Embodiments of the present disclosure generally relate to a carrier for transferring a carrier for transferring substrates of varying sizes between semiconductor processing chambers.
Semiconductor processing chambers, such as deposition, etching, or annealing chambers are configured to process substrates of one particular size. In many instances, processing chambers are configured to process either a 300 mm substrate or a 200 mm substrate. However, in some applications, smaller substrates are utilized than the processing chamber is configured to process. In these instances, a processing chamber originally configured to process a 300 mm substrate would process a 200 mm, a 150 mm, or a 100 mm substrate. In another embodiment, a processing chamber originally configured to process a 200 mm substrate would process a 150 mm or a 100 mm substrate.
When smaller substrates than the processing chambers are originally configured to handle are being treated, the original transfer devices and chamber clamping mechanisms are not always compatible with the smaller substrate. However, replacing transfer devices and/or chamber clamping mechanisms within processing chambers is expensive, requires extensive downtime, and prevents quick changes between substrate sizes being processed.
Reduced substrate sizes are often utilized when manufacturing optical devices, such as waveguides, flat optical devices, metasurfaces, color-filters, and anti-reflective coatings. Optical devices are engineered to exhibit a high refractive index and low absorption loss properties. During optical device formation, temperature control and scratch reduction assist in improving optical device performance.
Substrate carriers are utilized which mimic the size and shape of a larger substrate, which the processing chambers are configured to process, while a smaller substrate is being processed. Substrate carriers are similar in composition to a substrate and hold the substrate as the substrate passes between different processing chambers and transfer chambers. However, substrate carriers are limited in ability and control of heating and cooling of substrates positioned therein and substrates often shift during transfer. Limited heating/cooling control sometimes causes over or under processing of a substrate, or substrate shifting. Substrate shifting may lead to uneven processing or scratches on the substrate itself.
Therefore, there is a need to improve substrate heating/cooling and reduce substrate shift while utilizing substrate carriers.
The present disclosure generally relates to substrate carriers, configured for use during semiconductor processing. In one embodiment, the substrate carrier includes a carrier base and a clamp ring. The carrier base includes an outer base surface, a lower base surface disposed radially inward of the outer base surface, an upper base surface disposed radially inward of the outer base surface and opposite the lower base surface, a substrate pocket disposed from the upper base surface and towards the lower base surface, a plurality of gas channels formed between the lower base surface and the substrate pocket, and one or more base alignment features formed on the upper base surface. The clamp ring is disposed on the upper base surface. The clamp ring includes an outer clamp surface, a lower clamp surface disposed radially inward of the outer clamp surface, an upper clamp surface disposed radially inward of the outer clamp surface and opposite the lower clamp surface, and an inner clamp surface radially inward of the outer clamp surface and connecting the lower clamp surface and the upper clamp surface. The inner clamp surface extends radially inward over the substrate pocket.
In another embodiment, another substrate carrier is described. The substrate carrier includes a carrier base and a clamp ring. The carrier base includes an outer base surface, a lower base surface, an upper base surface opposite the lower base surface, a substrate pocket disposed from the upper base surface and towards the lower base surface, one or more substrate support features extending from the substrate pocket, a plurality of gas channels formed between the lower base surface and the substrate pocket, and one or more base alignment features formed on the upper base surface. The clamp ring is disposed on the upper base surface. The clamp ring includes an outer clamp surface extending in line with or radially outward from the outer base surface, a lower clamp surface, an upper clamp surface opposite the lower clamp surface, an inner clamp surface radially inward of the outer clamp surface and extending radially inward over the substrate pocket, and one or more clamp ring alignment features on the lower clamp surface.
In yet another embodiment, a substrate carrier is described which includes a carrier base. The carrier base includes an outer base surface having a diameter of about 300 mm to about 325 mm, a lower base surface radially inward of the outer base surface, an upper base surface opposite the lower base surface and radially inward of the outer base surface, a substrate pocket disposed from the upper base surface and towards the lower base surface, a substrate support ring extending from the substrate pocket, and a plurality of gas channels formed between the lower base surface and the substrate pocket and disposed radially inward of the substrate support ring. The plurality of gas channels include over 100 gas channels with each gas channel having a diameter of about 10 mils to about 75 mils. One or more base alignment features are formed on the upper base surface.
