TW202025198A - Rf system used for multiple plasma processing chambers - Google Patents

Abstract

An RF system used for multiple plasma processing chambers includes plural adjustable matching units electrically coupled to a matching network to generate an RF signals adaptive for plasma treatment. Each of the adjustable matching units includes a first variable electronic component and a second variable electronic component. The first variable electronic component has an output coupling to the matching network and an input coupling to an electrode of a processing chamber, and the second variable electronic component, with a terminal, connects to the output of the first variable electronic component while with another terminal connects to the chamber, matching network or ground.

Description

Radio frequency system for multiple plasma processing chambers

The present invention relates to a radio frequency system used in a plasma processing chamber in semiconductor processing equipment, wherein the radio frequency system is connected to a plurality of plasma processing chambers.

The plasma processing equipment used for wafer processing includes a radio frequency (RF) control circuit. The radio frequency control circuit is configured to provide radio frequency signals and transmit them to electrodes in the plasma processing equipment, thereby generating an electric field in a processing area in a processing chamber. The reactive gas is ionized by the application of an electric field and reacts with the wafer to be processed, such as etching or deposition. Generally speaking, the RF control circuit includes an RF signal generator and an impedance matching circuit, where the impedance matching circuit has a resistance element, a capacitance element, an inductance element, or a combination of these. The impedance matching circuit is appropriately configured to match the impedance of the RF signal source with the impedance of the load. The impedance matching circuit receives the RF signal from the RF signal generator and modulates the circuit to become the RF signal supplied to the plasma processing equipment.

In order to increase the production volume, the number of processing chambers in the semiconductor processing equipment has also increased in response to demand, thereby increasing the load and efficiency. For a multi-chamber plasma processing device that shares a single radio frequency power supply and a matching network, usually due to differences in the components of different chambers and differences in assembly, the impedances of these chambers are inconsistent. In this regard, although sharing a single RF power supply and matching circuit can maintain the consistency of the signal, it may not be possible to generate a consistent electric field, current or power in multiple chambers due to the difference in impedance, resulting in a plasma treatment process ( Deposition or etching), such as inconsistent film deposition rates.

Therefore, it is necessary to develop a radio frequency system suitable for the multi-chamber plasma processing apparatus with the above-mentioned conditions.

The object of the present invention is to provide a radio frequency system for multiple plasma processing chambers, including: a radio frequency power supply, which generates one or more radio frequency signals; a matching network, which is electrically coupled to the radio frequency power supply to receive and process the one or A plurality of radio frequency signals; and a plurality of matching adjustment units, which are electrically coupled with the matching network to receive and adjust the processed radio frequency signals. Each of the plurality of matching adjustment units includes a first variable electronic element and a second variable electronic element, wherein the first variable electronic element is connected to an output end of the matching network and connected to a processing chamber An input end of an electrode, one end of the second variable electronic element is electrically connected to the first variable electronic element, and the other end is connected to the cavity, the matching network or the ground.

In a specific embodiment, the other end of the second variable electronic element is grounded.

In a specific embodiment, the other end of the second variable electronic component is electrically connected to the output terminal of the first variable electronic component.

In a specific embodiment, the first variable electronic component is a first variable capacitor, and the second variable electronic component is a second variable capacitor.

In a specific embodiment, the first variable electronic component is a variable capacitor, and the second variable electronic component is a variable inductor.

In a specific embodiment, the capacitance value of the first variable capacitor or the second variable capacitor is in the range of 50 pF to 5 nF.

In a specific embodiment, each of the plurality of matching adjustment units further has a plurality of switches to respectively connect and control the conduction of the variable capacitor and the variable inductor.

In a specific embodiment, the values of the first and second variable electronic elements of any one of the plurality of matching adjustment units are different from the other of the plurality of matching adjustment units, thereby maintaining the multiple plasma The power in the processing chamber is consistent.

In the following detailed descriptions of several exemplary embodiments, reference is made to the accompanying drawings, which form a part of the present invention. And it is shown by way of example, by which the described specific embodiments can be implemented. Sufficient details are provided to enable those skilled in the art to implement the specific embodiments, and it should be understood that other specific embodiments can be used and other changes can be made without departing from the spirit or scope thereof. In addition, although this may be the case, the reference to "a specific embodiment" does not necessarily belong to the same or singular specific embodiment. Therefore, the following detailed description does not have a limiting idea, and the scope of the specific embodiments of the description is only defined by the scope of the additional patent applications.

