Semiconductor structure processing methods

Abstract

This disclosure relates to the semiconductor field and provides a method for processing a semiconductor structure. The method includes: providing a semiconductor structure comprising a plurality of spaced-apart patterned layers and trenches located between adjacent patterned layers; cleaning the semiconductor structure with a cleaning solution, the cleaning solution filling the trenches; after cleaning, evaporating the cleaning solution in the trenches to remove a portion of the cleaning solution; freezing the remaining cleaning solution in the trenches to solidify the cleaning solution; and sublimating the solidified cleaning solution to remove the solidified cleaning solution. This disclosure can at least avoid the problems of patterned layer tilting and collapse, thereby improving the yield of the semiconductor structure.

Description

Technical Field

[0001] This disclosure pertains to the field of semiconductors, specifically relating to a method for processing a semiconductor structure. Background Technology

[0002] In semiconductor fabrication, the cleaning process is being repeated more and more frequently. After cleaning, the semiconductor structure is typically dried to remove the cleaning solution. However, during the removal of the cleaning solution, the internal patterns of the semiconductor structure are prone to tilting and collapse, thus reducing the yield of the semiconductor structure. Summary of the Invention

[0003] This disclosure provides a method for processing semiconductor structures, which at least helps to avoid the problems of tilting and collapse of the pattern layer, thereby improving the yield of semiconductor structures.

[0004] According to some embodiments of this disclosure, one aspect of this disclosure provides a method for processing a semiconductor structure, comprising: providing a semiconductor structure, the semiconductor structure including a plurality of spaced patterned layers and trenches located between adjacent patterned layers; cleaning the semiconductor structure with a cleaning solution, the cleaning solution filling the trenches; after the cleaning process, evaporating the cleaning solution in the trenches to remove a portion of the cleaning solution; freezing the remaining cleaning solution in the trenches to solidify the cleaning solution; and sublimating the solidified cleaning solution to remove the solidified cleaning solution.

[0005] In addition, the evaporation process further includes: weighing to obtain the total weight of the semiconductor structure and the cleaning liquid in the trench; determining whether the total weight is greater than a weight threshold; if so, continuing the evaporation process; if not, stopping the evaporation process.

[0006] In addition, prior to the evaporation process, the method includes: pre-setting a weight range for the remaining cleaning solution; determining the evaporation time and evaporation rate based on the weight range; and performing the evaporation process according to the evaporation time and the evaporation rate. The cleaning solution includes deionized water.

[0007] In addition, the cleaning process for the semiconductor structure includes: performing a first cleaning process on the semiconductor structure using deionized water; after the first cleaning process, performing a second cleaning process on the semiconductor structure using a chemical solvent; after the second cleaning process, performing a third cleaning process on the semiconductor structure using deionized water; the deionized water used in the third cleaning process is filled in the trench; after the third cleaning process, the evaporation process, the freezing process, and the sublimation process are performed sequentially.

[0008] Furthermore, the third cleaning process includes a first rotation stage and a second rotation stage performed sequentially; the semiconductor structure has a first rotational speed in the first rotation stage, and a second rotational speed in the second rotation stage, wherein the second rotational speed is less than the first rotational speed. In the freezing process, a chuck is used to control the temperature of the semiconductor structure, and the temperature range of the chuck is -1℃ to -30℃.

[0009] In addition, during the freezing process, the temperature change of the chuck does not exceed 10°C.

[0010] In addition, the temperature of the chuck remains constant during the freezing process.

[0011] In addition, during the sublimation process, a chuck is used to control the temperature of the semiconductor structure, and the temperature range of the chuck is -20℃ to 0℃.

[0012] In addition, during the sublimation process, the chamber pressure ranges from 200 mTorr to 100 Torr.

[0013] In addition, the height of the remaining cleaning fluid in the trench is directly proportional to the depth-to-width ratio of the trench.

[0014] In addition, the height of the remaining cleaning fluid in the trench is greater than 1 / 10 of the trench depth and less than 1 / 2 of the trench depth.

[0015] In addition, after the cleaning process and before the sublimation process, a vacuuming process is also included.

[0016] In addition, after the vacuuming process, nitrogen gas is introduced into the chamber.

