Protective windows for semiconductor vacuum equipment and semiconductor vacuum equipment

Abstract

This invention discloses a protective window for a semiconductor vacuum device and the semiconductor vacuum device itself. The semiconductor vacuum device includes: a vacuum chamber with an extraction port; a molecular pump installed at the extraction port to extract airflow from the vacuum chamber; a switching valve located between the molecular pump and the extraction port to open or close the extraction port; and a protective window located at the extraction port and on the side of the switching valve facing the vacuum chamber. The protective window includes a frame and multiple blades. The shape of the frame matches the shape of the extraction port. The multiple blades are evenly spaced radially outward from the center of the frame. On an axial section perpendicular to the plane of the protective window, the two sides of each blade form a predetermined angle α. A predetermined overlap area α corresponding to the predetermined angle is provided between two adjacent blades in the radial direction. According to the embodiment of this invention, the protective window can ensure the extraction speed and prevent etching products or sputterings from entering the molecular pump.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a protective window for semiconductor vacuum equipment and semiconductor vacuum equipment. Background Technology

[0002] Vacuum equipment is widely used in the semiconductor industry, including inductively coupled plasma etching (ICP), ion beam etching (IBE), electron beam evaporation stages, and sputtering platforms. These vacuum devices share the common characteristic of operating under high vacuum conditions. High-frequency electromagnetic waves provided by radio frequency (RF) excite gas molecules into plasma. The direction and momentum of ion movement are then controlled by electric or magnetic fields, causing ions to strike the wafer etching layer or the target surface. Upon contact with the film, complex physicochemical reactions occur, generating new chemical groups (sputtering and IBE involve only physical reactions, not chemical reactions). Subsequent ions collide with these chemical groups, sputtering (the sputtered material is the etching product) which is deposited on the vacuum chamber liner and enters the molecular pump. Especially for top-mounted and side-mounted evacuation methods, the molecular pump of the vacuum equipment is installed at the top or side of the chamber, making it easier for etching products to be deposited.

[0003] Furthermore, since molecular pumps rely on high-speed rotating blades (typically up to 30,000 rpm) to pulverize gas molecules, the dynamic balance of the blades is crucial. However, in existing technologies, the pump ports of vacuum equipment connected to molecular pumps lack dedicated anti-deposition protection or have very poor protection. As a result, during the process, a large amount of etching products or sputterings can enter the molecular pump and deposit on the blades, causing rotor dynamic balance failure. In severe cases, this can lead to pump explosion, thereby damaging the molecular pump. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] Therefore, the present invention proposes a protective window for semiconductor vacuum equipment, which can effectively prevent etching products or sputterings in the vacuum chamber from entering the molecular pump, so as to ensure the performance of the molecular pump.

[0006] The present invention also proposes a semiconductor vacuum device having the above-mentioned protective window for semiconductor vacuum devices.

[0007] According to a first aspect of the present invention, a protective window for a semiconductor vacuum device includes: a vacuum chamber having an extraction port; a molecular pump installed at the extraction port for extracting airflow from the vacuum chamber; a switching valve disposed between the molecular pump and the extraction port to open or close the extraction port; and a protective window disposed at the extraction port and located on the side of the switching valve facing the vacuum chamber. The protective window includes a frame and a plurality of blades. The shape of the frame is consistent with the shape of the extraction port. The plurality of blades are evenly spaced radially outward from the center of the frame. On an axial section perpendicular to the plane of the protective window, the two sides of each blade form a predetermined angle α. A predetermined overlap area a corresponding to the predetermined angle is provided between two adjacent blades in the radial direction.

[0008] According to an embodiment of the present invention, a protective window for a semiconductor vacuum device has gaps between adjacent blades, which allows gas molecules to pass through and ensures the pumping speed, while effectively preventing etching products or sputterings from entering the molecular pump.

[0009] According to one embodiment of the present invention, the predetermined angle α ranges from 60° to 120°, and the predetermined overlap area a ranges from 5mm to 30mm.

[0010] According to an optional example of the present invention, the axial thickness h of each blade is in the range of 30 mm to 60 mm.

[0011] According to another embodiment of the present invention, a plurality of blades in the radial direction are fixedly connected to the frame by a first fixed shaft and a second fixed shaft, the first fixed shaft and the second fixed shaft being in a cross shape.

[0012] According to another embodiment of the present invention, on an axial section perpendicular to the plane of the protective window, the two sides of each blade are symmetrically arranged with respect to the first fixed axis or the second fixed axis.

