TWI474395B - A plasma processing device - Google Patents

Description

Plasma processing device

The present invention relates to the field of semiconductor technology, and more particularly to a plasma processing apparatus.

At present, in the manufacturing process of a semiconductor device or the like, a plasma-generating plasma processing device is generally used to generate a gas plasma to react with a wafer surface to perform a corresponding process on the wafer. The process may be a plasma etching process or a plasma enhanced chemical vapor deposition process.

Please refer to the schematic diagram of the structure of the conventional plasma processing apparatus shown in FIG. The plasma processing apparatus is of a capacitive coupling type. Specifically, the plasma processing apparatus includes: a vacuum processing chamber 10 for introducing a reaction gas, and the first electrode 11 and the first electrode are disposed in parallel in the vacuum processing chamber 10. a second electrode 12, between the first electrode 11 and the second electrode 12 for placing a wafer to be processed, the first electrode 11 having a first surface and a second surface disposed opposite to each other, the first surface being close to the The wafer is processed, a plasma is generated between the first electrode 11 and the second electrode 12, the second surface is electrically connected to a radio frequency power source, and the second electrode 12 is grounded.

Taking the plasma processing apparatus applied to the etching process as an example, the radio frequency signal forms a radio frequency electric field between the first electrode 11 and the second electrode 12, and the radio frequency is between the first electrode 11 and the second electrode 12 The electrons accelerated by the electric field, the secondary electrons released from the first electrode 11 and/or the second electrode 12, and the molecules of the reaction gas are ionized and collided to generate a plasma of the reaction gas, and the radicals and ion pairs of the plasma are utilized. The surface of the wafer to be processed is etched.

Further information on conventional plasma processing apparatus can be found in U.S. Patent Application Serial No. US20100224323.

In practice, it has been found that the uniformity of the wafer after processing by a conventional plasma processing apparatus cannot meet the process requirements.

The problem to be solved by the embodiments of the present invention is to provide a plasma processing apparatus that solves the problem of wafer non-uniformity after processing by a conventional plasma processing apparatus.

In order to solve the above problems, an embodiment of the present invention provides a plasma processing apparatus including: a vacuum processing chamber; a first electrode located in the vacuum processing chamber, and a platform on which a wafer to be processed is placed is mounted above the first electrode, The first electrode is electrically connected to two RF power sources, wherein the first RF power source is greater than 1.5 times the frequency of the second RF power source; the non-dielectric material layer is located between the first electrode and the platform on which the wafer to be processed is placed, The resistivity of the layer of non-dielectric material is greater than the resistivity of the first electrode.

Optionally, the material of the non-dielectric material layer is a semiconductor material or a metal, and the semiconductor material material layer is one or a combination of ruthenium, osmium, iridium, and tantalum carbide, and the material of the first electrode is metal.

Optionally, the non-dielectric material layer is located on a surface of the first electrode, or a groove is formed in the first electrode, and the non-dielectric material layer is at least partially embedded in the groove.

Optionally, the non-dielectric material layer has a resistivity ranging from 50 ohms/cm to 106 ohms/cm.

Optionally, the platform for placing the wafer to be processed comprises: an electrostatic chuck disposed opposite to a surface of the first electrode on a side of the non-dielectric material layer, the electrostatic chuck being used for placing The shape and size of the side of the electrostatic chuck that is away from the wafer to be processed corresponds to the shape and size of the layer of non-dielectric material.

Optionally, the vacuum processing chamber is made of metal, and the vacuum processing chamber is grounded.

Optionally, the first electrode is cylindrical, the non-dielectric material layer has a circular lower surface corresponding to the first electrode, and a resistance of the non-dielectric material layer along a radius of the circular lower surface The outward direction decreases.

Optionally, the frequency of the first RF power source is greater than 40 MHz, and the frequency of the second RF power source is less than 27 MHz.

Optionally, the non-dielectric material layer is cylindrical, truncated cone, conical, stepped.

Optionally, the method further includes: a second electrode located at a position opposite to the first electrode in the vacuum processing chamber.