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 exemplary embodiments and are therefore not to be considered limiting of its scope, 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. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
The present disclosure is directed towards a substrate carrier with improved temperature control and reduced sliding. To run small substrate sizes in a system configured for larger substrate (e.g., wafer) sizes, substrate carriers similar to those described herein are utilized. The substrate carrier is used to transfer and process smaller sized substrates. However, previous substrate carriers have poor substrate temperature control. Poor substrate temperature control degrades process performance.
The substrate carrier described herein enables improved substrate temperature control by enabling backside gas flow on the back of the substrate. Flowing backside gas on the back of the substrate enhances thermal conductivity and control of the substrate temperature, such that the temperature of the substrate is closer to the temperature of a heater or pedestal. Backside gas flow therefore improves process performance for a variety of substrate processing operations, such as deposition processes, etching processes, and annealing processes. Deposition processes include atomic layer deposition (ALD), chemical vapor deposition (CVD), and physical vapor deposition (PVD). Etching processes include dry etching processes such as reactive ion etching (RIE). Annealing processes include rapid thermal processing (RTP) or furnace processing. Other processes which utilize substrate temperature control to improve processing results may also benefit from the substrate carrier as described herein. The embodiments described herein are particularly beneficial during PVD operations as the carrier is configured to enable improved heating/cooling control while still enabling a uniform electric field to pass through the substrate between an electrode within a pedestal on which the carrier is positioned and an electrode formed as part of a magnetron assembly.
In particular, the substrate carrier described herein is beneficial during deposition processes such as amorphous niobium oxide (α-NbOx) deposition or high refractive index Titanium oxide (TiOx) deposition. α-NbOx and TiOx deposition benefit from increased process control. During α-NbOx deposition, it is desired to have low film loss with improved amorphization. Forming the α-NbOx layer includes applying a direct current (DC) power and electric field across the substrate while flowing a process gas, such as a purge gas, as a backside gas and within the process chamber. α-NbOx deposition is cycled between deposition and cooling operations until the α-NbOx is a predetermined thickness. In some embodiments, formation of an α-NbOx layer with a thickness of greater than 250 nm and a film loss of less than about 0.03% is obtained. During α-NbOx layer formation, low substrate temperatures are utilized to obtain good layer formation results and improved amorphization.
During TiOx depositing, it is beneficial to have low film loss while forming a layer with a refractive index of equal to or greater than about 2.75. Forming the TiOx layer includes applying a bias power to form an electric field across the substrate while heating the substrate. Crystalline (rutile phase) TiOx has been shown to have a higher refractive index. Higher substrate processing temperatures as well as the application of a radio frequency (RF) bias across the substrate has been shown to increase the refractive index of the TiOx layer while reducing film loss. Higher RF bias has been shown to densify the TiOx film and increases to the substrate temperature have been shown to more effectively form rutile phase TiOx.
The substrate carrier described herein has a pocket which is sized to receive a smaller substrate. Gas channels are formed between the bottom surface of the base of the carrier and the pocket in which the substrate is positioned. The gas channels are configured to increase substrate temperature control by increasing thermal conductivity between the substrate and the carrier as well as between the substrate and a heater and/or pedestal on which the carrier is positioned. The substrate carrier described herein provides greatly improved temperature control. In embodiments described herein, the substrate carrier assists in controlling the temperature of the substrate between about 20° C. to about 400° C.
A clamp ring is installed over the substrate to hold the substrate in place within the substrate carrier. The clamp ring prevents the substrate from shifting as gas is applied to the back of the substrate by applying a downward force on the clamp ring opposite the upward force applied by the backside gas and the pressure difference between the volume above the substrate and the volume below the substrate.
In processes such as the NbOx and TiOx deposition processes described above, a pressure differential is applied between the pressure within the processing region above the substrate and a volume between the substrate and the substrate carrier. The pressure differential is caused by the application of the backside gas flow. In embodiments in which the process chamber is originally configured to process a 300 mm substrate and a 200 mm substrate is being held by the substrate carrier, the pressure above the substrate is about 1 mTorr to about 6 mTorr while the backside pressure below the substrate is about 3 Torr to about 8 Torr. Therefore, a pressure differential of about 3 to about 8 Torr is applied across the substrate. The clamp ring assists in applying downward force to the substrate. In some embodiments, the clamp ring itself has a mass of greater than about 3 kilograms (kg), such as about 4 kg. In embodiments where a larger pressure differential is utilized, heavier clamp rings may be utilized, such as a clamp ring with a mass of greater than about 7 kg, such as greater than about 8 kg, such as greater than about 9 kg.
