Semiconductor wafer surface pretreatment device and process

Abstract

The invention discloses a semiconductor wafer surface pretreatment device and process, the semiconductor wafer surface pretreatment device comprises a lower cavity and an upper cavity, a micro-cavity for accommodating a semiconductor wafer is formed between the upper cavity and the lower cavity, and the semiconductor wafer surface pretreatment device is characterized in that the bottom of the micro-cavity is respectively provided with a lower hole and a discharge hole which are communicated with the bottom of the lower cavity; the top of the lower hole is arranged in the middle of the bottom surface of the micro-cavity, and the top of the discharge hole is arranged at the outer edge of the bottom of the micro-cavity; and at least one vent hole communicated with the top of the upper cavity is formed in the top of the micro-cavity. According to the invention, the surface pretreatment efficiency and quality of the semiconductor wafer are improved, and the test efficiency and quality are also improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor production and processing, and in particular to a semiconductor wafer surface pretreatment device and process. Background Art

[0002] Wafer inspection is a critical link in semiconductor production. Its main purpose is to ensure the quality of the produced chips, improve production efficiency and reduce costs. Wafer inspection is usually divided into three aspects: optical inspection, electrical inspection and metallographic inspection. Electrical inspection is used to detect the electrical properties of the wafer, including resistance, capacity, current and other parameters. Based on the results of electrical inspection, manufacturers can adjust the wafer to ensure the stability and reliability of wafer quality.

[0003] Before using MCV to test the resistance of P-type epitaxial wafers, the wafers need to be pre-processed to remove the natural oxide layer and related impurities on the surface of the wafer. The current processing method for P-type epitaxial wafers is mainly to soak them in hydrofluoric acid liquid, corrode the natural oxide layer and related impurities that need to be removed from the surface, and then wash them with water to rinse the hydrofluoric acid liquid and the corroded related impurities from the surface of the semiconductor wafer. Then, the surface of the semiconductor wafer is blown dry before testing its resistance value. This process has the problems of high hydrofluoric acid consumption, inability to retain the back seal, and some wafers need to be left to stand for two hours. Some wafers cannot be tested with accurate data. Summary of the invention

[0004] The purpose of the present invention is to provide a semiconductor wafer surface pretreatment device and process. By using the device and process, the efficiency and quality of semiconductor wafer surface pretreatment can be improved, the stability of subsequent resistance value test data can be improved, and the efficiency of subsequent resistance value testing can be improved.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a semiconductor wafer surface pretreatment device, comprising a lower cavity and an upper cavity, wherein a micro chamber for accommodating the semiconductor wafer is formed between the upper cavity and the lower cavity,

[0006] The bottom of the micro chamber is respectively provided with a lower hole and a discharge hole which are connected with the bottom of the lower cavity, the top of the lower hole is arranged at the middle of the bottom surface of the micro chamber, and the top of the discharge hole is arranged at the outer edge of the bottom of the micro chamber;

[0007] The top of the micro chamber is provided with at least one vent hole which is in communication with the top of the upper cavity.

[0008] In the above technical solution, the vent hole includes an upper center hole and multiple upper edge holes, the bottom of the upper center hole is set at the top center of the microchamber, and the multiple upper edge holes are evenly distributed in an annular shape outside the upper center hole.

[0009] In the above technical solution, there are multiple discharge holes, and the multiple discharge holes are evenly distributed in a ring shape at the outer edge of the bottom of the micro chamber.

[0010] In the above technical solution, a nitrogen supply mechanism for providing nitrogen is also provided, and the nitrogen supply mechanism is connected to the vent hole, and the nitrogen provided by the nitrogen supply mechanism is delivered into the microchamber above the semiconductor wafer through the vent hole.

[0011] In the above technical solution, the lower hole includes a lower center hole and a plurality of lower outer edge holes, the top of the lower center hole is arranged at the center of the bottom surface of the microchamber, the lower outer edge holes are evenly distributed in a ring shape outside the lower center hole, and the lower outer edge holes are arranged between the discharge hole and the lower center hole.

[0012] In the above technical solution, a fluid providing mechanism connected to the lower hole is further provided, and the fluid provided by the fluid providing mechanism is delivered into the micro-chamber below the semiconductor wafer through the lower hole.

[0013] In the above technical solution, the fluid providing mechanism includes a liquid fluid providing mechanism for providing liquid fluid and a gaseous fluid providing mechanism for providing gaseous fluid;

[0014] And / or, the liquid fluid provided by the liquid fluid providing mechanism corrodes or cleans the bottom surface of the semiconductor wafer;

[0015] And / or, the gaseous fluid provided by the gaseous fluid providing mechanism dries the bottom surface of the semiconductor wafer.

[0016] In the above technical solution, a negative pressure discharge mechanism connected to the discharge hole is further provided, and the negative pressure discharge mechanism sucks out the liquid fluid or gaseous fluid in the micro chamber.