[0017] The technical solutions provided in this disclosure have at least the following advantages:

[0018] In this embodiment, removing part of the cleaning solution through evaporation avoids excessive expansion of the cleaning solution during subsequent freezing, which could damage the pattern layer. The remaining cleaning solution is then frozen to solidify, and the solidified material is removed by sublimation. Since sublimation does not cause the solidified cleaning solution to exert capillary forces on the pattern layer, it prevents the pattern layer from tilting or collapsing under capillary forces. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] Figures 1-3 Schematic diagrams are shown for each stage of the evaporation process of a semiconductor structure in the cleaning liquid.

[0021] Figure 4 A flowchart of a processing method for a semiconductor structure according to an embodiment of the present disclosure is shown;

[0022] Figure 5 A schematic diagram of a semiconductor structure according to an embodiment of the present disclosure is shown;

[0023] Figure 6 A schematic diagram of the semiconductor structure described in an embodiment of the present disclosure during a first cleaning process is shown;

[0024] Figure 7 A schematic diagram of the semiconductor structure described in an embodiment of the present disclosure during a second cleaning process is shown;

[0025] Figure 8 A schematic diagram of the semiconductor structure described in an embodiment of the present disclosure during a third cleaning process is shown;

[0026] Figure 9 A schematic diagram of a cleaning chamber according to an embodiment of the present disclosure is shown;

[0027] Figure 10 A schematic diagram of the semiconductor structure described in one embodiment of the present disclosure during an evaporation process is shown;

[0028] Figure 11 A schematic diagram of an evaporation chamber according to an embodiment of the present disclosure is shown;

[0029] Figure 12 A schematic diagram of a semiconductor structure according to an embodiment of the present disclosure during a freeze-drying process is shown;

[0030] Figure 13 A schematic diagram of a freezing chamber according to an embodiment of the present disclosure is shown;

[0031] Figure 14 A schematic diagram of the semiconductor structure described in an embodiment of the present disclosure during sublimation processing is shown;

[0032] Figure 15 A schematic diagram of a sublimation chamber according to an embodiment of the present disclosure is shown;

[0033] Figure 16 A schematic diagram of a process line for processing a semiconductor structure according to an embodiment of the present disclosure is shown. Detailed Implementation

[0034] As is known from the background art, during the removal of cleaning fluid, the internal patterns of semiconductor structures are prone to tilting and collapse. Analysis revealed that the main reason is that the direct evaporation drying method generates significant capillary forces, which cause both cleaning and pattern collapse. Specifically, refer to... Figures 1-3 , Figure 1 A schematic diagram of the initial stage of evaporating the cleaning fluid is shown. Figure 2 A schematic diagram of the later stages of evaporating the cleaning fluid is shown. Figure 3 A schematic diagram is shown after the evaporation of the cleaning solution is completed, in which... Figure 1 and Figure 2 The black arrows in the diagram indicate the flow direction of the cleaning fluid in the trench, while the white arrows indicate the cleaning fluid vapor. During evaporation, the cleaning fluid in the upper part of the trench 62 continuously transforms into vapor and detaches from the semiconductor structure 6; the remaining cleaning fluid in the trench 62 moves towards the side of the patterned layer 61, forming a concave liquid surface, which compresses the patterned layer 61, causing the upper part of the patterned layer 61 to tilt, stick, and collapse. In other words, the evaporation process generates significant capillary forces, which can damage the patterned layer 61.

[0035] The formula for calculating capillary force is: Where γ is the surface tension, H is the height of the patterned layer, D is the width of the trench 62, S is the depth of the cleaning fluid in the trench 62, t is the duration of the force application, and θ is the contact angle between the cleaning fluid and the patterned layer 61. The surface tension γ is related to the type of cleaning fluid. Based on the above calculation formula, it can be seen that factors such as a cleaning fluid with a higher surface tension, a trench 62 with a larger aspect ratio, and a longer application time will increase capillary force.

[0036] Furthermore, during the evaporation process, the semiconductor structure 6 is typically immersed in isopropanol. Isopropanol is miscible with water, thus dissolving the water in the trench 62 into the isopropanol. The semiconductor structure 6 is then heated, causing the liquid isopropanol to convert into vapor, which eventually escapes from the interior of the semiconductor structure 6. Although the surface tension of isopropanol is lower than that of water, it still generates significant capillary forces, thereby damaging the patterned layer 61. In addition, since all the isopropanol evaporates, the evaporation time is relatively long, extending the duration of the force application and further increasing the capillary forces.