However, the increased weight of the clamp rings cause the total substrate carrier and substrate weight to be greater than a general 300 mm substrate. Therefore, transfer devises, such as robots positioned in a transfer chamber or a factory interface, will encounter difficulty moving the carrier accurately and quickly without being redesigned or retrofit. Therefore, additional embodiments which utilize a lighter weight clamp ring are also described. The embodiments with a lighter weight clamp ring make use of clamp rings positioned within each individual process chamber to hold down the clamp ring when a pressure differential is applied.
In yet other embodiments, the clamp ring and the base of the substrate carrier are configured to lock together, such that the clamp ring is not weighted, but still exerts a downward force on the substrate.
The PVD chamber 100 is utilized to form optical devices on a substrate 102. The PVD chamber 100 is configured for utilization of a substrate carrier 111 which holds the substrate 102. The PVD chamber 100 includes a plurality of cathodes including at least one dielectric target cathode 101 and at least one optical device material target cathode 103 having a corresponding plurality of targets including at least one dielectric target 104 and at least one optical device material target 106, for example, a metallic or semiconductor target, attached to the chamber body 108. While
The PVD chamber 100 is configured to include a substrate support 110 having a support surface 112 to support the substrate carrier 111 and the substrate 102. The PVD chamber 100 includes an opening 134 (e.g., a slit valve) through which the optical device substrate may enter a process volume 105 of the PVD chamber 100.
The substrate support 110 includes an RF bias power source 114 coupled to a bias electrode 116 disposed in the substrate support 110. The PVD chamber 100 includes a sputter gas source 136 that provides a sputter gas, such as argon (Ar). The PVD chamber 100 includes a reactive gas source 138 that provides a reactive gas, such as an oxygen-containing gas or a nitrogen-containing gas.
The substrate support 110 includes a mechanism, such as a chamber clamp 142, that retains the substrate carrier 111 or a substrate, such as the substrate 102, on a support surface 112 of the substrate support 110. The mechanism may also include an electrostatic chuck, a vacuum chuck, or the like. The chamber clamp 142 is a retaining clamp and is disposed on top of a shield 140 within the PVD chamber 100. The substrate support 110 is configured to include a cooling conduit 118 disposed in the substrate support 110 where the cooling conduit 118 controllably cools the substrate support 110, the substrate carrier 111, and the substrate 102 positioned thereon to a predetermined temperature, for example between about 20° C. to about 400° C. The cooling conduit 118 is coupled to a cooling fluid source 120 to provide cooling fluid. The substrate support 110 is further configured to include a heater 122 embedded therein. The heater 122, such as a resistive element, disposed in the substrate support 110 is coupled to an optional heater power source 124 and controllably heats the substrate support 110 and the substrate 102 positioned thereon to a predetermined temperature, for example between about 30° C. to 300° C. Each target, for example, the dielectric target 104 or the optical device material target 106, has a DC power source 126 or an RF power source 128 and an associated magnetron. The multiple power sources enable both DC powered processes and RF powered processes to occur in the same PVD chamber 100.
The PVD chamber 100 includes a process gas supply 130 to supply a predetermined process gas to the process volume 105 of the PVD chamber 100. For example, the process gas supply 130 supplies oxygen-containing gas to the process volume 105 to form an oxidizing environment in the process volume 105. The PVD chamber 100 may also include a precursor gas source 132 to supply a precursor gas, for example a gaseous dopant precursor, which is controlled by precursor gas flow controller 131.
The substrate support 110 includes an electrode 210 and a susceptor 204. A backside gas passage 202 is disposed through the substrate support 110 and extends to the support surface 112. One or more exhaust passages may also formed through the substrate support 110 and extend from the support surface 112. The one or more exhaust passages enable pressure buildup caused by the introduction of gas from the backside gas passage 202 to be relieved. A plurality of lift pin holes 206 are formed through the substrate support 110 and are configured to raise and lower the substrate carrier 111 and the substrate 102. The lift pin holes 206 may include a socket disposed therein to assist in maintaining backside pressure and reduce gas leakage through the lift pin holes 206. The docket is disposed at a top of the lift pin holes 206 in a flared portion of the lift pin holes 206 adjacent to the support surface 112.
