Patent Application
20240282605
Embodiments of the present disclosure generally relate to a semiconductor process chamber. More specifically, embodiments of the disclosure relate to a semiconductor process chamber having a particle shield.
In semiconductor manufacturing, integrated circuits (IC) are formed on semiconductor substrates through various manufacturing steps, including etching, deposition, ion implantation, and annealing. These processes may inadvertently create and deposit undesired particles on surfaces within the processing chamber. These particles may break from the surface and move about the chamber causing process deposition contamination of the semiconductor substrate. Rotating equipment coupled to the processing chamber may draw loose particle towards the equipment and cast the particle towards the processing area. Thus, there is a need for minimizing particle return to the processing area of the chamber for improved semiconductor manufacturing.
An apparatus and system for minimizing particle return to the processing area of a semiconductor processing chamber are disclosed herein. In one example, a particle shield for a semiconductor vacuum processing chamber includes an annular ring, a plurality of rib supports, and a plurality of louver fins. The annular ring has top surface, a bottom surface, and a plurality of cutaways. The top surface has an upper outer portion and a lower inner portion. The plurality of rib supports are disposed on and supported by the lower inner portion. The plurality of louver fins have a truncated conical shape, a bottom surface of the louver fins supported in a recess formed in a top surface of the rib supports. Each of the plurality of louver fins are disposed between adjacent concentric louver fins that have an outer diameter greater than an inner diameter of the outwardly adjacent louver fin.
In another example, a system particle shield for a semiconductor vacuum processing chamber includes a chamber, a substrate support pedestal, a vacuum pump, a valve, a louver particle shield with an annular ring, a plurality of rib supports, and a plurality of louver fins. The chamber comprises one or more sidewalls, a bottom wall, and a lid enclosing a chamber interior volume. The substrate support pedestal is disposed within the chamber volume. The vacuum pump is coupled to the chamber and is in fluid communication with the chamber interior volume. The valve is positioned between the chamber and the vacuum pump and is configured to isolate the vacuum pump from the chamber interior volume. The louver particle shield is positioned between the vacuum pump and the chamber. The annular ring of the louver particle shield has a top surface and a bottom surface, and a plurality of cutaways. The top surface of the annular ring has an upper outer portion and a lower inner portion. The plurality of rib supports of the louver particle shield are disposed on and are supported by the lower inner portion of the annular ring. The plurality of louver fins of louver particle shield has a truncated conical shape and a bottom surface of the louver fins supported in a recess formed in a top surface of the rib supports. Each of the plurality of louver fins are disposed between adjacent concentric louver fins which have an outer diameter greater than an inner diameter of the outwardly adjacent louver fin.
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 the scope of the disclosure, as the disclosure 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 to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Many of the details, dimensions, angles, and other features shown in the Figures are merely illustrative of particular implementations. Accordingly, other implementations can have other details, components, dimensions, angles, and features without departing from the spirit or scope of the present disclosure. In addition, further implementations of the disclosure can be practiced without several of the details described below
The present disclosure describes an apparatus and system for minimizing loose particle float within a processing system. It has been found that contamination of particles in a processing chamber may increase the difficulty of achieving a desired deposition on a substrate. Over time, the deposition of particles from various processes on unintended surfaces within the chamber begin to accumulate and flake off causing loose particles within the process volume of the processing chamber. Cleaning processes are utilized to reduce the amount of surface build up; however, between cycles of cleaning, these surface particles may begin to flake. These flaked particles are known to break and fall into the processing volume of the chamber and may land on surfaces designated for processing, such as the substrate, causing imperfections. These undesired particles may also be inadvertently forced to break off from the surfaces as the chamber pressure reducing equipment reduces the pressure in the process volume. Generally, these loose particles flow towards a vacuum pump impeller, strike the impeller, and are chaotically flung within the processing chamber and may land on the substrate—leading to unacceptable defects. To resolve this issue, a louver particle shield is disclosed herein which impedes the trajectory of the particles which contact an impeller and cause the particles to refrain from returning into the processing chamber volume. This advantageously results in more uniform processing of substrates, increased yield, reduced waste, increased efficiency of processing, and lower cost of ownership.
In the embodiment of
The processing chamber 100 utilizes pressure reducing equipment 126 to reduce the pressure within the interior volume 110 of the chamber body 102 and evacuate processing by-products during processing of the substrate 114. As shown in
The pressure reducing equipment 126 also includes an isolation valve 124 positioned between the chamber body 102 and the vacuum pump 120. The isolation valve 124 may include a gate valve, which can be closed to fluidly separate the interior volume 110 of the chamber body 102 and the vacuum pump 120 for purposes such as, but not limited to, cleaning and maintenance. After a number of designated cycles of processing, a cycle of cleaning is performed. The general sequence to clean a processing chamber 100 is to isolate the vacuum pump 120 from the chamber body 102 using the isolation valve 124 to provide protection against the cleaning agent used for removing deposited particles from interior portions of the chamber body 102 as the vacuum pump impeller may be made of material incompatible with the cleaning agent used to clear the surfaces of the interior volume 110. The isolation valve 124 may be one of various types of typical valves such as, for example, butterfly, ball, v-ball, gate, pendulum, globe, or angle valve suitable to isolate the chamber body 102 from the vacuum pump 120. The isolation valve 124 may be fast acting, having a throttling speed of less than one second, or may be tight shut off to prevent gaseous escape.
