Patent Application
20210238744
Embodiments of the present disclosure generally relate to showerhead assemblies, and more particularly, to showerhead assemblies for use in substrate processing systems.
Conventional showerhead assemblies configured for use with process chambers, such as those used in microelectronic device fabrication, for example, typically include a gas distribution plate that has a backing plate coupled thereto. For example, the backing plate can be coupled to the gas distribution plate using one or more connecting devices, e.g., bolts, screws, clamps, etc. While such connecting devices are suitable for connecting the backing plate to the gas distribution plate, after extended use of the gas distribution plate assemblies, the torque and moment forces present at the connecting devices can sometimes compromise the connection between the gas distribution plate and the backing plate, which, in turn, can result in the gas distribution plate assemblies not operating as intended.
Accordingly, improved showerhead assemblies and methods of manufacturing the same are described herein.
In some embodiments, a showerhead assembly includes a gas distribution plate including an inner portion and an outer portion, the inner portion made from single crystal silicon (Si) and the outer portion made from one of single crystal Si or polysilicon (poly-Si); a first ring body formed from silicon (Si) and silicon carbide (SiC) as a major component thereof, wherein the first ring body is bonded to and extends from one of the inner portion or outer portion of the gas distribution plate; and a backing plate configured to connect to the gas distribution plate via the first ring body.
The backing plate can include a corresponding annular groove that receives the first ring body for connecting the backing plate to the gas distribution plate. The first ring body can include a stepped configuration, and wherein the first ring body is one of continuous or discontinuous along a circumference thereof.
A jacket can cover the first ring body, and includes a corresponding stepped configuration for coupling the jacket and the first ring body to each other. The jacket can be made from at least one of aluminum (Al), stainless steel, silicon carbide (SiC), or aluminum nitride (AlN).
A second ring body can be formed from silicon (Si) and silicon carbide (SiC) as a major component thereof, and wherein the second ring body is bonded to and extends from the other one of the inner portion or outer portion.
A bonding layer can be made of aluminum silicon alloy or aluminum that bonds the first ring body to the gas distribution plate.
In accordance with at least some embodiments a process chamber includes a showerhead assembly that includes a gas distribution plate comprising an inner portion and an outer portion, the inner portion made from single crystal silicon (Si) and the outer portion made from one of single crystal Si or polysilicon (poly-Si); a first ring body formed from silicon (Si) and silicon carbide (SiC) as a major component thereof, wherein the first ring body is bonded to and extends from one of the inner portion or outer portion of the gas distribution plate; and a backing plate configured to connect to the gas distribution plate via the first ring body.
The backing plate can include a corresponding annular groove that receives the first ring body for connecting the backing plate to the gas distribution plate. The first ring body can include a stepped configuration, and wherein the first ring body is one of continuous or discontinuous along a circumference thereof.
A jacket can cover the first ring body, and includes a corresponding stepped configuration for coupling the jacket and the first ring body to each other. The jacket can be made from at least one of aluminum (Al), stainless steel, silicon carbide (SiC), or aluminum nitride (AlN).
A second ring body can be formed from silicon (Si) and silicon carbide (SiC) as a major component thereof, and wherein the second ring body is bonded to and extends from the other one of the inner portion or outer portion.
A bonding layer can be made of aluminum silicon alloy or aluminum that bonds the first ring body to the gas distribution plate.
In accordance with at least some embodiments a method of forming a showerhead assembly includes bonding a first ring body formed from silicon (Si) and silicon carbide (SiC) as a major component thereof to one of an inner portion and outer portion of a gas distribution plate, the inner portion made from single crystal silicon (Si) and the outer portion made from one of single crystal Si or polysilicon (poly-Si; and connecting a backing plate to the gas distribution plate via the first ring body.
The first ring body can include a stepped configuration, and wherein the first ring body is one of continuous or discontinuous along a circumference thereof.
The method can include covering the first ring body with a jacket. The backing plate can include a corresponding annular groove, and the method can further include receiving the first ring body including the jacket within the annular groove for connecting the backing plate to the gas distribution plate. The jacket can be made from at least one of aluminum (Al), stainless steel, silicon carbide (SiC), or aluminum nitride (AlN). The first ring body can be bonded to one of the inner portion and outer portion of the gas distribution plate using a bonding layer made of made of aluminum silicon alloy or aluminum
In some embodiments, a showerhead assembly includes a gas distribution plate including an inner portion and an outer portion, the inner portion made from single crystal silicon (Si) and the outer portion made from one of single crystal Si or polysilicon (poly-Si); A connector comprises a circular configuration and is formed from silicon (Si) and silicon carbide (SiC) as a major component thereof, wherein the connector is bonded to at least one of an inner portion and outer portion of the gas distribution plate; and a backing plate configured to connect to the gas distribution plate via the connector. The connector can substantially cover the inner portion and outer portion of the gas distribution plate. The inner portion and outer portion of the gas distribution plate can each include a plurality of concentric grooves in which a corresponding plurality of aluminum (Al) rings are seated.