The carrier base 230a of the substrate carrier 111 is disposed on top of the substrate support 110. The support surface 112 of the substrate support 110 includes a carrier support protrusion 212. The carrier support protrusion 212 is disposed radially outward of each of the lift pin holes 206 and the backside gas passage 202. The carrier support protrusion 212 has a top surface 214 which contacts a lower base surface 232 of the carrier base 230a and forms a first backside gas plenum 226 between the support surface 112 and the lower base surface 232.
The substrate pocket 239 is a depression extending inward from an upper base surface 222 of the carrier base 230a. The substrate pocket 239 is sized to receive a substrate, such as a 200 mm substrate, a 150 mm substrate, or a 100 mm substrate. The substrate pocket 239 extends from the upper base surface 222 towards the lower base surface 232, but does not pass completely to the lower base surface 232. The substrate pocket 239 is centered about a central axis A of the substrate carrier 111. The central axis A is an axis which extends normally to the bottom surface 502 (
Within the substrate pocket 239 is one or more substrate support features 236 and a plurality of gas channels 234. The plurality of gas channels 234 are formed between the lower base surface 232 and the substrate pocket 239, such that the lower base surface 232 and the substrate pocket 239 are in fluid communication. The plurality of gas channels 234 are configured to allow backside gas to flow from the first backside gas plenum 226 and the backside gas passage 202.
The one or more substrate support features 236 are disposed radially outward of the plurality of gas channels 234. In some embodiments, the one or more substrate support features 236 is a substrate support ring. The one or more substrate support features 236 protrude away from the bottom surface 502 of the substrate pocket 239 and towards a plane in which the upper base surface 222 is disposed. The one or more substrate support features 236 are configured to support the substrate 102 and separate the substrate 102 from the bottom surface 502 of the substrate pocket 239. The one or more substrate support features 236 are centered about the central axis A and configured to form a seal between the substrate 102 and the bottom surface 502 of the substrate pocket 239 to form a second backside gas plenum 238 therebetween. The plurality of gas channels 234 are configured to supply gas to the second backside gas plenum 238 from the first backside gas plenum 226.
The upper base surface 222 further includes one or more base alignment features 248. In some embodiments, the base alignment features 248 are openings extending inward from the upper base surface 222 as shown in
The clamp ring 240a of the substrate carrier 111 is coupled to the upper base surface 222 of the carrier base 230a. A lower clamp surface 302 (
The lower clamp surface 302 (
An inner protrusion 244 extends radially inward of the main body of the clamp ring 240a and over an edge of the substrate 102. Therefore, the inner protrusion 244 forms a lip 242 over the substrate 102 and extends over the substrate pocket 239.
The clamp ring 240a and the carrier base 230a form a gap in which the substrate 102 is disposed. The lip 242 of the inner protrusion 244 and the bottom surface 502 of the substrate pocket 239 form a substrate receiving space. The height H1 between the lip 242 of the inner protrusion 244 and the bottom surface 502 of the substrate pocket 239 is sized to accommodate a substrate.
In embodiments in which the substrate carrier 111 is configured to hold a 100 mm substrate, the height H1 is about 500 μm to about 550 μm, such as about 515 μm to about 535 μm, such as about 525 μm to about 530 μm. In embodiments in which the substrate carrier 111 is configured to hold a 125 mm substrate, the height H1 is about 600 μm to about 650 μm, such as about 615 μm to about 635 μm, such as about 625 μm to about 630 μm. In embodiments in which the substrate carrier 111 is configured to hold a 150 mm substrate, the height H1 is about 650 μm to about 700 μm, such as about 665 μm to about 690 μm, such as about 675 μm to about 680 μm. In embodiments in which the substrate carrier 111 is configured to hold a 200 mm substrate, the height H1 is about 700 μm to about 750 μm, such as about 715 μm to about 735 μm, such as about 725 μm to about 730 μm. The height H1 is large enough to accommodate a substrate of a specific size, but small enough to prevent shifting of the substrate within the substrate pocket 239.
