Encoder Sensors for Semiconductor Processing – Wafer Inspection and Surface Metrology Systems

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The patterning on semiconductors must be highly precise and inspection processes must be thorough.

MicroE has worked with several semiconductor manufacturors to develop state of the art inspection systems that use encoder sensors to determine the wafer position relative to the machine. Read on to find out more about MicroE's projects on wafer inspection and surface metrology.

Wafer Inspection

The Challenge

Wafers and process tools need to be monitored with state-of-the art equipment and measurement systems to fulfill the need to continuously improve the yield of existing semiconductor manufacturing processes as well as to reduce time to market for new and increasingly complex designs and processes.

Normally, precision rotary stages are used to move the wafers during their inspection. The throughput and efficacy of the wafer inspection process can be maximized by low overall stage height and a large aperture for the sensing and inspection equipment. A number of commercially available rotary stages do not meet all of the application requirements, but achieve the required levels of repeatability and accuracy.

The Solution

Celera Motion Omni Series direct drive motors with apertures over 400 mm and axial heights as low as 8 mm offer a best-in-class form factor with the accurate and smooth motion expected from a direct drive motor. Rotary stages designed with Omni Series motors are capable of achieving very low profiles and providing a large aperture for sensing, scanning and inspection equipment.

The Benefit

The Omni Series motors from Celera Motion have been used in a number of low profile rotary stages and allowed the wafer inspection systems to attain the desired yield and throughput. Fully assembled and tested rotary stages and mechatronics packages, designed by an expert engineering staff with several years of experience, are also provided by Celera Motion.

During the project, engineers at Celera Motion work closely with the customer to develop a highly optimized solution. When in serial production, Celera’s end deliverable can be encoder components, motor components, or a fully assembled and tested rotary stage.

Inspection and Metrology

The Challenge

Yield management and process control are of the utmost importance when manufacturing of integrated circuits, reticles, LEDs, and wafers.

Competitive advantages can be achieved by inspection and metrology equipment manufacturers by enhancing the capabilities of their equipment to feed high quality, real-time data back into the manufacturing process rapidly to detect and then eliminate defects in the manufacturing process as early as possible.

It is essential to have extremely smooth rotation of wafers, reticles, and devices on a stage with a large aperture that provide optical and scanning systems with a clear path for inspection and scanning.

The Solution

Industry leading zero cogging smooth motion is provided by Celera Motion’s Agility Series motor kits. These kits are available in form factors with through holes of 265 mm and larger and outer diameters from 19 mm to more than 292 mm.

Celera Motion’s Agility Series smooth and accurate slotless motors have been integrated into a wide range of rotary stages to solve multiple semiconductor inspection and metrology application challenges for equipment manufacturers around the world.

The Benefit

Cogging torque is eliminated by Celera Motion’s ZeroCogTM slotless motor technology. The resulting accurate and smooth motion enables the highest quality image and scanning data to be collected.

The Agility Series has large apertures that provide the optical inspection and scanning systems with access to significant areas of the inspection surface; and the fast settling times possible from direct drive stages enable the equipment to obtain huge volumes of data rapidly.

This information has been sourced, reviewed and adapted from materials provided by MicroE.

For more information on this source, please visit MicroE.

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