Patent Application
20150078874
Embodiments of the present disclosure generally relate to semiconductor processing apparatus.
Semiconductor substrates are subjected to many different processes in order to manufacture a semiconductor die on the substrate. Modern semiconductor processing systems typically integrate a number of process chambers on a single platform to perform sequential processing steps without removing the substrate from the processing environment. For efficiency purposes, a transfer robot may be used to transfer the substrates between chambers. In some processing systems, transfer robots are used to move substrates outside of the processing environment. A substrate transfer robot blade associated with the transfer robot may be used to engage and support individual substrates during transfer.
Current substrate transfer robot blades support the substrate on non-compliant, or rigid, substrate support surfaces. However, the inventors have observed that acceleration of the robot blades in some transfers result in a force on the substrate which can cause defects in the substrate.
Accordingly, the inventors have provided an improved substrate transfer robot blade.
Embodiments of substrate transfer robot blades to engage and support a substrate during transfer are provided herein. In some embodiments, the substrate transfer robot blade includes a body having a blade support surface; and a plurality of compliant pads each comprising a contact surface and an opposite bottom surface supported by the body and arranged to support a substrate when disposed on the robot blade.
In some embodiments, a substrate transfer device comprises a robot comprising an arm coupled to the robot at a first end; a robot blade coupled to a second end of the arm, the robot blade comprising: a body having a blade support surface; and a plurality of compliant pads comprising a contact surface and an opposite bottom surface supported by the body and arranged to support a substrate when disposed on the robot blade.
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. 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.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. The figures are not drawn to scale and may be simplified for clarity. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Embodiments of the present disclosure relate to substrate transfer robot blades to engage and support a substrate during transfer and a substrate transfer apparatus having such a substrate transfer robot blade.
In the non-limiting embodiment illustrated in
In a non-limiting embodiment of the disclosed blade 100, a plurality of compliant substrate supports, for example compliant pads 300, may be supported by the body 102 and arranged to support a substrate 312 when a lower substrate surface 313 is disposed on the blade 100. As illustrated in
The compliant pad 300 may be made from materials compatible with the environment in which it is used and the substrate being transferred. Non-limiting examples of suitable materials for the compliant pad 300 include one or more of polymer materials, such as polyimide-based plastics such as Vespel® manufactured by DuPont and polyether ether ketone (PEEK); ceramic materials such as titanium nitride (TiN), alumina (Al2O3) and silicon carbide (SiC); and metal composites, such as aluminum silicon (AISi). Surface characteristics of the contact surface 302 may be enhanced by coating the compliant pad 300 with coatings such as diamond-like carbon (DLC) or alumina. In some embodiments, the compliant pad 300 may comprise an electrically conductive material.
A resilient element, for example a compression spring, such as helically wound spring 308, may be at least partially disposed within the passage 108 such that the helical axis of the helically wound spring 308 is aligned with the passage axis 206. For example as illustrated in
In some embodiments, at least a portion of a compliant pad 300 is disposed within a passage 108. For example as illustrated in
As illustrated, in some embodiments the helically wound spring 308 is adjacent to the wall of the passage 108 and axially aligned with the passage axis 206. The projection 306 may extend into the axial space 323 encircled by the coils, for example at least the uppermost coil 316 and lowermost coil 318. The helically wound spring 308 supports the compliant pad 300 as above.
Some embodiments may include one or more displacement attenuators, attenuators 310, disposed in the body 102 proximate to the passage 108. The attenuators 310 may include magnets or magnetic materials to reduce the amplitude of the displacement of the projection 306 within the passage 108. The attenuators 310 therefore also reduce the amplitude of the displacement of the compliant pad 300. If magnets are used as attenuators 310, the inventors believe, without being bound by theory, that displacement of the projection 306 and the helically wound spring 308 in the varying magnetic field between the magnets causes eddy currents which causes a drag effect on the moving components.
Alternately, or additionally, attenuators 310 may comprise an energy absorbing material to absorb and dissipate the impact energy. For example, the energy absorbing material could be placed in the passage 108 to dampen the motion of the projection 306. An energy absorbing material could also be placed between a portion of the compliant pad 300 and the blade support surface 202 to achieve a similar result.