[0013] According to another embodiment of the present invention, the surfaces of the plurality of blades and the frame are all sandblasted to enhance the roughness of the protective window surface.

[0014] Furthermore, the surface roughness of the protective window is maintained between 2.0 and 5.0.

[0015] According to another embodiment of the present invention, the border is formed as a circle, an ellipse or a polygon.

[0016] A semiconductor vacuum device according to a second embodiment of the present invention includes:

[0017] A vacuum chamber, wherein the vacuum chamber is provided with an air extraction port;

[0018] A molecular pump, which is installed at the extraction port to extract airflow from the vacuum chamber;

[0019] A switching valve is disposed between the molecular pump and the suction port to open or close the suction port;

[0020] According to the protective window for semiconductor vacuum equipment described in the above embodiments, the protective window is located at the air extraction port and on the side of the switching valve facing the vacuum chamber.

[0021] According to one embodiment of the present invention, the protective window includes a plurality of protective windows, which are stacked sequentially in the axial direction of the air extraction port.

[0022] According to another embodiment of the present invention, the semiconductor vacuum device further includes:

[0023] A dry pump is located outside the vacuum chamber, and the dry pump and the molecular pump are connected by a pumping pipe.

[0024] A wafer stage is disposed within the vacuum chamber and is positioned directly opposite the evacuation port. A wafer is placed on the wafer stage.

[0025] An ion source is installed on one side of the vacuum chamber.

[0026] According to an embodiment of the semiconductor vacuum device of the present invention, the gap between adjacent blades of the protective window allows gas molecules to pass through and ensures the pumping speed, while effectively preventing etching products or sputterings from entering the molecular pump.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0029] Figure 1 This is a schematic diagram of the structure of a semiconductor vacuum device in the prior art;

[0030] Figure 2 This is a schematic diagram of the structure of a semiconductor vacuum device according to an embodiment of the present invention;

[0031] Figure 3 This is a top view of the protective window according to an embodiment of the present invention;

[0032] Figure 4 yes Figure 3 Sectional view along line AA ；

[0033] Figure 5 yes Figure 4 Schematic diagram of the structure at point C;

[0034] Figure 6 It is the etching products and airflow in Figure 4 A schematic diagram of the flow direction in the middle;

[0035] Figure 7 This is a perspective view of a protective window according to an embodiment of the present invention.

[0036] Figure label:

[0037] Figure 1 The labels in the attached figures are as follows:

[0038] Vacuum chamber 10', air extraction port 11', molecular pump 20', switching valve 30'.

[0039] Figures 2-7 The accompanying figure labels are as follows:

[0040] Semiconductor vacuum equipment 100

[0041] Vacuum chamber 10, air extraction port 11, molecular pump 20, switching valve 30, protective window 40, frame 41, blade 42, highest deposition area 421, cover plate 43, first fixed shaft 44, second fixed shaft 45, frame positioning hole 46, pre-stage air extraction pipe 47, dry pump 48, wafer stage 49, wafer 50, ion source 60, air inlet pipe 61, grid 70. Detailed Implementation

[0042] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] Taking an ion beam etching (IBE) system as an example, the structure is as follows: Figure 1 As shown, when the ion source glows and generates ions, they are ejected along the grid apertures in the direction indicated by the right arrow. The ions are then neutralized by electrons excited by the neutralizer. The neutralized particles move rapidly and collide with the wafer surface. Etching products are sputtered out and deposited upwards onto the inner wall of the vacuum chamber 10'. Some etching products enter the switching valve 30' and the molecular pump 20', adhering to the blades of the molecular pump 20', thus reducing the lifespan of the molecular pump 20' and weakening its pumping capacity.

[0045] The main reason for the aforementioned problems in the existing technology is that no protective structure is installed at the evacuation port 11' of the vacuum chamber 10'. Even if a protective structure is added, it must not only not affect the evacuation speed, but also prevent etching products from entering the molecular pump 20', and the installation of the protective structure must not change the flow direction of the airflow within the vacuum chamber 10' (mainly to stabilize the chamber's process environment). Furthermore, during the process, the opening amplitude of the switching valve 30' is needed to control the internal pressure of the vacuum chamber 10', which requires a one-to-one correspondence between the vacuum level signal and the evacuation speed of the molecular pump 20', with no delay between them. Moreover, the replacement of the protective structure must be convenient and simple.

