The disclosure relates to plasma processing chambers for plasma processing a wafer. More specifically, the disclosure relates to plasma processing chambers with a component that is resistant to plasma damage.
Plasma processing is used in forming semiconductor devices. During the plasma processing, components of the plasma processing chamber may be eroded by the plasma.
To achieve the foregoing and in accordance with the purpose of the present disclosure, a component for use as part of a plasma processing chamber for processing a wafer is provided. The component comprises a component body of silicon carbide doped with at least one of tungsten, tantalum, or boron.
In another manifestation, an apparatus for processing a wafer is provided. A processing chamber is provided. A wafer support for supporting a wafer is within the processing chamber. A gas inlet provides gas into the processing chamber. A component within the processing chamber comprises silicon carbide doped with at least one of tungsten, tantalum, or boron.
In another manifestation, a method for forming a component for use in a plasma processing chamber is provided. The component is formed out of silicon carbide doped with at least one of tungsten, tantalum, or boron.
These and other features of the present disclosure will be described in more details below in the detailed description and in conjunction with the following figures.
The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
The present disclosure will now be described in detail with reference to a few preferred embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one skilled in the art, that the present disclosure may be practiced without some or all of these specific details. In other instances, well-known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present disclosure.
A radio frequency (RF) source 130 provides RF power to a lower electrode and/or an upper electrode. In this embodiment, the ESC 108 is a lower electrode and the gas distribution plate 106 is an upper electrode. In an exemplary embodiment, 400 kilohertz (kHz), 60 megahertz (MHz), 2 MHz, 13.56 MHz, and/or 27 MHz power sources make up the RF source 130 and the ESC source 148. In this embodiment, the upper electrode is grounded. In this embodiment, one generator is provided for each frequency. In other embodiments, the generators may be separate RF sources, or separate RF generators may be connected to different electrodes. For example, the upper electrode may have inner and outer electrodes connected to different RF sources. Other arrangements of RF sources and electrodes may be used in other embodiments. In other embodiments, an electrode may be an inductive coil.
A controller 135 is controllably connected to the RF source 130, the ESC source 148, an exhaust pump 120, and the gas source 110. A high flow liner 104 is a liner within the etch chamber 149, which confines gas from the gas source and has slots 102, which allows for a controlled flow of gas to pass from the gas source 110 to the exhaust pump 120. A C-shroud is an example of a high flow liner 104.
In this embodiment, the edge ring 109, the gas distribution plate 106, and the high flow liner 104 are made of silicon carbide (SiC) doped with between 0.01% to 10% tantalum (Ta) by number of atoms or molecules. In other embodiments, the dopant may be one or more of tungsten (W), boron (B), or Ta. In other embodiments, the part is made of SiC doped with W, B, or Ta. In various embodiments, a ratio of at least one of tungsten, tantalum, or boron to silicon carbide in the component body is between 0.01% to 10% by number of atoms or molecules. In some embodiments, only the edge ring 109 is made of SiC doped with Ta.
It has been found that SiC doped with one or more of W, B, or Ta is etch-resistant. The etch rate of SiC is high in reactive etch plasmas containing both fluorine and oxygen radicals. It has been found that SiC doped with one or more of W, B, or Ta is more etch resistant to plasmas with both fluorine and oxygen radicals.
In a method for forming a part, a part is formed out of SiC doped with one or more of W, B, or Ta.
In other embodiments, different vapor dopants may be used. For example, vapor dopants may be at least one of tantalum dichloride (TaCl2), tungsten hexafluoride (WF6), boron trichloride (BCl3), diborane (B2H6), or WClx (where x is an integer from 2 to 6 inclusive). In various embodiments, the vapor precursor comprises a vapor comprising silicon and carbon. In some embodiments, the vapor precursor may be trichlorosilane (HSiCl3) and either ethylene (C2H4) or propane (C3H8). In other embodiments, the vapor precursor is methyltrichlorosilane (CH3SiCl3). In some embodiments, the doped SiC coating 308 is a cubic crystal form of SiC with a dopant of B, W, or Ta. In other embodiments, the dopant forms a separate phase, such as a boron carbide (BC4), tantalum carbide (TaC), or tungsten carbide (WC). The separate phase is combined in a SiC crystal.
The substrate 304 is exposed (step 216). In this example, the doped SiC coating 308 on the edge of the disk-shaped substrate 304 is removed by machining
The substrate 304 is removed from the doped SiC coating 308 (step 220). In this example, the substrate 304 can be removed by heating. Since the substrate 304 is a graphite disk, when the substrate 304 is heated to a high temperature, the substrate 304 is burnt off. Two free-standing discs of the doped SiC coating 308 remain.
The two free-standing discs of the doped SiC coating 308 are formed into parts (step 224). In this example, each free-standing disc of the doped SiC coating 308 is formed into an edge ring. In this example, machining is used to form the free-standing discs of doped SiC coating 308 into rings.
While this disclosure has been described in terms of several preferred embodiments, there are alterations, modifications, permutations, and various substitute equivalents, which fall within the scope of this disclosure. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present disclosure. It is therefore intended that the following appended claims be interpreted as including all such alterations, modifications, permutations, and various substitute equivalents as fall within the true spirit and scope of the present disclosure.
This application claims the benefit of priority of U.S. Application No. 62/742,152, filed Oct. 5, 2018, which is incorporated herein by reference for all purposes.
Filing Document | Filing Date | Country | Kind |
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PCT/US2019/053459 | 9/27/2019 | WO | 00 |
Number | Date | Country | |
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62742152 | Oct 2018 | US |