In an alternate non-limiting embodiment illustrated in
According to some embodiments, a compliant pad 500 comprises a contact surface 502 to engage and support a substrate 312 and an opposite surface, lower surface 504. As illustrated in
The compliant pad 500 may comprise one or more of the suitable materials listed above.
Compliant pads 500 or 600 elastically deform, or deflect, under a force applied to their contact surfaces 502, 602, respectively, directed towards the body 102.
In some embodiments shown in
Under a force applied to the contact surface 716 in the direction of the body 102, the arm 704 deflects in the direction of the force.
In some embodiments shown in
The arm 904 may comprise a contact element 920 disposed on the second end 908 and may include a contact surface 916 configured to engage and support a substrate (e.g., substrate 312). In some embodiments, the arm 904 is formed of titanium and the contact element 920 may include, for example, at least 6 microns of titanium nitride (TiN). The TiN layer may be thermally grown on the second end 908 of the arm 904. In some embodiments, the upper surface 918 of the arm 904 may lie above or below the plane P as long as the contact surface 916 of the contact element 920 lies above the base 902.
In some embodiments, and as shown in
The platform 1004 may comprise a contact element 1020 disposed on the second end 1008 and may include a contact surface 1016 configured to engage and support a substrate 312. In some embodiments, the platform 1004 is formed of titanium and the contact element 1020 may include, for example, at least 6 microns of titanium nitride (TiN). The TiN layer may be thermally grown on the platform 1005 at or near a center of the platform 1004. In some embodiments, the upper surface 1018 of the platform 1004 may lie above or below the plane P as long as the contact surface 1016 of the contact element 1020 lies above the base 1002.
Contact elements 920, 1020 including a titanium nitride top layer as described above advantageously provide increased wear resistance and defect reduction. The inventors have also observed that such contact elements provide a tunable compliance with high temperature resistance based on the thickness of the titanium nitride layer.
During some segments of substrate transfer, the substrate transfer robot blade accelerates from a first velocity to a second velocity when moving from one location to another. When a substrate is supported at rest, for example on lift pins in a chamber, the substrate is at a velocity of 0 relative to the chamber. A substrate transfer robot blade, coupled to a transfer robot, may be used in a segment of a transfer process to transfer the substrate from the lift pins to another location. During the transfer process, the substrate transfer robot blade accelerates the substrate from a velocity of 0 to a transfer speed, typically between about 1 mm/sec. to about 8 mm/sec. For purposes of this disclosure, velocity and acceleration will be in relation to a fixed point, such as a point on the ground or on a process chamber.
If the substrate is accelerated in the vertically upward direction, the acceleration causes a force exerted by the substrate against the substrate transfer robot blade. The force can be represented by the equation F=ma, where “F” represents force, “m” represents mass, and “a” represents acceleration. In the present case, “m” is the mass of the substrate, “a” is the vertical acceleration of the substrate, and “F” is the force exerted by the substrate upon the substrate transfer robot blade as a result of the acceleration. The inventors have noted that the force F generated during a typical transfer of a substrate is in some cases sufficient to damage the substrate at the areas of contact between the substrate and the substrate transfer robot blade.
The mass of the substrate is generally fixed based on the size of the substrate. Therefore, for a substrate of a given mass, a decrease in acceleration can proportionally decrease the force “F” exerted on the substrate during transfer. The acceleration “a” is generally understood mathematically to be the change in velocity divided by the change in time of the velocity change (i.e., “a”=delta V/delta t). In order to decrease the acceleration “a”, the change in velocity can be decreased or the time of the velocity change can be increased. For productivity reasons, it is often desirable to transfer the substrate as quickly as possible. It may be desirable, therefore, to decrease the acceleration by increasing the time of the velocity change.
The inventors noted that during substrate transfers, a substrate is supported initially at rest and accelerated to a transfer speed. If this is effected on a transfer robot blade with unyielding, or non-compliant, pads, the substrate experiences a change in velocity over a very short period of time, leading to a significant acceleration as described above. As the delta t in the expression above approaches 0, the handoff becomes an impact as the substrate transfer robot blade contacts the substrate, leading to defect generation.
