CyberOptics Semiconductors published an application note on its web site recently explained the working of its WaferSense Vibration and Leveling Sensors to enable a vertical diffusion group to determine how and to what extent a wafer could be damaged during high volume processing in a boat.
The device can detect non-aligned components. It can reduce calibration time by uninterrupted functioning, thus reducing overall costs and time. It travels across the tool to detect and control three-axis accelerations and vibrations. It is compatible with the existing tools. The vacuum-compatible device in x, y and z sizes and wafer tilt in x and y moved across the tool in the diffusion process. Wafer tilt and vibrations are also determined in a storage rack when the fan was turned on and off, and while carts were run at different speeds and weights in the aisle and transfer racks. The resulting information enabled engineers to make the necessary changes.
The designer positioned both the vibration and the leveling sensor within the same cassette, comparing the movements of the tool at varying spots in an endeavor to identify causes of wafer damage.
The Leveling Sensor is able to detect the tilt of semiconductor tools. It does not dismantle the tools or vacuum chambers, and minimizes time need for calibration by 80% or more. The Vibration sensor monitors three-axis speeds and vibrations. The design makes it suitable for wireless communication platforms to transmit data to facilitate both installation and maintenance.