Nitrogen doping device

Abstract

The utility model relates to the field of semiconductors, and discloses a nitrogen doping device which comprises a processing chamber, a bearing table and a nitrogen doping monitoring assembly, the bearing table is located in the processing chamber, and the bearing table comprises a bearing surface for bearing a wafer; the nitrogen doping monitoring assembly comprises an electronic filter and a charge signal collector; in the normal direction of the bearing surface, the electronic filter comprises a first surface and a second surface which are opposite, and the first surface is located in the processing chamber and protrudes out of the bearing surface; the electronic filter is used for filtering electrons entering from the first surface and allowing positive charges entering from the first surface to be emitted through the second surface; and the charge signal collector is positioned on one side of the second surface of the electronic filter and is used for collecting positive charges emitted from the second surface. According to the nitrogen doping device provided by the embodiment of the utility model, electrons can be filtered through the electronic screener, positive charges are allowed to pass through, and the positive charges filtered by the electronic screener are collected through the charge collector, so that real-time monitoring of nitrogen doping is realized.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a nitrogen-doping device. Background Technology

[0002] In decoupled plasma nitrogen doping processes, temperature, pressure, and gas flow are monitored in real time, but there is no effective mechanism for directly monitoring the nitrogen doping process. During equipment verification, it was found that the gas was not ionized, but the processing was not interrupted, rendering the nitrogen doping process ineffective. Therefore, effective monitoring of this process is necessary. Utility Model Content

[0003] This utility model discloses a nitrogen doping device for real-time monitoring of the nitrogen doping process, avoiding monitoring lag.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A nitrogen doping device includes: a processing chamber, a support platform, and a nitrogen doping monitoring component;

[0006] The support stage is located inside the processing chamber, and the support stage includes a support surface for supporting the wafer;

[0007] The nitrogen-doped monitoring component includes an electron filter and a charge signal collector;

[0008] Along the normal direction of the bearing surface, the electron filter includes a first surface and a second surface opposite each other, the first surface being located inside the processing chamber and protruding from the bearing surface; the electron filter is used to filter electrons entering from the first surface and allow positive charges entering from the first surface to exit through the second surface.

[0009] The charge signal collector is located on one side of the second surface of the electron filter and is used to collect positive charges emitted through the second surface.

[0010] The aforementioned nitrogen-doping device has a processing chamber for performing nitrogen doping on wafers. A support platform is installed inside the processing chamber to support the wafer. The support platform has a support surface, and nitrogen doping is performed on the side of the wafer facing away from the support surface. Along the normal direction of the support surface, the plasma formed within the processing chamber is located above the wafer. To ensure real-time monitoring of the wafer's nitrogen doping process, the first surface of the electron filter in the nitrogen-doping assembly is located in the processing chamber and protrudes from the support surface. In actual use, the wafer is placed on the support surface of the support platform, and the plasma used for nitrogen doping is located above the wafer. The first surface protruding from the support surface allows it to be as close as possible to the surface of the wafer facing away from the support surface, thus ensuring accurate monitoring. The first surface of the electron filter filters out electrons entering from it, preventing them from penetrating the electron filter and exiting from the second surface. However, positively charged ions such as N+ can enter the electron filter from the first surface, penetrate it, and finally exit from the second surface, where they are collected by a charge collector located on the second surface. The nitrogen doping status is then detected based on the collected positive charges.

[0011] Therefore, the nitrogen doping device provided in this embodiment of the present invention can filter electrons through an electron filter and allow positive charges to pass through, and collect the positive charges filtered by the electron filter through a charge collector to achieve real-time monitoring of nitrogen doping.

[0012] In some embodiments, the electron filter includes a deflection magnetic field located between the first surface and the second surface, the deflection magnetic field being configured to cause electrons entering from the first surface to exit from the first surface.

[0013] In some embodiments, the direction of the deflecting magnetic field is parallel to the first surface.

[0014] In some embodiments, the first surface is parallel to the bearing surface.

[0015] In some embodiments, the first surface is configured such that when the carrier surface carries the wafer, the first surface is flush with the surface of the wafer on the side opposite to the carrier surface.

[0016] In some embodiments, the first surface is circular in shape.

[0017] In some embodiments, the charge signal collector includes a collection end, a detection end, and a grounding circuit;

[0018] The acquisition end faces the second surface and is electrically connected to the grounding circuit, and is used to guide the positive charge emitted from the second surface into the grounding circuit;

[0019] The detection terminal is located in the grounding circuit and is used to detect the magnitude of the current in the grounding circuit.