Pressure reduction of the interior volume 110 may be a time intensive process that may require up to several hours to achieve ideal low pressure processing conditions. Furthermore, as pressure is reduced within the chamber body 102, a suction effect may be experienced on all surfaces contacting the interior volume. As previously discussed, unwanted particle formation on surfaces within the interior volume 110 may break off and cause defective substrate processing. The suction flow of the pressure reducing equipment 126 floats the particles towards the equipment suction inlet 128.
In some embodiments a pump inlet screen 118 is utilized to prevent large particles from coming in contact with the vacuum pump impellers (not shown) of the vacuum pump 120. The pump screen 118 may be located either upstream or downstream of the isolation valve 124 as shown by pump screen 118A and pump screen 118B in
In one embodiment, the pressure reducing equipment 126, further includes a louver particle shield 150 disposed between the chamber body 102 and the vacuum pump 120. In the example shown in
During substrate processing, in addition to unwanted deposition of particles to the interior of the chamber body 102, unwanted deposition of particles may also take place on the vacuum pump 120 being used to evacuate by-products during deposition processes. In particular, impellers (not shown) of the vacuum pump 120 may be susceptible to unwanted deposition. As the vacuum pump impellers rotate, any loose particles on the surface of the impellers or particles drawn towards the impellers are struck by the impellers causing the particles to bounce off the impellers and towards the direction of the chamber volume 110. The louver particle shield 150 allows loose floating particles to reach the screen 118 or the vacuum pump 120 impellers while simultaneously reducing any particles returning in the chamber by behaving as an obstruction of particle flow.
The second portion 204 of the annular ring 202 has a top surface 220, an inner surface 222, and a bottom surface (not shown on
A second portion 346 of the rib support 208 has two surfaces, an above surface 326 and a below surface 328. In some embodiments the second portion 346 may be formed from a single piece of material, such as aluminum. The above surface 326 may have a plurality of surface positioning locations 318 utilized to position the louver fins 210. In one embodiment, a rib support 208 may be formed from strategic bending of flat aluminum into the desired shape to rest on the annular ring 202 and support the louver fins 210 at the desired surface positioning locations 318. In the aforementioned embodiment, the below surface 328 would result in a mirrored construction of the above surface 326. In yet another embodiment, the rib support 208 may be constructed from a single piece of material with the surface positioning locations 318 machined into the above surface 326 of the second portion 346 of the rib support 208 with a substantially flat below surface 328 as shown in
Each rib support 208 has a length less than the outer diameter of the second portion 204 of the annular ring. Each rib support 208 also has a coupling design 340 at half the length. The coupling design 340 of the rib support 208 has a cross over structure to couple with adjacent rib supports. In one embodiment with a two rib support design, one rib support 208 may have an above block cutaway (as shown in
The plurality of surface positioning locations 318 may be directional. Within each half length of the rib supports 208, each of the plurality of the surface positioning locations 318 has three faces: a first face 320, a second face 322, and a third face 324. The first face 320 may be substantially perpendicular to the above surface 326 of the rib support 208. The second face 322 may be substantially parallel to the above surface 326 of the rib support 208. The third face 324 may be of various angles such as, but not limited to, between 45 to 150 degrees from the plane of the second face 322 or 0 to 30 from second face reference line 352. The angle selected may allow for proper alignment of the louver fins 210.
A third portion 348 of the rib support 208 couples the first portion 344 to the second portion 346 in a suitable manner. Suitable coupling of the first and second portion, 344 and 346, respectively, of the rib support 208 may be, but not limited to, a weld or fastener. In some embodiments, the third portion 348 is a transition portion from the first 344 portion of the rib support 208 to the second portion 346 of the rib support 208 having a strategic bend. In some embodiments the length of the third portion 348 allows the below surface 328 to be substantially aligned with a bottom surface 304 of the first portion 218 of the annular ring 202 as depicted in
Each of the plurality of louver fins 210 include a disk-like structure with a center cut out pressed into a cone shape. This results in a shallow cone structure with a truncated top where the outside angle of the louver fin is about 135 to 170 degrees from horizontal or stated differently, where the inside angle of the louver fin is about 10 to 45 degrees, such as about 10 to 30 degrees, or such as about 15 to 30 degrees from horizontal. While
The center piece 338 of
The louver fins 210 and the center piece 338 may be connected or fastened to the rib supports 208 by any suitable manner. These include, but are not limited to, tack or spot welding, vertical retention pins, fasteners, and the like. In one embodiment, the louver fins, including the center piece, may extend beyond the height of the top surface 302 of the annular ring 202 but do not exceed a profile height, H, of about one inch form the bottom surface 304 of the annular ring 202 to the top end 354 of the plurality of louver fins 210. It has been discovered that one inch height of the louver particle shield 350 provides for a minimal redesign in the processing chamber system 100 component spacing. It has been contemplated that the length of each of the louver fins and center piece may vary so long as the profile height, H, is not exceeded thereby allowing for multiple combinations of angles and lengths to achieve the desired overlaps of louver fins and profile height.
While the foregoing utilizes specific equipment terminology, it is contemplated that other terms may be used to refer to the same, or similar aforementioned equipment. A specific term is not meant to be limiting. For example, a vacuum pump may be referred to as a turbo pump, an evacuation pump, pressure reducing machinery or equipment, and the like.
While the foregoing is directed to embodiments of the disclosure, other and further embodiments may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. All documents described herein are incorporated by reference herein, including any priority documents and/or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby.
Certain embodiments and features have been described using a set of numerical minimum values and a set of numerical maximum values. It should be appreciated that ranges including the combination of any two values, e.g., the combination of any minimum value with any maximum value, the combination of any two minimum values, and/or the combination of any two maximum values are contemplated unless otherwise indicated. Certain minimum values, maximum values, and ranges appear in one or more claims below.