However, compliant pads allow the substrate to change velocity from 0 to the transfer speed over a longer period of time. Therefore, a substrate supported on compliant pads would experience a lesser acceleration, and a proportionally lesser force F. The decreased force F may reduce defect generation caused by the impact the same change in velocity over a longer time period.
In
Optional attenuators 310 may lessen the amplitude of the harmonic motion associated with a mass (such as the substrate 312) on a spring (such as helically wound spring 308).
As illustrated in
Resilient elements, other than helically wound spring 308 and spring 402, may be used to support the compliant pad 300 such that the lower surface 304 is spaced a distance from the blade support surface 202. Non-limiting examples of alternate resilient elements include wave springs, disc springs (e.g., Belleville springs), torsion springs, or the like.
In some embodiments, the compliant pad is formed from a compatible material listed above with a hardness such that a resilient element is not needed. For example, as illustrated in
As a blade 100 comprising compliant pads 500 contacts a substrate at contact surface 502 during a substrate transfer, the pad body 508 yields, and the time period during which the substrate 312 changes velocity from 0 to transfer speed is extended. As described above, a velocity change over an extended time period decreases the acceleration, and proportionally decreases the force F generated at the contact surface 502 between the substrate 312 and the compliant pad 500.
The compliant pads may be formed from more than one of the compatible materials above. For example, compliant pad 600 in
Returning to
As a blade 100 comprising compliant pads 700 contacts a substrate at contact surface 716 during substrate transfer, the arm 704 yields, and the time period during which the substrate 312 changes velocity from 0 to transfer speed is extended. As described above, a velocity change over an extended time period decreases the acceleration, and proportionally decreases the force F generated at the contact surface 716 between the substrate 312 and the compliant pad 700.
Returning to
Returning to
Any combination of the non-limiting examples of compliant pads 300, 500, 600, 700, 900, or 1000 (collectively, compliant pads 1120) may be used on a blade 100 to achieve the desired results of decreased defect generation.
The inventors have also noted that with typical transfer robot blades, a worn or defective substrate support surface needs replacement of the blade itself, leading to extended idle time for the robot, and possibly the processing system. In the present disclosure, a defective or worn compliant pad may be removed from the blade 100 and replaced with minimal impact on productivity. Compliant pads may also be changed based on the substrate or processing environment. A softer compliant pad may be desirable for some substrates or processes, while a harder compliant pad may be desirable for others. Rather than changing the transfer robot blade to accommodate specific needs, with the associated interruption to production, the compliant pads in the inventive substrate transfer blade can be changed quickly to a more suitable compliant pad.
A substrate transfer apparatus may beneficially include a plurality of compliant pads as disclosed herein. For example, a substrate transfer apparatus 1100 may comprise a robot 1102 comprising a robot arm, arm 1104, coupled to the robot 1102 for vertical and rotational displacement at a first end 1106. The arm 1104 may comprise one or more links, for example first link 1108 and second link 1110 pinned together at 1112. A second end 1114 of the arm 1104 may include a wrist 1116 to which the first end 104 of a blade 100 is coupled. The blade 100 may include any of the compliant pads 1120, or combinations thereof, as disclosed herein.
In operation, the substrate transfer apparatus 1100 may be operated such that the blade 100 is positioned below a substrate 312 supported at rest, for example on a plurality of lift pins 1118. Through mechanical manipulations of the robot 1102 and the arm 1104, the blade 100 is raised from a position below the substrate 312 to bring the compliant pads 1120 into contact with the lower substrate surface 313 to transfer the substrate 312 off of lift pins 1118. In doing so, the robot 1102, through the arm 1104 and the blade 100, accelerate the substrate from a velocity of 0 to a transfer speed. As described above, the acceleration results in a force F at contact points between the substrate 312 and the blade 100. As also described above, the compliant pads 1120 yield to the force such that the change in velocity of the substrate 312 takes place over a longer time period, decreasing the acceleration of the substrate 312 and proportionally decreasing the force F.
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.
This application claims benefit of U.S. provisional patent application Ser. No. 61/878,585, filed Sep. 16, 2013, which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61878585 | Sep 2013 | US |
