Electrostatic adsorption device and processing equipment of semiconductor device

Abstract

The invention provides an electrostatic adsorption device and semiconductor device processing equipment, and relates to the field of semiconductor device processing. In the electrostatic adsorption device, a pressure monitoring groove, an air exhaust hole and a pressure monitoring channel are additionally arranged on the first surface, making contact with the back face of the wafer, of the electrostatic chuck, the warping condition of the wafer can be monitored by monitoring the pressure change of the pressure monitoring channel, the adsorption voltage of the electrostatic chuck to the wafer is adjusted, and the problem of wafer warping can be solved.

Description

Technical Field

[0001] This application relates to the field of semiconductor device processing, and more particularly to an electrostatic adsorption device and a semiconductor device processing equipment. Background Technology

[0002] A wafer is a substrate used to fabricate semiconductor devices. To fabricate semiconductor devices (such as integrated circuits, semiconductor light-emitting devices, solar cells, etc.), wafers need to be placed in a semiconductor processing chamber (also called a reaction chamber). The wafers are fixed on a heated tray inside the semiconductor processing chamber by electrostatic adsorption or other methods, and then heated and deposited (e.g., chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), etc.) to deposit a thin film on the surface of the wafer.

[0003] During thin film deposition, the difference in thermal expansion coefficients between the newly formed film and the wafer substrate causes stress between them, leading to wafer warping. When the film stress is high, especially when the film thickness is high, the wafer may warp significantly and partially detach from the heating tray. Wafer warping reduces heating efficiency, worsens film uniformity, and in severe cases, may cause electric arcing.

[0004] Therefore, how to alleviate wafer warpage during thin film deposition has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, this application provides an electrostatic adsorption device and a semiconductor device processing equipment, which is beneficial to solving the problem of wafer warping.

[0006] In a first aspect, this application provides an electrostatic adsorption device, comprising:

[0007] An electrostatic chuck has a first surface for contacting a wafer and includes at least one pressure monitoring groove, in which at least one evacuation port is provided.

[0008] A pressure monitoring channel connected to the air extraction port; a pressure monitoring device for monitoring the pressure of the pressure monitoring channel and obtaining pressure monitoring results;

[0009] A controller is used to receive the pressure monitoring results and adjust the adsorption voltage of the electrostatic chuck on the wafer based on the pressure monitoring results.

[0010] In some embodiments, the pressure monitoring channel and the back side of the wafer to the first surface are in a vacuum state before the wafer warps.

[0011] In some embodiments, the system further includes: a pressure adjustment channel for adjusting the pressure of the reaction chamber, the two ends of which are respectively connected to the reaction chamber and a vacuum pump; wherein the pressure monitoring channel further includes a main gas channel and a first gas guide branch connected to the main gas channel, the first gas guide branch being connected to the pressure adjustment channel; the main gas channel includes a first valve, and the first gas guide branch includes a second valve; the controller is further configured to control the operation of the vacuum pump when both the first valve and the second valve are open.

[0012] In some embodiments, the pressure monitoring channel further includes a second air guide branch connected to the main air guide channel, the second air guide branch being closer to the electrostatic chuck than the first air guide branch; wherein the second air guide branch includes a third valve;

[0013] The controller is further configured to control the first valve and the third valve to open and the second valve to close when a desorption command for the wafer is detected.

[0014] In some embodiments, the electrostatic chuck further includes electrodes, and adjusting the adsorption voltage of the electrostatic adsorption device on the wafer based on the pressure monitoring result includes:

[0015] When the pressure monitoring result matches the preset gas leakage pressure value, the voltage of the electrode is increased.

[0016] In some embodiments, controlling the increase of the voltage of the electrode includes:

[0017] The voltage of the electrode is continuously increased according to a preset voltage adjustment value and a preset time interval until the warpage of the wafer is determined to be restored based on the currently received pressure monitoring results, at which point the voltage adjustment of the electrode is stopped.