[0046] The following is for reference. Figures 1-6 A protective window 40 for a semiconductor vacuum device 100 according to an embodiment of the first aspect of the present invention is described. It should be noted that the semiconductor vacuum device 100 may be a physical vapor deposition system (PVD), an ion beam etching system (IBE), a chemical vapor deposition system (CVD), etc. In this embodiment of the present invention, the vacuum chamber 10 of the semiconductor vacuum device 100 adopts a top-down evacuation method.

[0047] According to an embodiment of the present invention, a protective window 40 is provided for a semiconductor vacuum device 100, wherein the semiconductor vacuum device 100 includes a vacuum chamber 10, a molecular pump 20, a switching valve 30, and a protective window 40.

[0048] Specifically, the vacuum chamber 10 is provided with an air extraction port 11 (e.g., Figure 2 As shown, a suction port 11 is provided at the top of the vacuum chamber 10. A molecular pump 20 is installed at the suction port 11 to extract the airflow from the vacuum chamber. A switching valve 30 is located between the molecular pump 20 and the suction port 11 to open or close the suction port 11. A protective window 40 is located at the suction port 11 and is situated on the side of the switching valve 30 facing the vacuum chamber 10 (e.g., ...). Figure 2 The protective window 40 shown is located below the switch valve 30.

[0049] It should be noted that the air extraction port 11 on the vacuum chamber 10 can be located on the top wall or the side wall of the vacuum chamber 10.

[0050] Furthermore, the protective window 40 includes a frame 41 and multiple blades 42. For example, the shape of the frame 41 is the same as the shape of the air vent 11, which can be circular, elliptical, or polygonal.

[0051] Multiple blades 42 are evenly spaced radially outward from the center of the frame 41. This means that the spacing between adjacent blades 42 is equal radially from the center of the frame 41. On the axial section perpendicular to the plane of the protective window 40, the two sides of each blade 42 form a predetermined angle α (e.g., ...). Figure 4 As shown by angle α), a predetermined overlap area a (e.g., between two radially adjacent blades 42) is provided, corresponding to a predetermined angle. Figure 4 (As shown).

[0052] In this way, by setting a predetermined angle α between the two sides of each blade 42, and by providing a predetermined overlap area a between two adjacent blades 42, it is possible to effectively prevent the etching material in the vacuum chamber 10 from entering the molecular pump 20, and to ensure that the gap between adjacent blades 42 is large so that the airflow resistance is small and thus does not affect the pumping speed.

[0053] According to an embodiment of the present invention, a protective window 40 for a semiconductor vacuum device 100 has gaps between adjacent blades 42, which allows gas molecules to pass through and ensures the pumping speed, while effectively preventing etching products or sputterings from entering the molecular pump 20.

[0054] According to one embodiment of the present invention, the predetermined angle α ranges from 60° to 120°, specifically 60°, 80°, 90°, 100°, and 120°. The predetermined overlap area a ranges from 5 mm to 30 mm.

[0055] According to an optional example of the present invention, the axial thickness h of each blade 42 ranges from 30 mm to 60 mm, specifically 30 mm, 40 mm, 50 mm, and 60 mm. It is understood that the axial thickness h of each blade 42 is the same as the axial thickness of the protective window 40.

[0056] like Figure 4 As shown, the predetermined angle α between the two sides of each blade 42 is 90°. Under the same conditions, compared with other angles (i.e., other angles between 60° and 120°), this allows for the maximum gap between adjacent blades 42 and smoother airflow. The axial thickness h of each blade 42 is 40 mm, and the predetermined overlap area a is 5 mm to 20 mm.

[0057] According to another embodiment of the present invention, a plurality of radially arranged blades 42 are fixedly connected to a frame 41 via a first fixed shaft 44 and a second fixed shaft 45, respectively, the first fixed shaft 44 and the second fixed shaft 45 being arranged in a cross shape. Figure 3 As shown, the first blade 42 fixing shaft and the second blade 42 fixing shaft are perpendicularly intersecting to make the adjacent blades 42 evenly arranged. Specifically, the first fixing shaft 44 and the second fixing shaft 45 can be fixed by relative welding or by using equal-length bushings to make the interval between adjacent blades 42 equal.

[0058] According to another embodiment of the present invention, in an axial section perpendicular to the plane of the protective window 40, the two sides of each blade 42 are symmetrically arranged with respect to a first fixed axis 44 or a second fixed axis 45. This ensures that the stable flow of airflow within the vacuum chamber 10 is not altered.