In the overall application and the scope of the patent application, unless otherwise clearly stated in the context, the following terminology has the meaning clearly associated with this. When used here, unless expressly stated otherwise, the term "or" is an inclusive usage of "or" and is equivalent to the term "and/or". Unless clearly stated otherwise in the context, the term "based" is not exclusive and allows the basis for most other factors that are not stated. In addition, in the overall application, the meanings of "one", "one" and "the" include plural references. The meaning of "in" includes "in" and "on".

The following is a brief summary of these innovative themes to provide a basic understanding of some aspects. This short description is not expected to be a complete overview. This short description is not expected to be used to identify main or key elements, or to describe or limit the scope. Its purpose is only to present certain concepts in a brief form as a prelude to the more detailed description that will be presented later.

The first figure shows the plasma multi-processing chamber of the present invention and a common radio frequency system. The number of chambers shown here is three, but in other embodiments, more or less numbers are also feasible. The plasma processing chamber (100, only referred to as processing chamber below) is a space where plasma processing takes place on wafers or substrates. It usually includes a wafer support seat, a spray element, an exhaust channel and an electrode element. The electrode element includes the upper electrode (101) And the lower electrode (102). The upper electrode (101) is usually arranged on a certain layer of the shower element, and the lower electrode (102) is arranged on a certain layer of the wafer support base. According to the configuration of the radio frequency signal source, the upper electrode (101) can be the radio frequency transmitting end and the lower electrode (102) can be grounded. In other embodiments, the two are opposite.

The radio frequency system for plasma processing of the present invention includes a radio frequency power supply (300), a matching network (400), and a plurality of matching adjustment units (200). The radio frequency power supply (300) or RF signal generator is configured to generate one or more radio frequency signals. In some embodiments, the radio frequency power supply (300) may include one or more radio frequency generating units and have different or the same operating frequencies. In the known technology, the RF power supply (300) can be implemented by at least one low-frequency RF signal generating unit and at least one high-frequency RF signal generating unit.

The matching network (400) is electrically coupled to the radio frequency power supply (300) to receive the aforementioned one or more radio frequency signals. The matching network (400) is used to match the impedance of all processing chambers, so that the energy provided by the radio frequency power supply (300) is effectively transmitted to each processing chamber. Specifically, the matching network (400) is configured to achieve impedance matching between the radio frequency power supply (300) and the load end (each component of the processing chamber). The matching network (400) includes an impedance matching circuit. In the known technology, the impedance matching can be achieved by controlling the reactance of the impedance matching circuit by a control means. The matching network (400) receives the one or more radio frequency signals and processes them into radio frequency signals suitable for plasma processing and outputs them through a plurality of radio frequency connection components (500). The radio frequency connection component (500) can be conductive material such as copper tape or coaxial cable.

The matching adjustment unit (200) receives and adjusts the radio frequency signal output from the matching network (400), and transmits the adjusted radio frequency signal to the upper electrode (101) of each plasma processing chamber. These matching adjustment units (200) further match the impedance of each processing cavity (100), so that the radio frequency energy output by the matching network (400) can be transmitted to each processing cavity (100) as expected.

The second diagram A and the second diagram B respectively show the circuit configuration of the matching adjustment unit (200) of the present invention. The matching adjustment unit (200) has an output terminal (201) electrically coupled to the matching network (400) and an input terminal (202) electrically coupled to the upper electrode (101). The matching adjustment unit (200) has a first variable electronic component (210) and a second variable electronic component (220), wherein the first variable electronic component (210) is electrically connected to the matching network (400) Between the output terminal (201) and the input terminal (202) of the electrode, the arrangement of the second variable electronic component (220) may have some changes. The second variable electronic element (220) of the second figure A is electrically connected to the input end (202) of the electrode with one end and grounded with the other end. The second variable electronic component (220) in the second figure B is electrically connected to the output terminal (201) of the matching network and the input terminal (202) of the electrode, which means that the first variable electronic component (210) and the second The variable electronic components (220) are connected in parallel. Based on the foregoing configuration, by adjusting the combination and characteristics of the first variable electronic component (210) and the second variable electronic component (220), the overall impedance of the corresponding processing chamber (100) can be changed, so that the radio frequency power supply (300) ) The provided RF energy is evenly distributed to each processing chamber (100).

