Patent Application
20180005851
The present disclosure relates the production of semiconductor devices. More specifically, the present disclosure relates to the plasma processing of a substrate in the formation of semiconductor devices.
During semiconductor wafer processing, features may be etched into a dielectric layer.
To achieve the foregoing and in accordance with the purpose of the present disclosure, an embodiment provides a chamber filler kit for balancing electric fields in a dielectric etch chamber is provided, wherein the dielectric etch chamber comprises a partially cylindrical chamber body with a partial cylindrical bore with a transport aperture and a bias housing aperture opposite the transport aperture, and a bias housing wall adjacent to the bias housing aperture. A transport module filler comprises an electrical conductive body, an etch resistant surface, wherein the etch resistant surface comprises an inner curved surface, which matches the partial cylindrical bore, and a wafer transport aperture for allowing a wafer and a robotic arm to pass into the partial cylindrical bore, wherein the transport module filler fits into the transport aperture and fills at least half of a volume of the transport aperture. A transport module sealer plate is adapted to be mechanically and electrically connected to the partially cylindrical chamber body and the transport module filler and comprises a seal for creating a seal around the transport aperture. A bias housing filler is adapted to be mechanically and electrically connected to the bias housing wall and comprises a conductive body and an etch resistant surface, wherein the bias housing filler fills at least 75% of a volume of the bias housing aperture, and wherein the etch resistant surface comprises a curved surface, which matches the partial cylindrical bore.
In another manifestation, an embodiment provides chamber filler kit for balancing electric fields in a dielectric etch chamber, wherein the dielectric etch chamber comprises a partially cylindrical chamber body with a partial cylindrical bore with a transport aperture and a bias housing aperture and a bias housing wall adjacent to the bias housing aperture. A transport module filler comprises an electrical conductive body, an etch resistant surface, wherein the etch resistant surface comprises an inner curved surface, which matches the partial cylindrical bore, and a wafer transport aperture for allowing a wafer and a robotic arm to pass into the partial cylindrical bore, wherein the transport module filler fits into the transport aperture and fills at least half of a volume of the transport aperture. A bias housing filler is adapted to be mechanically and electrically connected to the bias housing wall. The bias housing filler comprises a conductive body and an etch resistant surface, wherein the bias housing filler fills at least 75% of a volume of the bias housing aperture, and wherein the etch resistant surface comprises a curved surface, which matches the partial cylindrical bore.
These and other features of the present disclosure will be described in more detail below in the detailed description of embodiments 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 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.
To facilitate understanding,
A gas source 124 is connected to the processing chamber 149 and supplies gas into a plasma region of the processing chamber 149 during the etch or open processes.
A bias RF source 148, a first excitation RF source 152, and a second excitation RF source 156 are electrically connected to the processing chamber 149 through a controller 135 to provide power to the electrodes 104, 106, 108, and 110. The bias RF source 148 generates bias RF power and supplies the bias RF power to the processing chamber 149. In this example, the bias RF power has a frequency of 2 MHz. The first excitation RF source 152 generates source RF power and supplies the source RF power to the processing chamber 149. In this example, this source RF power has a frequency of 27 MHz. The second excitation RF source 156 generates another source RF power and supplies the source RF power to the processing chamber 149, in addition to the RF power generated by the first excitation RF source 152. In this example, this source RF power has a frequency of 60 MHz. A temperature controller 160 is connected to control the temperature of the central electrode 108 forming the ESC.
The different RF signals may be supplied to various combinations of the top and bottom electrodes. Preferably, the lowest frequency of the RF should be applied through the bottom electrode on which the material being etched is placed, which in this example is the bottom central electrode 108. In this example, the top electrodes are grounded and power is only provided to the bottom central electrode 108.
The controller 135 is connected to the gas source 124, the temperature controller 160, the bias RF source 148, the exhaust pump 120, the first excitation RF source 152, and the second excitation RF source 156. The controller 135 controls the flow of the etch gas into the processing chamber 149, the chamber pressure, as well as the generation of the RF power from the three RF sources 148, 152, 156, the electrodes 104, 106, 108, and 110, and the exhaust pump 120.
The top central electrode 106 also serves as a gas distribution plate, which is connected to the gas source 124, and serves as a gas inlet for gas from the gas source 124. The exhaust pump 120 serves as a gas outlet removing gas, which passes from the top central electrode 106 through the plasma region to the exhaust pump 120. The exhaust pump 120 may help to control pressure.
A Flex FL® dielectric etch system made by Lam Research Corporation™ of Fremont, Calif. may be used in a preferred embodiment of the invention. In the Flex EX+ the upper electrodes are grounded.
The chamber body 150 has a bias housing aperture, which is sealed by a bias housing wall 128. A transport module aperture 164 is also formed into the housing wall 128, and is adapted to allow a wafer 180 to be transported into and out of the chamber body 150. The substrate support 116 is connected and supported by the bias housing wall 128 through a connector 132. The plasma processing system 100 is a variable gap system, where the connector 132 is able to move the substrate support 116 up or down, to vary the gap between the substrate support 116 and the top central electrode 106. Because the chamber body 150 has a bias housing aperture and the bias housing wall 128, which seals the bias housing aperture, is placed further from the substrate 180 than other parts of the chamber body 150. An asymmetric electrostatic field is applied at the substrate 180.
Without being bound by theory, it is believed that electrostatic asymmetries created by the apertures cause the uneven etching. These asymmetries created by the apertures also interfere with the gas flow, which may create additional uneven processing. It is believed that the retrofit kit being formed by a conductive material, similar to the chamber helps to correct electrostatic asymmetries created by the asymmetric chamber, which provides a more uniform result. It is also believed that the kit may improve physical symmetry, which may also provide a more uniform gas flow. The more uniform electrostatic field and gas flow provide a more uniform processing of the substrate.
Some embodiments allow for a grounded plasma. Various components are attached to the grounded sidewall. Various embodiments allow for the support to move the substrate support vertically to adjust the gap above the substrate support, providing a processing lever.
While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, modifications, 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, permutations, and various substitute equivalents as fall within the true spirit and scope of the present invention.