Optionally, the plasma processing device is a plasma etching device or a plasma enhanced chemical vapor deposition device.

Compared with the prior art, the embodiment of the invention has the following advantages: the embodiment of the invention provides a layer of non-dielectric material between the first electrode of the vacuum processing chamber and the platform on which the wafer to be processed is placed, the non-dielectric material layer The resistivity is greater than the resistivity of the first electrode; the non-dielectric material layer is capable of electrically connecting the first electrode to the first RF power source (the frequency of the first RF power source is greater than 1.5 times the frequency of the second RF power source) The non-dielectric material layer is capable of eliminating the standing wave effect caused by the high frequency signal of the first radio frequency power source, and attenuating the energy of a portion of the high frequency signal of the vacuum processing chamber at a position corresponding to the non-dielectric material layer, Thereby, the energy distribution in the vacuum processing chamber is more uniform, thereby ensuring that the density of the plasma in the vacuum processing chamber is more uniform when the first electrode is electrically connected to the first RF power source, thereby ensuring the first electrode and the first RF The etching rate of the wafer to be processed is more uniform when the power source is electrically connected; and insulation is provided between the first electrode and the platform on which the wafer to be processed is placed The non-dielectric material layer disposed between the first electrode and the platform on which the wafer to be processed is disposed does not cause the position of the vacuum processing chamber corresponding to the position of the non-dielectric material layer, as compared to the excessive attenuation of the low frequency signal. The energy of the low frequency signal is greatly attenuated, so that the density distribution of the plasma in the vacuum processing chamber is more uniform, and therefore, the etching rate when the first electrode is electrically connected to the second RF power source is more uniform.

The uniformity of the wafer after processing by a conventional plasma processing apparatus cannot meet the process requirements. According to the inventor's research, the uniformity of the processed wafer is not good due to the uneven distribution of the plasma on the wafer surface during the process, and the plasma distribution on the wafer surface is uneven due to the application of RF signals. The energy of the first electrode or the second electrode near the surface of the wafer to be processed (the energy in the vacuum processing chamber) is unevenly distributed.

Referring to FIG. 1 , a plasma processing device is applied to the plasma etching process as an example, and a radio frequency signal is applied on the second surface of the first electrode 11 , and the radio frequency signal is applied from the second surface to the outside of the first electrode 11 . The first surface transmission, when the radio frequency signal is a high frequency signal, generates a standing wave effect in the vacuum processing chamber 10; when the radio frequency signal is a low frequency signal, it is substantially not generated in the vacuum processing chamber 10. Standing wave effect.

Specifically, the high frequency signal is transmitted from the second surface to the first surface along the outside of the first electrode 11, and when the high frequency signal is transmitted to the first surface, the high frequency signal is from the outside of the first surface to the first surface The middle portion of a surface is transmitted, and therefore, in the middle of the first surface, a plurality of high frequency signals from the outside are superimposed, which makes the radio frequency signal in the middle of the first surface stronger than the external radio frequency signal. The stronger the RF signal, the higher its energy, and the higher the degree of ionization of the reactive gas at the corresponding position. Since the radio frequency signal in the middle of the first surface is stronger than the external radio frequency signal, the middle portion of the first surface provides higher ionization energy than the externally supplied ionization energy, which makes the reaction gas in the middle of the first surface highly ionized. The degree of ionization of the external reactive gas such that the density of ions in the middle of the first surface is greater than the density of ions outside the first surface, which results in an etch rate in the middle of the wafer to be processed that is greater than the etch rate outside the wafer to be processed.

In view of the above problem at a high frequency, the inventors considered that if an insulating layer is provided at a corresponding position on the first surface of the first electrode 11, the insulating layer may have a large electric resistance on the insulating layer due to a large electric resistance. The voltage drop, so that the insulating layer can consume part of the energy of the radio frequency signal in the middle portion, and can compensate for the problem that the energy of the radio frequency signal in the middle of the first surface caused by the standing wave effect is greater than the energy of the external radio frequency signal, so that the middle of the first surface The energy of the external RF signal tends to be the same, thereby improving the etching uniformity of the wafer to be processed under the high frequency signal.

