Cavity structure for semiconductor process

Abstract

The utility model provides a cavity structure for a semiconductor process. The cavity structure comprises a chuck, a metal tube, a cover plate and an inductive switch. The chuck is used for fixing a wafer; the metal pipe is suspended above the chuck, one end of the metal pipe is a connecting end, and the metal pipe can rotate in a horizontal plane around the connecting end; a guide groove is formed in the surface, facing the chuck, of the cover plate, and when the metal pipe is clamped into the guide groove, the metal pipe is located at a target position; the inductive switch is arranged on the cover plate, the inductive switch is connected to a switch signal circuit, when the inductive head induces the metal tube, the switch signal circuit is switched on, and when the inductive head does not induct the metal tube, the switch signal circuit is switched off. According to the cavity structure for the semiconductor process, the phenomena of non-uniform and insufficient drying in the wafer passivation process can be avoided, so that the phenomenon of chip metal corrosion is prevented, and the quality and stability of a product are improved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductors, and more particularly to a cavity structure for semiconductor processes. Background Technology

[0002] In semiconductor wafer manufacturing, the biggest risks of metal etching processes are resist residue and metal corrosion. Resin residue occurs in the resist removal chamber and can be detected promptly through routine Statistical Process Control (SPC) and visual inspection. After re-resin application, it almost never leads to chip scrapping. However, metal corrosion cannot be detected through routine SPC monitoring and visual inspection; it can only be clearly seen after the product is completed and scanned by KLA. If severe corrosion is found at this stage, the chip must be scrapped.

[0003] There are three main ways to overcome metal etching: (1) Ensure that the chloride and fluoride ions in the environment do not exceed the standard, and that the temperature, humidity and fresh air control are stable, and that the filter screen can be replaced periodically to ensure a good production environment for wafer manufacturing; (2) In the process flow, ensure that the wafer after metal etching is cleaned for no more than 4 hours; (3) Ensure that the wafer produced by the machine process is sufficiently passivated to avoid slight corrosion of the chip.

[0004] Regarding the third scenario: In the actual process, chlorine (Cl2) is used for metal etching. After the main process is completed, a large amount of residual chlorine remains on the wafer surface. After the resist is removed from the wafer surface in the resist removal chamber, the residual chlorine evaporates in large quantities along with the resist. Then, the wafer is placed in the passivation chamber for passivation to further remove the trace amounts of residual chlorine remaining on the wafer surface.

[0005] Therefore, providing a cavity structure that allows residual chlorine on the wafer surface to be completely removed during passivation processes within the cavity structure, thereby ensuring the corrosion resistance and wear resistance of the chip surface, is of great value for improving product yield and reducing production costs. Summary of the Invention

[0006] The technical problem to be solved by this utility model is to provide a cavity structure for semiconductor processes, which avoids insufficient drying during wafer passivation processes, thereby preventing chip metal corrosion caused by equipment problems and improving product quality and stability.

[0007] To address the aforementioned problems, this utility model provides a cavity structure for semiconductor processes, comprising: a chuck for fixing a wafer; a metal tube suspended above the chuck, one end of which is a connecting end, and the metal tube is rotatable in a horizontal plane around the connecting end; a cover plate with a guide groove on its surface facing the chuck, wherein the metal tube is positioned at a target location when it is inserted into the guide groove; and a sensor switch located within the vertical projection area of ​​the target location on the cover plate, wherein the vertical distance between the sensor head of the sensor switch and the target location is less than the actuation distance, and the sensor switch is connected to a switch signal circuit, wherein the switch signal circuit is activated when the sensor head detects the metal tube, and deactivated when the sensor head does not detect the metal tube.

[0008] In some embodiments, the inductive switch is a two-wire switch or a three-wire switch.

[0009] In some embodiments, the switching signal circuit is a cylinder lifting solenoid valve circuit.

[0010] In some embodiments, the inductive switch is an NPN normally open inductive proximity switch.

[0011] In some embodiments, the brown wire of the inductive switch is connected to the positive voltage of the cylinder lifting solenoid valve circuit, and the black wire of the inductive switch is connected to the neutral wire of the cylinder lifting solenoid valve circuit.

[0012] In some embodiments, the other end of the metal tube is provided with an air inlet, and when the metal tube is located at the target position, the air inlet is vertically downward aligned with the center of the chuck.

[0013] In some embodiments, the action distance is 4 millimeters.

[0014] In some embodiments, the guide groove is defined by two guide bars, the guide bars being made of a non-metallic material.

