Impedance adjuster for adjusting radio frequency power and semiconductor processing equipment

Abstract

The invention discloses an impedance adjuster for adjusting radio frequency power and semiconductor processing equipment. The impedance adjuster is connected with a radio frequency electrode of the heating plate and comprises a high-frequency path and a low-frequency path which are independently adjusted; the low-frequency path comprises a high-frequency filtering unit and a low-frequency impedance adjusting unit, one end of the high-frequency filtering unit is connected with the heating disc radio-frequency electrode, and the other end of the high-frequency filtering unit is connected with the low-frequency impedance adjusting unit; the high-frequency path comprises a low-frequency filtering unit and a high-frequency impedance adjusting unit, one end of the low-frequency filtering unit is connected with the heating disc radio-frequency electrode, and the other end of the low-frequency filtering unit is connected with the high-frequency impedance adjusting unit. And the low-frequency impedance adjusting unit and the high-frequency impedance adjusting unit are independently adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and more particularly to an impedance adjuster for adjusting radio frequency power and a semiconductor processing device. Background Art

[0002] In the prior art, the wafer stage of a PECVD (plasma enhanced chemical vapor deposition) machine is usually connected in series with an impedance adjuster to form a radio frequency circuit. By adjusting the impedance adjuster, the radio frequency power coupled into the plasma can be fine-tuned, that is, the radio frequency power passing through the wafer stage and the chamber side wall can be proportionally adjusted to achieve good film performance.

[0003] However, the impedance adjuster only adjusts the high-frequency RF power. In dual-frequency PECVD applications, the low-frequency power also has a great impact on the process results, so low-frequency impedance adjustment is particularly important. Summary of the invention

[0004] In order to overcome the problem that low-frequency impedance cannot be adjusted in the PECVD process, the present invention provides an impedance adjuster and a semiconductor processing device for adjusting radio frequency power.

[0005] The impedance adjuster for adjusting radio frequency power of the present invention is connected to the radio frequency electrode of the heating plate, and the impedance adjuster comprises: a high-frequency path and a low-frequency path which are adjusted independently of each other.

[0006] The low-frequency path includes a high-frequency filter unit and a low-frequency impedance adjustment unit, wherein one end of the high-frequency filter unit is connected to the RF electrode of the heating plate, and the other end is connected to the low-frequency impedance adjustment unit.

[0007] The high-frequency path includes a low-frequency filter unit and a high-frequency impedance adjustment unit, wherein one end of the low-frequency filter unit is connected to the RF electrode of the heating plate, and the other end is connected to the high-frequency impedance adjustment unit.

[0008] The low-frequency impedance adjustment unit and the high-frequency impedance adjustment unit are adjusted independently of each other.

[0009] In one embodiment, the high frequency filtering unit prevents high frequency from entering into a low frequency path, and the high frequency filtering unit comprises an LC filtering circuit.

[0010] In one embodiment, the low-frequency filtering unit prevents low-frequency signals from entering a high-frequency path, and the low-frequency filtering unit includes an LC filtering circuit.

[0011] In one embodiment, the low-frequency impedance adjustment unit includes an adjustable capacitor.

[0012] In one embodiment, the low-frequency impedance adjustment unit includes an adjustable inductor.

[0013] In one embodiment, the low-frequency impedance adjustment unit includes a capacitor and an inductor connected in parallel, wherein the capacitor and / or the inductor is adjustable.

[0014] In one embodiment, the high frequency impedance adjustment unit includes an adjustable capacitor.

[0015] In one embodiment, the high frequency impedance adjustment unit includes an adjustable inductor.

[0016] In one embodiment, the high-frequency impedance adjustment unit includes a capacitor and an inductor connected in parallel, wherein the capacitor and / or the inductor is adjustable.

[0017] The present invention also provides a semiconductor processing device, comprising: a reaction chamber, a shower plate, a heating plate, a radio frequency power supply, a radio frequency electrode of the heating plate and the impedance adjuster as described above.

[0018] The shower plate is located inside the reaction chamber and provides reaction gas to the substrate to be processed.

[0019] The heating plate is located below the shower plate, and supports and heats the substrate to be processed.