However, there is substantially no standing wave problem in the middle of the first surface under the low frequency signal, that is, the central portion of the first surface is substantially identical to the external RF signal. If an insulating layer is disposed in the middle of the first surface, the insulating layer will be in the middle of the first surface. The energy is excessively consumed, so that the central energy of the first surface is significantly lower than the external energy, thereby causing a problem of uneven etching of the wafer to be etched under the low frequency signal.

In order to solve the above problems, the inventors have proposed a plasma processing apparatus, which is a schematic structural view of the plasma processing apparatus of the first embodiment of the present invention shown in FIG. The plasma processing apparatus includes: a vacuum processing chamber 100 for providing a vacuum reaction environment, and the vacuum processing chamber 100 is for introducing a reaction gas according to a plasma The process to be performed is specifically set, that is, when the plasma etching process is to be performed, the reaction gas may be an etch gas such as one of oxygen, a nitrogen-containing gas, a hydrogen-containing gas or a carbon-containing gas. Or a mixture thereof; the first electrode 101 is located in the vacuum processing chamber 100, and the first electrode 101 is electrically connected to a first RF power source (not shown), and the first electrode 101 is mounted on the top of the first electrode 101 to be processed. a platform 105 of the wafer, the first electrode 101 is electrically connected to two RF power sources, the two RF power sources include a first RF power source and a second RF power source, where the first RF power source is greater than the second RF power source frequency 1.5 times; a non-dielectric material layer 103 is located between the first electrode 101 and the platform 105 on which the wafer to be processed is placed, and the resistivity of the non-dielectric material layer 103 is greater than the resistance of the first electrode 101 The non-dielectric material layer 103 is configured to eliminate a standing wave effect formed in the vacuum processing chamber 100 when the signal of the first radio frequency power source is a high frequency signal, and the non-dielectric material layer 103 is in the When the signal of the first electrode 101 electrically connecting the second RF power source is a low frequency signal, the non-dielectric material layer does not cause attenuation of the low frequency signal.

As an embodiment, the plasma processing apparatus further includes: a second electrode 102, the second electrode 102 is disposed opposite to the first electrode 101, the second electrode 102 is grounded or connected to a third RF power source; and the second electrode 102 and the first electrode 101 constitute a parallel capacitance. The material of the first electrode 101 and the second electrode 102 is metal. Generally, a plasma is formed between the first electrode 101 and the second electrode 102.

As another embodiment, when the material of the vacuum processing chamber 100 is made of metal, the vacuum processing chamber 100 may be grounded, and the vacuum processing chamber 100 may serve as a second electrode to form a parallel capacitance with the first electrode 101.

As an embodiment, the platform 105 on which the wafer to be processed is placed includes: an electrostatic chuck disposed opposite to a surface of the first electrode 101 on the side of the non-dielectric material layer 103, where the electrostatic chuck is used to place the crystal to be processed Round, the size and shape of the electrostatic chuck away from the plasma side corresponds to the size and shape of the non-dielectric material layer 103.

The position of the non-dielectric material layer 103 corresponding to the position of the first electrode 101 means that the non-dielectric material layer 103 should be located at a position where the first electrode 101 generates a standing wave effect to utilize the non-dielectric material. Layer 103 more effectively eliminates the standing wave effect at high frequency signals and does not have excessive attenuation of the energy of the low frequency signal. In this embodiment, the first electrode 101 is a structurally symmetric cylindrical shape, and the standing wave effect occurs in the middle of the first electrode 101 toward the side of the wafer 104 to be processed. Therefore, the non-dielectric material layer 103 should be Located in the middle of the surface of the first electrode 101 near the side of the wafer 104 to be processed.

