Patent Application
20240420924
Embodiments of the disclosure are directed to cooling flanges for semiconductor manufacturing equipment. In particular, embodiments of the disclosure are directed to cooling flanges without isolation valves for remote plasma source (RPS) connection.
Reliably producing submicron and smaller features is one of the key requirements of very large scale integration (VLSI) and ultra large scale integration (ULSI) of semiconductor devices. However, with the continued miniaturization of circuit technology, the dimensions of the size and pitch of circuit features, such as interconnects, have placed additional demands on processing capabilities. The various semiconductor components (e.g., interconnects, vias, capacitors, transistors) require precise placement of high aspect ratio features. Reliable formation of these components is critical to further increases in device and density.
Additionally, the electronic device industry and the semiconductor industry continue to strive for larger production yields while increasing the uniformity of layers deposited on substrates having increasingly larger surface areas. These same factors in combination with new materials also provide higher integration of circuits per unit area on the substrate.
Some semiconductor manufacturing processes use remote plasma sources (RPS) for generation of a plasma that is flowed into the process region of a processing chamber. To maintain sufficient temperature control of the process within the processing chamber, a cooling flange is often positioned between the RPS and the processing chamber. Current cooling flanges positioned between the remote plasma source (RPS) and the processing chamber include an isolation valve to allow for an inert gas (e.g., argon (Ar)) purge. These isolation valves impose resistance to the flow of plasma from the RPS to the processing chamber and are inadequate for purging effectiveness. Additionally, current cooling flanges are constrained to lower temperatures (less than about 70° C.). Furthermore, the current cooling flanges provide a 2-point contact with mating processing chamber parts leading chamber-to-chamber temperature variations.
Accordingly, there is a need in the art for improved cooling flanges to connect the RPS to a semiconductor manufacturing process chamber.
In some aspects, the techniques described herein relate to a cooling flange to connect a remote plasma source (RPS) to a semiconductor manufacturing processing chamber, the cooling flange including: a flange body with an inlet face and an outlet face defining a length of the cooling flange, an inlet flange on an inlet end of the flange body, the inlet flange including the inlet face and having an inlet flange thickness, an outlet flange on an outlet end of the flange body, the outlet flange including the outlet face and having an outlet flange thickness; a gas channel extending through the length of the flange body, the gas channel having an inlet opening in the inlet face of the flange body and an outlet opening in the outlet face of the flange body; and a purge gas inlet opening in a side of the flange body along the length of the flange body between the inlet flange and the outlet flange, the purge gas inlet opening in fluid communication with the gas channel.
In some aspects, the techniques described herein relate to a cooling flange to connect a remote plasma source (RPS) to a semiconductor manufacturing processing chamber, the cooling flange including: a flange body with an inlet face and an outlet face defining a length of the cooling flange, an inlet flange on an inlet end of the flange body, the inlet flange including the inlet face and having an inlet flange thickness, an outlet flange on an outlet end of the flange body, the outlet flange including the outlet face and having an outlet flange thickness; a gas channel extending through the length of the flange body, the gas channel having an inlet opening in the inlet face of the flange body and an outlet opening in the outlet face of the flange body, the gas channel having an inlet funnel, a middle tube and an outlet funnel, the middle tube connecting the inlet funnel with the outlet funnel; and a purge gas inlet opening in a side of the flange body along the length of the flange body between the inlet flange and the outlet flange, the purge gas inlet opening in fluid communication with the middle tube of the gas channel.
In some aspects, the techniques described herein relate to a semiconductor manufacturing processing chamber including: a chamber lid including a gas inlet, the gas inlet having an inlet opening in a top face of the chamber lid; a remote plasma source (RPS) above the chamber lid; and a cooling flange connecting the remote plasma source (RPS) to the chamber lid, the cooling flange including: a flange body with an inlet face and an outlet face defining a length of the cooling flange, an inlet flange on an inlet end of the flange body, the inlet flange including the inlet face and having an inlet flange thickness, an outlet flange on an outlet end of the flange body, the outlet flange including the outlet face and having an outlet flange thickness, a gas channel extending through the length of the flange body, the gas channel having an inlet opening in the inlet face of the flange body and an outlet opening in the outlet face of the flange body, and a purge gas inlet opening in a side of the flange body along the length of the flange body between the inlet flange and the outlet flange, the purge gas inlet opening in fluid communication with the gas channel, wherein the gas channel of the cooling flange is in fluid communication with the remote plasma source (RPS) and the gas inlet of the chamber lid.
