamber, adding a dry cleaning process after periodic maintenance and adding a chamber pre-conditioning (WAC) process before each operation of the chamber, it is possible to ensure that the polymer in the chamber is maintained in a balanced state, and the problem of the photoresist etching rate continuously decreasing due to excessive polymer will not occur.

[0135] Corresponding to the chamber cleaning control method provided in the above embodiments, this embodiment of the invention provides a semiconductor process apparatus, which includes: a process chamber, an air intake assembly, an upper electrode assembly, a lower electrode assembly, and a controller. The controller includes at least one processor and at least one memory. The memory stores a computer program, and when the computer program is executed by the processor, it implements the chamber cleaning control method provided in the above embodiments.

[0136] The device provided in this embodiment has the same implementation principle and technical effects as the aforementioned embodiments. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0137] This invention provides an electronic device, which includes a processor and a memory. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements the steps of the method provided in the above embodiments.

[0138] This invention provides a computer-readable medium storing computer-executable instructions. When these computer-executable instructions are invoked and executed by a processor, they cause the processor to implement the methods described in the above embodiments.

[0139] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the system described above can be referred to the corresponding process in the foregoing embodiments, and will not be repeated here.

[0140] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0141] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0142] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0143] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A chamber cleaning control method, comprising: The method comprises the following steps: a cleaning step, after the chamber is maintained, a preset cleaning gas is introduced into the chamber to remove the residual polymer and chloride ions in the chamber by dry cleaning; wherein the preset cleaning gas comprises an oxygen-containing gas and a hydrogen-containing gas; a pre-cleaning step, before the chamber starts to work each time, a set cleaning gas is introduced into the chamber to remove the residual polymer and chloride ions in the chamber; wherein the set cleaning gas comprises an oxygen-containing gas and a hydrogen-containing gas; the pre-cleaning step comprises: a chamber upper cleaning stage, the chamber is controlled to be at a first set pressure, the proportion of the hydrogen-containing gas in the set cleaning gas introduced in the cleaning process is controlled to decrease in a step-by-step manner, and the proportion of the oxygen-containing gas in the set cleaning gas introduced in the cleaning process is controlled to increase in a step-by-step manner; a chamber lower cleaning stage, the chamber is controlled to be at a second set pressure, and the proportion of the oxygen-containing gas in the set cleaning gas introduced in the cleaning process is controlled to increase in a step-by-step manner; wherein the second set pressure is less than the first set pressure.

2. The chamber cleaning control method of claim 1, wherein, In the cleaning step, the preset cleaning gas is ionized, and the chamber pressure is controlled to decrease in a step-by-step manner during the dry cleaning process, so that the plasma runs vertically downward.

3. The chamber cleaning control method of claim 1, wherein, The cleaning step comprises: a passivation step, the chamber is controlled to be at a first preset pressure, a hydrogen-containing gas is introduced into the chamber, and a radio frequency power source is controlled to be turned on to ionize the hydrogen-containing gas; a first cleaning step, the chamber is controlled to be at a second preset pressure, an oxygen-containing gas and the hydrogen-containing gas are introduced into the chamber, and a radio frequency power source is controlled to be turned on to ionize the oxygen-containing gas and the hydrogen-containing gas; wherein the second preset pressure is less than the first preset pressure, and the flow rate of the oxygen-containing gas is greater than that of the hydrogen-containing gas; a second cleaning step, the chamber is controlled to be at a third preset pressure, an oxygen-containing gas and the hydrogen-containing gas are introduced into the chamber, and a radio frequency power source is controlled to be turned on to ionize the oxygen-containing gas and the hydrogen-containing gas; wherein the third preset pressure is less than the second preset pressure; the passivation step and the second cleaning step are cyclically executed until the execution times reach a preset number of times.

4. The chamber cleaning control method of claim 3, wherein, The hydrogen-containing gas is H2O gas, and the oxygen-containing gas is O2; In the passivation step, the value range of the upper electrode power is 1500W-2500W, the value range of the first preset pressure is 3T-6T, and the value range of the flow rate of the introduced H2O gas is 1500sccm-3000sccm; In the first cleaning step, the value range of the upper electrode power is 1500W-2500W, the value range of the second preset pressure is 2T-3T, the value range of the flow rate of the introduced H2O gas is 1500sccm-3000sccm, and the value range of the flow rate of the introduced O2 is 1000sccm-3000sccm; The second cleaning step, the value range of the upper electrode power is 1500W~2500W, the value range of the third preset pressure is 0.5T~1T, the flow value range of the H2O gas is 1000sccm~1500sccm, and the flow value range of the O2 is 800sccm~1500sccm.