[0020] The radio frequency power source is connected to the reaction chamber, and provides radio frequency power to the shower plate through a radio frequency matcher, and forms an electric field between the shower plate and the heating disk.

[0021] The radio frequency electrode of the heating plate is located in the support seat of the heating plate;

[0022] The impedance adjuster is located below the reaction chamber and connected to the radio frequency electrode of the heating plate.

[0023] The impedance adjuster and semiconductor processing equipment provided by the present invention can proportionally distribute the radio frequency power at the center and edge of the wafer by adjusting the low-frequency impedance, thereby achieving more uniform plasma density and energy, thereby improving the performance of the thin film. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above invention content and the following specific embodiments of the present invention will be better understood when read in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are only examples of the claimed invention. In the accompanying drawings, the same reference numerals represent the same or similar elements.

[0025] Figure 1 An overall schematic diagram of a semiconductor processing device according to an embodiment of the present invention is shown;

[0026] Figure 2 An equivalent circuit of a chamber loop according to an embodiment of the present invention is shown;

[0027] Figure 3 An impedance adjuster according to an embodiment of the present invention is shown;

[0028] Figure 4 A schematic diagram of a semiconductor processing device according to an embodiment of the present invention is shown;

[0029] Figure 5 FIG. 4 shows a film thickness distribution diagram according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The detailed features and advantages of the present invention are described in detail in the specific embodiments below, and the content is sufficient to enable any person skilled in the art to understand the technical content of the present invention and implement it accordingly, and according to the description, claims and drawings disclosed in this specification, those skilled in the art can easily understand the relevant purposes and advantages of the present invention. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, many specific details will be included in the following description. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In addition, the terms "upper", "lower", "left", "right", "top", "bottom", "horizontal" and "vertical" used in the following description should be understood as the directions shown in the paragraph and the related drawings. Such relative terms are only used for the convenience of description and do not mean that the device described therein must be manufactured or operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0033] It is understood that although the terms "first", "second", "third", etc. may be used herein to describe various components, channels, components, regions, layers and / or parts, these components, channels, components, regions, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, channels, components, regions, layers and / or parts. In addition, the terms "first", "second", "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0034] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0035] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0036] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0037] Figure 1 The overall schematic diagram of a semiconductor processing device according to an embodiment of the present invention is shown. The semiconductor processing device includes but is not limited to a reaction chamber 101, a shower plate 102, a heating plate 104, a radio frequency power supply 105, a heating plate radio frequency electrode 103 and an impedance adjuster 106.

[0038] The reaction chamber 101 is a sealed chamber that can provide a stable process environment for the substrate to be processed.

[0039] The shower plate 102 is located inside the reaction chamber 101 and is used to provide reaction gas to the substrate to be processed. During the operation of the equipment, the reaction gas is sprayed on the substrate to be processed through the shower plate 102, so that it reacts chemically with the substances on the surface of the substrate to be processed, thereby achieving the purpose of process treatment. The design of the shower plate 102 also takes into account the flow and distribution of the gas to ensure that the gas can evenly cover the entire surface of the substrate to be processed.

[0040] The heating plate 104 is located below the shower plate 102, supporting the substrate to be processed and providing a suitable heating environment for the substrate to be processed, so that the substrate to be processed reaches the temperature required by the process. This heating method can achieve efficient and uniform heat distribution and ensure the thermal stability and reliability of the substrate to be processed.

[0041] In order to enhance the efficiency and stability of the process, the semiconductor processing equipment further includes a radio frequency power supply 105 and a heating plate radio frequency electrode 103 .

[0042] The RF power supply 105 is connected to the reaction chamber 101, and provides RF power to the shower plate 102 through the RF matcher, and forms an electric field between the shower plate 102 and the heating plate 104. The reaction gas is ionized under the action of the electric field and reacts with the wafer to be processed, such as etching or deposition.

[0043] The heating plate RF electrode 103 is disposed in a supporting seat of the heating plate.

[0044] The impedance adjuster 106 is used to fine-tune the RF power coupled into the plasma, that is, the RF power passing through the heating plate and the side wall of the chamber can be proportionally adjusted.

[0045] The impedance adjuster 106 is located below the reaction chamber 101 and connected to the heating plate RF electrode 103 .