[0037] To address the aforementioned issues, this disclosure provides a method for processing semiconductor structures that avoids removing all cleaning solution at once through evaporation. Instead, it removes the cleaning solution using a combination of evaporation, freezing, and sublimation. Evaporation removes a portion of the cleaning solution, reducing its expansion during freezing and preventing damage to the patterned layer. Freezing solidifies the remaining cleaning solution, and sublimation removes the solidified material. The solidified material does not compress the patterned layer during sublimation, preventing tilting or collapse and thus improving the yield of the semiconductor structure.

[0038] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the embodiments. However, the technical solutions claimed in the embodiments of this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0039] like Figures 4-16 As shown, this disclosure provides a method for processing a semiconductor structure 1, which includes steps S1 to S4. The method will be described in detail below with reference to the accompanying drawings.

[0040] refer to Figures 4-5 Step S1: Provide a semiconductor structure 1, which includes a plurality of spaced patterned layers 11 and trenches 12 located between adjacent patterned layers 11, i.e., adjacent patterned layers 11 are used to form trenches 12.

[0041] For example, the semiconductor structure 1 can be a wafer, the patterned layer 11 of the semiconductor structure 1 can be a capacitor structure, and the trench 12 can be located between adjacent capacitor structures. To increase the capacitance of the capacitor structure, the capacitor structure usually has a large height and a large arrangement density. Therefore, the trench 12 between adjacent capacitor structures has a large aspect ratio.

[0042] For example, the semiconductor structure 1 may contain residues generated by previous steps such as etching processes. These residues may include impurities such as dust, metal ions, and organic matter. Therefore, the semiconductor structure 1 needs to be cleaned with a cleaning solution.

[0043] refer to Figure 4 and Figures 6-9 Step S2: The semiconductor structure 1 is cleaned with a cleaning solution, which is filled into the trench 12.

[0044] The cleaning solution can be selected based on the pattern layer 11 and the type of residue, such as deionized water 2, sulfuric acid, hydrogen peroxide, ozone water, ammonia, or hydrochloric acid, to achieve high selectivity cleaning of the semiconductor structure 1. In other words, the effective structure within the semiconductor structure 1 is removed without removing the residue.

[0045] The following will illustrate the specific steps of the cleaning process with examples.

[0046] refer to Figure 6 The semiconductor structure 1 is first cleaned using deionized water 2. The deionized water 2 is used for preliminary cleaning of the semiconductor structure 1, which removes easily detached particles and helps reduce the amount of subsequent chemical solvents used. After the first cleaning, since it has not yet undergone drying, the deionized water 2 remains in the trench 12.

[0047] refer to Figure 7 After the first cleaning process, the semiconductor structure 1 is subjected to a second cleaning process using chemical solvent 3. In the second cleaning process, the chemical solvent 3 gradually replaces the deionized water 2 and fills the trench 12.

[0048] Chemical solvent 3 can react with stubborn residues in semiconductor structure 1, thereby dissolving the residues in the liquid. For example, chemical solvent 3 can be SC1 cleaning solution (a mixture of ammonium hydroxide, hydrogen peroxide, and deionized water), which can remove minor organic contaminants and some metallized contaminants. Chemical solvent 3 can also be SC2 cleaning solution (a mixture of hydrochloric acid, hydrogen peroxide, and deionized water 2), which can dissolve alkali metal ions and hydroxides of aluminum, iron, and magnesium. Chemical solvent 3 can also be SC3 cleaning solution (a mixture of sulfuric acid, hydrogen peroxide, and deionized water 2), which can remove organic contaminants.

[0049] refer to Figure 8 After the second cleaning process, the semiconductor structure 1 is subjected to a third cleaning process using deionized water 2. The deionized water 2 washes away the chemical solvent 3 and dissolved residues in the trench 12, thereby improving the cleanliness of the semiconductor structure 1 and consequently enhancing its performance. In the third cleaning process, the deionized water 2 gradually replaces the chemical solvent 3, thus filling the trench 12.

[0050] In some embodiments, the third cleaning process includes a first rotational stage and a second rotational stage performed sequentially; the semiconductor structure 1 has a first rotational speed in the first rotational stage, and the semiconductor structure 1 has a second rotational speed in the second rotational stage, wherein the second rotational speed is less than the first rotational speed. That is, the first cleaning process includes a high-speed cleaning stage and a low-speed cleaning stage. For example, the first rotational speed is 500 rpm to 1000 rpm, such as 600 rpm, 700 rpm, or 800 rpm; the second rotational speed is 10 rpm to 30 rpm, such as 15 rpm, 23 rpm, or 27 rpm.