[0017] In the above technical solution, a sealing ring for sealing the micro-chamber is also provided at the outer edge of the lower cavity.

[0018] The present invention also provides a semiconductor wafer surface pretreatment process, the steps of which are:

[0019] ① Placing the semiconductor wafer in the micro chamber between the upper cavity and the lower cavity, with a distance between the outer edge of the semiconductor wafer and the outer edge of the micro chamber;

[0020] ② Send nitrogen gas into the microchamber above the semiconductor wafer from the vent at a certain pressure;

[0021] Then, the liquid fluid is sent into the micro-chamber below the semiconductor wafer through the lower hole at a certain pressure;

[0022] When the liquid fluid is sent under the semiconductor wafer, the semiconductor wafer is pushed away from the bottom surface of the microchamber by the liquid fluid, so that the semiconductor wafer does not contact the inner wall of the microchamber, and the nitrogen gas sent out from the vent hole makes the liquid fluid contact only with the bottom surface of the semiconductor wafer, and the bottom surface of the semiconductor wafer is corroded and cleaned by the liquid fluid;

[0023] After the liquid fluid has completed etching and cleaning the bottom surface of the semiconductor wafer, the discharge hole discharges all the liquid fluid in the micro-chamber;

[0024] ③ Then the gaseous fluid is sent into the micro-chamber at the bottom of the semiconductor wafer through the lower hole, and the bottom surface of the semiconductor wafer is dried by the gaseous fluid. During the drying process, the discharge hole will discharge the gaseous fluid until the bottom of the semiconductor wafer is dried;

[0025] ④ After the bottom surface of the semiconductor wafer is dried, the semiconductor wafer is taken out from the microchamber to complete the pretreatment of the surface of the semiconductor wafer.

[0026] In the above technical solution, in step ②, the liquid fluids are respectively a corrosive liquid and a cleaning liquid;

[0027] The bottom surface of the semiconductor wafer is first corroded by an etching liquid, and after the etching liquid is discharged through the discharge hole, the bottom surface of the semiconductor wafer is cleaned by a cleaning liquid to clean the hydrofluoric acid remaining on the bottom surface of the semiconductor wafer, and the cleaning liquid is discharged through the discharge hole.

[0028] In the above technical solution, the etching liquid is hydrofluoric acid, and the concentration of the hydrofluoric acid is 20%;

[0029] The cleaning liquid is pure water.

[0030] In the above technical solution, the step ② includes the following steps:

[0031] a. Etching of the bottom of the semiconductor wafer: The etching liquid is sent into the micro-chamber at the bottom of the semiconductor wafer from the lower hole, and the bottom surface of the semiconductor wafer is corroded by the etching liquid. After a predetermined time, the discharge hole discharges the etching liquid at the bottom of the micro-chamber and the debris etched out from the semiconductor wafer;

[0032] Repeat step a at least 3 times;

[0033] b. Cleaning the bottom of the semiconductor wafer: After the semiconductor wafer is etched in step a, a cleaning liquid is introduced into the micro-chamber at the bottom of the semiconductor wafer, and the bottom surface of the semiconductor wafer is cleaned by the cleaning liquid to clean the hydrofluoric acid remaining on the bottom surface of the semiconductor wafer, and the cleaning liquid is discharged through the discharge hole;

[0034] The step b is repeated at least 6 times.

[0035] In the above technical solution, the corrosive liquid is placed in a liquid storage bottle, and is delivered into the liquid storage bottle by nitrogen, and the corrosive liquid is pressed from the liquid storage bottle into the micro chamber by nitrogen.

[0036] In the above technical solution, in step ②, the discharge hole sucks the liquid fluid out of the micro chamber through negative pressure;

[0037] In step ③, the gaseous fluid is nitrogen, and the discharge hole sucks the gaseous fluid out of the microchamber through negative pressure.

[0038] In the above technical solution, in step ②, the vent hole is filled with nitrogen in advance to fill the micro chamber, and then the liquid fluid is sent into the micro chamber from the lower hole;

[0039] When the liquid fluid enters the micro-chamber from the lower hole, the liquid fluid diffuses outward from the lower hole of the micro-chamber, and the liquid fluid first contacts the middle part of the bottom surface of the semiconductor wafer, then flows along the middle part of the bottom surface of the semiconductor wafer toward the outer edge of the semiconductor wafer, and finally is discharged from the discharge hole;

[0040] In the step ③, the flow trajectory of the gaseous fluid is the same as the flow trajectory of the liquid fluid.

