Constellation HA Series Vacuum Transmission System Selection Guide

HA-71A (for HA-200): Flat mounted vacuum optical aligner

HA-75 (for HA-400 and above): A more powerful vacuum optical aligner

The alignment function is used to correct the angle and center offset of wafers during transportation, especially suitable for processes that require precise alignment such as photolithography and bonding. When selecting, it is necessary to evaluate whether the wafer edge notch/flation recognition capability needs to be aligned.

Vacuum performance and cleanliness specifications

For high vacuum processes, the background pressure and leakage rate of the system directly determine the start-up time of the process chamber and the final product quality. The vacuum indicators of the Constellation series are as follows:

Base operating pressure:<5.00 × 10 ⁻⁷ Torr (approximately 6.7 × 10 ⁻⁵ Pa)

Leakage rate:<5.00 × 10 ⁻⁹ sccm He/sec (helium leakage rate)

This leakage rate level meets the requirements of most semiconductor thin film processes. But after on-site installation or maintenance, a complete helium leak test must be performed. Common leakage points include:

Metal sealing ring for mechanical arm through wall flange (such as Helicoflex)

Vacuum sealing of windows (borosilicate glass) and cavities

Sealing surfaces of gate valves for each port (load port, slide valve)

Leakage diagnosis steps:

Pump the transfer chamber to the ultimate vacuum, close the main valve, and observe the rate of rise in pressure.

If the rate of increase exceeds the standard, use a helium mass spectrometer leak detector to scan the flanges, welding seams, and penetrations of movable parts.

For O-ring seals, check for scratches or foreign objects, and apply a thin layer of vacuum grease before installation (if the material allows).

In addition, the materials exposed to vacuum in the system are all low emission materials (6061-T6 aluminum, stainless steel, etc.) Viton、 Glass can be baked at a maximum temperature of 100 ℃. If the process is sensitive to water vapor, it can be baked in a chamber at 80-100 ℃, but attention should be paid to the upper temperature limit of the robotic arm motor and sensor.

Electrical and Control Integration: RS-232/Ethernet

The Constellation series offers standard RS-232 serial interfaces and Ethernet control interfaces. As an OEM integrator, you need to integrate these command sets into the overall control system of the equipment (usually based on the SECS/GEM protocol layer of PLC or PC).

Key integration points:

Command set: including initialization, zeroing, pick, place, wafer mapping, alignment, interlock status query, etc.

Status feedback: Real time reading of robot arm position, elevator height, vacuum level, door valve status, etc. is required.

Safety interlock logic: It is necessary to implement the principle of 'if the door valve is not opened, the robotic arm will not extend into the process chamber';

I/O Hardwired Interlocking: In addition to serial commands, it is recommended to retain the hard wiring of safety interlocks (such as EMO, door switch directly cutting off driver enable) to comply with SEMI S2's requirements for independent safety circuits.

Common debugging issues:

Communication timeout: Check if the baud rate, parity check, and stop bit of RS-232 are consistent with the controller settings. Ethernet communication requires confirmation that there is no conflict between the IP address and port number.

Movement unresponsive: Confirm that the system is not in the "emergency stop" state and all interlock conditions are met. Check the LED status indicator of the robotic arm (if any) or read the error code.

Wafer dropping or collision: usually caused by wafer mapping data not matching the actual cassette slot position, or mechanical arm grasping height (Z-axis) offset. It can be taught piece by piece in manual mode and the true position coordinates can be recorded.

Wafer Mapping and Cross Slot Detection: Configuration and Verification

Wafer mapping is the process of scanning each slot in a cassette using sensors on a robotic arm (usually transmissive or reflective optical sensors) to generate a wafer presence map. Cross slot detection is the process of checking whether the wafer is tilted and protruding before picking it up.

Configuration steps:

Set the mapping sensor type and trigger threshold in the configuration software of the transmission system.

Perform a 'learn mapping' on the empty cassette and record the background value (sensor signal without wafer).

Manual verification of cassette with wafers: The software should correctly display the presence/absence status of each slot.

Artificially creating cross slots (inserting a wafer at an angle) to verify whether the system can recognize and reject wafer retrieval.

Troubleshooting:

Mapping sensor false alarm (all slots display wafers): The sensor is dirty or the gain setting is too high. Clean the sensor window and recalibrate.

Sensor not triggered: Check the power supply and signal lines of the sensor, or replace the photoelectric switch of the same model.

Cross slot detection unresponsive: Check the logic trigger threshold of the detection algorithm, which may be due to the wafer tilt not reaching the default alarm value. The tilt sensitivity can be reduced in the configuration.