[0018] In some embodiments, the area of ​​the wafer covering the electrode is greater than 50%.

[0019] In some embodiments, the shape of the pressure monitoring trench matches the shape of the wafer, and the pressure monitoring trench includes at least one, each pressure monitoring trench being radially distributed around the center point of the electrostatic chuck, and the distance between the edge pressure monitoring trench and the edge of the wafer being greater than 0 and less than or equal to 5 mm; wherein the edge pressure monitoring trench is the pressure monitoring trench that is farthest from the center point among at least one of the pressure monitoring trenches.

[0020] In some embodiments, the air extraction port includes at least one, and each air extraction port is symmetrically distributed about the center of the electrostatic chuck; and / or

[0021] The diameter of the air extraction hole is 1mm-3mm.

[0022] Secondly, this application provides a semiconductor device processing apparatus, including a reaction chamber and the electrostatic adsorption device proposed in the first aspect. Attached Figure Description

[0023] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application. In the drawings:

[0024] Figure 1 This is a side view schematic diagram of an electrostatic adsorption device provided in an embodiment of this application;

[0025] Figure 2 This is a top view schematic diagram of an electrostatic chuck provided in an embodiment of this application;

[0026] Figure 3 This is a schematic diagram illustrating wafer warping according to an embodiment of this application;

[0027] Figure 4 This is a partial schematic diagram of an electrostatic adsorption device provided in an embodiment of this application.

[0028] The reference numerals in the figure are as follows:

[0029] 10. Electrostatic adsorption device;

[0030] 100. Electrostatic chuck;

[0031] 101. Wafer;

[0032] 102. Pressure monitoring trench;

[0033] 103. Air extraction port;

[0034] 104. Pressure monitoring channel;

[0035] 105. Pressure monitoring device;

[0036] 106. Controller;

[0037] 107. Electrode;

[0038] 108. Reaction chamber;

[0039] 109. Pressure adjustment channel;

[0040] 1070, External electrode;

[0041] 1071. Internal electrode;

[0042] 1040, Main gas passage;

[0043] 1041. First air guide branch;

[0044] 1042. Second air guide branch. Detailed Implementation

[0045] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0046] As indicated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0047] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. 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. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0048] Furthermore, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of the description herein. Moreover, this application is to be understood not only by the actual terms used, but also by the meaning implied by each term.

[0049] It should be understood that when a component is referred to as "on another component," "connected to another component," "coupled to another component," or "in contact with another component," it can be directly on, connected to, coupled to, or in contact with that other component, or there may be an inserting component. In contrast, when a component is referred to as "directly on another component," "directly connected to," "directly coupled to," or "directly in contact with" another component, there is no inserting component.

[0050] It should be noted that the terms "front," "rear," "up," "down," "left," "right," "longitudinal," and "lateral" used in this application are all based on the installation structure. Figure 1 The perspectives shown are for the purpose of facilitating and simplifying the description of this application, 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, and therefore should not be construed as limiting this application.

[0051] To overcome the shortcomings of the existing technology, this application provides an electrostatic adsorption device and a semiconductor device processing equipment. The electrostatic adsorption device adds a pressure monitoring groove, an air extraction hole, and a pressure monitoring channel to the first surface of the electrostatic chuck that contacts the back of the wafer. By monitoring the pressure changes in the pressure monitoring channel, the wafer warpage can be monitored, and the adsorption voltage of the electrostatic chuck on the wafer can be adjusted, which helps to solve the wafer warpage problem.

[0052] Please refer to the reference. Figure 1 and Figure 2 . Figure 1 A side view schematic diagram of an electrostatic adsorption device provided according to some embodiments of this application is shown. Figure 2 A top view schematic diagram of an electrostatic chuck provided according to some embodiments of this application is shown.