The chamber clamp 142 is configured to hold the substrate carrier 111 on the substrate support 110. The chamber clamp 142 is configured to actuate upwards and downwards as the substrate support 110 is raised and lowered. The chamber clamp 142 is positioned to rest on the shield 140 while the substrate support 110 is in a lowered position and is raised when the substrate support 110 and/or the substrate carrier 111 contact a clamping surface 220 of the chamber clamp 142. The shield 140 includes a vertical portion 218 which is configured to extend inside of a support slit 216 of the chamber clamp 142. The support slit 216 is formed from a lower surface of the chamber clamp 142 and is configured to receive the vertical portion 218 of the shield 140 to enable the chamber clamp 142 to be supported by the shield 140 when in a lowered position and to be lifted off of the shield 140 when in a raised position. The clamping surface 220 is a lower surface of the inner chamber clamp protrusion 224, which is a portion of the chamber clamp 142 which extends radially inward over at least a portion of the substrate carrier 111. The chamber clamp 142 may be configured to contact either the carrier base 230a, the clamp ring 240a, or both the carrier base 230a and the clamp ring 240a. The chamber clamp 142 is weighted to help keep the carrier base 230a and the clamp ring 240a in place on the substrate support 110. The chamber clamp 142 therefore has a mass of greater than about 3 kg, such as about 4 kg. In embodiments where a larger pressure differential is utilized, heavier chamber clamps 142 may be utilized, such as a chamber clamp 142 with a mass of greater than about 7 kg, such as greater than about 8 kg, such as greater than about 9 kg. The increased mass of the chamber clamp 142 does not cause alignment or transfer errors within the overall substrate carrier 111, as the chamber clamp 142 remains in the PVD chamber 100 between process operations.
The clamp ring 240a includes an outer clamp surface 306 and an inner clamp surface 308. Both the outer clamp surface 306 and the inner clamp surface 308 are circular surfaces and are centered about the central axis A. The inner clamp surface 308 and the outer clamp surface 306 are concentric. In some embodiments, one or both of the outer clamp surface 306 and the inner clamp surface 308 include a flat edge, such as the flat edge 402 of the outer clamp surface 306 shown in
The lower clamp surface 302 is disposed radially inward of the outer clamp surface 306 and extends between the outer clamp surface 306 and the inner clamp surface 308. An upper clamp surface 304 is disposed radially inward of the outer clamp surface 306 and also extends between the outer clamp surface 306 and the inner clamp surface 308. The upper clamp surface 304 and the lower clamp surface 302 are formed opposite one another. The one or more clamp ring alignment features 246 extend from the lower clamp surface 302.
The inner clamp surface 308 forms an innermost surface of the clamp ring 240a, such that the inner clamp surface 308 is the radially innermost surface of the inner protrusion 244. The inner clamp surface 308 is configured to have a first diameter D1. The first diameter D1 is less than the diameter of a substrate positioned within the substrate carrier 111. The lip 242 extends from the bottom of the inner clamp surface 308 and radially outwards. The lip 242 is parallel to one or both of the lower clamp surface 302 and the upper clamp surface 304 as well as the top surface of a substrate positioned within the substrate carrier 111.
The first diameter D1 varies with the size of the substrate being processed. When a 100 mm substrate is positioned within the substrate carrier 111, the first diameter D1 is about 75 mm to about 98 mm, such as about 80 mm to about 95 mm, such as about 85 to about 95 mm. When a 125 mm substrate is positioned within the substrate carrier 111, the first diameter D1 is about 100 mm to about 123 mm, such as about 115 mm to about 120 mm, such as about 118 to about 120 mm. When a 150 mm substrate is positioned within the substrate carrier 111, the first diameter D1 is about 125 mm to about 148 mm, such as about 130 mm to about 145 mm, such as about 135 to about 145 mm, such as about 140 mm to about 145 mm. When a 200 mm substrate is positioned within the substrate carrier 111, the first diameter D1 is about 175 mm to about 198 mm, such as about 180 mm to about 195 mm, such as about 185 to about 195 mm.