[0051] It is worth noting that the higher rotational speed in the first rotational stage increases the centrifugal force, which is beneficial for removing residues from the semiconductor structure 1. The lower rotational speed in the second rotational stage ensures that the deionized water 2 remains on the surface of the semiconductor structure 1.

[0052] refer to Figure 9 , Figure 9 This is a schematic diagram of the cleaning chamber 41. The support stage 51 can be used to support the semiconductor structure 1. The support stage 51 can rotate to drive the semiconductor structure 1 to rotate. The rotational speed of the support stage 51 can be adjusted to achieve a first rotational speed stage and a second rotational speed stage. Furthermore, during the cleaning process, cleaning fluid can be sprayed towards the semiconductor structure 1, or the semiconductor structure 1 can be immersed in the cleaning fluid.

[0053] After the third cleaning process, evaporation, freezing, and sublimation treatments are performed sequentially. It should be noted that the evaporation of deionized water does not completely evaporate it; some deionized water remains in the trench. Therefore, the capillary force generated during the evaporation of deionized water 2 is relatively small, which avoids damage to the pattern layer 11.

[0054] refer to Figure 4 and Figures 10-11 Step S3: Evaporate the cleaning solution in trench 12 to remove part of the cleaning solution.

[0055] The main purpose of evaporation of a portion of the cleaning solution is that, during subsequent freezing, the cleaning solution may expand, potentially compressing the pattern layer 11. Evaporation removes a portion of the cleaning solution, reducing the degree of expansion during freezing. In other words, evaporation reduces the height of the cleaning solution in the trenches 12, thus providing space for expansion. The cleaning solution then expands upwards along the height of the trenches 12, reducing the lateral force on the pattern layer 11 and preventing it from tilting or collapsing. Furthermore, evaporation reduces the amount of cleaning solution, which helps shorten the duration of subsequent freezing and sublimation processes, thereby improving processing efficiency. Additionally, since only a portion of the cleaning solution needs to be evaporated, the evaporation time is shorter. According to the capillary force calculation formula, a shorter force duration results in a correspondingly lower capillary force. Therefore, compared to complete evaporation, partial evaporation helps avoid damage to the pattern layer 11.

[0056] It is worth noting that excessive evaporation can create significant capillary forces, potentially causing the pattern layer 11 to tilt or collapse. Therefore, a preset safety water level can be set. The preset safety water level varies depending on the product and process, and the aspect ratio of the trench 12 is related to the preset safety water level. A higher aspect ratio in the trench 12 results in greater capillary forces on the pattern layer 11. Therefore, a higher preset safety water level can be selected to reduce the force exerted on the pattern layer 11. In other words, the height of the remaining cleaning fluid in the trench 12 is directly proportional to the aspect ratio of the trench 12.

[0057] In some embodiments, the height of the remaining cleaning fluid in the trench 12 is greater than 1 / 10 of the depth of the trench 12 and less than 1 / 2 of the depth of the trench 12. When the height of the cleaning fluid in the trench 12 and the depth of the trench 12 satisfy the above relationship, it is beneficial to balance both the degree of expansion and capillary force, thereby avoiding damage to the pattern layer 11. For example, when the aspect ratio of the trench 12 is 10:1, the height of the remaining cleaning fluid in the trench 12 can be 1 / 5 of the depth of the trench 12.

[0058] In some embodiments, the preset safety water level can be converted into the weight of the remaining cleaning fluid to facilitate monitoring of the evaporation process. To achieve precise control of the weight of the remaining cleaning fluid, the following two examples can be used.

[0059] Example 1: The evaporation process also includes: weighing to obtain the total weight of the cleaning liquid in the semiconductor structure 1 and the trench 12; determining whether the total weight is greater than the weight threshold; if so, continuing the evaporation process; if not, stopping the evaporation process.

[0060] For example, the total weight of the semiconductor structure 1 and the cleaning solution can be weighed in real time during the evaporation process, and the real-time weighing result can be compared with a weight threshold to determine subsequent processing steps. In other embodiments, weighing can also be performed based on the stage and time of the evaporation process.