Specifically, as an embodiment of the present invention, a middle portion of a surface of the first electrode 101 adjacent to a side of the wafer 104 to be processed is formed with a groove, and the non-dielectric material layer 103 is completely embedded in the The surface of the non-dielectric material layer 103 adjacent to the side of the wafer 104 to be processed is flush with the surface of the first electrode 101 adjacent to the side of the wafer 104 to be processed. In other embodiments, the surface of the non-dielectric material layer 103 adjacent to the side of the wafer 104 to be processed may also partially exceed the surface of the first electrode 101 adjacent to the side of the wafer 104 to be processed. Thereby forming a protruding portion on the first electrode 101; or the non-dielectric material layer 103 may be completely embedded in the groove, and the non-dielectric material layer 103 is close to the side of the wafer 104 to be processed The surface is lower than the surface of the first electrode 101 near the side of the wafer 104 to be processed.

The shape and position of the electrostatic chuck of the present invention should correspond to the shape and position of the layer of non-dielectric material 103. Since the electrostatic chuck is used for placing the wafer 104 to be processed, the surface of the electrostatic chuck adjacent to the wafer 104 to be processed should be a flat surface to maintain the corresponding processing of the wafer 104 to be processed. During the process, the wafer 104 to be processed maintains a relatively stable positional relationship with the electrostatic chuck. When the surface of the non-dielectric material layer 103 close to the wafer 104 to be processed is higher than the surface of the first electrode 101 close to the wafer 104 to be processed, the electrostatic chuck is close to the non-dielectric A side of the material layer 103 (below the electrostatic chuck in the figure) should be provided with a groove corresponding to the shape of the non-dielectric material layer to accommodate a portion closer to the wafer to be processed than the first electrode 101. a portion of the non-dielectric material layer 103 on the surface of the 104 side; a surface of the non-dielectric material layer 103 adjacent to the side of the wafer 104 to be processed and the first electrode 101 adjacent to the wafer 104 to be processed When flushing with the surface of the plasma, the surface of the electrostatic chuck adjacent to the side of the non-dielectric material layer 103 should be flush with the first electrode 101 and the non-dielectric material layer 103; when the non-dielectric material layer When the surface of the side of the wafer 104 to be processed 104 is lower than the surface of the first electrode 101 near the side of the wafer 104 to be processed, the electrostatic chuck is adjacent to the non-dielectric material layer 103. One side can be set to Bumps, so as to fill the gap between the non-dielectric material layer 103 and the first electrode 101, thus contributing to maintaining the stability of the electrostatic chuck.

The material of the electrostatic chuck may be ceramic or other known materials. The electrostatic chuck should be electrically connected to the DC power source for the purpose of generating an electrostatic force on the wafer 104 to be processed to prevent the wafer 104 to be processed from being fixed; the electrostatic chuck should be provided with a cooling hole, and the cooling hole can pass through A cooling gas (for example, nitrogen or an inert gas or the like) is used for cooling the wafer 104 to be processed during the process.

The shape and size of the surface of the first electrode 101, the second electrode 102, and the surface of the electrostatic chuck adjacent to the wafer 104 to be processed are consistent with the shape and size of the wafer 104 to be processed. In this embodiment, the shape of the wafer 104 to be processed is circular, so that the shape of the surface of the first electrode 101, the second electrode 102, and the surface of the electrostatic chuck adjacent to the wafer 104 to be processed is also The size of the first electrode 101, the second electrode 102, and the surface of the electrostatic chuck adjacent to the side of the wafer 104 to be processed may be specifically set according to the size of the wafer 104 to be processed, wherein the wafer to be processed is The outer side of the 104 may be slightly larger than the shape of the electrostatic chuck (the diameters of the two may be 0.5 to 3 mm apart) to ensure that the wafer 104 to be processed completely covers the electrostatic chuck, preventing the electrostatic chuck from being damaged by the plasma.

The first electrode 101 is electrically connected to the first RF power source or the second RF power source, and the first RF power source and the second RF power source may be high frequency signals or low frequency signals. Wherein, the high frequency signal of the present invention means that the signal frequency is greater than 40 MHz, and the low frequency signal of the present invention is that the signal frequency is less than 27 MHz.