The lower portion 305 of the inner clamp surface 308 is disposed radially outward from the innermost portion of the inner clamp surface 308. The lower portion 305 is similarly centered about the central axis A, but had a larger diameter than the inner clamp surface 308. The lower portion 305 has a second diameter D2. The second diameter D2 is slightly larger than the first diameter D1. The second diameter D2 is configured to be slightly larger than the substrate which is positioned within the substrate carrier 111.
When a 100 mm substrate is positioned within the substrate carrier 111, the second diameter D2 is about 101 mm to about 110 mm, such as about 102 mm to about 105 mm, such as about 103 to about 105 mm. When a 125 mm substrate is positioned within the substrate carrier 111, the second diameter D2 is about 126 mm to about 140 mm, such as about 126 mm to about 130 mm, such as about 128 mm to about 130 mm. When a 150 mm substrate is positioned within the substrate carrier 111, the second diameter D2 is about 151 mm to about 165 mm, such as about 152 mm to about 160 mm, such as about 152 to about 155 mm. When a 200 mm substrate is positioned within the substrate carrier 111, the second diameter D2 is about 201 mm to about 215 mm, such as about 202 mm to about 210 mm, such as about 202 to about 205 mm. The difference between the first diameter D1 and the second diameter D2 is about 1 mm to about 15 mm, such as about 3 mm to about 10 mm, such as about 5 mm to about 10 mm.
The outer clamp surface 306 has a third diameter D3. The third diameter D3 greater than both the first diameter D1 and the second diameter D2. The third diameter D3 varies depending upon the configuration of the substrate carrier 111. In some embodiments, the third diameter D3 varies with the size of the substrate positioned within the substrate carrier 111. When a 100 mm substrate is positioned within the substrate carrier 111, the third diameter D3 is about 125 mm to about 310 mm, such as about 150 mm to about 310 mm, such as about 200 mm to about 305 mm. When a 125 mm substrate is positioned within the substrate carrier 111, the third diameter D3 is about 150 mm to about 310 mm, such as about 200 mm to about 310 mm, such as about 225 mm to about 305 mm. When a 150 mm substrate is positioned within the substrate carrier 111, the third diameter D3 is about 175 mm to about 310 mm, such as about 200 mm to about 310 mm, such as about 250 mm to about 305 mm. When a 200 mm substrate is positioned within the substrate carrier 111, the third diameter D3 is about 225 mm to about 310 mm, such as about 250 mm to about 310 mm, such as about 275 mm to about 305 mm.
The flat edge 402 forms a chord along one side of the outer clamp surface 306, such that the circular portion of the outer clamp surface 306 and the flat edge 402 intersect at a first end 404 and a second end 406 of the flat edge 402. The flat edge 402 is disposed between the first end 404 and the second end 406. The flat edge 402 forms a small portion of the outer clamp surface 306, such that an angular difference 8 between the first end 404 and the second end 406 along the outer clamp surface 306 is small. In embodiments described herein, the angular difference 8 is less than about 20 degrees, such as about 1 degrees to about 20 degrees, such as about 2 degrees to about 15 degrees, such as about 2 degrees to about 10 degrees. The angular difference 8 is the angle about the central axis A in which the flat edge 402 is formed. Having a relatively small angular difference 8 enables alignment of the clamp ring 240a and the carrier base 230a while reducing force imbalance between different portions of a substrate and enables more uniform thermal conduction.
The carrier base 230a includes an outer base surface 506 which connects the upper base surface 222 and the lower base surface 232. The upper base surface 222 and the lower base surface 232 protrude radially inward from the outer base surface 506. The upper base surface 222 and the lower base surface 232 are on opposite sides of the carrier base 230a, such that the carrier base 230a forms a disk with the outer base surface 506 forming the outer circumference of the disk.
The bottom surface 502 of the substrate pocket 239 includes the plurality of gas channels 234 formed therethrough as well as the one or more substrate support features 236. In embodiments described herein, the one or more substrate support features 236 is a singular substrate support feature and includes an annular substrate support ring extending from the bottom surface 502 upwards towards the upper base surface 222. The substrate support feature 236 forms a seal between a substrate and the carrier base 230a, such that the gas introduced by the plurality of gas channels 234 is maintained within a plenum between the substrate and the bottom surface 502.
