How to arrange ULPA in the wafer loading and transfer area? Local protection and installation scope

Wafer loading and transfer areaULPA filter placement should be designed around wafer exposure locations, mechanism actions, and entry and exit boundaries. Local clean air supply should be confirmed with equipment exhaust, openings and material control. The wafer loading and transfer area (EFEM) is the area where wafers are most frequently exposed in semiconductor equipment: the wafer is taken out of the carrier, transported by the robot, and enters the process chamber. The entire process is completed in this area. The goal of particle control in this area is very specific—protect the wafer surface from particle contamination during transport. The ULPA layout needs to be designed around the wafer path and mechanical motion, rather than simply laying a layer of filters on top of the device. Aili Industrial's product line covers the equipment sideEFU equipment end fan filter unit andHEPA/ULPA filter，Ultra-thin EFU and small size models can match the local air supply structure according to EFEM space conditions.PTFE HEPA/ULPA filters can be evaluated for suitability based on material outgassing requirements.

1. Define the scope of wafer protection: loading, docking, transmission and temporary storage

Clear the loading, docking, transmission and temporary storage status, record the opening of the door or vehicle and the movement of the manipulator, not only protecting the center point when stationary.

The wafer protection range is not just a fixed position, but a dynamic area that changes with movement. When the wafer is taken out of the carrier, transferred on the robot, and before entering the process chamber, the exposure positions are different and the protection requirements are also different. The moment the carrier door opens, the path the robot extends, and the temporary storage location of the wafers, all must be included in the scope of protection. Aili Industry isIn the EFU equipment end fan filter unit package, confirm the air supply coverage according to the wafer path and mechanical action.The ultra-thin EFU configures the air outlet direction according to the cavity structure in the limited space of EFEM.The small size EFU equipment fan filter unit corresponds to a more compact loading area. The relationship between levels and filtering requirements can be found inISO cleanliness level comparison。

2. Coordinate the filtration surface and air path: overhead or lateral space, obstacles and return airflow

Consider overhead or lateral space, obstacles, return airflow and fan position to avoid contaminated air crossing the wafer surface and take into account accessibility for installation and leak detection.

The internal space of EFEM is compact, and the installation location of the filter is limited by the mechanism, cables and sensors. Whether the filter surface is placed above, sideways or obliquely depends on the wafer path and mechanism action. The air flow direction is such that the clean air first passes through the wafer surface and then takes away the particles, rather than blowing directly from the pollution source to the wafer. Aili Industry isIn the non-standard ULPA filter project, confirm the filter surface position and air outlet direction according to the EFEM internal structure.Materials such as PTFE HEPA/ULPA filters can be evaluated according to low outgassing requirements, and the accessibility of internal testing of the equipment is confirmed at the structural plan stage. For coordination of air path and filter surface position, please refer toHEPA FAQs and Selection Guide。

3. Verify with the actual movements of the equipment: robot movement, vehicle door opening and closing

Check the air volume distribution, integrity and performance related to the process area. Material and AMC requirements are determined individually based on the process and are not directly inferred from the ULPA grade.

The protection effect of the wafer area must be confirmed under the actual operating state of the equipment. Whether the air supply path is blocked when the manipulator moves to the extreme position, whether the air flow direction changes when the carrier door is opened, and whether the local particle concentration fluctuates when the wafer enters and exits, these must be tested according to the action sequence. Aili Industry isthe EFU equipment end fan filter unit .The air supply conditions can be confirmed according to the equipment action sequence when matching The FFU computer group control system records the equipment operating status and air volume parameters, which can be compared with the actual action status during verification. For methods of device-side action verification, please refer toEFU FAQ and technical support。

4. When the manipulator moves to the extreme position and blocks the air supply path, this state should be included in the verification

When the manipulator moves to the extreme position and blocks the air supply path, this state should be included in the verification instead of only testing when the manipulator returns to zero. The manipulator may temporarily block the air supply surface or change the direction of the air flow during movement. The test in the zero return state cannot represent the entire process.

Aili Industry isNon-standard ULPA filters andIn the EFEM project of the fan filter unit at the EFU equipment end , the impact of occlusion is evaluated based on the robot stroke and the position of the air supply surface. If necessary, the position of the filter surface is adjusted or local air supply is increased so that the airflow can cover the wafer path throughout the entire range of the robot movement.The small size EFU equipment fan filter unit provides a more flexible installation method when space is limited. The relationship between mechanical action and air supply path can be referred toULPA ultra-high efficiency filter FAQ and selection guide。

5. Related questions and answers

Does the equipment need a local ULPA if it is located in a clean room?
Judgments need to be combined with wafer exposure and equipment dust production, and room conditions cannot automatically represent internal protection.

The internal space of EFEM is small, can ULPA be installed in it?
It can be installed through small size or ultra-thin EFU with compact structure. The details are confirmed according to the internal dimensions of EFEM and the mechanism stroke.

Do material outgassing requirements need to be confirmed separately?
need. ULPA particle filtration does not involve material outgassing, and material outgassing within EFEM should be evaluated individually based on process requirements.

6. Related articles

ULPA ultra-high efficiency filter FAQ and selection guide

Ultra-thin EFU

Small size EFU equipment fan filter unit

PTFE HEPA/ULPA high efficiency filter

7. Key points for selection and acceptance inspection

8. Product matching and technical support from Aili Industrial

Aili Industrial's product line covers the equipment sideEFU equipment end fan filter unit andHEPA/ULPA filter，Ultra-thin EFU and small size models can match the local air supply structure according to EFEM space conditions.PTFE HEPA/ULPA filters can be evaluated for suitability based on material outgassing requirements.The EFU equipment end fan filter unit is equipped with a wafer path and mechanical action to confirm the air supply coverage.The ultra-thin EFU configures the air outlet direction according to the cavity structure in the limited space of EFEM.The small size EFU equipment fan filter unit corresponds to a more compact loading area;The non-standard ULPA filter project confirms the filter surface position and air outlet direction according to the EFEM internal structure, and the accessibility of the internal inspection of the equipment is confirmed in the structural plan stage.The EFU equipment-end fan filter unit can confirm the air supply conditions according to the equipment action sequence.The FFU computer group control system records the equipment operating status and air volume parameters, and compares them with the actual action status during verification; evaluates the impact of occlusion based on the robot stroke and air supply surface position, and adjusts the filter surface position or increases local air supply if necessary. Provide process objectives, installation drawings, operating conditions and acceptance requirements, and can further communicate ULPA standard specifications, non-standard interfaces, samples and batch matching. The specific parameters and test range are based on the confirmed model and technical documents.