[0053] exist Figure 1 and Figure 2 In the illustrated embodiment, the first aspect of this application provides an electrostatic adsorption device 10, including an electrostatic chuck 100. The electrostatic chuck 100 achieves electrostatic adsorption of a wafer 101 by internal charging, and releases the wafer 101 by discharging to eliminate the adsorption force (i.e., desorption).

[0054] The electrostatic chuck 100 has a first surface for contacting the wafer 101, and includes at least one pressure monitoring groove 102, in which at least one vent hole 103 is provided. The electrostatic adsorption device 10 also includes a pressure monitoring channel 104 connected to the vent hole 103, a pressure monitoring device 105, and a controller 106. The pressure monitoring device 105, for example, can be a pressure gauge. The pressure monitoring device 105 monitors the pressure in the pressure monitoring channel 104, obtains the pressure monitoring result, and transmits it to the controller 106. The controller 106 adjusts the adsorption voltage of the electrostatic chuck 100 on the wafer 101 based on the received pressure monitoring result.

[0055] During the thin film deposition process, when wafer 101 does not warp, the entire back side of wafer 101 is adhered to the first surface of electrostatic chuck 100, for example... Figure 1 As shown, wafer 101 is generally flat. When wafer 101 warps, for example... Figure 3 As shown, a portion of wafer 101 leaves the first surface of the electrostatic chuck 100, causing gas leakage. The leaked gas flows through the pressure monitoring groove 102 into the extraction port 103 and into the pressure monitoring channel 104, causing pressure changes in the channel. Since the pressure monitoring device 105 monitors the pressure in the pressure monitoring channel 104 in real time and transmits the monitoring results to the controller 106, the controller 106 can determine whether the pressure monitoring result matches the preset gas leakage pressure value. If they do not match, it indicates good wafer adsorption without warping, and no operation is performed. If they match, it indicates abnormal wafer adsorption and warping, and a signal to increase the adsorption voltage is sent to the power supply (not shown) of the electrostatic adsorption device, controlling the increase in the adsorption voltage on wafer 101. Under the action of the increased adsorption voltage, wafer 101 will... Figure 3 The warped state shown has been restored to Figure 1 The flatness shown.

[0056] In some embodiments, before wafer 101 warps, the entire back side of wafer 101 is adhered to the first surface of electrostatic chuck 100, and the pressure monitoring channel and the area from the back side of the wafer to the first surface are in a vacuum state. This vacuum state may refer, for example, to a pressure lower than [a certain value]. Torr can be considered as a near-gas-free state. In this case, the controller 106 determines whether the pressure monitoring result matches the preset gas leakage pressure value, including: comparing the pressure value in the pressure monitoring result with the preset gas leakage pressure value; if the pressure value is greater than or equal to the preset gas leakage pressure value, then the pressure monitoring result matches the preset gas leakage pressure value; otherwise, the pressure monitoring result does not match the preset gas leakage pressure value. The preset gas leakage pressure value is a value pre-set based on experimental data or theoretical analysis, for example, it can be 10 Torr, and its value can be adjusted as needed.

[0057] In some embodiments, the electrostatic chuck further includes electrodes, with the wafer covering more than 50% of the electrode area. For example... Figure 1 The area of ​​the electrode 107 covered by the wafer 101 is greater than 50%. After the controller 106 sends a signal to the power supply of the electrostatic adsorption device to increase the adsorption voltage, the power supply can control the increase of the voltage of the electrode 107 (i.e. the adsorption voltage mentioned above) based on the signal to enhance the adsorption effect of the electrostatic chuck 100 on the wafer 101.

[0058] In some embodiments, the controller 106 controls the increase of the electrode voltage, including: continuously increasing the electrode voltage according to a preset voltage adjustment value and a preset time interval until wafer warpage is determined to have recovered based on the currently received pressure monitoring results, at which point the adjustment of the electrode voltage is stopped. As a possible approach, the pressure value in the pressure monitoring results can be restored to the value corresponding to the aforementioned vacuum state (e.g., less than...). When Torr is used, the warpage recovery of the wafer is determined.

