Semiconductor processing equipment

Abstract

The utility model provides semiconductor processing equipment, which comprises an electrostatic chuck, a radio frequency power source, a direct current power supply and a radio frequency filter, a direct-current electrode is arranged in the electrostatic chuck, the direct-current electrode is electrically connected with the radio-frequency power source and the direct-current power source, a radio-frequency filter is connected between the direct-current electrode and the direct-current power source in series, and the radio-frequency filter comprises a first end and a second end; a quarter-wavelength transmission line equivalent circuit is arranged between the first end and the second end; the quarter-wavelength transmission line equivalent circuit comprises an inductance element, a first capacitor and a second capacitor. The radio frequency filter not only can prevent radio frequency signals coupled to the direct current electrode from damaging the direct current power supply, but also can filter odd harmonic components of electrode radio frequency power generated by a plasma nonlinear system.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor equipment technology, and in particular to a semiconductor processing equipment. Background Technology

[0002] In the semiconductor device manufacturing process, the substrate base is usually made of electrostatic chuck. The electrostatic attraction generated by the electrostatic chuck can attract the substrate placed on it, so as to support the semiconductor substrate during processes such as deposition and etching.

[0003] The electrostatic chuck has a built-in DC electrode, which is electrically connected to a DC power supply. The DC power supply provides a DC bias voltage to the DC electrode, causing the electrostatic chuck to generate electrostatic attraction for adsorbing the substrate. Furthermore, since substrate deposition and etching processes need to be performed in a plasma environment, the DC electrode of the electrostatic chuck is also electrically connected to an RF power source to excite and form plasma. Because both the DC power supply and the RF power source are electrically connected to the DC electrode, an RF filter is typically connected in series at the output of the DC power supply to prevent damage from the RF signal coupled to the DC electrode. This filter filters the RF signal returning from the RF power source to the DC power supply. Moreover, since plasma is a nonlinear system, the RF power coupled from the DC electrode to the plasma will generate odd harmonic components, which can also couple to the DC power supply and cause damage. Existing RF filters are insufficient to filter out these odd harmonic components. Utility Model Content

[0004] The purpose of this invention is to provide a semiconductor processing apparatus having a radio frequency (RF) filter. This RF filter can not only prevent the RF signal coupled to the DC electrode from damaging the DC power supply, but also filter out the odd harmonic components of the DC electrode RF power generated by the plasma nonlinear system.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a semiconductor processing device, comprising an electrostatic chuck, an RF power source, a DC power supply, and an RF filter; the electrostatic chuck has a built-in DC electrode, which is electrically connected to the RF power source and the DC power supply respectively; an RF filter is connected in series between the DC electrode and the DC power supply, the RF filter comprising: a first end and a second end; a quarter-wavelength transmission line equivalent circuit is provided between the first end and the second end; the quarter-wavelength transmission line equivalent circuit includes an inductor, a first capacitor, and a second capacitor; one end of the inductor is electrically connected to the first end, and the other end of the inductor is electrically connected to the second end; one end of the first capacitor is electrically connected to one end of the inductor, and the other end of the first capacitor is grounded; one end of the second capacitor is electrically connected to the other end of the inductor, and the other end of the second capacitor is grounded.

[0006] Preferably, the inductor element satisfies the following relationship:

[0007]

[0008] Where L is the inductance; Z0 is the characteristic impedance; and f is the radio frequency of the radio frequency power source.

[0009] Preferably, the first capacitor and the second capacitor are the same, and the first capacitor and the second capacitor satisfy the following relationship:

[0010]

[0011] Where C is the capacitor; L is the inductor; and f is the radio frequency of the radio frequency power source.

[0012] Preferably, the inductor is one of the following: enameled wire air core inductor, enameled wire magnetic core inductor, PCB planar inductor, and PCB magnetic core inductor.

[0013] Preferably, the number of the inductor element is one.

[0014] Preferably, the first capacitor and the second capacitor are ceramic radio frequency capacitors.

[0015] Preferably, the first capacitor is formed by connecting multiple capacitors in parallel; the second capacitor is formed by connecting multiple capacitors in parallel.

[0016] Preferably, a protective resistor is connected in series between the first end and the equivalent circuit of the quarter-wavelength transmission line.

[0017] Preferably, the range of the protective resistor is 1MΩ to 5MΩ.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. This utility model uses a quarter-wavelength transmission line equivalent circuit for filtering, which can not only prevent the radio frequency signal coupled to the DC electrode from damaging the DC power supply, but also filter out the odd harmonic components of the DC electrode radio frequency power generated by the plasma nonlinear system.