[0020] In some embodiments, the charge signal collector further includes a data collector connected to the detection terminal signal.

[0021] In some embodiments, there are multiple nitrogen doping monitoring components, and the multiple nitrogen doping monitoring components are arranged at intervals around the support platform.

[0022] In some embodiments, a first gap exists between the nitrogen-doped monitoring component and the support platform. Attached Figure Description

[0023] Figure 1 A schematic diagram of a nitrogen-doping device provided in an embodiment of this utility model;

[0024] Figure 2 A schematic diagram of a nitrogen-doping device provided in an embodiment of this utility model;

[0025] Figure 3 A schematic diagram of the structure of an electronic filter in a nitrogen-doping device provided in this embodiment of the present invention;

[0026] Figure 4 A schematic diagram of the structure of a charge signal collector in a nitrogen-doped device provided in this embodiment of the present invention;

[0027] Figure 5 A distribution diagram of nitrogen doping monitoring components in a nitrogen doping device provided for an embodiment of this utility model;

[0028] Icons: 100-Processing chamber; 110-Gas inlet; 200-RF component; 300-Support platform; 400-Nitrogen-doped monitoring component; 500-Wafer; 210-Plasma; 301-Support surface; 410-Electron filter; 420-Charge signal collector; 411-First surface; 412-Second surface; 413-Deflection magnetic field; 4131-First magnetic pole; 4132-Second magnetic pole; 421-Acquisition end; 422-Detection end; 423-Grounding circuit. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model. In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in the text is only a description of the relationship between related objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0030] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0031] like Figures 1 to 2 As shown, this utility model embodiment provides a nitrogen doping device, including: a processing chamber 100, a support platform 300, and a nitrogen doping monitoring component 400;

[0032] The support stage 300 is located inside the processing chamber 100, and the support stage 300 includes a support surface 301 for supporting the wafer;

[0033] The nitrogen doping monitoring component 400 includes an electron filter 410 and a charge signal collector 420;

[0034] Along the normal direction of the bearing surface 301, the electron filter 410 includes a first surface 411 and a second surface 412 opposite to each other. The first surface 411 is located inside the processing chamber 100 and protrudes from the bearing surface 301. The electron filter 410 is used to filter electrons entering from the first surface 411 and allow positive charges entering from the first surface 411 to exit through the second surface 412.

[0035] The charge signal collector 420 is located on one side of the second surface 412 of the electron filter 410 and is used to collect the positive charges emitted through the second surface 412.

[0036] like Figure 1 and Figure 2As shown, the nitrogen doping device includes a processing chamber 100, an RF assembly 200, a support stage 300, and a nitrogen doping monitoring assembly 400. The processing chamber 100 has a gas inlet 110 for connection to a gas source. The gas source provides the processing chamber 100 with a gas source, such as nitrogen molecules. The support stage 300 is located inside the processing chamber 100 and includes a support surface 301 for supporting the wafer.

[0037] The radio frequency (RF) component 200 is located at the top of the processing chamber 100 and is used to apply radio frequency (RF) to the processing chamber 100 to generate plasma 210. The RF gas decoupling ionization process of the RF component 200 involves inducing an RF electric field through a high-frequency current, where electrons are accelerated and ionized by the electric field, thereby generating plasma 210. For example, when no ionization occurs, the processing chamber 100 contains nitrogen molecules, which are uncharged. Under the action of the RF electric field, when the nitrogen molecules ionize, the gas atoms lose electrons to generate positively charged nitrogen ions N+ and negatively charged electrons e-. Under the action of the RF electric field, the N+ accelerates and bombards the wafer surface to perform nitrogen doping, while the electrons are conducted away through the wall ground of the processing chamber 100.

[0038] like Figure 2 As shown, plasma 210 is located above wafer 500. During nitrogen doping, under the electric field of radio frequency component 200, N+ and e- accelerate towards wafer 500 from top to bottom. Nitrogen doping monitoring component 400 is located near support stage 300, i.e., near wafer 500. Nitrogen doping monitoring component 400 includes electron filter 410 and charge signal collector 420. From top to bottom, electron filter 410 includes a first surface 411 and a second surface 412. The first surface 411 is higher than support surface 301 and is used to contact nitrogen ions N+ and negatively charged electrons e- in plasma 210, such as... Figure 1 As shown in the figure, H can be determined by the thickness of the wafer to be doped with nitrogen.