[0041] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0042] 1. In the present invention, a semiconductor wafer is accommodated in a microchamber, a fluid is fed into the microchamber through a lower hole, and nitrogen is fed into the microchamber through a vent hole. The semiconductor wafer is suspended in the microchamber by the pressure of the nitrogen and the fluid, and the fluid is in contact with only the bottom surface of the semiconductor wafer, so that the fluid can only perform pretreatment of etching, cleaning, and drying on the bottom surface of the semiconductor wafer, thereby improving the efficiency and quality of the semiconductor wafer surface pretreatment, allowing the semiconductor wafer to be directly measured without being left to stand, and without damaging the semiconductor wafer back seal, thereby improving the measurement efficiency and quality;

[0043] 2. In the present invention, the bottom surface of the semiconductor wafer is rapidly corroded by hydrofluoric acid, the bottom surface of the corroded semiconductor wafer is rapidly cleaned by pure water, and the cleaned semiconductor wafer is rapidly dried by nitrogen, thereby improving the pretreatment efficiency and quality of the semiconductor wafer surface;

[0044] 3. When the fluid is used to pre-treat the bottom surface of the semiconductor wafer in the present invention, the fluid is pre-treated from the center of the bottom surface of the semiconductor wafer to its edge, so that the surface of the semiconductor wafer can be pre-treated stably, and the micro-chamber can also be completely dried, thereby improving the pre-treatment quality and ensuring the cleanliness of the pre-treatment device;

[0045] 4. In the present invention, hydrofluoric acid is introduced into the microchamber, and the consumption of hydrofluoric acid is relatively low, thereby reducing the pretreatment cost of the semiconductor wafer surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a structural schematic diagram of the first embodiment of the present invention;

[0047] Figure 2 yes Figure 1 A partial enlarged view of

[0048] Figure 3 is a schematic diagram of the top surface structure of the lower cavity in the first embodiment of the present invention;

[0049] Figure 4 It is a schematic diagram of the bottom structure of the upper cavity in the first embodiment of the present invention.

[0050] Among them: 1. upper cavity; 2. lower cavity; 3. semiconductor wafer; 4. micro chamber; 5. lower hole; 6. discharge hole; 7. vent hole; 8. upper center hole; 9. upper edge hole; 10. lower center hole; 11. lower outer edge hole; 12. sealing ring. DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0052] Example 1: See Figures 1 to 4 As shown, a semiconductor wafer surface pretreatment device comprises a lower cavity 1 and an upper cavity 2, wherein a micro chamber 4 for accommodating a semiconductor wafer 3 is formed between the upper cavity 1 and the lower cavity 2.

[0053] The bottom of the microchamber 4 is respectively provided with a lower hole 5 and a discharge hole 6 which are connected with the bottom of the lower cavity 2, the top of the lower hole 5 is arranged in the middle of the bottom surface of the microchamber 4, and the top of the discharge hole 6 is arranged at the outer edge of the bottom of the microchamber 4; wherein, the lower hole and the discharge hole can also be connected with the outer side wall of the lower cavity, and it is only necessary that the lower hole and the discharge hole can connect the bottom of the microchamber with the outside.

[0054] The top of the micro chamber 4 is provided with at least one vent hole 7 connected to the top of the upper cavity 1. The vent hole can also be connected to the outer wall of the upper cavity, as long as the vent hole can connect the top of the micro chamber with the outside.

[0055] In the present invention, a nitrogen supply mechanism is provided for supplying nitrogen, the nitrogen supply mechanism is connected to the vent hole, and the nitrogen provided by the nitrogen supply mechanism is delivered into the microchamber above the semiconductor wafer through the vent hole. A fluid supply mechanism is also provided, which is connected to the lower hole, and the fluid provided by the fluid supply mechanism is delivered into the microchamber below the semiconductor wafer through the lower hole.

[0056] The fluid providing mechanism includes a liquid fluid providing mechanism for providing liquid fluid and a gaseous fluid providing mechanism for providing gaseous fluid; the liquid fluid provided by the liquid fluid providing mechanism corrodes or cleans the bottom surface of the semiconductor wafer; the gaseous fluid provided by the gaseous fluid providing mechanism dries the bottom surface of the semiconductor wafer.

[0057] The present invention also provides a semiconductor wafer surface pretreatment process, the steps of which are:

[0058] ① Placing the semiconductor wafer in the micro chamber between the upper cavity and the lower cavity, with a distance between the outer edge of the semiconductor wafer and the outer edge of the micro chamber;

[0059] The upper cavity and the lower cavity are split structures, the upper cavity can move between an open position and a closed position relative to the lower cavity, when the upper cavity is in a closed position relative to the lower cavity, a micro-chamber is formed between the upper cavity and the lower cavity, the semiconductor wafer can be accommodated in the micro-chamber, when the upper cavity is in an open position relative to the lower cavity, the semiconductor wafer can be taken out or put in. The outer diameter of the semiconductor wafer is slightly smaller than the diameter of the micro-chamber, therefore, when the semiconductor wafer is placed in the micro-chamber, there is a gap between the outer surface of the semiconductor wafer and the inner wall at the outer edge of the micro-chamber, at this time, the semiconductor wafer is affected by its own gravity and is placed on the bottom surface of the micro-chamber. A sealing ring 12 is also provided at the outer edge of the lower cavity to seal the micro-chamber. In this way, when the upper cavity and the lower cavity are in a closed position, the micro-chamber is a sealed chamber.