[0061] In addition to the cleaning fluid in the trench 12, the surface of the pattern layer 11 may also have some cleaning fluid. Therefore, the weight of this part of the cleaning fluid can also be taken into account when calculating the total weight to improve the accuracy of the weighing process.

[0062] In addition, the weight threshold can also be set as a weight range, and the evaporation process will stop when the total weight is within this weight range.

[0063] refer to Figure 11 , Figure 11 This is a schematic diagram of the evaporation chamber 42. The chuck 52 is used to provide a heat source; three supports 53 on the chuck 52 are used to support the semiconductor structure 1. A weight sensor 54 can be installed below the chuck 52 to sense the total weight of the semiconductor structure 1 and the cleaning fluid. Figure 11 The arrows in the diagram are used to indicate the steam produced during the evaporation process.

[0064] Example 2:

[0065] The remaining cleaning solution is preset to a specific weight range; the evaporation time and rate are determined based on the weight range; and evaporation is performed according to the evaporation time and rate.

[0066] For example, the weight of the cleaning fluid to be evaporated is calculated in advance based on a preset safe water level; the evaporation rate is calculated based on factors such as chamber temperature, chamber pressure, and the type of cleaning fluid; and the evaporation time is determined based on the evaporation rate and the evaporated weight. In this way, subsequent evaporation can be carried out directly according to the calculated evaporation rate and evaporated weight without the need for weighing.

[0067] In other embodiments, the evaporation process can be monitored by combining the methods of Example 1 and Example 2. For example, evaporation can be carried out first according to a preset evaporation time and rate, and then monitored by weighing, without the need for real-time weighing. Combining the two methods helps reduce the number of weighings and improves the accuracy of monitoring. Furthermore, based on the data from the weighing process, the preset evaporation time and rate can be adjusted so that subsequent batches of evaporation can better meet the preset safe water level requirements.

[0068] refer to Figure 4 and Figures 12-13 Step S4: Freeze the remaining cleaning fluid in the trench 12 to solidify the cleaning fluid.

[0069] For example, the cleaning solution can be deionized water 2, which is frozen into solid ice. During the process of deionized water 2 changing from liquid to solid, expansion occurs. To suppress the side effects of expansion on the patterned layer 11, the freezing rate can be controlled to avoid the cleaning solution expanding rapidly and thus laterally compressing the patterned layer 11.

[0070] In some embodiments, during the freezing process, a chuck 52 is used to control the temperature of the semiconductor structure 1, meaning the temperature of the chuck 52 can be transferred to both the semiconductor structure 1 and the cleaning solution. Taking deionized water 2 as the cleaning solution as an example, the temperature range of the chuck 52 is -1℃ to -30℃, such as -5℃, -10℃, or -20℃. It is worth noting that if the temperature of the chuck 52 is too low, the cleaning solution may cool down rapidly, thereby increasing the degree of lateral expansion; if the temperature of the chuck 52 is too high, the freezing process time may be prolonged. When the temperature of the chuck 52 is within the above-mentioned range, it is beneficial to reduce the degree of lateral expansion of the cleaning solution and improve freezing efficiency.

[0071] During the freezing process, the temperature change of chuck 52 shall not exceed 10°C, for example, a change of 2°C, 6°C, or 9°C. It is worth noting that if the temperature change of chuck 52 is too large, it may cause rapid cooling. Therefore, controlling the temperature change within 10°C helps to control the expansion rate. For example, during the freezing process, the temperature of chuck 52 remains constant, thus making the solidification process more gentle.

[0072] refer to Figure 13 , Figure 13 A schematic diagram of the freezing chamber 43 is shown. A refrigerant unit 54 can be installed below the chuck 52 for transferring and recovering refrigerant to and from the chuck 52. That is, after the refrigerant is transferred to the chuck 52, it can absorb heat from the chuck 52, thereby cooling the chuck 52. The refrigerant that has absorbed heat is transferred to the outside of the freezing chamber 43 through the refrigerant unit 54, where it can re-enter the freezing chamber 43 after releasing heat. This achieves cyclic cooling, which helps reduce the amount of refrigerant used.

[0073] refer to Figure 4 and Figures 14-15 Step S5: Sublime 2a of the cleaning solution is sublimated to remove it. During sublimation, the solidified 2a of the cleaning solution directly changes from solid to gas without producing liquid. Therefore, sublimation does not generate capillary force on the pattern layer 11, which is beneficial to improving the quality of the pattern layer 11.