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 typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.
Before describing several exemplary embodiments of the disclosure, it is to be understood that the disclosure is not limited to the details of construction or process steps set forth in the following description. The disclosure is capable of other embodiments and of being practiced or being carried out in various ways.
As used in this specification and the appended claims, the term “substrate” refers to a surface, or portion of a surface, upon which a process acts. It will also be understood by those skilled in the art that reference to a substrate can also refer to only a portion of the substrate, unless the context clearly indicates otherwise. Additionally, reference to depositing on a substrate can mean both a bare substrate and a substrate with one or more films or features deposited or formed thereon
A “substrate” as used herein, refers to any substrate or material surface formed on a substrate upon which film processing is performed during a fabrication process. For example, a substrate surface on which processing can be performed include materials such as silicon, silicon oxide, strained silicon, silicon on insulator (SOI), carbon doped silicon oxides, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. Substrates include, without limitation, semiconductor wafers. Substrates may be exposed to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure and/or bake the substrate surface. In addition to film processing directly on the surface of the substrate itself, in the present disclosure, any of the film processing steps disclosed may also be performed on an underlayer formed on the substrate as disclosed in more detail below, and the term “substrate surface” is intended to include such underlayer as the context indicates. Thus, for example, where a film/layer or partial film/layer has been deposited onto a substrate surface, the exposed surface of the newly deposited film/layer becomes the substrate surface.
“Atomic layer deposition” or “cyclical deposition” as used herein refers to a process comprising the sequential exposure of two or more reactive compounds to deposit a layer of material on a substrate surface. As used in this specification and the appended claims, the terms “reactive compound”, “reactive gas”, “reactive species”, “precursor”, “process gas” and the like are used interchangeably to mean a substance with a species capable of reacting with the substrate surface or material on the substrate surface in a surface reaction (e.g., chemisorption, oxidation, reduction, cycloaddition). The substrate, or portion of the substrate, is exposed sequentially to the two or more reactive compounds which are introduced into a reaction zone of a processing chamber.
The cooling flange 100 connects to the gas funnel 130 through a flange 140. O-ring grooves 150 are formed in one or more of the bottom of the cooling flange 100, the top of the gas funnel 130, top of the flange 140 or bottom of the flange 140. The presence of the O-ring grooves 150 impacts the contact points between the cooling flange 100 and the gas funnel 130. In the conventional cooling flange illustrated, there are two points; a first contact point 151 and a second contact point 152. The first contact point 151 is between the gas channel 120 and the O-ring groove 150 on the bottom of the cooling flange 100, between the cooling flange 100 and the gas funnel 130. The second contact point 152 is at the outer edge of the cooling flange 100 outside the O-ring grooves 150 between cooling flange 100 and the flange 140. The region between the first contact point 151 and the second contact point 152 may not be completely sealed or have full contact, affecting the temperature control, resulting in chamber-to-chamber variations in temperature uniformity.
The pneumatic valves 110 all for the addition of an inert gas flow to the gas channel 120 either during flow of a plasma through the cooling flange 100, as a diluent gas, or without plasma flow, as a purge gas. The pneumatic valves 110 interrupt the flow path of the gas channel 120, causing inefficient purging of the cooling flange 100 and increasing turbulence of the flow from the plasma supply. Additionally, the pneumatic valves 110 impose temperature constraints on the cooling flange. The pneumatic valves 110 have a maximum operating temperature of about 70° C.
One or more embodiments of the disclosure advantageously provide cooling flanges that provide improved purging efficiency. Some embodiments advantageously provide an efficient flow of plasma without flow restrictions. Some embodiments advantageously provide cooling flanges with improved temperature constraints.
In some embodiments, the removal of the pneumatic isolation valves from the cooling flange removes the temperature constraint of 70° C., allowing for higher temperature processes.
In some embodiments, a single point contact between the cooling flange and the processing chamber is provided. The single point contact eliminates temperature fluctuation issues. In some embodiments, the cooling flange is in direct contact with the mixer and/or the lid of the processing chamber.
Some embodiments of the disclosure help avoid or minimize precursor back streaming towards the remote plasma source. The length of the cooling flange is configured to avoid back streaming of precursors.
Some embodiments of the disclosure provide for improved cooling flange purging efficiency by connecting the purge gas line closer to the inlet funnel and/or by removing the isolation valves. Without the isolation valves, the flow path of the plasma through the cooling flange is not obstructed, minimizing flow restrictions. Elimination of the isolation valves simplifies construction and costs of the cooling flange. Some embodiments reduce leakage points by eliminating the isolation valves.