[0060] ② Send nitrogen gas into the microchamber above the semiconductor wafer from the vent at a certain pressure;

[0061] After the semiconductor wafer is placed in the microchamber, the vents, lower holes and discharge holes are sealed, that is, the microchamber is a closed space, and then the nitrogen supply mechanism is opened, that is, nitrogen is sent into the microchamber through the vents, and the nitrogen fills the microchamber, wherein the nitrogen is a protective gas, providing a suitable processing space for the subsequent fluid to pre-treat the bottom surface of the semiconductor wafer, so as to ensure the pre-treatment quality of the bottom surface of the semiconductor wafer by the fluid. The nitrogen supply mechanism can be a nitrogen source, and the nitrogen source delivers nitrogen to the microchamber through the vents.

[0062] Then, the liquid fluid is sent into the micro-chamber below the semiconductor wafer through the lower hole at a certain pressure;

[0063] When the liquid fluid is sent under the semiconductor wafer, the semiconductor wafer is pushed away from the bottom surface of the microchamber by the liquid fluid, so that the semiconductor wafer does not contact the inner wall of the microchamber, and the nitrogen gas sent out from the vent hole makes the liquid fluid contact only with the bottom surface of the semiconductor wafer, and the bottom surface of the semiconductor wafer is corroded and cleaned by the liquid fluid;

[0064] After the liquid fluid has completed etching and cleaning the bottom surface of the semiconductor wafer, the discharge hole discharges all the liquid fluid in the micro-chamber;

[0065] Among them, the flow path or trajectory of the liquid fluid is: when the liquid fluid enters the microchamber from the lower hole, the liquid fluid diffuses outward from the lower hole of the microchamber, and the liquid fluid will first contact the middle part of the bottom surface of the semiconductor wafer, and then flow along the middle part of the bottom surface of the semiconductor wafer toward the outer edge of the semiconductor wafer, and finally be discharged from the discharge hole.

[0066] In this embodiment, the liquid fluid enters the microchamber from the lower hole. Since the microchamber is filled with nitrogen, when the liquid fluid enters the microchamber, it will push the same volume of nitrogen out of the vent hole at the same time, and then the liquid fluid gradually enters the microchamber. In this process, the nitrogen pressure maintained by the vent hole makes the liquid fluid always at the bottom of the semiconductor wafer, and pushes the semiconductor wafer upward to make it leave the bottom of the microchamber, that is, the semiconductor wafer is equivalent to floating in the microchamber, so that the liquid fluid can completely fill the semiconductor wafer. The bottom surface of the wafer is covered, and because the vents give a certain pressure to the nitrogen sent into the microchamber, and the nitrogen is above the semiconductor wafer at this time, the nitrogen will pass through the gap between the edge of the semiconductor wafer and the edge of the microchamber, giving pressure to the liquid fluid, so that the liquid fluid cannot flow upward from this gap and contact the top surface of the semiconductor wafer, that is, the liquid fluid can only contact the bottom surface of the semiconductor wafer, and the bottom surface of the semiconductor wafer is corroded and cleaned by the liquid fluid, thereby achieving pretreatment of its surface and removing the oxide layer and related impurities on its surface. Moreover, its flow direction flows outward from the middle of the bottom surface of the semiconductor wafer, so that the liquid fluid can fully, quickly and stably pretreat the bottom surface of the semiconductor wafer. Then the liquid fluid is discharged from the microchamber through the discharge hole. Among them, there is also a negative pressure discharge mechanism connected to the discharge hole, and the negative pressure discharge mechanism sucks out the liquid fluid in the micro chamber. The negative pressure discharge mechanism adopts a vacuum generator, preferably CDA to drive the vacuum generator, and the liquid fluid in the micro chamber is extracted by vacuum negative pressure, so that the liquid fluid is discharged and collected from the micro chamber, ensuring that the liquid fluid in the micro chamber is discharged as cleanly as possible, and the efficiency is also high. Among them, the top surface of the semiconductor wafer is the back seal area, so that the liquid fluid will not contact the back seal area, so that the back seal of the semiconductor wafer can be completely retained, thereby ensuring the accuracy of subsequent tests.

[0067] Among them, a main discharge hole connected to multiple discharge holes will be set in the lower cavity, one end of the main discharge hole is connected to multiple discharge holes, and the other end is connected to the outer wall or bottom of the lower cavity, so that the negative pressure discharge mechanism is connected to the main discharge hole through a pipeline, that is, the negative pressure discharge mechanism can be connected to multiple discharge holes, and negative pressure can be generated for each discharge hole through a negative pressure discharge mechanism for discharge, which is more cost-effective. Of course, the bottom of each discharge hole can also be connected to the bottom or side wall of the lower cavity, connected to each discharge hole through multiple branch pipes, and then connected to the multiple branch pipes and the negative pressure discharge mechanism through a main pipe, and the selection can be made according to the actual situation.