Other and further embodiments of the present disclosure are described below.
Embodiments of the present disclosure, briefly summarized above and discussed in greater detail below, can be understood by reference to the illustrative embodiments of the disclosure depicted in the appended drawings. However, the appended drawings illustrate only typical embodiments of the disclosure and are therefore not to be considered limiting of scope, for 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. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Embodiments of a showerhead assembly comprising a gas distribution plate including a connector bonded thereto, and method of manufacturing the same, are provided herein. More particularly, the gas distribution assemblies described herein include a gas distribution plate that includes an inner portion and an outer portion respectively made from single crystal silicon (Si) and single crystal Si or polysilicon (poly-Si). Additionally, one or both of the inner portion and outer portion have bonded thereon a connector formed of Si and varying quantities of silicon carbide (SiC). The bonded connector is used to connect the gas distribution plate to a backing plate of the showerhead assembly. Unlike conventional gas distribution plate assemblies that use one or more of bolts, screws, clamps, etc. to connect a backing plate to a gas distribution plate, the relatively strong bond provided between the connector and inner portion and/or outer portion maintains the gas distribution plate connected to the backing plate under the torque and moment forces that are present during operation of the showerhead assembly. Additionally, the bonded connector provides equal distribution of loading along the gas distribution plate. Additionally, a jacket that is coupled to the connector (e.g., ring body), allows the gas distribution plate to be removed from the backing plate for replaces the gas distribution plate (e.g., no debonding is required).
The processing chamber 100 may be used for various plasma processes. In one embodiment, the processing chamber 100 may be used to perform dry etching with one or more etching agents. For example, the processing chamber may be used for ignition of plasma from a precursor CxFy (where x and y can be different allowed combinations), O2, NF3, or combinations thereof.
The processing chamber 100 includes a chamber body 102, a lid assembly 104, and a support assembly 106. The lid assembly 104 is positioned at an upper end of the chamber body 102. The support assembly 106 is disclosed in an interior volume 108, defined by the chamber body 102. The chamber body 102 includes a slit valve opening 110 formed in a sidewall thereof. The slit valve opening 110 is selectively opened and closed to allow access to the interior volume 108 by a substrate handling robot (not shown) for substrate transfer.
The chamber body 102 may further include a liner 112 that surrounds the support assembly 106. The liner 112 may be made of a metal such as (Al), a ceramic material, or any other process compatible material. In one or more embodiments, the liner 112 includes one or more apertures 114 and a pumping channel 116 formed therein that is in fluid communication with a vacuum port 118. The apertures 114 provide a flow path for gases into the pumping channel 116. The pumping channel 116 provides an egress for the gases within the processing chamber 100 to vacuum port 118.
A vacuum system 120 is coupled to the vacuum port 118. The vacuum system 120 may include a vacuum pump 122 and a throttle valve 124. The throttle valve 124 regulates the flow of gases through the processing chamber 100. The vacuum pump 122 is coupled to the vacuum port 118 disposed in the interior volume 108.
The lid assembly 104 includes at least two stacked components configured to form a plasma volume or cavity therebetween. In one or more embodiments, the lid assembly 104 includes a first electrode (“upper electrode”) 126 disposed vertically above a second electrode (“lower electrode”) 128. The first electrode 126 and the second electrode 128 confine a plasma cavity 130, therebetween. The first electrode 126 is coupled to a power source 132, such as an RF power supply. The second electrode 128 is connected to ground, forming a capacitor between the first electrode 126 and second electrode 128. The first electrode 126 is in fluid communication with a gas inlet 134 that is connected to a gas supply (not shown), which provides gas to the process chamber 100 via the gas inlet 134. The first end of the one or more gas inlets 134 opens into the plasma cavity 130.
The lid assembly 104 may also include an isolator ring 136 that electrically isolates the first electrode 126 from the second electrode 128. The isolator ring 136 may be made from aluminum oxide (AlO) or any other insulative, processing compatible, material.
