Patent Application
20060045718
The present invention pertains generally to wafer processing equipment, and more particularly, to end effectors for such equipment.
Modem semiconductor processing systems include cluster tools that integrate a number of process chambers together in order to perform several sequential processing steps without removing the substrate from the highly controlled processing environment. These chambers may include, for example, degas chambers, substrate pre-conditioning chambers, cooldown chambers, transfer chambers, chemical vapor deposition chambers, physical vapor deposition chambers, and etch chambers. The combination of chambers in a cluster tool, as well as the operating conditions and parameters under which those chambers are run, are selected to fabricate specific structures using a specific process recipe and process flow.
Once the cluster tool has been set up with a desired set of chambers and auxiliary equipment for performing certain process steps, the cluster tool will typically process a large number of substrates by continuously passing them, one by one, through a series of chambers or process steps. The process recipes and sequences will typically be programmed into a microprocessor controller that will direct, control and monitor the processing of each substrate through the cluster tool. Once an entire cassette of wafers has been successfully processed through the cluster tool, the cassette may be passed to yet another cluster tool or stand alone tool, such as a chemical mechanical polisher, for further processing.
One example of a fabrication system is the cluster tool disclosed in U.S. Pat. No. 6,222,337 (Kroeker et al.), and reproduced in
A second robot 28 is located in transfer chamber 30 to transfer substrates between various chambers, such as the cooldown chamber 26, preclean chamber 24, CVD A1 chamber (not shown) and a PVD A1Cu processing chamber (not shown). The specific configuration of the chambers illustrated in
When magnet clamps 80,80′ rotate in the same direction with the same angular velocity, then the robot also rotates about axis x in this same direction with the same velocity. When magnet clamps 80, 80′ rotate in opposite directions with the same absolute angular velocity, then there is no rotation of assembly 14, but instead there is linear radial movement of wafer blade 86 to a position illustrated by dashed elements 81′-89′.
A wafer 35 is shown being loaded on wafer blade 86 to illustrate that the wafer blade can be extended through a wafer transfer slot 810 in a wall 811 of a chamber 32 to transfer such a wafer into or out of the chamber 32. The mode in which both motors rotate in the same direction at the same speed can be used to rotate the robot from a position suitable for wafer exchange with one of the adjacent chambers 12, 20, 22, 24, 26 (see
To keep wafer blade 86 directed radially away from the rotation axes x, an interlocking mechanism is used between the pivots or cams 85, 89 to assure an equal and opposite angular rotation of each pivot. The interlocking mechanism may take on many designs. One possible interlocking mechanism is a pair of intermeshed gears 92 and 93 formed on the pivots 85 and 89. These gears are loosely meshed to minimize particulate generation by these gears. To eliminate play between these two gears because of this loose mesh, a weak spring 94 (see
Although robots of the type depicted in U.S. Pat. No. 6,222,337 (Kroeker et al.) have some desirable properties, robots of this type also have some shortcomings. In particular, it has been found that robots of this type often suffer excessive wear in the hub assembly 14 and in the wrist 85′, 89′ and elbow 84′, 88′ joints, and exhibit deviations from parallelism between the opposing arms. These problems result in excessive maintenance requirements and in deviations in the manufacturing process. There is thus a need in the art for a robotic assembly which overcomes these infirmities, and for a method for making the same. These and other needs are met by the devices and methodologies disclosed herein and hereinafter described.
In one aspect, a robotic hub assembly is provided which comprises first and second spacers disposed in opposing relation to each other, and a device, such as a plurality of pins, for restricting the relative motion of the first and second spacers in a lateral direction. The device preferably comprises first and second sets of pins which extend through the first and second spacers. Preferably, the first set of pins extend through holes in the first spacer and rotatingly engage threaded apertures provided in said second spacer, and the second set of pins extend through holes in said second spacer and rotatingly engage threaded apertures provided in said first spacer.
One skilled in the art will appreciate that the various aspects of the present disclosure may be used in various combinations and sub-combinations, and each of those combinations and sub-combinations is to be treated as if specifically set forth herein.
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals indicate like features and wherein:
The aforementioned needs are met by the devices and methodologies disclosed herein. In particular, after careful investigation, it has now been found that, in conventional robotic arms of the type illustrated in
In a frog-leg construction such as that depicted in
In a completed hub assembly, the first 103 and second 105 spacers are disposed between first and second bearing rings (not shown), and one arm of the robot is attached to each bearing ring. The spacers 103, 105 maintain the first and second bearing rings (not shown) in a proper orientation with respect to each other. The first and second bearing rings rotate in the same direction when the robotic arms (not shown) are to be moved in a lateral direction, and rotate in opposing directions when the robotic arms are to be extended or retracted.
As noted above, in hub assemblies of the prior art which contain spacer configurations somewhat similar in design to the configuration depicted in
The spacer configuration 101 depicted in
The through holes 113 for the pins in the spacers are constructed such that the pins can move in a vertical direction, but are restricted in their motion in the lateral direction. In one particular embodiment, for example, the pins are 18/8 hardened steel pins, and the through holes are designed to permit motion of less than about 0.001 inches in the lateral direction.
The pins may be disposed in various manners throughout the spacers. Preferably, however, four pins are utilized, with the pins being spaced 90° apart. It is also preferred that the pins are arranged in pairs such that the pairs are facing opposing directions, and such that each of the pins in the pair are disposed on opposite sides of a spacer.
Although the present invention is described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention.
| Number | Date | Country | |
|---|---|---|---|
| 60560798 | Apr 2004 | US | |
| 60560406 | Apr 2004 | US |