[0068] ③ Then the gaseous fluid is sent into the micro-chamber at the bottom of the semiconductor wafer through the lower hole, and the bottom surface of the semiconductor wafer is dried by the gaseous fluid. During the drying process, the discharge hole will discharge the gaseous fluid until the bottom of the semiconductor wafer is dried;

[0069] Wherein, the gaseous fluid is nitrogen, and the discharge hole sucks the gaseous fluid out of the microchamber through negative pressure. Moreover, the flow trajectory of the gaseous fluid is the same as the flow trajectory of the liquid fluid. In this way, the gaseous fluid first contacts the center of the bottom surface of the semiconductor wafer, and then flows along the center of the bottom surface of the semiconductor wafer toward the outer edge of the semiconductor wafer, so that all the liquid fluid remaining on the bottom surface of the semiconductor wafer can be blown away, and all sucked out from the discharge hole through negative pressure. At the same time, in this process, all the liquid fluid remaining at the bottom of the microchamber will also be discharged, so that the semiconductor wafer and the liquid fluid in the microchamber can be completely discharged through the gaseous fluid, so that the semiconductor wafer and the microchamber are quickly dried, so that the liquid fluid will not affect the cleanliness of the microchamber, and the drying of the semiconductor wafer and the microchamber can be achieved.

[0070] ④ After the bottom surface of the semiconductor wafer is dried, the upper cavity and the lower cavity are separated, that is, the microchamber is opened, and then the semiconductor wafer is taken out of the microchamber to complete the pretreatment of the semiconductor wafer surface.

[0071] In the present invention, the surface of the semiconductor wafer can be quickly pre-processed without damaging the back seal of the semiconductor wafer.

[0072] See also Figure 4 As shown, the vent hole 7 includes an upper center hole 8 and a plurality of upper edge holes 9, the bottom of the upper center hole is arranged at the top center of the micro chamber, and the plurality of upper edge holes are evenly distributed in an annular shape outside the upper center hole.

[0073] In this embodiment, the upper edge hole is arranged close to the upper center hole, and the upper edge hole is also arranged close to the middle of the top surface of the microchamber, so that when the nitrogen enters the microchamber from the top of the microchamber, it is sent downward from the middle of the top surface of the microchamber, so that the flow trajectory of the nitrogen will flow from the middle of the top surface of the semiconductor wafer toward the outer edge of the semiconductor wafer, and the nitrogen will also flow from the middle of the top surface of the microchamber along the top surface of the microchamber toward the outer edge of the microchamber, so that the nitrogen flows downward from the outer edge of the semiconductor wafer, thereby restricting the liquid fluid and the gaseous fluid below the semiconductor wafer to prevent the fluid from damaging the back seal of the top surface of the semiconductor wafer. In this embodiment, there are 8 upper edge holes, which are evenly distributed in a ring outside the upper center hole.

[0074] See also Figure 3 As shown, there are multiple discharge holes, and the multiple discharge holes are evenly distributed in a ring shape at the bottom outer edge of the micro chamber.

[0075] In the present embodiment, the discharge hole is arranged at the outer edge of the bottom surface of the microchamber, so that the flow trajectory of the fluid flows from the middle of the bottom surface of the semiconductor wafer toward the outer edge of the bottom surface of the semiconductor, and flows from the inside to the outside, and then is discharged from the discharge hole. In order to ensure smooth discharge of the fluid, a plurality of discharge holes are arranged, which are evenly distributed in a ring on the lower cavity. Preferably, in the present embodiment, 8 discharge holes are arranged, which are evenly distributed in a ring at the outer edge of the lower cavity and are connected to the outer edge of the bottom surface of the microchamber. This can ensure smooth discharge of the fluid and prevent the fluid from remaining in the microchamber.

[0076] See also Figure 3 As shown, the lower hole 5 includes a lower center hole 10 and a plurality of lower outer edge holes 11, the top of the lower center hole is arranged at the center of the bottom surface of the microchamber, the lower outer edge holes are evenly distributed in an annular shape outside the lower center hole, and the lower outer edge holes are arranged between the discharge hole and the lower center hole.

[0077] Among them, the lower outer edge hole is arranged close to the lower center hole, so that the lower holes are arranged close to the center of the microchamber, so that the flow trajectory of the fluid entering the microchamber is: flowing from the middle of the bottom of the microchamber toward the edge of the microchamber, so that there will be no residue on the bottom surface of the semiconductor wafer, thereby ensuring the stability and quality of the pretreatment of the bottom of the semiconductor wafer by the fluid.