Some embodiments avoid back streaming of gases into the RPS without the use of valves. Some embodiments allow for improved contact between the cooling flange and the mixer or process chamber lid reducing temperature variations and improving chamber-to-chamber matching.
Some embodiments of the cooling flange are designed in such a way, that the length of cooling flange is configured to eliminate back streaming of gases. Sufficient length of the cooling flange prevents back flow of precursors from getting close to the RPS generator. In some embodiments, use of hydrogen (H2) as the purge gas shows negligible or no back diffusion of the precursor and with efficient purging from top completely restrict the diffusion of precursors.
When cooling is employed, a water channel can be used adjacent the RPS generator. The cooling channel can be moved to either or both ends of the flange. For purge gas, a direct gas line weldment can be connected to the cooling flange which reduces the flow path resistance.
The cooling flanges 200 of some embodiments are configured to connect a remote plasma source (RPS) 350 to a processing chamber 300.
Referring to
In some embodiments, an inlet flange 220 is on an inlet end 211 of the flange body 210. The inlet flange 220 of some embodiments includes the inlet face 212 of the flange body 210. The inlet flange 220 has an inlet flange thickness TIF.
In some embodiments, an outlet flange 225 is on the outlet end 213 of the flange body 210. The outlet flange 225 of some embodiments includes the outlet face 214 of the outlet face 214. The outlet flange 225 has an outlet flange thickness TOF.
In some embodiments, the flange body 210 includes both an inlet flange 220 on the inlet end 211 and an outlet flange 225 on the outlet end 213.
The flange body 210 can be made of any suitable material known to the skilled artisan. In some embodiments, the flange body 210 comprises stainless steel or aluminum.
In some embodiments, one or more of the inlet flange 220 or the outlet flange 225 comprises a cooling channel 230 formed in the inlet face 212. The embodiments illustrated in
The inlet end 211 of the illustrated embodiment includes the cooling channel 230 in the inlet face 212. The cooling channel 230 of some embodiments includes a cooling tube 235 that extends through the cooling channel 230 from a first end 231 of the cooling channel 230 to a second end 232 of the cooling channel 230. The embodiment illustrated in
The inlet flange 220 illustrated includes a plurality of apertures 236 that can be used to connect the cooling flange 200 to a remote plasma source, as is described below. The outlet flange 225 illustrated includes a plurality of apertures 238 that can be used to connect the cooling flange 200 to a gas distribution assembly of a processing chamber, as is described below. The skilled artisan will recognize the manner in which the plurality of apertures 236 in the inlet flange 220 and the plurality of apertures 238 in the outlet flange 225 can be used to form the respective connections. For example, a suitable fastener (e.g., bolts) can be used with the plurality of apertures 236 in the inlet flange 220 or plurality of apertures 238 in the outlet flange 225 to connect the cooling flange 200 to the adjacent components.
The inlet end 211 of some embodiments, as shown in
A gas channel 240 extends through the length LCF of the flange body 210. The gas channel 240 has an inlet opening 242 in the inlet face 212 and an outlet opening 244 in the outlet face 214 of the flange body 210.
The length LCF of the flange body 210 is configured to avoid back streaming of precursor gases from the outlet opening 244 reaching the inlet opening 242. In some embodiments, the length of the cooling flange is greater than 2 inches, 3 inches, 4 inches or 5 inches. In some embodiments, the length of the cooling flange is less than 15 inches, 14 inches, 13 inches, 12 inches, 11 inches, or 10 inches. In some embodiments, the cooling flange has a length in the range of 2 inches to 15 inches, or in the range of 3 inches to 14 inches, or in the range of 4 inches to 12 inches, or in the range of 5 inches to 10 inches. In some embodiments, the length LCF of the flange body 210 of the cooling flange 200 is greater than or equal to 2 inches and less than or equal to 15 inches, or greater than or equal to 4 inches and less than or equal to 12 inches.
The gas channel 240 of some embodiments, as shown in
The inlet funnel 250 is shaped with a largest diameter at the inlet opening 242 and the smallest diameter at the transition 255 with the middle tube 260. The inlet angle ΘI is measured relative to the central axis 245 of the gas channel 240. The inlet angle ΘI of the inlet funnel 250, according to some embodiments, is in the range of 15° to 55°, measured relative to the central axis 245 of the gas channel 240. In some embodiments, the angle ΘI is in the range of 20° to 45°, or about 30°.