[0074] In the sublimation process, a chuck 52 is used to control the temperature of the semiconductor structure 1. Taking solid ice as an example, the temperature range of the chuck 52 can be -20℃ to 0℃, such as -10℃, -5℃, or -2℃. It should be noted that the sublimation temperature should not be too low, otherwise it may reduce the sublimation rate; the sublimation temperature should also not be too high, otherwise it may cause the solidified cleaning solution 2a to transform into a liquid state, and then from a liquid state to a gas state. When the temperature of the chuck 52 is within the above range, it is beneficial to improve the sublimation rate and also avoid the formation of the intermediate liquid state.

[0075] In the sublimation process, the pressure range of the sublimation chamber 44 is 200 mTorr to 100 Torr, such as 10 Torr, 20 Torr, or 90 Torr. It should be noted that lower chamber pressure is more conducive to the transformation from solid to gas; however, sublimation is an endothermic process, and the enthalpy absorbed during sublimation is called the enthalpy of sublimation or heat of sublimation. Therefore, excessively low chamber pressure will also affect heat transfer, and slow heat transfer will result in slower energy gain for the condensate 2a of the cleaning fluid, potentially reducing the sublimation rate. Therefore, setting the chamber pressure within the aforementioned range is beneficial in balancing these two aspects.

[0076] In some embodiments, the process further includes a vacuum process before sublimation. Specifically, after the semiconductor structure 1 is transferred to the sublimation chamber 44, the sublimation chamber 44 is evacuated to a vacuum state under standard atmospheric pressure, and subsequent sublimation drying is performed under vacuum. It is worth noting that the vacuum process helps to reduce the pressure inside the chamber, thereby increasing the sublimation rate. In addition, vacuum sublimation also helps to lower the sublimation temperature, preventing the sublimated material from decomposing due to excessive temperature or being oxidized during sublimation.

[0077] In some embodiments, after the vacuuming process, nitrogen gas is introduced into the sublimation chamber 44. Nitrogen gas can blow away impurities from the semiconductor structure 1, increasing gas flow and thus improving the efficiency of the vacuum process. Furthermore, nitrogen gas helps remove residues from the surface of the semiconductor structure 1, thereby improving the cleanliness of the semiconductor structure 1.

[0078] refer to Figure 15 , Figure 15 This is a schematic diagram of the sublimation chamber 44. The vacuum tube 55 is connected to the sublimation chamber 44 and is used to pump out the air inside the sublimation chamber 44. The nitrogen transfer tube 56 is connected to the sublimation chamber 44. After vacuuming, nitrogen enters the sublimation chamber 44 through the nitrogen transfer tube 56.

[0079] To facilitate understanding, the processing method of semiconductor structure 1 will be illustrated below with a schematic diagram of the production line.

[0080] refer to Figure 16Taking semiconductor structure 1 as an example, 25 wafers can be placed in the same wafer cassette. Four wafer cassettes enter buffer 45 from the first loading port LP1, the second loading port LP2, the third loading port LP3, and the fourth loading port LP4, respectively. Buffer 45 transfers the four wafer cassettes to the production line. The production line includes a cleaning chamber 41, an evaporation chamber 42, a freezing chamber 43, and a sublimation chamber 44, each with a first chamber CH1, a second chamber CH2, a third chamber CH3, and a fourth chamber CH4, corresponding one-to-one with the four wafer cassettes. First, the robot arm 46 places the four wafer cassettes from buffer 45 into the first chamber CH1, the second chamber CH2, the third chamber CH3, and the fourth chamber CH4 of cleaning chamber 41, respectively. After cleaning, the robot arm 46 removes the four wafer cassettes from cleaning chamber 41 and places them into the first chamber CH1, the second chamber CH2, the third chamber CH3, and the fourth chamber CH4 of evaporation chamber 42, respectively. After evaporation, the robot arm 46 removes four wafer cassettes from the evaporation chamber 42 and places them into the first chamber CH1, second chamber CH2, third chamber CH3, and fourth chamber CH4 of the freezing chamber 43, respectively. After freezing, the robot arm 46 removes the four wafer cassettes from the freezing chamber 43 and places them into the first chamber CH1, second chamber CH2, third chamber CH3, and fourth chamber CH4 of the sublimation chamber 44, respectively. After sublimation, the robot arm 46 removes the four wafer cassettes from the sublimation chamber 44 and places them into the buffer zone 45. The buffer zone 45 then transfers the four wafer cassettes to the first loading port LP1, second loading port LP2, third loading port LP3, and fourth loading port LP4, respectively, thus completing the cleaning and drying processes.