The lid assembly 104 may also include showerhead assembly 150 and, optionally, a blocker plate 140. The showerhead assembly 150 includes a gas distribution plate 138, a backing (gas) plate 139, and a chill plate 151. The second electrode 128, the gas distribution plate 138, the chill plate 151, and the blocker plate 140 may be stacked and disposed on a lid rim 142, which is coupled to the chamber body 102.
The chill plate 151 is configured to regulate a temperature of the gas distribution plate 138 during processing. For example, the chill plate 151 may include one or more temperature control channels (not shown) formed therethrough such that a temperature control fluid may be provided therein to regulate the temperature of the gas distribution plate 138.
In one or more embodiments, the second electrode 128 may include a plurality of gas passages 144 formed beneath the plasma cavity 130 to allow gas from the plasma cavity 130 to flow therethrough. The backing plate 139 includes one of more gas passages 217 and one or more gas delivery channels 219 (see
The support assembly 106 may include a support member 180. The support member 180 is configured to support the substrate 101 for processing. The support member 180 may be coupled to a lift mechanism 182 through a shaft 184, which extends through a bottom surface of the chamber body 102. The lift mechanism 182 may be flexibly sealed to the chamber body 102 by a bellows 186 that prevents vacuum leakage from around the shaft 184. The lift mechanism 182 allows the support member 180 to be moved vertically within the chamber body 102 between a lower transfer portion and a number of raised process positions. Additionally, one or more lift pins 188 may be disposed through the support member 180. The one or more lift pins 188 are configured to extend through the support member 180 such that the substrate 101 may be raised off the surface of the support member 180. The one or more lift pins 188 may be active by a lift ring 190.
The processing chamber may also include a controller 191. The controller 191 includes programmable central processing unit (CPU) 192 that is operable with a memory 194 and a mass storage device, an input control unit, and a display unit (not shown), such as power supplies, clocks, cache, input/output (I/O) circuits, and the liner, coupled to the various components of the processing system to facilitate control of the substrate processing.
To facilitate control of the processing chamber 100 described above, the CPU 192 may be one of any form of general-purpose computer processor that can be used in an industrial setting, such as a programmable logic controller (PLC), for controlling various chambers and sub-processors. The memory 194 is coupled to the CPU 192 and the memory 194 is non-transitory and may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk drive, hard disk, or any other form of digital storage, local or remote. Support circuits 196 are coupled to the CPU 192 for supporting the processor in a conventional manner. Charged species generation, heating, and other processes are generally stored in the memory 194, typically as software routine. The software routine may also be stored and/or executed by a second CPU (not shown) that is remotely located from the processing chamber 100 being controlled by the CPU 192.
The memory 194 is in the form of computer-readable storage media that contains instructions, that when executed by the CPU 192, facilitates the operation of the processing chamber 100. The instructions in the memory 194 are in the form of a program product such as a program that implements the method of the present disclosure. The program code may conform to any one of a number of different programming languages. In one example, the disclosure may be implemented as a program product stored on a computer-readable storage media for use with a computer system. The program(s) of the program product define functions of the embodiments (including the methods described herein). Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media (e.g., read-only memory devices within a computer such as CD-ROM disks readable by a CD-ROM drive, flash memory, ROM chips, or any type of solid-state non-volatile semiconductor memory) on which information is permanently stored; and (ii) writable storage media (e.g., floppy disks within a diskette drive or hard-disk drive or any type of solid-state random-access semiconductor memory) on which alterable information is stored. Such non-transitory computer-readable storage media, when carrying computer-readable instructions that direct the functions of the methods described herein, are embodiments of the present disclosure.
In at least some embodiments, the inner portion 202 and outer portion 208, when made from the same material (e.g., single crystal Si), can be monolithically formed (e.g., formed as a homogeneous unitary body). Alternatively or additionally, the inner portion 202 and outer portion 208 can be connected to each other via one or more suitable connection devices or methods. For example, in the illustrated embodiment, the inner portion 202 and outer portion 208 are connected to each other via a mechanical interface (e.g., corresponding indent/detent) that uses a press fit, so that the inner portion 202 and outer portion 208 can be interlocked to each other. One or more thermal gaskets, O-rings, or other suitable device(s) can be provided at the mechanical interface to ensure a seal is provided between the inner portion 202 and outer portion 208.