[0015] In some embodiments, when the switch signal circuit is disconnected, a machine alarm is triggered.

[0016] In some embodiments, the cavity structure for semiconductor processes further includes an indicator light, which illuminates when the sensor head detects the metal tube and turns off when the sensor head does not detect the metal tube.

[0017] The above technical solution provides a cavity structure for semiconductor processes, including a chuck, a metal tube, a cover plate, and a proximity switch. The chuck is used to fix the wafer; the metal tube is suspended above the chuck, with one end serving as a connecting end, and the metal tube can rotate horizontally around the connecting end; the cover plate has a guide groove on its surface facing the chuck, and when the metal tube is inserted into the guide groove, it is at a target position; the proximity switch is located within the vertical projection area of ​​the target position on the cover plate, and the distance between the sensing head of the proximity switch and the target position is less than the operating distance. The proximity switch is connected to a switch signal circuit; when the sensing head detects the metal tube, the switch signal circuit is activated; when the sensing head does not detect the metal tube, the switch signal circuit is deactivated. The cavity structure described above for semiconductor processes defines the metal tube at the target position through the guide groove. By connecting the inductive switch to the switch signal circuit to cause the switch signal circuit to open and close, technicians can detect and address the metal tube position deviation problem as early as possible, thereby avoiding uneven or insufficient drying in the wafer passivation process, thus preventing chip metal corrosion and improving product quality and stability.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the present invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a cavity structure for semiconductor processes provided in an embodiment of the present invention;

[0021] Figure 2 This is a bottom view of the cover plate provided in one embodiment of the present utility model. Detailed Implementation

[0022] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] Please refer to this as well. Figures 1-2 , Figure 1 This is a schematic diagram of a cavity structure for semiconductor processes provided in an embodiment of the present invention; Figure 2 This is a bottom view of the cover plate provided in one embodiment of the present utility model.

[0024] like Figure 1 As shown, the cavity structure for semiconductor processing includes: a chuck 11, a metal tube 12, a cover plate 13, and a proximity switch 14. The chuck 11 is used to fix the wafer; the metal tube 12 is suspended above the chuck 11, with one end being a connecting end 121, allowing the metal tube 12 to rotate horizontally around the connecting end 121; the cover plate 13 has a guide groove 131 on its surface facing the chuck, so that when the metal tube 12 is engaged in the guide groove 131, it is at a target position; the proximity switch 14 is located within the vertical projection area of ​​the target position on the cover plate 13, with the vertical distance between the sensing head of the proximity switch 14 and the target position being less than the operating distance; the proximity switch 14 is connected to a switch signal circuit, which is activated when the sensing head detects the metal tube 12 and deactivated when the sensing head does not detect the metal tube 12. The inductive switch 14 is disposed on the cover plate 12 and is located in the vertical projection area of ​​the target position on the cover plate 13.

[0025] In this embodiment, the chuck 11 is a vacuum chuck, and the chuck 11 is rotatable. When the target wafer is adsorbed onto the chuck 11, the chuck 11 can drive the target wafer to rotate at high speed.

[0026] In this embodiment, the metal tube 12 is used for purging and drying the target wafer. The connecting end 121 is connected to a pipe outside the chuck 11. The other end of the metal tube 12 is provided with an air outlet, from which nitrogen (N2) is blown to dry the surface of the target wafer. The metal tube 12 can rotate horizontally around the connecting end 121, facilitating technicians to remove improperly positioned chips from the cavity while preventing the target wafer from touching the air outlet. The target position is the optimal position for the metal tube 12 during purging. When the metal tube 12 is at the target position, the air outlet is vertically downward and aligned with the center of the chuck 11. Correspondingly, when the target wafer is fixed on the chuck 11 and the metal tube 12 is at the target position, the air outlet is vertically downward and aligned with the center of the target wafer.

[0027] In this embodiment, the cover plate 13 is made of a transparent material, such as... Figure 1 As shown, the guide groove 131 of the cover plate 13 facing the chuck can be viewed from above. Also refer to... Figure 2 The guide groove 131 is defined by two guide strips 132. The guide groove 131 is used to engage the metal tube 12. When the metal tube 12 is engaged in the guide groove 131, the metal tube 12 is in the target position. There is no connecting material between the guide strips 132, that is, the bottom of the guide groove 131 is the bottom surface of the cover plate 13. Figure 2 The area marked by the dashed line is the vertical projection area of ​​the target position onto the cover plate 13.