In an optional embodiment, the frequency of the first radio frequency power source is higher than the frequency of the second radio frequency power source, for example, the frequency of the first radio frequency power source is greater than 1.5 times the frequency of the second radio frequency power source. In this embodiment, the frequency of the first RF power source is greater than 40 MHz, such as 60 MHz or 100 MHz, and the second RF power frequency is less than or equal to 27 MHz, such as 13.5 Mhz or 2 Mhz. In practice, the specific value of the frequency at which the first electrode 101 is connected to the high frequency or low frequency signal and the signal connected to the first electrode 101 depends on the requirements of the etching process, and those skilled in the art can flexibly select according to the needs.

The second electrode 102 can be grounded or electrically connected to a third RF power source, and the third RF power source can be a high frequency signal or a low frequency signal.

When a high frequency signal is applied to the first electrode 101, the non-dielectric material layer 103 can eliminate the standing wave effect caused by the high frequency signal, and eliminate the energy of a part of the high frequency signal at a position corresponding to the non-dielectric material layer 103. The energy distribution in the vacuum processing chamber 100 is more uniform, so that the density of the plasma in the vacuum processing chamber 100 is more uniform, thereby maintaining the uniformity of the wafer 104 to be processed under high frequency signals; The non-dielectric material layer 103 disposed on the first electrode 101 of the embodiment of the present invention does not cause the use of the insulating layer on the first electrode to attenuate the low-frequency signal, thereby causing the low-frequency energy of the corresponding position of the insulating layer to be low. The low frequency energy attenuation corresponding to the position of the non-dielectric material layer 103 is such that the energy distribution within the vacuum processing chamber 100 is more uniform, so that the density of plasma within the vacuum processing chamber 100 is more uniform, thereby maintaining the high frequency. The uniformity of the wafer 104 after processing is processed under the signal.

In order to achieve attenuation of the high frequency signal without excessive attenuation of the low frequency signal, the material of the non-dielectric material layer 103 should be other materials than the insulating layer, and the resistivity of the non-dielectric material layer 103 should be greater than The resistivity of the first electrode 101 is described. As an embodiment, the non-dielectric material layer 103 has a resistivity ranging from 50 ohms/cm to 106 ohms/cm. Under the premise that the resistivity of the non-dielectric material layer 103 is greater than the resistivity of the first electrode 101, the material of the non-dielectric material layer 103 may be a semiconductor material, for example, the non-dielectric material layer 103 may be doped. Or undoped single crystal germanium, doped or undoped polycrystalline germanium, doped or undoped single crystal germanium, one or a combination of doped or undoped polycrystalline germanium, tantalum carbide. In this embodiment, the material of the non-dielectric material layer 103 is doped polysilicon, wherein the doping ions may be N-type doping ions or P-type doping ions, and the pair of non-dielectric material layers 103 are controlled by The doping concentration of the doping ions can freely adjust and set the resistivity of the non-dielectric material layer 103, thereby optimally setting the material of the non-dielectric material layer 103 according to the frequency range of the radio frequency signal to which the first electrode 101 is connected. Of course, the non-dielectric material layer 103 may also be made of a metal material as long as the resistivity of the non-dielectric material layer 103 can be greater than the resistivity of the non-dielectric material layer 103.

As an embodiment, the non-dielectric material layer 103 is cylindrical in shape. By optimizing the plurality of parameters such as the shape, size, volume, doping concentration, and the like of the non-dielectric material layer 103, the non-dielectric material layer 103 has a suitable resistance, which enables the first a portion of the energy of an electrode 101 near the middle of the surface of the wafer to be processed 104, and the energy of the first electrode 101 near the middle of the surface of the wafer 104 to be processed is not at a low frequency. Consumption. Generally, the higher the frequency of the RF power source, the greater the resistance required by the layer of non-dielectric material 103. Those skilled in the art can make specific selections and settings, and will not be described in detail herein.