[0059] According to another embodiment of the present invention, the surfaces of the plurality of blades 42 and the frame 41 are all sandblasted to enhance the roughness of the surface of the protective window 40, so as to ensure the adsorption capacity of the deposits on the surface of the protective window 40 and prevent them from falling off.

[0060] Furthermore, the surface roughness of the protective window 40 is maintained between 2.0 and 5.0.

[0061] Alternatively, the material of the protective window 40 can be selected from metals such as aluminum, iron, and copper, or non-metallic materials, depending on the usage environment. For example, stainless steel SUS304 can be selected.

[0062] According to another embodiment of the present invention, the frame 41 is formed as a circle, an ellipse, or a polygon. For example, using a circle for the frame 41 to match the air extraction port 11 ensures that the protective window 40 is symmetrical in all directions, the air extraction method remains unchanged, and the airflow direction in the chamber is not affected. The diameter range of the frame 41 of the protective window 40 is... (The specific diameter depends on the inlet diameter of the molecular pump 20, such as...) Figure 3 The embodiments of the present invention shown herein use (For example). Optionally, the frame 41 has an L-shaped edge with a thickness of 1mm, and the frame 41 can be fixed to the wall of the vacuum chamber 10 during installation.

[0063] According to a second embodiment of the present invention, a semiconductor vacuum device 100 includes: a vacuum chamber 10, on which an extraction port 11 is provided; a molecular pump 20, which is installed at the extraction port 11 for extracting airflow from the vacuum chamber; a switching valve 30, which is disposed between the molecular pump 20 and the extraction port 11 to open or close the extraction port 11; and a protective window 40 for the semiconductor vacuum device 100 according to the above embodiment, which is disposed at the extraction port 11 and located on the side of the switching valve 30 facing the vacuum chamber 10.

[0064] According to one embodiment of the present invention, the protective window 40 includes a plurality of protective windows 40, which are stacked sequentially in the axial direction of the exhaust port 11. It is understood that in actual use, if the molecular pump 20 has high requirements for the protection accuracy against etched or sputtered materials, a plurality of protective windows 40 can be stacked at the exhaust port 11.

[0065] According to one embodiment of the present invention, the protective window 40 has a simple structure and can be fixed by only 4 screws or clips, making replacement very convenient.

[0066] According to another embodiment of the present invention, the semiconductor vacuum device 100 further includes: a dry pump 48, which is disposed outside the vacuum chamber 10 and connected to the molecular pump 20 via a suction pipe 47; a wafer stage 49, which is disposed inside the vacuum chamber 10 and is positioned opposite the suction port 11, on which a wafer 50 is placed; and an ion source 60, which is installed on one side of the vacuum chamber 10.

[0067] According to an embodiment of the semiconductor vacuum device 100 of the present invention, the gap between adjacent blades 42 of the protective window 40 allows gas molecules to pass through and ensures the pumping speed, while effectively preventing etching products or sputterings from entering the molecular pump 20.

[0068] like Figure 2 As shown, in this embodiment of the invention, the switching valve 30 is a slide gate valve, which is fixed to the top flange of the vacuum chamber 10. This slide gate valve isolates the molecular pump 20 from the vacuum chamber 10 and also controls the chamber pressure during the process. The molecular pump 20 is mounted on the upper surface of the slide gate valve, enabling upward air extraction.

[0069] Those skilled in the art will understand that the start-up of the molecular pump 20 requires a negative pressure in its pre-stage. Therefore, the pre-stage evacuation pipe 47 of the molecular pump 20 is connected between the molecular pump 20 and the dry pump 48 to achieve a negative pressure in the pre-stage of the molecular pump 20. A protective window 40 is installed inside the evacuation port 11 of the vacuum chamber 10 and is located below the slide gate valve to prevent etching products or sputtered materials from entering the molecular pump 20.

[0070] In one specific embodiment of the present invention, an ion source 60 is mounted on the side of the vacuum chamber 10. An inlet pipe 61 is connected to the side of the ion source 60 away from the vacuum chamber 10 to introduce process gas. An ion grid 70 is provided on the side of the ion source 60 facing the vacuum chamber 10. The ion source 60 can excite the ion grid 70 to provide a corresponding electric field for the ions. The wafer 50 is placed on a stage 49 or an electrostatic chuck inside the vacuum chamber 10. When the ion source 60 excites ions, the ions are neutralized into neutral high-speed particles, which move rapidly in the direction of the right arrow e within the vacuum chamber 10. Some of the particles hit the surface of the wafer 50, producing etching products that are sputtered out and deposited in the directions of the upward arrows m and n.

