Patent Application
20140151331
Embodiments of the present invention generally relate to plasma enhanced substrate processing apparatus.
During certain substrate processes, byproducts of the process can undesirably deposit on chamber components, such as a chamber lid. During plasma processes that use an inductively coupled plasma source disposed above the chamber lid, accumulation of byproducts (particularly conductive byproducts) can undesirably impact the coupling of RF power to the process gases in the process chamber. Such poor power coupling can result in loss of plasma, increased power requirements to maintain the plasma, and non-uniform plasma creation within the process chamber.
Therefore, the inventors have provided an improved apparatus for plasma processing of substrates in a process chamber.
Methods and apparatus for plasma processing of substrates are provided herein. In some embodiments, a deposition shield for use in processing a substrate having a given width may include a first plate having a first plurality of holes disposed through a thickness of the first plate; and a second plate disposed below the first plate and having a second plurality of holes disposed through a thickness of the second plate, wherein individual holes in the first plurality of holes and the second plurality of holes are not aligned.
In some embodiments, a process chamber for processing a substrate may include a chamber body having an inner volume and a dielectric lid; a gas inlet to provide a gas to the inner volume; an RF power source disposed above the dielectric lid to couple RF power to the gas during use; a substrate support disposed in the inner volume opposite the dielectric lid and having a support surface to support a substrate having a given width; and a deposition shield comprising one or more plates of a dielectric material supported in the inner volume that prevents any line of sight between the support surface of the substrate support and the dielectric lid.
In some embodiments, a method of processing a substrate may include forming a plasma in a process chamber using RF power inductively coupled to the plasma from an electrode disposed proximate a dielectric lid of the process chamber; processing a substrate disposed on a substrate support in the process chamber while the plasma is maintained; and providing a deposition shield disposed between the substrate and the dielectric lid while processing the substrate, wherein the deposition shield blocks any line of sight between the substrate and the dielectric lid.
Other and further embodiments of the present invention are described below.
Embodiments of the present invention, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the invention depicted in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention 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. The figures are not drawn to scale and may be simplified for clarity. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Embodiments of present invention provide a deposition shield that can substantially prevent substrate process byproducts (for example, during etch processes) from being deposited on the chamber lid. Deposition of such process byproducts could undesirably cause the lid to become a grounded surface which would reduce the ability of the RF source to couple RF power through the dielectric chamber lid. Thus, embodiments of the present invention advantageously maintain the efficient operation of the process chamber by preventing the weakening of RF power coupling through the dielectric lid.
In some embodiments, to minimize the deposition buildup on the dielectric lid, a deposition shield with one or more dielectric plates is positioned between the dielectric lid and the substrate. The one or more plates block the line of sight from the substrate to the dielectric lid to substantially prevent process byproducts from depositing on the dielectric lid. The process byproducts will preferentially deposit on the plates and not on the dielectric lid. The process chamber will operate with plasma even with the deposition on the deposition shield. Various embodiments of the deposition shield and process chambers having such deposition shields are disclosed below.
The process chamber 100 generally includes a chamber body 102 and the dielectric lid 104. An inductively coupled RF power supply 106 is disposed above the dielectric lid 104 to inductively couple RF power to one or more gases disposed within the process chamber 100 to form and maintain a plasma therein. The inductively coupled RF power source 106 generally includes an RF power supply 108 coupled to one or more electrodes (for example, one or more coil electrodes 112, 114) via a match network 110.
A substrate support 116 is disposed in an inner volume of the process chamber 100 generally opposite the dielectric lid 104. The substrate support 116 generally includes a substrate support surface for supporting substrate 120 having a given width thereon during processing (e.g., a 200 mm, 300 mm, 450 mm, or other diameter semiconductor wafer, or other substrate to be processed). An upper portion of the substrate support 116 may include an electrostatic chuck 118 as well as other components such as an electrode for coupling DC or RF bias power to the substrate 120.
A deposition shield 122 is disposed in the process chamber between the support surface of the substrate support 116 and the dielectric lid 104. The deposition shield 122 may be retained in a desired position in any suitable manner, such as by being supported on the substrate support 116 or other chamber components such as sidewalls or liners of the process chamber 100.