[0059] For example, assuming a preset voltage adjustment value of 50V and a preset time interval of 10s, the controller 106 determines that the pressure monitoring result matches the preset gas leakage pressure value, i.e., confirms that wafer warpage has occurred. The controller 106 sends a signal to the power supply of the electrostatic adsorption device to increase the adsorption voltage of the electrode 107 by 50V each time, stabilizing for 10s after each increase. The pressure monitoring device 105 provides real-time feedback of the pressure monitoring result until the controller 106 determines that the wafer warpage has been recovered based on the currently received pressure monitoring result. Figure 3 The warped state shown has been restored to Figure 1 Once the surface reaches the indicated level, stop adjusting the electrode voltage.

[0060] In some embodiments, the shape of the pressure monitoring trench matches the shape of the wafer. When the wafer is circular, the pressure monitoring trench can be circular or annular, such as... Figure 2The pressure monitoring trench 102 is used in the wafer. When the wafer has other shapes, such as rectangles, the shape of the pressure monitoring trench can also be a rectangular ring; this application does not specifically limit this. Any warping of the wafer in the area where the pressure monitoring trench 102 is located (e.g., ...) Figure 2 If a gas leak occurs at any point on the ring of the medium-circle annular groove, the leaked gas can be directed to the extraction port 103 through the pressure monitoring groove 102.

[0061] In addition, the pressure monitoring trench includes at least one, since wafer warping typically involves bowl-shaped warping (the wafer edges are raised, while the center remains attached to the electrostatic chuck, such as...). Figure 3 (as shown) or an inverted bowl-shaped warp (the center of the wafer is raised, while the edges remain attached to the electrostatic chuck). In some embodiments, when there is only one pressure monitoring groove, the pressure monitoring groove can be set near the center point of the electrostatic chuck (e.g., the pressure monitoring groove is ≤150mm from the center point) or near the outer edge (e.g., the pressure monitoring groove is ≤5mm from the outer edge of the electrostatic chuck).

[0062] In some embodiments, see Figure 1 As shown, electrode 107 includes an outer electrode 1070 and an inner electrode 1071. When there is only one pressure monitoring groove 102 and it is located near the center point of the electrostatic chuck 100, the voltage of the inner electrode 1071 can be adjusted only when adjusting the adsorption voltage. Alternatively, when there is only one pressure monitoring groove 102 and it is located near the outer edge of the electrostatic chuck 100, the voltage of the outer electrode 1070 can be adjusted only when adjusting the adsorption voltage.

[0063] In some embodiments, when there are multiple pressure monitoring trenches, each pressure monitoring trench is radially distributed around the center point of the electrostatic chuck, and the distance between the edge pressure monitoring trench and the edge of the wafer is greater than 0 and less than or equal to 5 mm. The edge pressure monitoring trench is the pressure monitoring trench that is farthest from the center point among at least one pressure monitoring trench, which can be understood as the pressure monitoring trench located at the outermost edge of the electrostatic chuck.

[0064] In some embodiments, the air extraction holes provided in the pressure monitoring trench include at least one, each air extraction hole being symmetrically distributed around the center of the electrostatic chuck, and the diameter of the air extraction hole being 1mm-3mm.

[0065] In addition, please continue to refer to Figure 4In some embodiments, the electrostatic adsorption device 101 provided in the first aspect of this application may optionally include a pressure adjustment channel 109 for adjusting the pressure of the reaction chamber 108. The two ends of the pressure adjustment channel 109 are respectively connected to the reaction chamber 108 and a vacuum pump (not shown in the figure). The pressure adjustment channel 109 includes two normally open valves, a pressure regulating valve and a throttle valve. The pressure regulating valve can adjust and control the pressure of the reaction chamber 108 by adjusting the valve opening. The pressure monitoring channel 104 also includes a main gas channel 1040 and a first gas guide branch 1041 connected to the main gas channel 1040. The first gas guide branch 1041 is connected to the pressure adjustment channel 109. The main gas channel 1040 includes a first valve, and the first gas guide branch 1041 includes a second valve. The controller 106 is further configured to control the vacuum pump to operate when both the first and second valves are open, so that the pressure monitoring channel 104 and the back side to the first surface of the wafer 101 are in a vacuum state.