5. The chamber cleaning control method of claim 4, wherein, The gas introduced in the first cleaning step further comprises nitrogen-containing gas; The flow value range of the nitrogen-containing gas introduced is 200sccm~500sccm.

6. The chamber cleaning control method of claim 1, wherein, The pre-cleaning step comprises: The first cleaning step controls the chamber to be at a first pressure, introduces the hydrogen-containing gas into the chamber, controls the radio frequency power to be turned on to ionize the hydrogen-containing gas, and removes the residual chloride ions in the chamber; The second cleaning step controls the chamber to be at a second pressure, introduces the oxygen-containing gas and the hydrogen-containing gas into the chamber, controls the radio frequency power to be turned on to ionize the oxygen-containing gas and the hydrogen-containing gas, and removes the residual polymer and chloride ions in the chamber; wherein the second pressure is less than the first pressure; wherein the second pressure is less than or equal to the first pressure; The third cleaning step controls the chamber to be at a third pressure, introduces the oxygen-containing gas into the chamber, controls the radio frequency power to be turned on to ionize the oxygen-containing gas, and removes the residual polymer in the chamber; The fourth cleaning step controls the chamber to be at a fourth pressure, introduces the oxygen-containing gas and the hydrogen-containing gas into the chamber, controls the radio frequency power to be turned on to ionize the oxygen-containing gas and the hydrogen-containing gas, and removes the residual polymer and chloride ions in the lower part of the chamber; wherein the fourth pressure is less than the third pressure; The fifth cleaning step controls the chamber to be at a fifth pressure, introduces the oxygen-containing gas and the hydrogen-containing gas into the chamber, controls the radio frequency power to be turned on to ionize the oxygen-containing gas and the hydrogen-containing gas, and removes the residual polymer in the lower part of the chamber.

7. The chamber cleaning control method of claim 6, wherein, The hydrogen-containing gas is H2O gas, and the oxygen-containing gas is O2; In the first cleaning step, the value range of the upper electrode power is 1500W~2500W, the value range of the first pressure is 3T~6T, and the flow value range of the H2O gas introduced is 1500sccm~3000sccm; In the second cleaning step, the value range of the upper electrode power is 1500W~2500W, the value range of the second pressure is 2T~5T, the flow value range of the H2O gas introduced is 300sccm~500sccm, and the flow value range of the O2 introduced is 3000sccm~5000sccm; In the third cleaning step, the value range of the upper electrode power is 1500W~2500W, the value range of the first pressure is 2T~5T, and the flow value range of the O2 introduced is 3000sccm~5000sccm; In the fourth cleaning step, the upper electrode power is in the range of 1500W-2500W, the first pressure is in the range of 0.5T-1T, the flow rate of the H2O gas is in the range of 300sccm-500sccm, and the flow rate of the O2 is in the range of 3000sccm-5000sccm; In the fifth cleaning step, the upper electrode power is in the range of 1500W-2500W, the first pressure is in the range of 0.5T-1T, the flow rate of the H2O gas is in the range of 300sccm-500sccm, and the flow rate of the O2 is in the range of 3000sccm-5000sccm.

8. The chamber cleaning control method of claim 7, wherein, The gas introduced in the second cleaning step, the third cleaning step and the fourth cleaning step further comprises a nitrogen-containing gas; The flow rate of the nitrogen-containing gas introduced in the second cleaning step, the third cleaning step and the fourth cleaning step is in the range of 300sccm-500sccm.

9. A semiconductor process apparatus, characterized by, It comprises: A process chamber, a gas inlet assembly, an upper electrode assembly, a lower electrode assembly and a controller, wherein the controller comprises at least one processor and at least one memory, the memory stores a computer program, and the computer program is executed by the processor to realize the chamber cleaning control method of any one of claims 1-8.

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