[0046] The impedance adjuster and semiconductor processing equipment provided by the present invention can proportionally distribute the radio frequency power at the center and edge of the wafer by adjusting the low-frequency impedance, thereby achieving more uniform plasma density and energy, thereby improving the performance of the thin film.

[0047] Figure 2 FIG. 2 shows a chamber loop equivalent circuit according to an embodiment of the present invention. The chamber loop equivalent circuit is Figure 1The chamber structure and the impedance adjuster below form an equivalent circuit of the RF loop. The chamber loop equivalent circuit includes the plasma and its sheath equivalent circuit, the impedance adjuster circuit and the chamber side wall circuit. Among them, "to the side wall" means that the RF current flows through the side wall to form a loop. "To the heating plate" means that the RF current flows through the lower heating plate to form a loop.

[0048] Figure 3 An impedance adjuster according to an embodiment of the present invention is shown. The impedance adjuster is located below the reaction chamber and connected to the RF electrode of the heating plate. The impedance adjuster includes a high-frequency path 306 and a low-frequency path 305 .

[0049] In dual-frequency PECVD applications, low-frequency power has a great impact on process results, while in the prior art, the impedance adjuster only adjusts the high-frequency RF power. The present invention achieves separate control of plasma flux and energy by adding a low-frequency path 305.

[0050] In one embodiment, the high-frequency path 306 and the low-frequency path 305 are independent of each other and do not affect each other.

[0051] The high frequency path 306 includes a low frequency filter unit 302 and a high frequency impedance adjustment unit 304. The low frequency filter unit 302 and the high frequency impedance adjustment unit 304 are connected in series.

[0052] In one embodiment, one end of the low frequency filter unit 302 is connected to the RF electrode of the heating plate, and the other end is connected to one end of the high frequency impedance adjustment unit 304. The other end of the high frequency impedance adjustment unit 304 is grounded.

[0053] The low frequency filter unit 302 is used to filter the low frequency to prevent the low frequency from entering the high frequency path.

[0054] The high-frequency impedance adjustment unit 304 is used for high-frequency impedance adjustment.

[0055] The low frequency path 305 includes a high frequency filter unit 301 and a low frequency impedance adjustment unit 303. The high frequency filter unit 301 and the low frequency impedance adjustment unit 303 are connected in series.

[0056] In one embodiment, one end of the high frequency filter unit 301 is connected to the RF electrode of the heating plate, and the other end is connected to one end of the low frequency impedance adjustment unit 303. The other end of the low frequency impedance adjustment unit 303 is grounded.

[0057] The high frequency filtering unit 301 is used to filter high frequencies to prevent high frequencies from entering the low frequency path.

[0058] The low-frequency impedance adjustment unit 303 is used for adjusting the low-frequency impedance.

[0059] The high and low frequency filter circuits can be connected in parallel with resonance or other circuits that meet the isolation requirements.

[0060] The high frequency impedance adjustment circuit 304 and the low frequency impedance adjustment circuit 303 can be adjusted independently of each other.

[0061] In one embodiment, the high frequency filtering unit 301 includes an LC filtering circuit.

[0062] In one embodiment, the low frequency filtering unit 302 includes an LC filtering circuit.

[0063] In one embodiment, the high frequency impedance adjustment unit 304 includes an adjustable inductor.

[0064] In one embodiment, the high frequency impedance adjustment circuit 304 includes an adjustable capacitor.

[0065] In one embodiment, the high frequency impedance adjustment circuit 304 includes a capacitor and an inductor connected in parallel, wherein the capacitor and / or the inductor is adjustable.

[0066] In one embodiment, the low frequency impedance adjustment unit 303 includes an adjustable inductor.

[0067] In one embodiment, the low frequency impedance adjustment circuit 303 includes an adjustable capacitor.

[0068] In one embodiment, the low-frequency impedance adjustment circuit 303 includes a capacitor and an inductor connected in parallel, wherein the capacitor and / or the inductor is adjustable.

[0069] Figure 4 The schematic diagram of a semiconductor processing device according to an embodiment of the present invention is shown, which includes but is not limited to a reaction chamber 101 , a shower plate 102 , a heating plate 104 , a radio frequency power supply 105 , a heating plate radio frequency electrode 103 and an impedance adjuster 106 .