[0039] The electron filter 410 is partially or entirely located inside the processing chamber 100, and can filter electrons in the plasma 210 to ensure that electrons do not pass through the electron filter 410. The charge signal collector 420 is located below the electron filter 410 and collects positively charged ions such as N+ that pass through the electron filter 410. By monitoring the positively charged ions, the nitrogen doping process can be monitored in real time.

[0040] The processing chamber 100 of the aforementioned nitrogen doping device is used to perform the nitrogen doping process on a wafer. A support platform 300 is installed inside the processing chamber 100 to support the wafer. The support platform 300 has a support surface 301, and nitrogen doping is performed on the side of the wafer facing away from the support surface 301. Along the normal direction of the support surface 301, plasma 210 formed within the processing chamber 100 is located above the wafer. To ensure real-time monitoring of the wafer nitrogen doping process, in the nitrogen doping assembly, the first surface 411 of the electron filter 410 is located in the processing chamber 100 and protrudes from the support surface 301. In actual use, the wafer is placed on the support surface 301 of the support platform 300, and the plasma 210 used for nitrogen doping is located above the wafer. The first surface 411 protrudes from the support surface 301, allowing it to be as close as possible to the surface of the wafer facing away from the support surface 301, thereby ensuring the accuracy of monitoring. The first surface 411 of the electron filter 410 filters out electrons entering from the first surface 411, preventing them from penetrating the electron filter 410 and exiting from the second surface 412. However, positively charged ions such as N+ can enter the electron filter 410 from the first surface 411, penetrate the electron filter 410, and finally exit from the second surface 412. They are then collected by the charge collector located on the second surface 412, thereby detecting nitrogen doping based on the collected positive charges.

[0041] Therefore, the nitrogen doping device provided in this embodiment of the present invention can filter electrons through the electron filter 410 and allow positive charges to pass through, and collect the positive charges filtered by the electron filter 410 through the charge collector to achieve real-time monitoring of nitrogen doping.

[0042] In some embodiments, such as Figure 3 As shown, the electron filter 410 includes a deflection magnetic field 413 located between a first surface 411 and a second surface 412, the deflection magnetic field 413 being configured to cause electrons entering from the first surface 411 to exit from the first surface 411.

[0043] The deflection radius of electrons in a magnetic field is much smaller than that of nitrogen ions. When nitrogen ions and electrons enter the deflection magnetic field 413 in the electron filter 410 from the first surface 411, the electrons are deflected back by the deflection magnetic field 413 and cannot pass through the electron filter 410. Because the deflection radius of nitrogen ions is much larger than that of electrons, they can pass through the electron filter 410 and exit from the second surface 412. At the same time, N2 molecules in the gas can also pass through the electron filter 410.

[0044] It should be noted that the specific parameters of the deflection magnetic field 413 are designed to ensure that all positive charges entering from the first surface 411 can be deflected and then pass through the second surface 412.

[0045] In some embodiments, the direction of the deflecting magnetic field 413 is parallel to the first surface 411.

[0046] like Figure 3 As shown, the electronic filter 410 includes a first magnetic pole 4131 and a second magnetic pole 4132. A deflecting magnetic field 413 is generated between the first magnetic pole 4131 and the second magnetic pole 4132, with the direction parallel to the bearing surface 301.

[0047] In some embodiments, the first surface 411 is parallel to the bearing surface 301, thereby making the first surface 411 parallel to the nitrogen-doped surface of the wafer. This allows the nitrogen ion and electron densities entering the first surface 411 to be as similar as possible, thereby improving the monitoring accuracy of the nitrogen-doped monitoring component 400.

[0048] In some embodiments, the first surface 411 is configured such that when the carrier surface 301 carries the wafer, the first surface 411 is flush with the surface of the wafer on the side opposite to the carrier surface 301.

[0049] like Figure 2 As shown, during the nitrogen doping process, the first surface 411 of the electron filter 410 is located on the same plane as the nitrogen-doped surface of the wafer 500, so that the nitrogen ions and electrons entering the first surface 411 and the nitrogen-doped surface of the wafer 500 have the same velocity and quantity, thereby further improving the real-time monitoring accuracy of the nitrogen doping monitoring component 400.

[0050] In some embodiments, the first surface 411 is circular in shape.

