Semiconductor Developments Drive Motion Control
Alan Feinstein, Bayside Motion Group, Port Washington, N.Y. -- Semiconductor International, 12/1/2000
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| Alan Feinstein, Bayside Motion Group, Port Washington, N.Y. |
This growth rate not only creates a ripple effect with the major suppliers to the semiconductor equipment builders, but has provided the resources for new initiatives to further advance semiconductor technology. Because these initiatives focus on improved yields, higher densities and more output with smaller factories and equipment, the impact on the motion control industry is quite significant. Motion control equipment manufacturers must keep pace with the small sizes, cleaner processes and higher accuracies simply to be competitive.
Though the 300 mm initiative may be the most common semiconductor program, its developments have taken a backseat to the development of copper tools. The delay in 300 mm relates to the fact that most productivity goals were met with 200 mm production and there is little, if any, factory-hardened production equipment available.
Copper tools
One primary directive is copper tools. In many instances this has taken priority over 300 mm because the copper is required for higher densities. Copper is being developed for the interconnects, and sales for copper tools are rising quickly (36% growth last year and 50% growth estimated for this year). The impact of copper is that it will allow for an easier transition to 0.18 µm technology and ultimately to 0.10 µm technology.
The switch to copper, in and of itself, does not affect the motion control side of the processing equipment, though you can expect that the lapping/polishing processes will change. Rather, it is the nature of copper that will allow the manufacturers to push to have finer lines closer together. This is where the real impact is felt. Motion control equipment will have to work to much finer resolutions, and will require greater stability.
In today's market, several stage, motor and control technologies support this production equipment. The technology to reach below the 248 nm level will likely require non-recirculating bearings, providing very high smoothness with virtually no friction, and non-contact, brushless linear motors. However, to support the position stability, these systems will need to incorporate high-resolution feedback to eliminate servo effects.
300 mm
The 300 mm wafer is still a major initiative and is necessary to increase yield. It is expected that memory chips will be the first implementation of 300 mm technology. Particularly with the cost of memory today, it is necessary for these chip manufacturers to implement 300 mm, to simply reduce production cost. Presently, there are issues not only with the amount of production-ready equipment for manufacturing and metrology, but also the facilities requirements to handle larger machines.
This is one area where companies, such as Bayside, will be pressed to develop smaller platforms to achieve greater travel. One of Bayside's multi-axis motion platforms has been developed for wafer metrology, providing 300 mm in the same space of a 200 mm platform. The expansion to 300 mm is not simply a travel issue, for if it were, all motion companies could provide equipment. Rather, as the wafer diameter increases, the total tolerance for the motion control system, in terms of flatness and positioning, is being reduced to allow for greater yield.
It is the ultimate test to provide more, in less space, with tighter tolerances. This will drive motion companies to develop systems that can provide greater stiffness in a small footprint. As a byproduct of the chips, the computers that control the motion/vision systems on these machines have become faster and more powerful; it will be up to the motion system to run at faster speeds while maintaining high-velocity control and positional accuracy.
Conclusions
Today's major semiconductor initiatives are being driven by the need to produce more electronics, cheaper, smaller and more powerful. As commonplace as cell phones are, the technology push today is to provide direct Internet access over a cell phone. The manufacturers of other devices, such as pagers, automobiles, appliances and, of course, computers demand smaller devices.
These initiatives — coupled with a drive to reduce product size significantly, increase flexibility and occupy less real estate — are driving the development of motion control systems and other support products. Greater accuracy is needed to both manufacture and inspect the devices that today's fabs are striving to produce. •