[0020] 2. This utility model uses a lumped element equivalent to a quarter-wavelength transmission line, which significantly reduces the size of the filter and optimizes the filter structure.

[0021] 3. In this invention, a high-resistance resistor is connected in series between the electrostatic chuck and the equivalent circuit of the quarter-wavelength transmission line. If the equivalent circuit of the quarter-wavelength transmission line fails, it can protect the DC power supply. Attached Figure Description

[0022] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings in the following description are one embodiment of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0023] Figure 1 This is a connection diagram of an electrostatic chuck with an RF filter.

[0024] Figure 2 A circuit diagram of a quarter-wavelength transmission line for the radio frequency filter provided by this utility model. Detailed Implementation

[0025] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the proposed solution of this utility model. The advantages and features of this utility model will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, intended only to facilitate and clearly illustrate the embodiments of this utility model. Please refer to the drawings to make the objectives, features, and advantages of this utility model more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this utility model, should still fall within the scope of the technical content disclosed in this utility model.

[0026] This utility model provides a semiconductor processing equipment, which can be a semiconductor etching equipment, a semiconductor deposition equipment, etc. Taking a semiconductor etching equipment as an example, such as... Figure 1As shown, the system includes a cavity 170, within which a substrate base is provided. An electrostatic chuck 160 is mounted on the substrate base, and a DC electrode 190 is embedded within the electrostatic chuck. An RF power source 140 is electrically connected to the DC electrode 190 via a matching adapter 150 to excite and form plasma. A DC power supply 130 is electrically connected to the DC electrode 190 to provide a certain DC bias voltage to the DC electrode, causing the ESC to generate electrostatic attraction to adsorb the substrate. Furthermore, an RF filter 120 is connected in series between the DC power supply 130 and the DC electrode 190 to prevent RF signals coupled to the DC electrode from damaging the DC power supply 130. Further, the cavity 170 also includes an upper electrode RF power supply 100, which is electrically connected to an upper electrode coupling coil 180 via an upper electrode matching adapter 110. The upper electrode coupling coil 180 includes an inner coil and an outer coil, which couples RF energy to the process gas inside the cavity, facilitating plasma formation within the cavity.

[0027] This utility model provides a radio frequency filter, including a first end and a second end; a quarter-wavelength transmission line equivalent circuit is provided between the first end and the second end; the quarter-wavelength transmission line equivalent circuit includes an inductor, a first capacitor and a second capacitor; one end of the inductor is electrically connected to the first end, and the other end of the inductor is electrically connected to the second end; one end of the first capacitor is electrically connected to one end of the inductor, and the other end of the first capacitor is grounded; one end of the second capacitor is electrically connected to the other end of the inductor, and the other end of the second capacitor is grounded.

[0028] like Figure 2As shown, the first end 202 of the RF filter is electrically connected to the DC electrode 190 of the electrostatic chuck, and the second end 201 of the RF filter is electrically connected to the DC power supply 130. A quarter-wavelength transmission line equivalent circuit is provided between the first end 202 and the second end 201. The quarter-wavelength transmission line equivalent circuit includes an inductor L1 122, a first capacitor C1 124, and a second capacitor C2 123. One end of the inductor L1 122 is electrically connected to the first end 202, and the other end of the inductor L1 122 is electrically connected to the second end 201. One end of the first capacitor C1 124 is electrically connected to one end of the inductor L1 122, and the other end of the first capacitor C1 124 is grounded; one end of the second capacitor C2 123 is electrically connected to the other end of the inductor L1 122, and the other end of the second capacitor C2 123 is grounded. In the equivalent circuit of a quarter-wavelength transmission line, for the RF power output from the RF power source 140 at the DC electrode 190, node 201 is a short circuit point and node 203 is an open circuit point, thus preventing the RF power from coupling to the DC power supply 130. Similarly, since plasma is a nonlinear system, for the odd harmonics it generates, node 201 is a short circuit point and node 203 is an open circuit point, also preventing the odd harmonics from coupling to the DC power supply 130 and causing damage to it.

[0029] The equivalent circuit of the quarter-wavelength transmission line consists of an inductor L1 122, a first capacitor C1 124, and a second capacitor C2 123, wherein the first and second capacitors are identical. The values ​​of the inductor, the first capacitor, and the second capacitor are determined by the frequency to be filtered out, and the specific principle is as follows:

[0030] The ABCD matrix of the transmission line is as follows:

[0031]

[0032] The ABCD matrix of the circuit consisting of the first capacitor, the inductor, and the second capacitor is as follows:

[0033]

[0034] When the circuit consisting of a first capacitor, an inductor, and a second capacitor is used as an equivalent quarter-wavelength transmission line, the following equation is satisfied:

[0035]

[0036] Where Z = j2πfL, Y = 1 / (j2πfC); Z0 is the characteristic impedance; f is the filtering frequency; βl is the electrical length of the transmission line, then the electrical length of the quarter-wavelength transmission line is...

