Patent Application
20150041062
The invention relates to a chamber for plasma processing semiconductor wafers.
In forming semiconductor devices plasma processing systems are used to process semiconductor wafers.
To achieve the foregoing and in accordance with the purpose of the present invention, an apparatus for plasma processing a wafer is provided. A bottom plate is provided. A tubular chamber wall with a wafer aperture is adjacent to the bottom plate. A bottom removable seal provides a vacuum seal between the bottom plate and the tubular chamber wall at a first end of the tubular wall. A top plate is adjacent to the tubular chamber wall. A top removable seal provides a vacuum seal between a second end of the tubular wall and the top plate. A vertical seal is provided, where a vertical movement of the tubular wall allows the vertical seal to create a seal around the wafer aperture. A bottom alignment guide aligns the tubular chamber wall with the bottom plate. A top alignment guide aligns the top plate with the tubular chamber wall. A wafer chuck is disposed between the bottom plate and the top plate.
In another manifestation of the invention, an apparatus for plasma processing a wafer is provided. A bottom plate is provided. A tubular chamber wall is adjacent to the bottom plate. A bottom removable seal provides a vacuum seal between the bottom plate and the tubular chamber wall at a first end of the tubular wall. A top plate is adjacent to the tubular chamber wall. A top removable seal provides a vacuum seal between a second end of the tubular wall and the top plate. A wafer chuck is disposed between the bottom plate and the top plate.
These and other features of the present invention will be described in more details below in the detailed description of the invention and in conjunction with the following figures.
The present invention 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 invention 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 invention. It will be apparent, however, to one skilled in the art, that the present invention 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 invention.
Within the chamber enclosure 124 is a wafer chuck 140 on a pedestal 144. Preferably, the wafer chuck 140 is an electrostatic chuck (ESC). A segmented bowl cover 148 is placed to surround the wafer chuck 140 and pedestal 144. A segmented bottom cover 152 is placed to cover the bottom plate 104 within the chamber enclosure 124.
In addition, the tubular chamber wall 108 has a wafer aperture 156. The upper alignment guide 132 also has a wafer aperture 160. A vertical seal 164 is provided, where the vertical movement of the tubular chamber wall 108 with respect to the alignment guide 132 forms a seal around and between the wafer apertures 156, 160, where the wafer may be transferred into the tubular chamber wall 108 in a direction perpendicular to the vertical movement of the tubular chamber wall 108.
A plasma power supply 406, tuned by a match network 408, supplies power to a TCP coil 410 located near a power window 412 formed in the top plate 112, to create a plasma in the chamber enclosure 124 by providing an inductively coupled power. The TCP coil (upper power source) 410 may be configured to produce a uniform diffusion profile within the chamber enclosure 124. For example, the TCP coil 410 may be configured to generate a toroidal power distribution. The power window 412 is provided to separate the TCP coil 410 from the chamber enclosure 124 while allowing energy to pass from the TCP coil 410 to the chamber enclosure 124. A wafer bias voltage power supply 416 tuned by a match network 418 provides power to wafer chuck 140 to set the bias voltage on a substrate 420 which is supported by the wafer chuck 140. The controller 424 sets points for the plasma power supply 406 and the wafer bias voltage power supply 416.
The plasma power supply 406 and the wafer bias voltage power supply 416 may be configured to operate at specific radio frequencies such as, for example, 13.56 MHz, 27 MHz, 2 MHz, 400 kHz, or combinations thereof. Plasma power supply 406 and wafer bias voltage power supply 416 may be appropriately sized to supply a range of powers in order to achieve desired process performance. For example, in one embodiment of the present invention, the plasma power supply 406 may supply the power in a range of 50 to 5000 Watts, and the wafer bias voltage power supply 416 may supply a bias voltage of in a range of 20 to 2000 V. In addition, the TCP coil 410 and/or the wafer chuck 140 may be comprised of two or more sub-coils or sub-electrodes, which may be powered by a single power supply or powered by multiple power supplies.
In operation of an embodiment of the invention, a substrate is processed by first placing the substrate 420 on the wafer chuck 140 in the chamber enclosure 124. The gas source 430 provides a gas through the gas inlet 440 into the chamber enclosure 124. The plasma power supply 406, through the match network 408 and TCP coil 410 provides RF power to form the gas into a plasma. The bias voltage power supply 416 may through the match network 418 provide bias on the wafer chuck 140. A plasma process such as an etch or deposition is performed. The substrate 420 is removed and another substrate 420 may be processed. After a number of substrates are processed, the chamber system 100 is cleaned.
To clean, service, or upgrade the chamber system 100, the top plate 112 is removed. The tubular chamber wall 108 may be removed by vertically hoisting the tubular chamber wall 108. The segmented bowl cover 148 and segmented bottom cover 152 may be removed. This disassembly allows all interior surfaces of the chamber system 100 to be easily exposed for cleaning by hand. Surfaces covered by the segmented bowl cover 148 and segmented bottom cover 152 may require minimal or no cleaning If the segmented bowl cover 148 or segmented bottom cover 152 needs significant cleaning, they may be replaced with a clean segmented bowl cover 148 and segmented bottom cover 152, while the dirty segmented bowl cover 148 and segmented bottom cover 152 are cleaned and seasoned at another location.
The chamber system 100 is then reassembled, by placing the clean segmented bottom cover 152 over the bottom plate 104 and placing the clean segmented bowl cover 148 around the pedestal 144 and wafer chuck 140. The tubular chamber wall 108 is lowered onto the bottom plate 104 guided by the upper alignment guide 132 and bottom rails 128 forming the lower removable seals 604. The top plate 112 is placed on the tubular chamber wall 108 forming the upper removable seals 504
Additional equipment may be attached or moved into position. For example, the TCP coil 410 and gas inlet 440 may be placed or connected to the top plate 112.
This embodiment of the invention allows for a quicker cleaning of the chamber system 100. Parts that are more difficult to clean and season may be substituted for clean and seasoned parts and the replaced parts may be cleaned and seasoned at another location, while the chamber system 100 is used. This allows for minimal down time. The segmented bowl cover 148 and segmented bottom cover 152 make up a segmented liner.
In the prior art, chambers are more difficult to clean. If such chambers are sufficiently large, a worker may be required to climb into a chamber, which may further contaminate or otherwise damage the chamber. In addition, such a process is more difficult and slower. In addition, seasoning parts in the chamber further increases chamber down time.
While this invention 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 invention. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. 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 invention.