[0070] The reaction chamber 101 is a sealed chamber that can provide a stable process environment for the substrate to be processed.

[0071] The shower plate 102 is located inside the reaction chamber 101 and is used to provide reaction gas to the substrate to be processed. During the operation of the equipment, the reaction gas is sprayed on the substrate to be processed through the shower plate 102, so that it reacts chemically with the substances on the surface of the substrate to be processed, thereby achieving the purpose of process treatment. The design of the shower plate 102 also takes into account the flow and distribution of the gas to ensure that the gas can evenly cover the entire surface of the substrate to be processed.

[0072] The heating plate 104 is located below the shower plate 102, supporting the substrate to be processed and providing a suitable heating environment for the substrate to be processed, so that the substrate to be processed reaches the temperature required by the process. This heating method can achieve efficient and uniform heat distribution and ensure the thermal stability and reliability of the substrate to be processed.

[0073] In order to enhance the efficiency and stability of the process, the semiconductor processing equipment further includes a radio frequency power supply 105 and a heating plate radio frequency electrode 103 .

[0074] The RF power supply 105 provides RF power to the shower plate 102 through a RF matcher, and forms an electric field between the shower plate 102 and the heating plate 104. The reaction gas is ionized under the action of the electric field and reacts with the wafer to be processed, such as etching or deposition.

[0075] The impedance adjuster 106 is located below the reaction chamber 101 and connected to the heating plate RF electrode 103 .

[0076] The impedance adjuster 106 is used to fine-tune the RF power coupled into the plasma, that is, the RF power passing through the heating plate and the side wall of the chamber can be proportionally adjusted.

[0077] The impedance adjuster 106 includes a high frequency path 306 and a low frequency path 305 .

[0078] In one embodiment, the high-frequency path 306 and the low-frequency path 305 are independent of each other and do not affect each other.

[0079] The high frequency path 306 includes a low frequency filter unit 302 and a high frequency impedance adjustment unit 304. The low frequency filter unit 302 and the high frequency impedance adjustment unit 304 are connected in series.

[0080] In one embodiment, one end of the low-frequency filter unit 302 is connected to the RF electrode of the heating plate, and the other end is connected to one end of the high-frequency impedance adjustment unit 304 .

[0081] The low frequency filter unit 302 is used to filter the low frequency to prevent the low frequency from entering the high frequency path.

[0082] The high-frequency impedance adjustment unit 304 is used for high-frequency impedance adjustment.

[0083] The low frequency path 305 includes a high frequency filter unit 301 and a low frequency impedance adjustment unit 303. The high frequency filter unit 301 and the low frequency impedance adjustment unit 303 are connected in series.

[0084] In one embodiment, one end of the high frequency filtering unit 301 is connected to the RF electrode of the heating plate, and the other end is connected to one end of the low frequency impedance adjusting unit 303 .

[0085] The high frequency filtering unit 301 is used to filter high frequencies to prevent high frequencies from entering the low frequency path.

[0086] The low-frequency impedance adjustment unit 303 is used for adjusting the low-frequency impedance.

[0087] The high and low frequency filter circuits can be connected in parallel with resonance or other circuits that meet the isolation requirements.

[0088] The high frequency impedance adjustment circuit 304 and the low frequency impedance adjustment circuit 303 can be adjusted independently of each other.

[0089] In one embodiment, the high frequency filtering unit 301 includes an LC filtering circuit.

[0090] In one embodiment, the low frequency filtering unit 302 includes an LC filtering circuit.

[0091] In one embodiment, the high frequency impedance adjustment unit 304 includes an adjustable inductor.

[0092] In one embodiment, the high frequency impedance adjustment circuit 304 includes an adjustable capacitor.

[0093] In one embodiment, the high frequency impedance adjustment circuit 304 includes a capacitor and an inductor connected in parallel, wherein the capacitor and / or the inductor is adjustable.

[0094] In one embodiment, the low frequency impedance adjustment unit 303 includes an adjustable inductor.

[0095] In one embodiment, the low frequency impedance adjustment circuit 303 includes an adjustable capacitor.

[0096] In one embodiment, the low-frequency impedance adjustment circuit 303 includes a capacitor and an inductor connected in parallel, wherein the capacitor and / or the inductor is adjustable.

