Patent Application
20230331633
The background description provided here is for the purpose of generally presenting the context of the disclosure. Information described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The disclosure relates to parts for use in a plasma processing chamber. More specifically, the disclosure relates to dielectric, plasma exposed parts in a plasma processing chamber.
In forming semiconductor devices, plasma processing chambers are used to process the substrates. Some plasma processing chambers have dielectric parts, such as liners, gas distribution plates, and edge rings.
For some of the dielectric parts for plasma processing chambers, silicon carbide (SiC) has been widely used due to the high etch resistance of SiC. The technique to produce a SiC edge ring is predominantly through a chemical vapor deposition (CVD) method where a thick SiC coating is grown onto a graphite mandrel. After the removal of the graphite mandrel, the CVD-produced SiC blank is then machined into an edge ring. With more aggressive plasma chemistries and more stringent demand in a part lifetime, CVD-produced pure SiC cannot meet lifetime requirements.
To achieve the foregoing and in accordance with the purpose of the present disclosure, a method for making a component for use in a plasma processing chamber is provided. A non-oxide silicon containing powder composition is placed in a mold, wherein the non-oxide silicon containing powder composition consists essentially of a non-oxide silicon containing powder and at least one of a B or B4C dopant. The non-oxide silicon containing powder composition is subjected to spark plasma sintering (SPS) to form a spark plasma sintered component. The spark plasma sintered component is machined into a plasma processing chamber component.
In another manifestation, an apparatus for processing a wafer is provided. A plasma processing chamber is provided. A wafer support for supports a wafer within the plasma processing chamber. A gas source for provides gas to the plasma processing chamber. A component comprises a spark plasma sintered body comprising a non-oxide material containing silicon consisting essentially of a non-oxide silicon containing material and at least one of a B or B4C dopant.
In another manifestation, a showerhead for use in a plasma processing chamber is provided. A disk shaped component body has a plasma facing surface, wherein the disk shaped component body comprises a spark plasma sintered body comprising a non-oxide material containing silicon consisting essentially of a non-oxide silicon containing material and at least one of a B or B4C dopant. A plurality of inlet holes is machined into the plasma facing surface of the disk shaped component body
These and other features of the present disclosure will be described in more detail 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.
To facilitate understanding,
Referring back to
As compared to conventional sintering processes, the SPS process (also referred to as pulsed electric current sintering (PECS), Field-Assisted Sintering (FAST) or Plasma Pressure Compaction (P2C)) involves contemporaneous use of pressure and high-intensity, low-voltage (e.g. 5-12 V), pulsed current to dramatically reduce processing/heating times (e.g. 5-10 minutes (min) instead of several hours) and yield high-density components. In one embodiment, a pulsed DC current is transmitted to the deposited the non-oxide material containing silicon 204a using conductive pads 212 as electrodes, while pressure (e.g. between 10 megapascals (MPa) up to 500 MPa or more) is simultaneously axially applied to the non-oxide material containing silicon 204a via reciprocation of the conductive pads 212 under mono-axial mechanical force. A “mono-axial force” is herein defined to mean a force applied along a single axis or direction creating mono-axial compression. The mold 208 and non-oxide material containing silicon 204a are generally placed under vacuum during at least a portion of the process. Pulsed-current patterns (ON:OFF), typically in milliseconds, enable high heating rates (up to 1000° C./min or more), and rapid cooling/quenching rates of (up to 200° C./min or more) for heating the non-oxide material containing silicon 204a to temperatures ranging from under 1000° C. to 2500° C. In one embodiment, the ON-OFF DC pulse-energizing of the SPS process generates one or more of the following in the SiC composition: 1) spark plasma, 2) spark impact pressure, 3) Joule heating, and 4) an electrical field diffusion effect.
It is appreciated that the scale and geometry of the mold 208, conductive pads 212, non-oxide material containing silicon 204a, and SPS-formed edge ring 204b provided in the schematic views of
In one embodiment of an SPS process, provided for exemplary purposes only, sintering of the composition of silicon carbide powder and sintering additives is conducted under vacuum (6<P(Pa)<14) while being simultaneously subjected to a pulsed current. The SPS thermal treatment may be implemented as follows: 1) a degassing treatment performed for a period between 3 min to 10 min, and preferably with the non-oxide material containing silicon 204a subjected to 3 min under limited applied load (e.g. between 10 MPa and 20 MPa) and 2 min under increasing load up to 40 MPa to 100 MPa, and 2) heating up to between 1850° C. and 1950° C. at 100° C. min−1 under an applied load between 40 MPa to 100 MPa and a soaking time of 5 min at maximum temperature then cooling down to room temperature. It is appreciated that one or more of the SPS process parameters, including composition constituent ratios and particulate size, pressures, temperatures, treatment periods, and current pulse sequences, may be varied as appropriate to optimize the SPS process.