The inlet diameter DIF is measured as the widest part of the inlet funnel 250 located at the inlet opening 242. The inlet diameter DIF is also referred to as the maximum diameter at the inlet face 212 of the flange body 210. In some embodiments, the inlet diameter DIF is in the range of 1 inch to 3 inches, or in the range of 1.5 inches to 2.5 inches, or about 2 inches.
The outlet funnel 270 is shaped with the largest diameter at the outlet opening 244 and the smallest diameter at the transition 265 with the middle tube 260. The outlet angle ΘO is measured relative to the central axis 245 of the gas channel 240. In some embodiments, the outlet angle ΘO of the outlet funnel 270, according to some embodiments, is in the range of 30° to 70°, measured relative to the central axis 245 of the gas channel 240. In some embodiments, the angle ΘO is in the range of 40° to 60°, or in the range of 50° to 55°.
The outlet diameter DOF is measured as the widest part of the outlet funnel 270 located at the outlet opening 244. The outlet diameter DOF is also referred to as the maximum diameter at the outlet face 214 of the flange body 210. In some embodiments, the maximum diameter at the outlet face 214 (the outlet diameter DOF) is in the range of 0.5 inches to 2 inches, or in the range of 1 inch to 1.5 inches or about 1.25 inches.
The middle tube 260 connecting the inlet funnel 250 with the outlet funnel 270 of some embodiments has a substantially uniform diameter DMT along the length LGCM of the middle tube 260. As used in this manner, a “substantially uniform diameter” varies at any point along the length LGCM by less than or equal to 10% relative to the average diameter. In some embodiments, the diameter DMT has a diameter in the range of 0.2 inches to 0.5 inches, or in the range of 0.3 inches to 0.4 inches.
Referring again to
The purge gas channel 282 can be connected to the gas channel 240 at any point along the length LCF of the flange body 210. In some embodiments, the purge gas inlet opening 280 is in fluid communication through the purge gas channel 282 with the middle tube 260 of the gas channel 240.
The location of the junction between the purge gas channel 282 and the middle tube 260 may affect the backflow of precursors from the outlet face 214 of the flange body 210 flowing backward to the inlet face 212 and into the remote plasma source connected to the inlet face 212. In some embodiments, the purge gas inlet opening 280 connects to the middle tube 260 of the gas channel 240 at a distance DPJ within 1 inch of the inlet funnel 250. The distance DPJ is measured from the transition 255 between the inlet funnel 250 and the middle tube 260 to the edge 284 of the purge gas channel 282 closest to the transition 255. In some embodiments, the distance DPJ is less than or equal to 2.5 inches, 2 inches, 1.5 inches, 1 inch, 0.75 inches, 0.5 inches or 0.25 inches.
The diameter of the purge gas inlet channel 282 is configured to provide a sufficient flow of purge gas into the gas channel 240 to prevent backflow of precursor through the flange body 210. In some embodiments, the purge gas inlet channel 282 has a diameter DPC in the range of 0.25 inches to 1.5 inches, or in the range of 0.5 inches to 1.25 inches, or in the range of 0.75 inches to 1 inch. In some embodiments, the diameter DPC of the purge gas inlet channel 282 is greater than or equal to the diameter DMT of the middle tube 260.
In some embodiments, the purge gas inlet opening 280 is in a flat face 286 in the cylindrical wall (side 215) of the flange body 210. The flat face 286 formed in the side 215 provides a location for the attachment of a gas inlet valve (not shown) to the flange body 210 of the cooling flange 200.
The chamber lid 308 of some embodiments includes a gas distribution assembly or gas injector, as will be understood by the skilled artisan. The chamber lid 308 of some embodiments comprises a gas inlet 315. The gas inlet 315 includes an inlet opening 316 in the chamber lid 308.
In the illustrated embodiment the inlet opening 316 includes a gas distribution assembly configured to provide a flow of one or more gases into the interior 309 of the semiconductor manufacturing processing chamber 300. In some embodiments, the gas distribution assembly includes a showerhead 320 located within the interior 309 semiconductor manufacturing processing chamber 300. In the illustrated embodiment, the showerhead 320 is connected to the chamber lid 308 and is coplanar with the chamber lid 308. However, the skilled artisan will recognize that this arrangement is merely an example of one possible configuration and that the showerhead 320 can be within the interior 309 of the semiconductor manufacturing processing chamber 300 or part of the chamber lid 308 that bound the interior 309. The showerhead 320 is part of the gas distribution assembly and may be referred to as a gas distribution plate.