[0066] In addition, continue to refer to Figure 4 In some embodiments, the pressure monitoring channel 104 further includes a second gas guide branch 1042 connected to the main gas guide channel 1040, which is connected in parallel with the first gas guide branch 1041. The second gas guide branch 1042 includes a third valve and is closer to the electrostatic chuck 100 than the first gas guide branch 1041. The controller 106 is also configured to control the first and third valves to open and the second valve to close when a desorption command for the wafer 101 is detected. During the wafer 101 processing, the wafer 101 is adsorbed onto the electrostatic chuck 100, and the electrostatic chuck 100 is placed in the reaction chamber. When it is necessary to remove the wafer 101 from the reaction chamber, that is, to desorb the wafer, the second valve is closed and the first and third valves are opened. Since the second gas guide branch 1042 is closer to the reaction chamber than the first gas guide branch 1041, opening the first and third valves makes the pressure in the reaction chamber and the lower pipelines (such as the second gas guide branch 1042 and the main gas guide channel 1040) equal, and the pressure at the back of the wafer remains consistent, which facilitates the desorption of the wafer 101.

[0067] It should be noted that the pressure monitoring device 105 is located in... Figure 1 , Figure 3 and Figure 4 This is merely one example; it can be located anywhere within the pressure monitoring channel 104 or externally connected to the pressure monitoring channel 104, as long as the pressure of the pressure monitoring channel can be monitored. This application does not limit this.

[0068] The following example illustrates one of the practical application scenarios of electrostatic adsorption devices. For example, see [link to relevant documentation]. Figure 4 ,pass Figure 4 The process of wafer processing using an electrostatic adsorption device may include:

[0069] Step 1: Place wafer 101 on electrostatic chuck 100. Electrostatic chuck 100 provides adsorption voltage to adsorb the wafer.

[0070] Step 2: Open the first valve and the second valve, close the third valve, and control the vacuum pump (not shown in the figure) to run, so that the pressure monitoring channel 104 and the back side of the wafer 101 to the first surface of the electrostatic chuck 100 are in a vacuum state.

[0071] Step 3: The pressure monitoring device 105 monitors the pressure of the pressure monitoring channel 104 in real time and transmits the pressure monitoring results to the controller 106. The controller 106 determines whether the pressure monitoring results match the preset gas leakage pressure value. If they do not match, it indicates that the wafer adsorption is good and warping has occurred, so no operation is performed. If they match, it indicates that the wafer adsorption is abnormal and warping has occurred, so the controller increases the adsorption voltage on the wafer 101. Under the action of the increased adsorption voltage, the wafer 101 will... Figure 3 The warped state shown has been restored to Figure 1 The flatness shown.

[0072] Step 4: The reaction gas is introduced into the reaction chamber 108 and the pressure is controlled at 500 torr for thin film deposition. During the thin film deposition process, the above step 3 is continuously executed. Once abnormal wafer adsorption is detected, the adsorption voltage on wafer 101 is increased to resolve wafer warping.

[0073] Another aspect of this application provides a semiconductor device processing apparatus, including a reaction chamber and the aforementioned electrostatic adsorption device, wherein the electrostatic chuck in the electrostatic adsorption device is placed inside the reaction chamber. This processing apparatus can be applied to various fields such as vacuum bonding in the panel industry, semiconductor chip packaging, microelectronic integrated circuits, precision optical component manufacturing, and solar photovoltaic production. The electrostatic adsorption device, by adding pressure monitoring grooves, venting holes, and pressure monitoring channels, can monitor wafer warpage by monitoring pressure changes in the pressure monitoring channels.