The deposition shield 122 includes one or more dielectric plates that are transparent to the electromagnetic field within the process chamber 100. The dielectric plates may be fabricated from process compatible materials such as quartz or ceramic, or the like. The one or more dielectric plates have a diameter that is greater than that of the substrate.
The one or more dielectric plates block any direct line of sight between the support surface of the substrate support 116, or the surface of the substrate 120, and the dielectric lid 104. As used herein, the phrase a direct line of sight refers to a line of sight in a direction normal to the substrate 120 and the dielectric lid 104. For example, in some embodiments, the one or more dielectric plates may include two or more dielectric plates having a plurality of holes formed therethrough, wherein the plurality of holes in each of the dielectric plates are not aligned. In embodiments consistent with
In some embodiments, a support 132 may be provided to hold the deposition shield 122 and a desired position. In some embodiments, the support may include a plurality of legs 136 support the deposition shield 122 in the desired position. In embodiments where more than one dielectric plate is provided, a plurality of spacers 138 may be provided to maintain each dielectric plate in a spaced apart position with respect to other dielectric plates. In some embodiments, an elongate member may be provided through the second dielectric plate 126 and may be coupled to the first doctor plate 124 such that the portion of the elongate member disposed between the first doctor plate and the second dielectric plate forms the spacer 138 and the portion of the elongate member extending away from the second dielectric plate away from the first doctor plate forms the leg.
In some embodiments, a base ring 134 is disposed atop the substrate support 116. The base ring 134 is a diameter larger than that of the substrate 120. For example, in some embodiments, the substrate support 116 may include an electrostatic chuck 118 and a support ledge disposed about the perimeter of the electrostatic chuck 118. The base ring 134 may be disposed on and/or coupled to the support ledge. The plurality of legs 135 extend from the base ring 134. In some embodiments, the plurality of legs 135 may be coupled to the base ring 134.
In some embodiments, the base ring may include a plurality of features to facilitate alignment retention the base ring on the substrate support. For example,
Returning to
Support equipment 144 may also be coupled to the process chamber 100 such as vacuum pumps additional RF or DC power supplies heat transfer fluid supplies or the like. A controller 146 may be provided to control aspects of the process chamber and generally includes a central processing unit or CPU 148 memory 150 and support circuits 152 software control algorithms may be stored in the memory 150 to control the operation of the process chamber 100, for example to implement any of the inventive methods as described herein.
In operation, the one or more gases are provided to the process chamber 100 while RF power is provided from the RF power supply 108 to the one or more electrodes disposed above the dielectric lid 104 to form a plasma 138 in the process chamber 100. Although shown in a position between the deposition shield 122 and the substrate 120, the plasma may alternatively or in combination be formed in between the deposition shield 122 and the dielectric lid 104 and/or in a region between adjacent plates of the deposition shield 122. The substrate 120 may be processed, for example etched, using the plasma 138 while any process byproduct is either exhausted from the chamber or may deposit on the deposition shield 122 or sidewalls of the process chamber 102. Little or no process byproducts will deposit on the dielectric lid 104.
The method generally begins at 302 where a plasma may be formed in a process chamber using RF power inductively coupled to the plasma from an electrode disposed proximate a dielectric lid of the process chamber.
At 304, a substrate disposed on a substrate support in the process chamber may be processed while the plasma is maintained. At 306, a deposition shield is disposed between the substrate and the dielectric lid while processing the substrate, wherein the deposition shield blocks any line of sight between the substrate and the dielectric lid.
Any deposition of byproducts from processing the substrate will more likely deposit on the deposition shield as compared to the dielectric lid. Thus, the deposition shield will prevent or reduce deposition on the dielectric lid, which advantageously maintains efficient power coupling from the RF power supply to allow the chamber lid to operate normally as a dielectric window to the RF power above the lid to create the plasma using the inductively coupled plasma source.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.
This application claims benefit of U.S. provisional patent application Ser. No. 61/733,568, filed Dec. 5, 2012, which is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61733568 | Dec 2012 | US |