The substrate support feature 236 has a second height H2. The substrate pocket 239 has a third height H3. The third height H3 is measured between the upper base surface 222 and the bottom surface 502 of the substrate pocket 239. The second height H2 is less than a third height H3. The second height H2 is a height large enough to separate a substrate positioned within the substrate pocket 239 from the bottom surface 502, such that the center of the substrate does not contact the bottom surface 502. The second height H2 and the third height H3 are changed to ensure the clamp ring alignment features 246 and the base alignment features 248 remain mated during processing, such that the second height H2 and the third height H3 are configured to control the amount of the substrate 102 positioned above the upper base surface 222.
The second height H2 is about 0.05 mm to about 0.15 mm, such as about 0.08 mm to about 0.12 mm, such as about 0.09 mm to about 0.11 mm. The third height H3 is configured to reduce sliding of the substrate 102 within the substrate pocket 239. In some embodiments, the difference between the third height H3 and the second height H2 is at least about 0.15 mm to about 0.3 mm, such as about 0.2 mm to prevent wafer sliding. The third height H3 is about 200 μm to about 450 μm, such as about 250 μm to about 400 μm, such as about 275 μm to about 350 μm.
Each of the gas channels 234 is disposed radially inward of the substrate support feature 236. The substrate support feature has an inner surface with a fourth diameter D4. The fourth diameter D4 is also the outermost diameter at which the gas channels 234 are formed through the bottom surface 502 of the substrate pocket 239. The overall substrate pocket 239 has a fifth diameter D5, such that the substrate pocket 239 has a cylindrical sidewall 504 with a fifth diameter D5. The fourth diameter D4 is smaller than the fifth diameter D5. The fourth diameter D4 is about 2.5 mm to about 10 mm less than the fifth diameter D5, such as about 3 mm to about 8 mm less than the fifth diameter D5, such as about 3 mm to about 7 mm less than the fifth diameter D5, such as about 3 mm to about 5 mm less than the fifth diameter D5. The fourth diameter D4 and the fifth diameter D5 vary depending on the size of the substrate. The fifth diameter D5 is larger than the size of the substrate positioned within the substrate pocket 239, but small enough to reduce shifting within the substrate pocket 239.
When a 100 mm substrate is positioned within the substrate carrier 111, the fifth diameter D5 is about 101 mm to about 110 mm, such as about 102 mm to about 105 mm, such as about 103 to about 105 mm. When a 125 mm substrate is positioned within the substrate carrier 111, the fifth diameter D5 is about 126 mm to about 140 mm, such as about 126 mm to about 130 mm, such as about 128 mm to about 130 mm. When a 150 mm substrate is positioned within the substrate carrier 111, the fifth diameter D5 is about 151 mm to about 165 mm, such as about 152 mm to about 160 mm, such as about 152 to about 155 mm. When a 200 mm substrate is positioned within the substrate carrier 111, the fifth diameter D5 is about 201 mm to about 215 mm, such as about 202 mm to about 210 mm, such as about 202 to about 205 mm.
When a 100 mm substrate is positioned within the substrate carrier 111, the fourth diameter D4 is about 90 mm to about 97 mm, such as about 94 mm to about 97 mm, such as about 95 to about 97 mm. When a 125 mm substrate is positioned within the substrate carrier 111, the fourth diameter D4 is about 115 mm to about 122 mm, such as about 118 mm to about 122 mm, such as about 120 mm to about 122 mm. When a 150 mm substrate is positioned within the substrate carrier 111, the fourth diameter D4 is about 140 mm to about 147 mm, such as about 142 mm to about 147 mm, such as about 145 to about 147 mm. When a 200 mm substrate is positioned within the substrate carrier 111, the fourth diameter D4 is about 190 mm to about 197 mm, such as about 193 mm to about 197 mm, such as about 195 to about 197 mm.
The outer base surface 506 has a sixth diameter D6. The sixth diameter D6 is configured to be similar to the diameter of a substrate which the PVD chamber 100 is configured to process. Therefore, the sixth diameter D6 is configured to be similar in diameter to a 300 mm or a 200 mm diameter substrate. When the PVD chamber 100 is configured to operate using a 300 mm substrate, the sixth diameter D6 is about 295 mm to about 305 mm, such as about 297 mm to about 303 mm, such as about 298 mm to about 302 mm, such as about 299 mm to about 301 mm. When the PVD chamber 100 is configured to operate using a 200 mm substrate, the sixth diameter D6 is about 195 mm to about 205 mm, such as about 197 mm to about 203 mm, such as about 198 mm to about 202 mm, such as about 199 mm to about 201 mm.