[0074] Adjusting the adsorption voltage of the electrostatic chuck on the wafer helps to solve the problem of wafer warping.

[0075] The preceding description is provided to enable any person skilled in the art to practice the various aspects described herein. However, it should be understood that the scope of protection of this application should be determined by the appended claims and should not be limited to the specific structures and components of the embodiments described above. Those skilled in the art can make various changes and modifications to the embodiments within the spirit and scope of this application, and these changes and modifications also fall within the scope of protection of this application.

Claims

1. An electrostatic adsorption device, characterized in that, include: An electrostatic chuck has a first surface for contacting a wafer and includes at least one pressure monitoring groove in which at least one evacuation port is provided. Pressure monitoring channel connected to the air extraction port; A pressure monitoring device is used to monitor the pressure in the pressure monitoring channel and obtain pressure monitoring results; A controller is used to receive the pressure monitoring results and adjust the adsorption voltage of the electrostatic chuck on the wafer based on the pressure monitoring results.

2. The electrostatic adsorption device as described in claim 1, characterized in that, Before the wafer warps, the pressure monitoring channel and the back side of the wafer to the first surface are in a vacuum state.

3. The electrostatic adsorption device as described in claim 2, characterized in that, Also includes: A pressure adjustment channel is used to regulate the pressure in the reaction chamber, and the two ends of the pressure adjustment channel are respectively used to connect the reaction chamber and the vacuum pump; The pressure monitoring channel further includes a main gas channel and a first gas guide branch connected to the main gas channel, the first gas guide branch being connected to the pressure adjustment channel; The main gas passage includes a first valve, and the first gas guide branch includes a second valve; The controller is also used to control the operation of the vacuum pump when both the first valve and the second valve are open.

4. The electrostatic adsorption device as described in claim 3, characterized in that, The pressure monitoring channel also includes a second air guide branch connected to the main air guide channel, the second air guide branch being closer to the electrostatic chuck than the first air guide branch; wherein the second air guide branch includes a third valve; The controller is further configured to open the first valve and the third valve, and close the second valve, when a desorption command for the wafer is detected.

5. The electrostatic adsorption device as described in claim 1, characterized in that, The electrostatic chuck further includes electrodes, and adjusting the adsorption voltage of the electrostatic adsorption device on the wafer based on the pressure monitoring result includes: When the pressure monitoring result matches the preset gas leakage pressure value, the voltage of the electrode is increased.

6. The electrostatic adsorption device as described in claim 5, characterized in that, The control to increase the voltage of the electrode includes: The voltage of the electrode is continuously increased according to a preset voltage adjustment value and a preset time interval until the warpage of the wafer is determined to be restored based on the currently received pressure monitoring results, at which point the voltage adjustment of the electrode is stopped.

7. The electrostatic adsorption device as described in claim 5, characterized in that, The area of ​​the wafer covering the electrode is greater than 50%.

8. The electrostatic adsorption device according to any one of claims 1-7, characterized in that, The shape of the pressure monitoring trench matches the shape of the wafer. The pressure monitoring trench includes at least one trench, and each pressure monitoring trench is radially distributed around the center point of the electrostatic chuck. The distance between the edge pressure monitoring trench and the edge of the wafer is greater than 0 and less than or equal to 5 mm. The edge pressure monitoring groove is the pressure monitoring groove that is farthest from the center point among at least one of the pressure monitoring grooves.

9. The electrostatic adsorption device according to any one of claims 1-7, characterized in that, The air extraction port includes at least one, and each air extraction port is symmetrically distributed about the center of the electrostatic chuck; and / or The diameter of the air extraction hole is 1mm-3mm.

10. A semiconductor device processing apparatus, characterized in that, include: Reaction chamber; The electrostatic adsorption device according to any one of claims 1-9, wherein the electrostatic chuck in the electrostatic adsorption device is placed in the reaction chamber.

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