The third figure shows a specific embodiment arranged according to the second A figure, in which the first variable electronic component (210) is a first variable capacitor, and the second variable electronic component (220) is a second variable capacitance. The capacitance value of the first variable capacitor or the second variable capacitor is in the range of 50 pF to 5 nF. The fourth figure shows a specific embodiment arranged according to the second figure B, in which the first variable electronic component (210) is a variable capacitor, and the second variable electronic component (220) is a variable inductor. In addition, the matching adjustment unit (200) also has a plurality of switches (S), which are respectively electrically connected to the output terminal (201) of the matching network and the variable capacitor and the output terminal (201) and variable inductance of the matching network. Between, used to selectively control the conduction of the variable capacitor and the variable inductor. The purpose of the switch (S) is to switch under the treatment of different plasma recipes to selectively apply the first variable electronic component (210) and/or the second variable electronic component (220). Thereby, each matching adjustment unit (200) can adjust the impedance between the radio frequency input terminal and the ground terminal of each processing cavity (100), and can also adjust the power distribution of these processing cavity (100).

Accordingly, the simultaneous process of multiple plasma processing chambers can have the same standard and quality. For example, if the previously disclosed method is used for the thin film deposition process, once the deposition rate of one of these plasma processing chambers is found to be too fast or lagging behind the others through real-time measurement, the first variable capacitance and the second variable capacitance of the third figure can be adjusted. The value of the capacitance makes the deposition speed of the processing chamber consistent with the speed of others.

In summary, although the RF system for multiple plasma processing chambers provided by the present invention initially generates a consistent RF signal, the dedicated matching adjustment unit (circuit) of these processing chambers is based on the actual conditions of each processing chamber. The impedance is appropriately matched to modulate a consistent radio frequency signal for processing in the processing chamber, which overcomes the inconsistency of radio frequency signal energy in conventional equipment.

The above content provides a complete description of the manufacture and use of the combination of the described specific embodiments. Because many specific embodiments can be produced without departing from the spirit and scope of this description, these specific embodiments will exist in the scope of these patent applications appended below.

100: Plasma processing chamber 00: RF power supply 101: Upper electrode 400: Matching network 102: Lower electrode 500: RF connecting part 200: Matching adjustment unit S: Switch 201: Input end of the matching adjustment unit; Output end of the matching network 210: the first variable electronic component 202: the output terminal of the matching adjustment unit; the input terminal of the electrode 220: the second variable electronic component

The foregoing and other features and advantages of the present invention will be more clearly understood with reference to the following description and drawings of the embodiments.

The first figure is a schematic diagram of multiple plasma processing chambers and radio frequency systems of the present invention.

The second diagram A and the second diagram B respectively show schematic diagrams of different embodiments of the matching adjustment unit of the present invention.

The third figure shows a schematic diagram of a specific embodiment of the matching adjustment unit of the present invention.

The fourth figure shows a schematic diagram of another specific embodiment of the matching adjustment unit of the present invention.

100: Plasma processing chamber

101: Upper electrode

102: Lower electrode

200: matching adjustment unit

300: RF power supply

400: matching network

500: RF connection parts

Claims (7)

A radio frequency system for multiple plasma processing chambers includes: a radio frequency power supply, which generates one or more radio frequency signals; a matching network, which is electrically coupled to the radio frequency power supply to receive and process the one or more radio frequency signals; And a plurality of matching adjustment units electrically coupled to the matching network to receive and adjust the processed one or more radio frequency signals, characterized in that: each of the plurality of matching adjustment units includes a first variable electronic Component and a second variable electronic component, wherein the first variable electronic component is connected to an output terminal of the matching network and connected to an input terminal of an electrode in a processing chamber, and one end of the second variable electronic component It is electrically connected to the first variable electronic element. The radio frequency system described in the first item of the scope of patent application, wherein the other end of the second variable electronic component is connected to the cavity, the matching network or the ground. According to the radio frequency system described in claim 2, wherein the first variable electronic element is a first variable capacitor, and the second variable electronic element is a second variable capacitor. According to the radio frequency system described in claim 2, wherein the first variable electronic component is a variable capacitor, and the second variable electronic component is a variable inductor. The radio frequency system described in item 2 of the scope of the patent application, wherein the capacitance value of the first variable capacitor or the second variable capacitor is in the range of 50pF to 5nF. For the radio frequency system described in item 4 of the scope of the patent application, each of the plurality of matching adjustment units further has a plurality of switches to respectively connect and control the conduction of the variable capacitor and the variable inductor. The radio frequency system as described in item 1 of the scope of patent application, wherein the values of the first and second variable electronic components of any one of the plurality of matching adjustment units are different from the other of the plurality of matching adjustment units, This keeps the power in the multiple plasma processing chambers consistent.

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