[0078] Wherein, in step ②, the liquid fluids are respectively a corrosive liquid and a cleaning liquid;

[0079] The bottom surface of the semiconductor wafer is first corroded by an etching liquid, and after the etching liquid is discharged through the discharge hole, the bottom surface of the semiconductor wafer is cleaned by a cleaning liquid to clean the hydrofluoric acid remaining on the bottom surface of the semiconductor wafer, and the cleaning liquid is discharged through the discharge hole.

[0080] In this embodiment, when the liquid fluid processes the bottom surface of the semiconductor wafer, the oxide layer and other impurities on the bottom surface of the semiconductor wafer are first corroded by the corrosive liquid to separate it from the bottom surface of the semiconductor wafer, and then the corrosive liquid and the corroded impurities mixed therein are sucked out by negative pressure through the discharge hole to be discharged as much as possible. Of course, some of the corrosive liquid and the corroded substances of the semiconductor wafer will remain between the bottom surface of the semiconductor wafer and the bottom surface of the microchamber. Therefore, the bottom surface of the semiconductor and the bottom of the microchamber are cleaned by the cleaning liquid, so as to rinse off the corrosive liquid temporarily retained inside and the corroded substances on the semiconductor wafer. Finally, the pure water remaining in the semiconductor wafer and the microchamber is blown dry by the gaseous fluid (nitrogen), so as to achieve rapid drying of the semiconductor wafer and the microchamber.

[0081] The etching solution is hydrofluoric acid, and the concentration of the hydrofluoric acid is 20%; the cleaning solution is pure water. The bottom surface of the semiconductor wafer is treated with hydrofluoric acid with a concentration of 20%, and then the residue is cleaned with pure water to ensure the subsequent detection accuracy and quality of the semiconductor wafer.

[0082] Wherein, the step ② includes the following steps:

[0083] a. Etching of the bottom of the semiconductor wafer: The etching liquid is sent into the micro-chamber at the bottom of the semiconductor wafer from the lower hole, and the bottom surface of the semiconductor wafer is corroded by the etching liquid. After a predetermined time, the discharge hole discharges the etching liquid at the bottom of the micro-chamber and the debris etched out from the semiconductor wafer;

[0084] In this embodiment, the etching liquid (hydrofluoric acid) is only fed into the micro-chamber from the lower center hole, that is, the etching liquid initially contacts the center of the bottom surface of the semiconductor wafer or the center of the bottom surface of the semiconductor wafer, and then flows toward the outer edge of the bottom surface of the semiconductor wafer, and contacts various positions of the bottom surface of the semiconductor wafer. The etching liquid removes the oxide layer and other impurities from the bottom surface of the semiconductor wafer, which can maximize the cleaning efficiency of the oxide and other impurities on the bottom surface of the semiconductor wafer, and the consumption of hydrofluoric acid is relatively small, and the cost of pre-treatment of the semiconductor wafer surface is lower. Moreover, the etching liquid is only fed into the micro-chamber from the lower center hole, which can extend the contact time between the etching liquid and the semiconductor wafer as much as possible, thereby ensuring the processing quality of the semiconductor wafer surface.

[0085] Step a is repeated at least 3 times. In this embodiment, it is sufficient to repeat 3 times;

[0086] In this embodiment, it is difficult to completely clean the bottom surface of the semiconductor wafer by only using hydrofluoric acid to etch the bottom surface of the semiconductor wafer once. Therefore, the introduction and discharge of hydrofluoric acid are repeated three times, so that the bottom surface of the semiconductor wafer can be thoroughly cleaned to ensure the cleaning quality. This can not only ensure the cleaning quality, but also reduce the amount of hydrofluoric acid used, thereby reducing costs as much as possible.

[0087] b. Cleaning the bottom of the semiconductor wafer: After the semiconductor wafer is etched in step a, a cleaning liquid is introduced into the micro-chamber at the bottom of the semiconductor wafer, and the bottom surface of the semiconductor wafer is cleaned by the cleaning liquid to clean the hydrofluoric acid remaining on the bottom surface of the semiconductor wafer, and the cleaning liquid is discharged through the discharge hole;

[0088] Step b is repeated at least 6 times. In this embodiment, step b is repeated 6 times.

[0089] In this embodiment, a single rinse with pure water is not clean enough, so multiple rinses are performed, preferably 6 times, to rinse the semiconductor wafer and the micro chamber clean. In this embodiment, pure water is fed into the micro chamber from the lower center hole and the lower edge hole, so that the rinse efficiency is high.

[0090] The corrosive liquid is placed in a liquid storage bottle, and is delivered into the liquid storage bottle by nitrogen, and the corrosive liquid is pressed from the liquid storage bottle into the micro chamber by nitrogen.

[0091] The liquid fluid is directly placed in the liquid storage bottle, one end of a pipe is inserted into the liquid fluid, and the other end is connected to the lower hole, one end of another pipe is connected to the nitrogen source, and the other end is also inserted into the liquid storage bottle and is above the liquid surface of the liquid fluid, so that the nitrogen is blown into the liquid storage bottle, and the liquid fluid is sent into the microchamber through the lower hole by positive pressure.