The width of the substrate support feature 236 along the radial direction from the central axis A is a first width W1. The width of the substrate support feature 236 is configured to enable good support of a substrate while reducing thermal interaction of the substrate with the carrier base 230a. The first width W1 is about 1.0 mm to about 3.0 mm, such as about 1.5 mm to about 2.5 mm, such as about 1.8 mm to about 2.2 mm, such as about 2.0 mm.
Each of the gas channels 234 further have a second width W2. The second width W2 is the diameter of each of the gas channels 234 as the gas channels pass through the carrier base 230a. The second width W2 is large enough to enable adequate gas flow through the carrier base 230a to control the temperature of the substrate, but small enough to reduce any non-uniformities formed through an electric field which passes through the substrate. If the gas channels 234 are larger in size, the gas channels will cause inconsistencies in the medium through which the electric field passes and cause non-uniformities on the substrate during processing. Large diameter gas channels 234 also increase the risk of plasma ignition within the gas channels 234 during application of an RF bias to a substrate support pedestal, such as the substrate support 110. The second width W2 is about 10 mils to about 75 mils, such as about 15 mils to about 55 mils, such as about 16 mils to about 50 mils. The plurality of gas channels 234 includes over 100 gas channels, such as over 200 gas channels, such as over 300 gas channels, such as over 500 gas channels, such as over 700 gas channels. The number of gas channels 234 changes depending upon the size of substrate positioned within the substrate pocket 239. The gas channels 234 fluidly connect the lower base surface 232 and the substrate pocket 239.
Extending the third diameter D3 to about the same as the sixth diameter D6 enables the clamp ring 240c to be clamped by the chamber clamp 142. The use of the chamber clamp 142 to clamp the clamp ring 240c enables the clamp ring mass to be reduced and reduces strain on transfer components within the processing system. The thickness of the total substrate carrier 700 is also reduced compared to the total thickness of the substrate carrier 111. In the embodiment of
The material of each of the clamp rings 240a, 240b, 240c and the carrier bases 230a, 230b, 230c is configured to enable good thermal conductivity while reducing contamination or damage to the substrate 102. As described herein, the substrate 102 is an optical device and is formed of silicon, such as glass. The clamp ring 240a and the carrier base 230a may be a similar material, such as mono-crystalline silicon. In other embodiments, the clamp ring 240a and the carrier base 230a are a metal material such as titanium or aluminum.
The inner edge 924 has a seventh diameter D7. The seventh diameter D7 is similar to the first diameter D1. The seventh diameter D7 varies with the size of the substrate being processed. When a 100 mm substrate is positioned within the substrate carrier 900, the seventh diameter D7 is about 75 mm to about 98 mm, such as about 80 mm to about 95 mm, such as about 85 to about 95 mm. When a 125 mm substrate is positioned within the substrate carrier 900, the seventh diameter D7 is about 100 mm to about 123 mm, such as about 115 mm to about 120 mm, such as about 118 to about 120 mm. When a 150 mm substrate is positioned within the substrate carrier 900, the seventh diameter D7 is about 125 mm to about 148 mm, such as about 130 mm to about 145 mm, such as about 135 to about 145 mm, such as about 140 mm to about 145 mm. When a 200 mm substrate is positioned within the substrate carrier 900, the seventh diameter D7 is about 175 mm to about 198 mm, such as about 180 mm to about 195 mm, such as about 185 to about 195 mm.
The outer edge of the chamber clamp ring 902 has an eighth diameter D8. The eighth diameter D8 is greater than the sixth diameter D6, such that the eighth diameter D8 extends radially outward of the outer base surface 506 of the carrier base 230a (
In the embodiment of
The unitary clamp ring 1202 is secured to the top surface 1104 of the multi-pocket carrier base 1102 using a plurality of alignment features 1204. The alignment features 1204 may be similar to the clamp ring alignment features 246 or the openings 310.
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, and the scope thereof is determined by the claims that follow.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 63/311,831, filed Feb. 18, 2022, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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63311831 | Feb 2022 | US |