Piezo motors and actuators in semiconductor manufacturing machines
Piezoelectric motors and actuators play a pivotal role in semiconductor manufacturing, particularly due to their remarkable resolution at the nanometer and sub-nanometer scales. They exhibit rapid response times, exceptional stiffness, and are well-suited for cleanroom and vacuum environments. .
Here are some of the processing stages that benefit from piezoelectric motors and actuators:
Wafer slicing and polishing
- Wafer slicing is achieved using piezo actuators positioning system. These systems ensure precise wafer thickness, ranging from approximately 250 to 750 micrometers. (LL10, LT20, LT40, LPS30)
- Precise control of the pressure applied to wafer polishing instruments ensures smoother surfaces and reduces the occurrence of defects. (LTC300, LTC450)
Multi-axis piezo actuator stages facilitate precise wafer positioning and autofocusing, which is paramount for defect identification in microscopy. (LT20, LT40)
Lithography
- Lithography, particularly in Extreme Ultraviolet (EUV) and Deep Ultraviolet (DUV) lithography machines, heavily relies on piezo actuators for ultra-precise positioning of wafers and masks (reticles). These machines are pivotal in fabricating minuscule features on silicon wafers. (LL10, LT20, LT40)
- The process requires aligning 300 mm wafers, which can be heavy, on chucks with sub-nanometer resolution. To achieve this precise alignment, a 3-dimensional piezo motor stage stack is used. The precise orientation of the wafer is crucial to prevent defects and maximize yield. (LPS30)
Ion implantation
- Wafer positioning: Piezo actuator positioning systems are employed to precisely align and scan the silicon wafer during ion implantation, thereby ensuring uniform and accurate doping. (LT20, LT40)
- Focusing and alignment: They can be used to adjust the focus of the ion beam and to align various optical components within the implanter, ensuring the ion beam is precisely directed at the wafer. (LT20, LT40, LPS30)
- Inspection and defect detection: Piezo actuator based nano positioning stages, and objective piezo actuators, along with electron beam microscopy, can inspect implanted wafers for defects and verify implantation accuracy at sub-nanometer scales. (LT20, LT40, LPS30)
Wafer Inspection and Metrology
- Piezo actuator objective scanners efficiently and accurately inspect photomasks for defects.
- Piezo motor stages facilitate rapid scanning for pattern defect identification, critical dimension variations, and contamination detection.
- Piezo motor stages precisely align and scan individual dies using sub-nanometer precision under electron beams, facilitating the development of advanced integrated circuits.
- Piezo actuator objective positioners are crucial for rapid and precise autofocusing in microscopy during wafer inspection.
Key advantages
The primary advantages of utilizing piezoelectric motors in semiconductor manufacturing processes encompass:
- Down to sub-nanometer resolution: Essential for precise feature alignment and positioning.
- High stiffness and rapid response: Essential for dynamic control and vibration mitigation.
- Closed-loop feedback and cleanroom compatibility: Verifying precise positioning and minimizing the likelihood of contamination.
- Non-magnetic and vacuum compatibility: Verifying their suitability for processes executed in high vacuum conditions.
- Self-locking: Retains position after power is disconnected.
Piezo motors and actuators play a pivotal role in contemporary semiconductor manufacturing, enabling the latest process geometry.