Substrate Transfer
Without human intervention, a substrate makes its way from a parked location (in a load lock or within the chamber itself on a specialized stage) to the stage in the processing module, ready for the deposition process.
Substrate transfer is achieved using an automated transfer arm. The movement of the arm is controlled using a closed-loop controller with a position feedback response (servomotor) that allows for precise control of position, velocity, and arm acceleration.
Positioning and Precision
Positioning and precision are carefully considered in the design and execution of this type of automation, as the goal is to save time and increase efficiency. If a substrate carrier, or a sample itself were to be dropped or hit another component in the system, time would be wasted. For this reason, Angstrom Engineering® employs a number of strategies to create a reliable and safe process to automatically transfer both substrates and their accompanying masks (if required).
The position of the stage (the substrate’s end goal) is determined and accurately controlled using a closed-loop controller, or an AC motor controlled by Aeres®. Its position is controlled using proximity sensors.
Single or Dual Process
In the case of a single or dual process module system, the transfer sequence occurs in the following manner:
- The transfer arm moves from its parked position into a load lock, and it picks up a substrate carrier from a vertically mobile substrate/mask cassette. This is a command generated through the Aeres® control software using position identifiers on both the substrate carrier and the cassette.
- The arm then moves into the process module (the deposition chamber) through an open gate valve, mounts on the stage using pneumatic clamps.
- Finally backs out of the process module, through the load lock, and back to its original position.
Angstrom Engineering® has worked to make their equipment highly functional, but not overly complex to use. Whenever I call I get immediate assistance. In an extremely busy facility like Princeton’s MNFL, these qualities have made Angstrom my first choice for PVD tools.
Joe Palmer
MNFL, Princeton University