[0028] In this embodiment, the guide strip 132 is made of a non-metallic material. Furthermore, the material used to form the guide groove is also non-metallic, ensuring a clear distinction from the material of the metal tube 12.

[0029] In some embodiments, the guide groove 131 is formed by creating a groove on a non-metallic plate and then mounting the non-metallic plate onto the bottom surface of the cover plate 13. The guide groove 131 formed in the above manner has a bottom material layer between the bottom of the groove and the cover plate 13.

[0030] In this embodiment, the inductive switch 14 is an inductive switch. An inductive switch, designed for metal objects, changes its state when the distance between the metal object and the switch's sensing head changes. In practical implementation, it is necessary to ensure that the vertical distance between the sensing head of the inductive switch 14 and the metal tube 12 is sufficient to trigger a state change in the inductive switch 14. In this embodiment, the actuation distance is 4 mm. Accordingly, the vertical distance between the sensing head of the inductive switch 14 and the target position must be less than the actuation distance. For example, the vertical distance between the sensing head of the inductive switch 14 and the target position can be set to 1.5 mm, 2 mm, or 3 mm. The inductive switch 14 used in this embodiment is cylindrical. When the inductive switch 14 is positioned within the vertical projection area of ​​the cover plate 13 at the target position, the inductive switch 14 is perpendicular to the cover plate 13, and the sensing head 141 is located at the bottom of the inductive switch 14. Figure 2 As shown, the dashed area is the vertical projection area of ​​the target position on the cover plate 13, and the sensor head 141 is located within the dashed area.

[0031] Furthermore, when selecting the specific position of the inductive switch 14, the metal tube 12 is inserted into the guide groove 131 so that the metal tube 12 is located at the target position, and the vertical distance of the inductive switch on the cover plate 13 is adjusted so that the vertical distance between the sensing head of the inductive switch 14 and the metal tube 12 is less than the action distance.

[0032] In this embodiment, the inductive switch 14 is a three-wire switch. Specifically, the inductive switch 14 is an NPN normally open inductive proximity switch, which is in the off state when there is no external excitation. Furthermore, the inductive switch 14 is an M8 threaded type, and its vertical position can be adjusted by drilling an 8mm diameter hole in the cover plate 13 with a pistol drill, tightening the thread, and thus adjusting the vertical distance between the sensing head 141 and the target position. It is then secured with a nut.

[0033] The inductive switch 14 includes three wires: a brown wire, a black wire, and a blue wire. The brown wire is connected to the positive power supply, the blue wire is connected to the negative power supply, and the black wire is the signal wire. The load is connected between the brown and black wires. When a metal object approaches the inductive switch 14, the black and blue wires conduct, and the black wire outputs a low level.

[0034] In this embodiment, the switch signal circuit is a cylinder lifting solenoid valve circuit. Based on the characteristics of an NPN normally open inductive proximity switch, the specific wiring method is as follows: the brown wire of the inductive switch 14 is connected to the positive voltage of the cylinder lifting solenoid valve circuit; the black wire of the inductive switch 14 is connected to the neutral wire of the cylinder lifting solenoid valve circuit; and the blue wire of the inductive switch 14 is connected to the neutral wire of the machine tool. When the metal tube 12 is inserted into the guide groove 131, i.e., when the metal tube 12 is at the target position, the cylinder lifting solenoid valve circuit forms a loop, and the cylinder can rise. When the metal tube 12 is not placed in the guide groove 131, i.e., when the metal tube 12 is not at the target position, the cylinder lifting solenoid valve circuit does not form a loop, the cylinder cannot rise, and the process step is interrupted. This allows technicians to promptly detect when the metal tube 12 is not in the correct position.

[0035] In some embodiments, when the switch signal circuit is disconnected, an alarm is triggered on the machine. In this embodiment, the alarm function of the cylinder rising solenoid valve circuit is utilized by the machine itself. When the metal tube 12 is not at the target position, the cylinder rising solenoid valve circuit does not form a loop, the cylinder does not rise, and the machine automatically triggers an alarm.

[0036] In some embodiments, the cavity structure for semiconductor processes further includes an indicator light, which illuminates when the sensor head detects the metal tube and turns off when the sensor head does not detect the metal tube.

[0037] In this embodiment, the indicator light is integrated into the sensor switch 14. When the sensor head detects the metal tube 12, the switch signal circuit is turned on and the indicator light is lit. When the sensor head does not detect the metal tube 12, the switch signal circuit is turned off and the indicator light is turned off.