[0092] In this embodiment, the liquid fluid providing mechanism is a liquid storage bottle and a nitrogen source, the nitrogen source is connected to the liquid storage bottle through a pipeline, the liquid storage bottle is connected to the lower hole through a pipeline, the liquid storage bottle stores liquid fluid, and the gaseous fluid providing mechanism is a nitrogen source.

[0093] Among them, one method is: there are two liquid storage bottles, and there are valves on the pipelines. Hydrofluoric acid is stored in one liquid storage bottle, and pure water is stored in the other liquid storage bottle. The connection of each pipeline is controlled by the valve. During pretreatment, the corresponding valve is opened or closed, and the nitrogen source pushes the hydrofluoric acid in the liquid storage bottle into the microchamber from the lower hole. When cleaning is required, the corresponding valve is opened or closed, and the nitrogen source pushes the pure water into the microchamber. When drying is required, the corresponding invention is opened or closed, and the nitrogen source is sent into the microchamber. It can also be two liquid storage bottles, one liquid storage bottle stores hydrofluoric acid, and the other liquid storage bottle stores pure water. The pipeline is connected on the lower hole, and a joint is set on the pipeline. The two liquid storage bottles and the nitrogen source are quickly switched through the joint and the joint of the pipeline on the lower hole. As long as the structure can be provided by the fluid that can realize the corrosive liquid, cleaning liquid, and nitrogen gas being sent to the microchamber through the lower hole.

[0094] In the present invention, the height to which the semiconductor wafer is lifted by the fluid can be adjusted by adjusting the intake pressure and time of each vent hole.

[0095] At the same time, in the present invention, the lifting height at the bottom edge of the micro-chamber in the lower cavity is reduced, and the edge height at the top edge of the micro-chamber in the upper cavity is reduced, so that it can ensure that the flow direction of the gas is stable when the nitrogen is drying the micro-chamber, and the semiconductor wafer can be dried stably from the center to the edge, so as to achieve complete drying of the semiconductor wafer and the micro-chamber.

[0096] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0097] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection, or an integral one; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, for example, the two can form a mechanical abutment or abutment connection through abutment, contact, etc., the two can also be directly hung or hung through an intermediate medium, etc., or it can be the internal connection of the two elements or the interaction relationship between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Claims

1. A semiconductor wafer surface pretreatment device, comprising a lower cavity and an upper cavity, wherein a micro-chamber for accommodating a semiconductor wafer is formed between the upper cavity and the lower cavity, characterized in that: The bottom of the micro-chamber is respectively provided with a lower hole and a discharge hole which are connected to the outer surface of the lower cavity, the top of the lower hole is arranged at the middle of the bottom surface of the micro-chamber, and the top of the discharge hole is arranged at the outer edge of the bottom of the micro-chamber; The top of the micro chamber is provided with at least one vent hole communicating with the outer surface of the upper cavity.

2. The semiconductor wafer surface pretreatment device according to claim 1, characterized in that: The vent hole comprises an upper center hole and a plurality of upper edge holes, the bottom of the upper center hole is arranged at the top center of the micro chamber, and the plurality of upper edge holes are evenly distributed in an annular shape outside the upper center hole.

3. The semiconductor wafer surface pretreatment device according to claim 1, characterized in that: There are a plurality of discharge holes, and the plurality of discharge holes are evenly distributed in an annular shape at the outer edge of the bottom of the micro chamber.

4. The semiconductor wafer surface pretreatment device according to claim 1, characterized in that: A nitrogen supply mechanism is also provided for supplying nitrogen. The nitrogen supply mechanism is connected to the vent hole. The nitrogen provided by the nitrogen supply mechanism is delivered into the micro chamber above the semiconductor wafer through the vent hole.

5. The semiconductor wafer surface pretreatment device according to claim 1, characterized in that: The lower hole includes a lower center hole and a plurality of lower outer edge holes, the top of the lower center hole is arranged at the center of the bottom surface of the micro chamber, the lower outer edge holes are evenly distributed in an annular shape outside the lower center hole, and the lower outer edge holes are arranged between the discharge hole and the lower center hole.

6. The semiconductor wafer surface pretreatment device according to claim 1, characterized in that: A fluid providing mechanism connected to the lower hole is also provided, and the fluid provided by the fluid providing mechanism is delivered into the micro chamber below the semiconductor wafer through the lower hole.

7. The semiconductor wafer surface pretreatment device according to claim 6, characterized in that: The fluid providing mechanism includes a liquid fluid providing mechanism for providing liquid fluid and a gaseous fluid providing mechanism for providing gaseous fluid; And / or, the liquid fluid provided by the liquid fluid providing mechanism corrodes or cleans the bottom surface of the semiconductor wafer; And / or, the gaseous fluid provided by the gaseous fluid providing mechanism dries the bottom surface of the semiconductor wafer.