The showerhead 320 has a front surface 322 and a back surface 324 that define the thickness of the showerhead 320. A plurality of apertures 326 extend through the thickness of the showerhead 320. The plurality of apertures 326 allow a gas to flow from the region adjacent the back surface 324 to the interior 309 of the semiconductor manufacturing processing chamber 300 through the showerhead 320.
The showerhead 320 can be made of any suitable material known to the skilled artisan. In some embodiments, the showerhead 320 is made of a conductive material that can be used to generate a plasma within the interior 309 of the semiconductor manufacturing processing chamber 300. In some embodiments, the showerhead 320 comprises one or more of stainless steel or aluminum.
A gas funnel 330 is positioned on the showerhead 320. The gas funnel 330 has a front surface 332 and a back surface 334. An opening 336 extends through the center of the gas funnel 330. The front surface 332 of some embodiments has a concave-shaped inner portion and a flat outer portion. The flat outer portion of the front surface 332 of the gas funnel 330 is in contact with the back surface 324 of the showerhead 320 to form a gas plenum between the back surface 324 of the showerhead 320 and the concave-shaped inner portion of the front surface 332 of the gas funnel 330.
A substrate support 340 is located within the interior 309 of the semiconductor manufacturing processing chamber 300. The substrate support 340 of some embodiments comprises a support body 341 positioned on a support shaft 342. The support body 341 has a support surface 343 configured to support a semiconductor wafer 345 for processing. The support shaft 342 of some embodiments is configured to move the support body 341 closer to/further from the showerhead 320 and/or around a rotational axis of the support shaft 342.
In some embodiments, the support body 341 includes a thermal element 344 configured to heat the semiconductor wafer 345 on the support surface 343. The thermal element 344 can be any suitable heating mechanism known to the skilled artisan. For example, in some embodiments, the thermal element 344 comprises a resistive heating element that is connected to a power supply (not shown) configured to apply power to the thermal element 344 to heat the support body 341. In some embodiments, the support body 341 includes an electrostatic chuck (ESC) (not shown). The skilled artisan will be familiar with the construction of the ESC and the manner in which the ESC is powered and employed.
The semiconductor manufacturing processing chamber 300 of some embodiments, as shown in
The cooling flange 200 connects the remote plasma source (RPS) 350 to the chamber lid 308. The cooling flange 200 illustrated has an inlet flange 220 and outlet flange 225. The inlet flange 220 is connected to the remote plasma source 350 and the outlet flange 225 is connected to the gas funnel 330 of the gas distribution assembly. In use, a plasma generated in the remote plasma source 350 flows through the gas channel 240 of the cooling flange 200 into the opening 336 in the back surface 334 of the gas funnel 330, into the plenum 325 between the front surface 332 of the gas funnel 330 and the back surface 324 of the showerhead 320, and then through the plurality of apertures 326 in the showerhead 320 into the process region 305 between the substrate support 340 and the showerhead 320.
In some embodiments, a purge gas flow is provided through the purge gas inlet opening 280 into the purge gas channel 282, and then into the gas channel 240. The purge gas flows through the gas channel 240 of the cooling flange 200 into the gas funnel 330 of the semiconductor manufacturing processing chamber 300. The purge gas flow can be provided in a constant flow, in pulses or varied. In some embodiments, the purge gas flow is provided through the cooling flange 200 into the gas funnel 330 when the remote plasma source 350 is not powered so that a flow of inert gas flows into the interior 309 of the semiconductor manufacturing processing chamber 300 through the showerhead 320 even without a plasma flow. In some embodiments, the remote plasma source 350 is used as a passthrough for a process gas that is not ignited into a plasma. The non-plasma process gas flows into the cooling flange 200 and is joined with the purge gas flow in the gas channel 240 to flow into the gas funnel 330.
In the embodiment illustrated in
A cooling tube 235 is illustrated in
Referring back to
Reference throughout this specification to “one embodiment,” “certain embodiments,” “one or more embodiments” or “an embodiment” means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of the phrases such as “in one or more embodiments,” “in certain embodiments,” “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.
Although the disclosure herein has been described with reference to particular embodiments, those skilled in the art will understand that the embodiments described are merely illustrative of the principles and applications of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and apparatus of the present disclosure without departing from the spirit and scope of the disclosure. Thus, the present disclosure can include modifications and variations that are within the scope of the appended claims and their equivalents.
