Patent Application
20190078204
Embodiments of the present disclosure generally relate to an electrostatic device which may be used to filter particles in a fluid stream.
Substrate processing methods generally involve exposing a substrate to a process gas in a chamber containing the substrate. A portion of the gas interacts with the substrate surface to form or modify a layer on the substrate. Examples of process methods include physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), and etching. Contaminants present in the process gas or the process gas delivery system may be deposited on the substrate causing manufacturing defects and reliability issues in the semiconductor device fabricated thereon.
In one embodiment, an electrostatic device comprises a body including a flow aperture extending therethrough, one or more electrodes disposed along the sides of the aperture, and one or more power sources coupled to the one or more electrodes.
In another embodiment, a system for processing a substrate, comprises a processing chamber including a gas inlet port, a gas source, and a filter. The filter further comprises a body including a flow aperture extending therethrough, two or more electrodes disposed along the sides of the flow aperture, and one or more power sources coupled to the two or more electrodes.
In yet another embodiment, a electrostatic device assembly comprises a body including an aperture therethrough, two or more electrodes disposed within the body, one or more power sources coupled to the two or more, and end connections attached to the body.
So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of their scope, and the disclosure hereof may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common in the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation of the features thereof.
Embodiments described herein generally pertain to an electrostatic device for use in a process system. Process gas may flow through an aperture formed in a tubular body of a filter. Electrodes disposed within the tubular body create an electric field. The field generated by the electrodes may be utilized to trap contaminate particles flowing through the aperture before entering the processing chamber.
A process gas from the process gas source 116 is introduced though a gas inlet line 121 into a gas dispersion region 132 of the process chamber 102 through a gas inlet port 120. The process gas source 116 may be any source suitable for use in the processing system such as a pressurized tank or boule, a gas formed by passing a carrier gas through a precursor material, or a source connected to a manufacturing facility gas line. An electrostatic device 118 is disposed in the gas inlet line 121 upstream of the gas inlet port 120. In certain embodiments, the electrostatic device 118 may be disposed at the gas inlet port 120. In certain embodiments, the electrostatic device may be disposed within the gas source in a location where gas is flowing toward a process gas use location. The process gas flows from the process gas source 116, through the gas inlet line 121 and electrostatic device 118, and into the gas dispersion region 132 via the gas inlet port 120 of the chamber 102. The process gas enters the process volume 110 from the gas dispersion area 132 through openings 124. The electrostatic device 118 is coupled to a power source 122 to electrostatically interact with the process gas flowing therein.
The electrodes 212 and 214 are disposed at different locations in the electrostatic device 200. In certain embodiments, electrodes 212 and 214 may be disposed at differing depths within the tubular body, for example, inwardly of the tubular body from the aperture 208 between 50 microns and 350 microns from the inner surface 210 of the tubular body. In further embodiments, the electrodes may be disposed with one surrounding the other. In still further embodiments, the one or more electrodes may define the inner surface 210 of the aperture 208. In still further embodiments, the electrodes may be disposed on the outer surface of the tubular body 202. Any configuration of electrodes suitable for forming the above described electric field or charge may be utilized.
The electrodes 212 and 214 are coupled to a power source 220 via terminals 218. The power source 200 imposes a voltage difference onto the electrodes. The voltage applied may have a range, for example, of up to 4000 volts. Multiple power sources may be coupled to the electrodes. A different voltage may be provided to each electrode individually. In certain embodiments, the voltages may have opposite polarity. The electrodes may be biased to be monopolar or bipolar. In further embodiments wherein multiple pairs of electrodes are utilized, the voltage difference imposed between each electrode pair may be equal or may be different.
In the embodiment of
Electrodes 312 and 314 are disposed within the tubular body 302. The electrodes have a thickness in a radius direction of the tubular body 302 of, for example, between 100 μm to 1 mm. Electrodes 312 and 314 are coupled to a power source (not shown). The power source imposes a voltage on the electrodes. Electrically charged contaminant particles in the process gas interact with an electric field created by the charged electrodes and are attracted electrostatically toward one of the electrodes 312, 314, and these particles then become attached to the inner surface 310 of the aperture 308, thus preventing the contaminant particles from entering the processing chamber 326 and depositing on a substrate or the interior surfaces of the process chamber. The inner surface 310 may have a roughened finish, such as an average surface roughness in a range of 8 Ra to 64 Ra, to increase capture of particles thereon. A buildup of contaminant particles on the inner surface 310 of the tubular body over a period of time will reduce the effectiveness of the filter. The filter may be cleaned or replaced to remove the buildup of contaminate particles.
Valves may be disposed along the gas supply conduit 328 upstream and downstream of the filter 300 to selectively isolate the filter 300. In order to perform maintenance on the filter 300, the valves are closed to isolate the filter 300 from the process gas source 324 and the process chamber 326. The filter 300 may then be removed from the gas supply line 328 in order to remove any contaminants along the inner surface 310 thereof. This may be accomplished, for example, by removing the existing filter 300 and installing the same filter 300 after cleaning, if desired, or replacing the filter 300 with a different identical filter 300. Upon the completion of the maintenance activity, the valves will then be reopened, thus reintroducing the process gas flow through the filter.
It is contemplated that the embodiments herein may also be practiced in other manners within a processing system. For example, the electrostatic device may be utilized as a electrostatic chuck. Further, arrays of the electrostatic device may be arranged and controlled individually to optimize electromagnetic fields.
While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