8. The semiconductor wafer surface pretreatment device according to claim 1, characterized in that: A negative pressure discharge mechanism connected to the discharge hole is also provided, and the negative pressure discharge mechanism sucks out the liquid fluid or gaseous fluid in the micro chamber.

9. The semiconductor wafer surface pretreatment device according to claim 1, characterized in that: A sealing ring is also provided at the outer edge of the lower cavity to seal the micro chamber.

10. A semiconductor wafer surface pretreatment process, the steps of which are: ① Placing the semiconductor wafer in the micro chamber between the upper cavity and the lower cavity, with a distance between the outer edge of the semiconductor wafer and the outer edge of the micro chamber; ② Send nitrogen gas into the microchamber above the semiconductor wafer from the vent at a certain pressure; Then, the liquid fluid is sent into the micro-chamber below the semiconductor wafer through the lower hole at a certain pressure; When the liquid fluid is sent under the semiconductor wafer, the semiconductor wafer is pushed away from the bottom surface of the microchamber by the liquid fluid, so that the semiconductor wafer does not contact the inner wall of the microchamber, and the nitrogen gas sent out from the vent hole makes the liquid fluid contact only with the bottom surface of the semiconductor wafer, and the bottom surface of the semiconductor wafer is corroded and cleaned by the liquid fluid; After the liquid fluid has completed etching and cleaning the bottom surface of the semiconductor wafer, the discharge hole discharges all the liquid fluid in the micro-chamber; ③ Then the gaseous fluid is sent into the micro-chamber at the bottom of the semiconductor wafer through the lower hole, and the bottom surface of the semiconductor wafer is dried by the gaseous fluid. During the drying process, the discharge hole will discharge the gaseous fluid until the bottom of the semiconductor wafer is dried; ④ After the bottom surface of the semiconductor wafer is dried, the semiconductor wafer is taken out from the microchamber to complete the pretreatment of the surface of the semiconductor wafer.

11. The semiconductor wafer surface pretreatment process according to claim 10, characterized in that: In step ②, the liquid fluids are respectively a corrosive liquid and a cleaning liquid; The bottom surface of the semiconductor wafer is first corroded by an etching liquid, and after the etching liquid is discharged through the discharge hole, the bottom surface of the semiconductor wafer is cleaned by a cleaning liquid to clean the hydrofluoric acid remaining on the bottom surface of the semiconductor wafer, and the cleaning liquid is discharged through the discharge hole.

12. The semiconductor wafer surface pretreatment process according to claim 11, characterized in that: The etching solution is hydrofluoric acid, and the concentration of the hydrofluoric acid is 20%; The cleaning liquid is pure water.

13. The semiconductor wafer surface pretreatment process according to claim 11, characterized in that: The step ② includes the following steps: a. Etching of the bottom of the semiconductor wafer: The etching liquid is sent into the micro-chamber at the bottom of the semiconductor wafer from the lower hole, and the bottom surface of the semiconductor wafer is corroded by the etching liquid. After a predetermined time, the discharge hole discharges the etching liquid at the bottom of the micro-chamber and the debris etched out from the semiconductor wafer; Repeat step a at least 3 times; b. Cleaning the bottom of the semiconductor wafer: After the semiconductor wafer is etched in step a, a cleaning liquid is introduced into the micro-chamber at the bottom of the semiconductor wafer, and the bottom surface of the semiconductor wafer is cleaned by the cleaning liquid to clean the hydrofluoric acid remaining on the bottom surface of the semiconductor wafer, and the cleaning liquid is discharged through the discharge hole; The step b is repeated at least 6 times.

14. The semiconductor wafer surface pretreatment process according to claim 13, characterized in that: The corrosive liquid is placed in a liquid storage bottle, and is delivered into the liquid storage bottle by nitrogen gas, and the corrosive liquid is pressed from the liquid storage bottle into the micro chamber by the nitrogen gas.

15. The semiconductor wafer surface pretreatment process according to claim 10, characterized in that: In the step ②, the discharge hole sucks the liquid fluid out of the micro chamber through negative pressure; In step ③, the gaseous fluid is nitrogen, and the discharge hole sucks the gaseous fluid out of the microchamber through negative pressure.

16. The semiconductor wafer surface pretreatment process according to claim 10, characterized in that: In the step ②, the vent hole is filled with nitrogen in advance to fill the micro chamber, and then the liquid fluid is sent into the micro chamber from the lower hole; When the liquid fluid enters the micro-chamber from the lower hole, the liquid fluid diffuses outward from the lower hole of the micro-chamber, and the liquid fluid first contacts the middle part of the bottom surface of the semiconductor wafer, then flows along the middle part of the bottom surface of the semiconductor wafer toward the outer edge of the semiconductor wafer, and finally is discharged from the discharge hole; In the step ③, the flow trajectory of the gaseous fluid is the same as the flow trajectory of the liquid fluid.

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