[0051] Typically, the surface of a wafer to be doped with nitrogen is circular. The first surface 411 of the electron filter 410 is also set to be circular to facilitate the conversion of subsequent detection signals, thereby facilitating the real-time monitoring of the nitrogen doping monitoring component 400.

[0052] In some embodiments, such as Figure 4 As shown, the charge signal collector 420 includes a collection terminal 421, a detection terminal 422, and a grounding circuit 423;

[0053] The acquisition end 421 faces the second surface 412 and is electrically connected to the grounding circuit 423, which is used to guide the positive charge emitted from the second surface 412 into the grounding circuit 423.

[0054] The detection terminal 422 is located in the grounding circuit 423 and is used to detect the magnitude of the current in the grounding circuit 423.

[0055] Nitrogen ions enter the charge signal collector 420, and the positive charge contacts the surface of the acquisition terminal 421, neutralizing it with the grounding circuit 423 and generating a current signal, which can be detected by the detection terminal 422. At the same time, the charge signal collector 420 does not react to electrically neutral nitrogen gas, and the signal detected by the detection terminal 422 is the nitrogen ion signal, and the magnitude of the current signal indicates the concentration of nitrogen ions.

[0056] In some embodiments, the charge signal collector 420 further includes a data collector connected to the detection terminal 422, and the monitoring data collector reading can monitor the nitrogen doping situation in real time.

[0057] In some embodiments, such as Figure 5 As shown, there are multiple nitrogen doping monitoring components 400, and these multiple nitrogen doping monitoring components 400 are arranged at intervals around the support platform 300 to ensure the accuracy of real-time monitoring of the nitrogen doping process.

[0058] In some embodiments, a first gap D exists between the nitrogen doping monitoring component 400 and the support platform 300.

[0059] When the wafer is placed on the support stage 300, there is a second gap between the nitrogen-doped detection component and the wafer. This second gap can be equal to or smaller than the first gap. It is understood that the first gap D needs to ensure the normal monitoring function of the nitrogen-doped detection component 400 while avoiding affecting the wafer's movement in the processing chamber 100, such as rotating with the support surface 301.

[0060] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this utility model without departing from the spirit and scope of this utility model. Therefore, if these modifications and variations of this utility model fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A nitrogen-doping device, characterized in that, include: Processing chamber, support platform, and nitrogen doping monitoring components; The support stage is located inside the processing chamber, and the support stage includes a support surface for supporting the wafer; The nitrogen-doped monitoring component includes an electron filter and a charge signal collector; Along the normal direction of the bearing surface, the electron filter includes a first surface and a second surface opposite each other, the first surface being located inside the processing chamber and protruding from the bearing surface; the electron filter is used to filter electrons entering from the first surface and allow positive charges entering from the first surface to exit through the second surface. The charge signal collector is located on one side of the second surface of the electron filter and is used to collect positive charges emitted through the second surface.

2. The nitrogen-doping device according to claim 1, characterized in that, The electron filter includes a deflection magnetic field located between the first surface and the second surface, the deflection magnetic field being configured to cause electrons entering from the first surface to exit from the first surface.

3. The nitrogen-doping device according to claim 2, characterized in that, The direction of the deflecting magnetic field is parallel to the first surface.

4. The nitrogen-doping device according to claim 1, characterized in that, The first surface is parallel to the bearing surface.

5. The nitrogen-doping device according to claim 4, characterized in that, The first surface is configured such that when the bearing surface carries the wafer, the first surface is flush with the surface of the wafer on the side opposite to the bearing surface.

6. The nitrogen-doping device according to claim 5, characterized in that, The first surface is circular in shape.

7. The nitrogen-doping device according to claim 1, characterized in that, The charge signal collector includes a collection end, a detection end, and a grounding circuit; The acquisition end faces the second surface and is electrically connected to the grounding circuit, and is used to guide the positive charge emitted from the second surface into the grounding circuit; The detection terminal is located in the grounding circuit and is used to detect the magnitude of the current in the grounding circuit.

8. The nitrogen-doping device according to claim 7, characterized in that, The charge signal collector also includes a data collector connected to the detection terminal signal.

9. The nitrogen-doping device according to any one of claims 1-8, characterized in that, There are multiple nitrogen-doping monitoring components, and the multiple nitrogen-doping monitoring components are arranged at intervals around the support platform.

10. The nitrogen-doping device according to claim 9, characterized in that, There is a first gap between the nitrogen-doped monitoring component and the support platform.

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