Next, please refer to the structural schematic diagram of the plasma processing apparatus of the second embodiment of the present invention shown in FIG. The difference from the first embodiment is that the non-dielectric material layer 103 of the first embodiment has a cylindrical shape, and the non-dielectric material layer 103 of the present embodiment has a truncated cone shape. The area of the surface of the truncated cone near the side of the wafer 104 to be processed is larger than the area of the surface away from the side of the wafer 104 to be processed. In other embodiments of the present invention, the truncated cone The surface area near the side of the wafer 104 to be processed may also be smaller than the area of the surface away from the side of the wafer 104 to be processed. With the truncated cone structure, the resistance of the non-dielectric material layer 103 from the center of the surface of the first electrode 101 close to the surface of the wafer to be processed 104 in the radial direction can be sequentially decreased, so that The amount of energy attenuation of the high-frequency signal in the radial direction of the center is sequentially reduced, thereby compensating better with the standing wave effect of the RF power source, so that the energy distribution in the vacuum processing chamber 100 is more uniform, which is advantageous for further improving the vacuum processing. The uniformity of the distribution of the plasma within the chamber 100.

Please refer to the structural schematic diagram of the plasma processing apparatus of the third embodiment of the present invention shown in FIG. The difference between this embodiment and the previous embodiment is that the non-dielectric material layer of the previous embodiment has a cylindrical shape, and the non-dielectric material layer 103 of the present embodiment has a conical shape.

Please refer to the schematic diagram of the structure of the plasma processing apparatus of the third embodiment of the present invention shown in FIG. The difference between this embodiment and the previous embodiment is that the non-dielectric material layer of the previous embodiment has a conical shape, and the non-dielectric material layer 103 of the present embodiment has a stepped shape.

Please refer to the structural schematic diagram of the plasma processing apparatus of the fourth embodiment of the present invention shown in FIG. 6. The non-dielectric material layer 103 of this embodiment and the first embodiment are both cylindrical, but in the present embodiment, the resistance of the non-dielectric material layer 103 in the radial direction is different from the center of the non-dielectric material layer 103.

It should be noted that each of the above embodiments has two electrodes in the vacuum processing chamber 100, namely, a first electrode 101 and a second electrode 102, and the wafer 104 to be processed is placed on the first electrode 101 through the electrostatic chuck. on. In other embodiments of the present invention, when the second electrode and the first electrode are opposed to each other, an electrostatic chuck may be disposed on a surface of the second electrode adjacent to the first electrode, and the wafer to be processed is placed on the surface. The electrostatic chuck applies a radio frequency signal to the first electrode to generate a plasma between the first electrode and the wafer to be processed. At this time, the structure of the electrostatic chuck and the first electrode is the same as that of the first embodiment. This is not described in detail; in still another embodiment of the present invention, when the vacuum processing chamber 100 has only one electrode, that is, the first electrode 101, the material of the vacuum processing chamber 100 should be metal. The vacuum processing chamber 100 can be grounded, and the vacuum processing chamber 100 serves as a second electrode to form a capacitance with the first electrode 101. At this time, the first electrode 101 can be provided with an electrostatic chuck and a crystal to be processed. For the positional relationship of the wafer, the non-dielectric material layer and the electrostatic chuck, refer to the first embodiment, and no detailed description is given here.

The plasma processing apparatus of the present invention may be a plasma etching apparatus or a plasma enhanced chemical vapor deposition apparatus.

In summary, in the embodiment of the present invention, a non-dielectric material layer is disposed between a first electrode of the vacuum processing chamber and a platform on which the wafer to be processed is placed, and the resistivity of the non-dielectric material layer is greater than the resistivity of the first electrode. The non-dielectric material layer can be eliminated when the first electrode is electrically connected to the first RF power source (the frequency of the first RF power source is greater than 1.5 times the frequency of the second RF power source) a standing wave effect caused by a high frequency signal of a radio frequency power source, attenuating the energy of a part of the high frequency signal of the vacuum processing chamber corresponding to the non-dielectric material layer, thereby making the energy distribution in the vacuum processing chamber more uniform, Therefore, the density of the plasma in the vacuum processing chamber is more uniform when the first electrode is electrically connected to the first RF power source, and the wafer to be processed is ensured when the first electrode is electrically connected to the first RF power source. The etching rate is more uniform; providing an insulating layer between the first electrode and the platform on which the wafer to be processed is placed causes the low frequency signal to be excessively attenuated compared to the present invention. The non-dielectric material layer disposed between the first electrode and the platform on which the wafer to be processed is disposed does not cause a large attenuation of the energy of the low-frequency signal of the vacuum processing chamber corresponding to the position of the non-dielectric material layer, thereby The density distribution of the plasma in the vacuum processing chamber is more uniform, and therefore, the etching rate when the first electrode is electrically connected to the second RF power source is also more uniform.