The inner portion 202 and the outer portion 208 can be made from one or more materials suitable for being bonded to one or more connectors 201. For example, the inner portion 202 and the outer portion 208 can be made from single crystal silicon (Si) and/or polysilicon (poly-Si). In at least some embodiments, the inner portion 202 can be made from single crystal silicon (Si) and the outer portion 208 made from one of single crystal Si or poly-Si.
The one or more connectors 201 are configured to be bonded to the inner portion 202 and/or the outer portion 208 of the gas distribution plate 138 and are configured to connect the gas distribution plate 138 to the backing plate 139, as will be described in greater detail below (see
In at least some embodiments, the one or more connectors 201 includes one or more ring bodies (see
In at least some embodiments, only one of the inner portion 202 and the outer portion 208 can include a ring body. For example, in at least some embodiments, the inner portion 202 can be provided with a ring body and the outer portion 208 can be provided without a ring body, or vice versa.
Each of the inner ring body 214 and outer ring body 222 can be made from one or more materials suitable for being bonded to the inner portion 202 and the outer portion 208. For example, in at least some embodiments, each of the inner ring body 214 and outer ring body 222 can be made from materials having silicon (Si) at varying quantities with silicon carbide (SiC) as a major component thereof (e.g., SiSiC). Si content (volume %) of the ring bodies may be about 20 to about 30 with the remainder being SiC.
While the inner ring body 214 and outer ring body 222 are shown having a continuous or non-interrupted configuration along a circumference thereof, the present disclosure is not so limited. For example, in at least some embodiments, one or both of the inner ring body 214 and outer ring body 222 can have a discontinuous or interrupted configuration. In such embodiments, one or more gaps or spaces 223 can be provided along a circumference of the inner ring body 214 and/or outer ring body 222. For illustrative purposes,
Continuing with reference to
The jackets 230, 232 are configured to couple to the corresponding inner ring body 214 and outer ring body 222 via a mechanical interface. For example, the ring body 214 and outer ring body 222 have one or more features formed therein and the jackets 230, 232 have one or more corresponding mating (interlock) features that lock the ring body 214 and outer ring body 222 to the jackets 230, 232, thus preventing separation thereof when assembled. For example, in at least some embodiments, the jackets 230, 232 include a corresponding stepped configuration. The corresponding stepped configuration allows coupling of the jackets 230, 232 to the corresponding inner ring body 214 and outer ring body 222 via a press fit (e.g., interlocked to each other), see indicated areas of detail 234, 236 of
Disposed along a top surface 238, 240 of the jackets 230, 232 are a plurality of threaded apertures 242 that are configured to receive a corresponding plurality of threaded screws or bolts (not shown). The plurality of screws or bolts are driven through a corresponding plurality of apertures 244 that extend through a top surface 246 of the backing plate 139 for connecting the backing plate 139 to the gas distribution plate 138 (see
One or more temperature detection assemblies 250 (
The gas distribution plate 400 includes an inner portion 402 and an outer portion 404, which can be made from the same materials as described above with respect to the inner portion 202 and an outer portion 208. Unlike the inner portion 202 and an outer portion 208 of the gas distribution plate 138, however, one or both of the inner portion 402 and the outer portion 404 of the gas distribution plate 400 include a plurality of concentric grooves. In the illustrated embodiment, each of the inner portion 402 and the outer portion 404 includes a plurality of concentric grooves 406, 408, respectively, defined on a top surface 407 of the inner portion 402 and a top surface 409 of the outer portion 404. The concentric grooves 406, 408 are configured to receive a corresponding plurality of rings 410 used for bonding a connector 401 to the inner portion 202 and the outer portion 208. The rings 410 can be made from, for example, Al or an aluminum silicon alloy AlSi material.
Unlike the connector 201 that includes the ring bodies of
A bottom surface 412 of the connector 401 is supported on the top surface 407 of the inner portion 402 and the top surface 409 of the outer portion 404, and atop the plurality of rings 410, e.g., for bonding the connector 201 to the inner portion 402 and outer portion 404, see
One or more gas passages (or channels) 414 are defined in the connector 401 and extend to the bottom surface 412 thereof. The one or more gas passages 414 are in fluid communication with one or corresponding more apertures 416 defined through a top surface 418 of the connector 401, thus allowing process gas to flow from the backing plate 139, through the connector 401, and into the processing region.
A plurality of threaded apertures 420 are defined through the top surface 418 of the connector 401 and are configured to receive one or more corresponding screws or bolts to connect the gas distribution plate 400 to the backing plate 139, see
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.