[0037] Therefore, the inductive element satisfies the following relationship:

[0038]

[0039] The first capacitor and the second capacitor satisfy the following relationship:

[0040]

[0041] Furthermore, the inductor is one of the following: enameled wire air-core inductor, enameled wire magnetic core inductor, PCB planar inductor, and PCB magnetic core inductor. There is no restriction on the type of inductor, but the number of inductors is limited to one. On the one hand, multiple inductors connected in series cause the magnetic lines of force generated by adjacent inductors to influence each other, forming coupling capacitance and affecting the filtering effect of the filter. On the other hand, increasing the number of inductors significantly increases the size of the filter, which is not conducive to compressing the overall circuit size.

[0042] Furthermore, both the first and second capacitors are high-voltage ceramic radio frequency capacitors. The first capacitor can be formed by connecting multiple capacitors in parallel, which improves the overcurrent capacity and extends the capacitor's lifespan. The multiple capacitors can be identical capacitors, and the total capacitance of the parallel capacitors must be equal to the capacitance of the first capacitor C1 124; similarly, the second capacitor can also be formed by connecting multiple capacitors in parallel.

[0043] Furthermore, a protection resistor 121 is connected in series between the first terminal 201 and the equivalent circuit of the quarter-wavelength transmission line. The protection resistor is a high-resistance power resistor, with a range of 1MΩ-5MΩ. When the equivalent circuit of the quarter-wavelength transmission line fails, the power of the RF power source will pass through the protection resistor 121, causing the protection resistor 121 to burn out and open, thereby protecting the DC power supply from being burned out by the high-power RF signal.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, the term "connection" in this document indicates a direct connection between A and B, or an indirect connection between A and B, such as an indirect connection between A and B via C, or even via C and D, or more components. The connection between A and B can be integral or separate, detachable or fixed. The term "optional" in this document indicates that the technical feature can be combined with or not combined with any feature in the document.

[0045] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above content. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A semiconductor processing apparatus, characterized in that, It includes an electrostatic chuck, an RF power source, a DC power supply, and an RF filter; the electrostatic chuck has a built-in DC electrode, which is electrically connected to the RF power source and the DC power supply respectively. A radio frequency filter is connected in series between the DC electrode and the DC power supply. The radio frequency filter includes: A first end and a second end; a quarter-wavelength transmission line equivalent circuit is provided between the first end and the second end; The equivalent circuit of the quarter-wavelength transmission line includes an inductor, a first capacitor, and a second capacitor. One end of the inductor is electrically connected to the first terminal, and the other end of the inductor is electrically connected to the second terminal; One end of the first capacitor is electrically connected to one end of the inductor, and the other end of the first capacitor is grounded; One end of the second capacitor is electrically connected to the other end of the inductor, and the other end of the second capacitor is grounded.

2. The semiconductor processing equipment according to claim 1, characterized in that, The inductor element satisfies the following relationship: Where L is the inductance; Z0 is the characteristic impedance; and f is the radio frequency of the radio frequency power source.

3. The semiconductor processing equipment according to claim 2, characterized in that, The first capacitor and the second capacitor are identical, and the first capacitor and the second capacitor satisfy the following relationship: Where C is the capacitor; L is the inductor; and f is the radio frequency of the radio frequency power source.

4. A semiconductor processing apparatus according to claim 2, characterized in that, The inductor is one of the following: enameled wire air core inductor, enameled wire magnetic core inductor, PCB planar inductor, and PCB magnetic core inductor.

5. A semiconductor processing apparatus according to claim 4, characterized in that, The number of inductors is 1.

6. A semiconductor processing apparatus according to claim 3, characterized in that, The first capacitor and the second capacitor are ceramic radio frequency capacitors.

7. A semiconductor processing apparatus according to claim 3, characterized in that, The first capacitor is formed by connecting multiple capacitors in parallel; the second capacitor is formed by connecting multiple capacitors in parallel.

8. A semiconductor processing apparatus according to claim 1, characterized in that, A protective resistor is connected in series between the first end and the equivalent circuit of the quarter-wavelength transmission line.

9. A semiconductor processing apparatus according to claim 8, characterized in that, The range of the protective resistor is 1MΩ to 5MΩ.

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