Although the invention has been disclosed above in the preferred embodiments, the invention is not limited thereto. Any changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be determined by the scope of the claims.

100. . . Vacuum processing chamber

101. . . First electrode

102. . . Second electrode

103. . . Non-dielectric material layer

104. . . Wafer to be processed

105. . . platform

10. . . Vacuum processing chamber

11. . . First electrode

12. . . Second electrode

1 is a schematic structural view of a conventional plasma processing apparatus;

2 is a schematic structural view of a plasma processing apparatus according to a first embodiment of the present invention;

3 is a schematic structural view of a plasma processing apparatus according to a second embodiment of the present invention;

4 is a schematic structural view of a plasma processing apparatus according to a third embodiment of the present invention;

Figure 5 is a schematic structural view of a plasma processing apparatus according to a fourth embodiment of the present invention;

Fig. 6 is a view showing the configuration of a plasma processing apparatus according to a fifth embodiment of the present invention.

100. . . Vacuum processing chamber

101. . . First electrode

102. . . Second electrode

103. . . Non-dielectric material layer

104. . . Wafer to be processed

105. . . platform

Claims (11)

A plasma processing apparatus includes: a vacuum processing chamber; a first electrode located in the vacuum processing chamber, a platform on which a wafer to be processed is placed, the first electrode is electrically connected to two RF power sources The first RF power source is greater than 1.5 times the frequency of the second RF power source; the non-dielectric material layer is located between the first electrode and the platform on which the wafer to be processed is placed, and the resistivity of the non-dielectric material layer is greater than the first The resistivity of an electrode. The plasma processing apparatus according to claim 1, wherein the non-dielectric material layer is made of a semiconductor material or a metal, and the semiconductor material layer is one or a combination of ruthenium, osmium, iridium, and tantalum carbide. The material of the first electrode is metal. The plasma processing apparatus of claim 1, wherein the non-dielectric material layer is located on a surface of the first electrode, or a groove is formed in the first electrode, and the non-dielectric material layer is at least partially embedded in Inside the groove. The plasma processing apparatus of claim 1, wherein the non-dielectric material layer has a resistivity ranging from 50 ohms/cm to 106 ohms/cm. The plasma processing apparatus of claim 3, wherein the platform on which the wafer to be processed is placed includes: an electrostatic chuck, opposite to a surface of a side of the first electrode on which the non-dielectric material layer is formed, An electrostatic chuck is used for placement, and the shape and size of the electrostatic chuck away from the side of the wafer to be processed corresponds to the shape and size of the layer of non-dielectric material. The plasma processing apparatus of claim 1, wherein the vacuum processing chamber is made of metal, and the vacuum processing chamber is grounded. The plasma processing apparatus of claim 1, wherein the first electrode is cylindrical, the non-dielectric material layer has a circular lower surface corresponding to the first electrode, and the resistance of the non-dielectric material layer is along the circle The radius of the lower surface of the shape decreases outward. The plasma processing apparatus of claim 1, wherein the first RF power source has a frequency greater than 40 MHz and the second RF power source frequency is less than 27 MHz. The plasma processing apparatus of claim 1, wherein the non-dielectric material layer is cylindrical, truncated, conical, or stepped. The plasma processing apparatus of claim 1, further comprising: a second electrode located at a position opposite to the first electrode in the vacuum processing chamber. The plasma processing apparatus of claim 1, wherein the plasma processing apparatus is a plasma etching apparatus or a plasma enhanced chemical vapor deposition apparatus.