[0038] In some embodiments, the inductive switch 14 is a two-wire switch. The wiring of a two-wire switch is relatively simple. The two wires are the positive power supply and the negative power supply, respectively. The signal line and the power supply line are shared. When the two-wire inductive switch 14 is connected to the switch signal circuit, the load that needs to be carried is...

[0039] The cavity structure used in semiconductor processes can be used in passivation processes. For example... Figure 1 As shown, the cavity structure for semiconductor processing also includes two water pipes 15, which are fixed in position and used to spray deionized water (DI water) onto the surface of the target wafer.

[0040] During the passivation process of the target wafer within the cavity structure for semiconductor processing, the target wafer is first adsorbed onto the chuck 11. The chuck 11 drives the target wafer to rotate at a low speed of 500 revolutions per minute. Deionized water is uniformly sprayed onto the surface of the target wafer through two water pipes 15. The water reacts with trace amounts of chlorine gas on the surface of the target wafer to produce hypochlorous acid and hydrochloric acid, with the following chemical reaction formula: Cl2 + H2O = HClO + HCl. The wastewater is discharged into the main wastewater pipe through a negative pressure device via the disc of the cavity structure for semiconductor processing.

[0041] Furthermore, the target wafer is rotated at a high speed of 2000 revolutions per minute by the chuck 11, and the moisture on the surface of the target wafer is removed by centrifugal force. Combined with nitrogen pressure of 40 pounds per square inch (PSI) to purge the center of the target wafer, the target wafer is thoroughly dried under the dual action of centrifugal force of the chuck 11 and nitrogen purging at the center.

[0042] In the above process, the guide groove 131 defines the target position of the metal tube 12, which makes it convenient for technicians to return the metal tube 12 to the target position so that the air outlet of the metal tube 12 is vertically downward aligned with the center of the chuck 11. The induction switch 14 is connected to the switch signal circuit. Whether the metal tube 12 is in the target position is determined by whether the switch signal circuit is on. This allows technicians to detect the positional deviation of the metal tube 12 as early as possible and return the metal tube 12 to its original position, thereby reducing the unevenness of the target wafer during the drying process and reducing the risk of corrosion of the target wafer.

[0043] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion. The various embodiments in this specification are described in a related manner, and similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.

[0044] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

Claims

1. A cavity structure for semiconductor processing, characterized in that, include: A chuck, used to hold a wafer; A metal tube is suspended above the chuck, with one end of the metal tube serving as a connecting end, and the metal tube is capable of rotating in a horizontal plane around the connecting end. A cover plate, the surface of which faces the chuck is provided with a guide groove, and when the metal tube is inserted into the guide groove, the metal tube is in the target position; An inductive switch is provided, wherein the target position is located within the vertical projection area of ​​the cover plate, the vertical distance between the sensing head of the inductive switch and the target position is less than the actuation distance, and the inductive switch is connected to a switch signal circuit. When the sensing head senses the metal tube, the switch signal circuit is turned on; when the sensing head does not sense the metal tube, the switch signal circuit is turned off.

2. The cavity structure for semiconductor processing according to claim 1, characterized in that, The inductive switch is a two-wire switch or a three-wire switch.

3. The cavity structure for semiconductor processing according to claim 1, characterized in that, The switching signal circuit is a cylinder lifting solenoid valve circuit.

4. The cavity structure for semiconductor processing according to claim 3, characterized in that, The inductive switch is an NPN normally open inductive proximity switch.

5. The cavity structure for semiconductor processing according to claim 4, characterized in that, The brown wire of the inductive switch is connected to the positive voltage of the cylinder lifting solenoid valve circuit, and the black wire of the inductive switch is connected to the neutral wire of the cylinder lifting solenoid valve circuit.

6. The cavity structure for semiconductor processing according to claim 1, characterized in that, The other end of the metal tube is provided with an air inlet. When the metal tube is located at the target position, the air inlet is vertically downward and aligned with the center of the chuck.

7. The cavity structure for semiconductor processing according to claim 1, characterized in that, The distance of the action is 4 millimeters.

8. The cavity structure for semiconductor processing according to claim 1, characterized in that, The guide groove is defined by two guide strips, the guide strips being made of non-metallic material.

9. The cavity structure for semiconductor processing according to claim 1, characterized in that, When the switch signal circuit is disconnected, the machine alarm is triggered.

10. The cavity structure for semiconductor processing according to claim 1, characterized in that, The cavity structure for semiconductor processes also includes an indicator light. When the sensor head detects the metal tube, the indicator light illuminates; when the sensor head does not detect the metal tube, the indicator light turns off.

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