[0097] Figure 5 FIG. 4 shows a film thickness distribution diagram according to an embodiment of the present invention. Figure 5 As shown, by adjusting the low-frequency impedance, the RF power at the center and edge of the wafer can be proportionally distributed to achieve a more uniform plasma density and energy, thereby improving the film performance.

[0098] The terms and expressions used above are for descriptive purposes only, and the present invention should not be limited to these terms and expressions. The use of these terms and expressions does not mean to exclude any equivalent features of the illustrations and descriptions (or parts thereof), and it should be recognized that various modifications that may exist should also be included in the scope of the claims. Other modifications, changes and substitutions may also exist. Accordingly, the claims should be deemed to cover all such equivalents.

[0099] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus facilitate the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of this application, multiple features are sometimes combined into one embodiment, drawing or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims.

[0100] Similarly, it should be pointed out that although the present invention has been described with reference to the current specific embodiments, ordinary technicians in this technical field should realize that the above embodiments are only used to illustrate the present invention, and various equivalent changes or substitutions may be made without departing from the spirit of the present invention. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present invention, they will fall within the scope of the claims of this application.

Claims

1. An impedance adjuster for adjusting radio frequency power, characterized in that: The impedance adjuster is connected to the radio frequency electrode of the heating plate, and the impedance adjuster comprises: Independent high-frequency and low-frequency pathways; The low-frequency path includes a high-frequency filter unit and a low-frequency impedance adjustment unit, wherein one end of the high-frequency filter unit is connected to the RF electrode of the heating plate, and the other end is connected to the low-frequency impedance adjustment unit; The high-frequency path includes a low-frequency filter unit and a high-frequency impedance adjustment unit, wherein one end of the low-frequency filter unit is connected to the RF electrode of the heating plate, and the other end is connected to the high-frequency impedance adjustment unit; The low-frequency impedance adjustment unit and the high-frequency impedance adjustment unit are adjusted independently of each other.

2. The impedance adjuster for adjusting radio frequency power according to claim 1, characterized in that: The high frequency filtering unit prevents high frequency from entering into a low frequency path, and the high frequency filtering unit includes an LC filtering circuit.

3. The impedance adjuster for adjusting radio frequency power according to claim 1, characterized in that: The low-frequency filtering unit prevents low frequencies from entering into high-frequency paths, and the low-frequency filtering unit includes an LC filtering circuit.

4. The impedance adjuster for adjusting radio frequency power according to claim 1, characterized in that: The low-frequency impedance adjustment unit includes an adjustable capacitor.

5. The impedance adjuster for adjusting radio frequency power according to claim 1, characterized in that: The low-frequency impedance adjustment unit includes an adjustable inductor.

6. The impedance adjuster for adjusting radio frequency power according to claim 1, characterized in that: The low-frequency impedance adjustment unit includes a capacitor and an inductor connected in parallel, wherein the capacitor and / or the inductor is adjustable.

7. The impedance adjuster for adjusting radio frequency power according to claim 1, characterized in that: The high-frequency impedance adjustment unit includes an adjustable capacitor.

8. The impedance adjuster for adjusting radio frequency power according to claim 1, characterized in that: The high-frequency impedance adjustment unit includes an adjustable inductor.

9. The impedance adjuster for adjusting radio frequency power according to claim 1, characterized in that: The high-frequency impedance adjustment unit includes a capacitor and an inductor connected in parallel, wherein the capacitor and / or the inductor is adjustable.

10. A semiconductor processing device, characterized in that: include: A reaction chamber, a shower plate, a heating plate, a radio frequency power supply, a radio frequency electrode of the heating plate, and an impedance adjuster as claimed in any one of claims 1 to 9; The shower plate is located inside the reaction chamber and provides reaction gas to the substrate to be processed; The heating plate is located below the spray plate, supporting and heating the substrate to be processed; The RF power source is connected to the reaction chamber, and provides RF power to the shower plate through a RF matcher, and forms an electric field between the shower plate and the heating disk; The radio frequency electrode of the heating plate is located in the support seat of the heating plate; The impedance adjuster is located below the reaction chamber and connected to the radio frequency electrode of the heating plate.

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