mechatronic calotte loader (mWL calotte)
Manual handling of wafers into calottes for PVD process has been identified to be a significant contributor for yield degradation (embedded particles, defects, scratches and wafer breakages). The development of a sorting system transferring wafers between calottes and cassettes is facing multiple challenge. mechatronic systemtechnik gmbh´s mWL.cl is a fully automated tranfer system which is capable to increase yield by eliminating all possible influencing factors from the manual handling operation.
mechatronic calotte loader (mWL calotte)
mechatronic calotte loader (mWL calotte)
This system is designed for loading wafers from cassettes into dome-shaped substrate holders for subsequent metal deposition. Evaporation process tools often utilize spherical carriers and rings to meet uniformity and defectivity targets. However, today integrated device manufacturers (IDMs) are using manual wafer loading in this step of the manufacturing process. This is resulting in yield degradation and an increased risk for misprocessing.
A fully automated stand-alone system for transferring wafers between cassettes and calottes, the mWL calotte provides IDMs an opportunity to increase yield and improve process traceability at a high throughput.
Key features
- Fully automated system for transferring wafers for loading and unloading of wafers into process rings
- Highest reliability for handling requirements
- Advance mapping to detect wafers in the process rings
- Advanced hand shake for maximized wafer safety
- mechatronic systemtechnik gmbh´s components and technology for maximized wafer safety
- Improved process traceability (host notification of WID, Cassette ID, Segment ID and position in the segment to avoid misprocessing , double processing and ensures traceability.
- Maximized throughput, one system can supply multiple deposition systems
- SECS/GEM integration
Key benefits
- No embedded defects in the film, dedicated end effectors to eliminate defects from contaminated wafers after deposition to incoming wafers
- Significantly reduced contamination, wafer breakage resulting in higher yield
- Meet conformity requirement of critical customer industries (e.g Automotive, high performance).
- Enables process quality improvement measures through improved traceability
- Easy insertion into existing process flow
Details
A position measurement system, in combination with auto teaching of the hand-off position (into the calotte), is the key element to achieve this goal.
The result is a highly reliable product with unmatched accuracy and productivity.
Measurement of the position and off set correction
mechatronic systemtechnik gmbh integrated an auto teaching system to meet the requirements and the tolerance of the placement location.
- Rx, Ry, x, y, z, and angle of the flat are measured
- The values are used for off-set correction of the robot´s hand-off position in all 3 axes and for the flat position
The measurement system is also used for mapping of the calotte.
- Determination of whether a segment, a ring, or a wafer is present
- Recognition of hand-off positions
Loading sequence
- Bernoulli vacuum is used to place the wafer, tilted into the ring
- When vacuum is switched off, the Bernoulli effect still holds on to the wafer, allowing it to float towards the flat in the ring
- Once the wafer has floated into the ring, the system is completing its placement of the wafer fully into the ring
- The accuracy of this placement approach is <50µm