Referring to the side view of
Following the SPS process, the component may be further processed (step 112, e.g., polishing, machining, or like process) to specifically adapt the component for use in a plasma processing chamber. It is appreciated that the mold and/or SPS process may be structured so that the further processing in step 112 is not required. The SPS-formed edge ring 204b may be formed as a near net shape part (NNS). A NNS part requires subsequent machining removing less that 20% of the volume of the NNS part.
Referring to the side view of
The processed SPS body is then mounted or otherwise installed in a plasma processing chamber (step 116), wherein the SPS component is used in the plasma processing chamber (step 120) for performing plasma processing of one or more wafers or substrates. During plasma processing, one or more surfaces of the SPS component is exposed to plasma and/or dielectric-etch processes.
The plasma processing performed by the plasma processing chamber may include one or more processes of etching, depositing, passivating, or another plasma process. The plasma processing may also be performed in combination with non-plasma processing. Such processes may expose the various components of the plasma processing chamber to plasmas containing halogen and/or oxygen that result in erosion or degradation of the part.
The SPS process illustrated in
Accordingly,
Referring to the cross-section view of
Referring to the respective plan and side views of
Referring to the respective plan and side views of
The plasma processing components (e.g. edge ring 204c, gas distribution plate 304c) generated from the SPS process are resistant to erosion from exposure to plasma, such that the component is either no longer a consumable, or substantially inhibits consumption to limit or obviate the need to change or replace the component due to erosion. Being more etch resistant, components fabricated and installed via the process illustrated in
The integrity of the dielectric components discussed above with respect to plasma processing chambers is crucial to maintain both electrical standoff, plasma erosion resistance, and chemical resistance. The SPS-formed components as detailed in the present description provide significant advantages over dielectric coated parts, as dielectric coatings that are too thick are more susceptible to cracking, and thinner dielectric coatings do not provide sufficient insulation to prevent damage caused by the voltage used by the plasma processing chamber.
Referring to the schematic system view of
In one exemplary configuration, the one or more processed and SPS-formed components comprise consumable plasma processing chamber components such as an edge ring, gas distribution plate, high flow liner, etc. In some embodiments, the plasma processing chamber 400 comprises a gas distribution plate 406, also referred to as a “showerhead” for providing a gas inlet within a plasma processing chamber 404. The gas distribution plate 406 may be mounted in a plasma processing chamber 404 along with an electrostatic chuck (ESC) 416, all being enclosed by a chamber wall 450. Within the plasma processing chamber 404, a substrate or wafer 407 is positioned on top of the ESC 416 that acts as a wafer support to support the substrate 407. The ESC 416 may provide a bias from an ESC power source 448. A gas source 410 is connected to the plasma processing chamber 404 through the gas distribution plate 406. An ESC temperature controller 451 is connected to the ESC 416 and provides temperature control of the ESC 416. A radio frequency (RF) power source 430 provides RF power to the ESC 416 and an upper electrode. In this embodiment, the upper electrode is the gas distribution plate 406. In a preferred embodiment, 13.56 megahertz (MHz), 2 MHz, 60 MHz, and/or optionally, 27 MHz power sources make up the RF power source 430 and the ESC power source 448. A controller 435 is controllably connected to the RF power source 430, the ESC power source 448, an exhaust pump 420, and the gas source 410.
A high flow liner 460 is a liner within the plasma processing chamber 404, and may also be formed, installed, and used in accordance with the steps illustrated in
An edge ring 464 surrounds the substrate 407. The plasma processing chamber 404 uses the edge ring 464 to plasma process the substrate 407. It is desirable that the top surface of the edge ring 464 be level with a top surface of the substrate 407. Therefore, the use of an SPS-formed edge ring 204c as edge ring 464 obviates various mechanisms that are typically provided to move the edge ring as the edge ring is consumed in order to keep the top surface of the edge ring even with the top surface of the substrate. In addition, once an edge ring is sufficiently consumed, the edge ring must be replaced, causing downtime for the plasma processing chamber. In other embodiments, such components may be placed in locations shielded from plasma. Ceramic edge rings have a low coefficient of thermal expansion and good electrical and thermal conductivity.
In other embodiments, the components may be parts of other types of plasma processing chambers such as a TCP (transformer coupled plasma) reactor, a bevel plasma processing chambers or like device. Examples of components of plasma processing chambers that may be provided in various embodiments are confinement rings, plasma exclusion rings, edge rings, the electrostatic chuck, ground rings, chamber liners, door liners, the pinnacle, a showerhead, a dielectric power window, gas injectors, edge rings, ceramic transfer arms, or other components.
In various embodiments, the non-oxide silicon containing powder comprises silicon powder with a B4C dopant. In some embodiments, the non-oxide silicon containing powder consists essentially of silicon powder with a B4C dopant. In one embodiment, the atomic fraction of boron to silicon is in the range of 0.01% to 30%. In other embodiments, the atomic fraction of boron to silicon is in the range of 1% to 20%. In other embodiments, the atomic fraction of boron to silicon is in the range of 10% to 20%.
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. 63/110,212, filed Nov. 5, 2020, which is incorporated herein by reference for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/057926 | 11/3/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63110212 | Nov 2020 | US |