[0071] Furthermore, the etching products and gas flow pass through the protective window 40 simultaneously. The etching products, consisting of solid particles, move in a straight line and deposit on the protective window 40. The gas flow is filtered through the protective window and enters the molecular pump 20. The most likely incident direction to enter the molecular pump 20 is arrow direction g, but it is blocked by the protective window 40 at the highest deposition area 421 of the sputtered products. Etching products at other incident angles can only deposit below this area and therefore cannot enter the molecular pump 20. The gas flow can enter the gap between adjacent blades 42 of the protective window 40 along arrow direction j, and finally enter the molecular pump 20 along the gas flow exit direction k. The molecular pump 20 delivers the incoming gas flow to the dry pump 48 through the pre-pump extraction pipe 47, and is finally discharged to the plant end by the dry pump 48.

[0072] Each blade 42 is fixed to the frame 41 of the protective window 40 by a first fixed shaft 44 and a second fixed shaft 45. The frame 41 is fixed inside the vacuum chamber 10 by four frame positioning holes 46. Specifically, each blade 42 is formed in a circumferential shape, and multiple blades 42 are radially overlapping. The blade 42 closest to the center of the frame 41 defines a through hole, which needs to be sealed by a cover plate 43 to prevent etching products from entering the molecular pump 20 through the through hole. In the description of the present invention, "multiple" means two or more.

[0073] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," 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 the invention. 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.

[0074] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A protective window for semiconductor vacuum equipment, characterized in that, The semiconductor vacuum device includes: a vacuum chamber, wherein the vacuum chamber is provided with an air extraction port; A molecular pump, which is installed at the extraction port to extract airflow from the vacuum chamber; A switching valve is disposed between the molecular pump and the suction port to open or close the suction port; The protective window is located at the air extraction port and on the side of the switch valve facing the vacuum chamber. The protective window includes a frame and multiple blades. The shape of the frame is the same as the shape of the air extraction port. The multiple blades are evenly spaced outward in a radial direction with the center of the frame as the center. On the axial section perpendicular to the plane of the protective window, the two sides of each blade form a predetermined angle α. A predetermined overlap area a corresponding to the predetermined angle is provided between two adjacent blades in the radial direction. The predetermined angle α ranges from 60° to 120°, and the predetermined overlap area a ranges from 5mm to 30mm.

2. The protective window for semiconductor vacuum equipment according to claim 1, characterized in that, The axial thickness h of each blade ranges from 30 mm to 60 mm.

3. The protective window for semiconductor vacuum equipment according to claim 1, characterized in that, The multiple blades in the radial direction are fixedly connected to the frame by a first fixed shaft and a second fixed shaft, which are arranged in a cross shape.

4. The protective window for semiconductor vacuum equipment according to claim 3, characterized in that, On an axial section perpendicular to the plane of the protective window, the two sides of each blade are symmetrically arranged with respect to either the first fixed axis or the second fixed axis.

5. The protective window for semiconductor vacuum equipment according to claim 1, characterized in that, The surfaces of multiple blades and the frame are sandblasted to enhance the roughness of the protective window surface.

6. The protective window for semiconductor vacuum equipment according to claim 5, characterized in that, The surface roughness of the protective window is maintained between 2.0 and 5.

0.

7. The protective window for semiconductor vacuum equipment according to claim 1, characterized in that, The border can be circular, elliptical, or polygonal.

8. A semiconductor vacuum device, characterized in that, include: A vacuum chamber, wherein the vacuum chamber is provided with an air extraction port; A molecular pump, which is installed at the extraction port to extract airflow from the vacuum chamber; A switching valve is disposed between the molecular pump and the suction port to open or close the suction port; The protective window for a semiconductor vacuum device according to any one of claims 1-7, wherein the protective window is disposed at the evacuation port and located on the side of the switching valve facing the vacuum chamber.

9. The semiconductor vacuum device according to claim 8, characterized in that, The protective window comprises multiple windows, which are stacked sequentially along the axial direction of the air extraction port.

10. The semiconductor vacuum apparatus according to claim 8 or 9, characterized in that, Also includes: dry The dry pump is located outside the vacuum chamber, and the dry pump and the molecular pump are connected by a pumping pipe. A wafer stage is disposed within the vacuum chamber and is positioned directly opposite the evacuation port. A wafer is placed on the wafer stage. An ion source is installed on one side of the vacuum chamber.

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