[0081] In summary, the embodiments of this disclosure combine evaporation, freezing, and sublimation processes to avoid directly evaporating and drying the semiconductor structure 1 with drying solutions such as isopropanol, thereby avoiding the problems of tilting of the pattern layer 11 and adhesion of the upper part caused by the capillary force of chemical solvents.

[0082] In the description of this specification, references to terms such as "some embodiments," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0083] Although embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure. Therefore, any changes or modifications made in accordance with the claims and description of the present disclosure should fall within the scope of the patent coverage of the present disclosure.

Claims

1. A method for processing a semiconductor structure, characterized in that, include: A semiconductor structure is provided, the semiconductor structure comprising a plurality of spaced patterned layers and trenches located between adjacent patterned layers; The semiconductor structure is cleaned using a cleaning solution, which is filled into the trench. After the cleaning process, the cleaning solution in the trench is evaporated to remove a portion of the cleaning solution. The remaining cleaning fluid in the trench is frozen to solidify it. The solidified material of the cleaning solution is sublimated to remove the solidified material.

2. The semiconductor structure processing method according to claim 1, characterized in that, The evaporation process further includes: Weighing process to obtain the total weight of the semiconductor structure and the cleaning solution in the trench; Determine whether the total weight is greater than a weight threshold. If yes, continue the evaporation process; otherwise, stop the evaporation process.

3. The semiconductor structure processing method according to claim 1, characterized in that, Prior to the evaporation process, the following is also included: The weight range of the remaining cleaning fluid is preset; The evaporation time and evaporation rate are determined based on the weight range; The evaporation process is performed according to the evaporation time and the evaporation rate.

4. The semiconductor structure processing method according to claim 1, characterized in that, The cleaning solution includes deionized water.

5. The semiconductor structure processing method according to claim 4, characterized in that, The cleaning process for the semiconductor structure includes: The semiconductor structure was first cleaned using deionized water. After the first cleaning process, the semiconductor structure is subjected to a second cleaning process using a chemical solvent; After the second cleaning process, the semiconductor structure is subjected to a third cleaning process using deionized water; The deionized water used in the third cleaning process is filled into the trench; After the third cleaning process, the evaporation process, the freezing process, and the sublimation process are performed in sequence.

6. The semiconductor structure processing method according to claim 5, characterized in that, The third cleaning process includes a first rotation stage and a second rotation stage performed sequentially; the semiconductor structure has a first rotation speed in the first rotation stage, and the semiconductor structure has a second rotation speed in the second rotation stage, wherein the second rotation speed is less than the first rotation speed.

7. The semiconductor structure processing method according to claim 4, characterized in that, In the freezing process, a chuck is used to control the temperature of the semiconductor structure, and the temperature range of the chuck is -1℃ to -30℃.

8. The semiconductor structure processing method according to claim 7, characterized in that, During the freezing process, the temperature change of the chuck does not exceed 10°C.

9. The semiconductor structure processing method according to claim 8, characterized in that, During the freezing process, the temperature of the chuck remains constant.

10. The method for processing a semiconductor structure according to claim 4, characterized in that, In the sublimation process, a chuck is used to control the temperature of the semiconductor structure, and the temperature range of the chuck is -20℃ to 0℃.

11. The semiconductor structure processing method according to claim 4, characterized in that, In the sublimation process, the chamber pressure ranges from 200 mTorr to 100 Torr.

12. The method for processing a semiconductor structure according to claim 1, characterized in that, The height of the remaining cleaning fluid in the trench is directly proportional to the depth-to-width ratio of the trench.

13. The semiconductor structure processing method according to claim 12, characterized in that, The remaining cleaning fluid in the trench is at a height greater than 1 / 10 of the trench depth and less than 1 / 2 of the trench depth.

14. The semiconductor structure processing method according to claim 1, characterized in that, After the cleaning process and before the sublimation process, the process further includes a vacuuming process.

15. The method for processing a semiconductor structure according to claim 14, characterized in that, After the vacuuming process, the method further includes: introducing nitrogen gas into the chamber.

Images