The chip manufacturing process is very complicated. When it comes to semiconductor manufacturing, people tend to pay more attention to materials such as silicon wafers, electronic special gases, masks, photoresists, targets, chemicals, and related equipment. Few people introduce the invisible elements that run through the entire semiconductor manufacturing process. Guardian – Plastic.
The biggest challenge facing semiconductor manufacturing is the control of pollution, especially with the development of semiconductor technology, as electronic components become smaller and more complex, their tolerance to impurities is lower and the production conditions are harsh , such as dust-free cleaning, high temperature, highly aggressive chemicals, etc.
Throughout the semiconductor manufacturing process, the role of plastics is mainly packaging and transmission, connecting each processing process, preventing pollution and damage, optimizing pollution control, and improving the yield of key semiconductor manufacturing processes. The plastic materials used include PP, ABS, PVC, PBT, PC, PPS, fluoroplastics, PEEK, PAI, COP, etc., and with the continuous development of semiconductor technology, the performance requirements for materials are also getting higher and higher.
Let’s learn about the application of these plastics in semiconductor manufacturing from the key semiconductor manufacturing processes including silicon wafer chemical mechanical polishing, wafer cleaning, photolithography, etching, ion implantation, packaging testing and packaging.
1. Clean room
Semiconductor manufacturing, from monocrystalline silicon wafer manufacturing to IC manufacturing and packaging, needs to be completed in a clean room, and the requirements for cleanliness are very high. Clean room panels are generally made of materials that are fireproof and not prone to electrostatic adsorption. The window material is also required to be transparent.
Material: Antistatic PC, PVC
2. CMP fixing ring
Chemical mechanical polishing (CMP) is a key process technology in the wafer production process. The CMP fixing ring is used to fix the silicon wafer and wafer during the grinding process. The selected material should have good wear resistance, stable size, Chemical corrosion resistance, easy processing, avoiding scratches and pollution on the surface of crystal silicon wafer/circle.
Material: PPS, PEEK
3. Wafer carrier
Wafer carriers, as the name suggests, are used to load wafers, including wafer carrier boxes, wafer transfer boxes, and wafer boats. The time for wafers to be stored in transport boxes accounts for a high proportion of the entire production process, and the material, quality, and cleanliness of the wafer box itself may have a greater or lesser impact on wafer quality.
Wafer carriers generally use materials with temperature resistance, excellent mechanical properties, dimensional stability, durability, anti-static, low outgassing, low precipitation, and recyclable materials. The materials used for wafer carriers used in different manufacturing processes are different.
Materials include: PFA, PP, PEEK, PES, PC, PEI, COP, etc., generally after antistatic modification.
4. Crystal boat handle
Wafer handle In the semiconductor manufacturing process, when entering the chemical acid and alkali etching process, the wafer boat needs to be held by the handle.
Material: PFA
5. FOUP manual opener
Front-opening wafer transfer pod (FOUP) manual opener is specially used to open the front door of FOUP. It can be used for FOUPs that meet the half-300mm specification.
The material is generally conductive engineering plastics.
6. Mask box
The photomask is the graphic master used in the photolithography process in chip manufacturing. It uses quartz glass as the substrate and is coated with chromium metal to shield light. Using the principle of exposure, the light source is projected onto the silicon wafer through the photomask to expose and display specific patterns. Any dust or scratches adhering to the photomask will degrade the quality of the projected image. Therefore, it is necessary to avoid contamination of the photomask, and to prevent particles produced by collision or friction from affecting the cleanliness of the photomask.
In order to avoid damage caused by fogging, friction or displacement of the photomask, the photomask pod is generally made of antistatic, low outgassing, durable materials.
Materials include: antistatic BAS, antistatic PC, antistatic PEEK, PP, etc.
7. Wafer tools
Tools used to clamp wafers or silicon wafers, such as wafer clamps, vacuum suction pens, etc., when clamping wafers, the materials used will not scratch the surface of the wafer and have no residue, ensuring the integrity of the wafer Surface cleanliness.
Material: PEEK
8. Chemical/electronic special gas transportation and storage
In the semiconductor manufacturing process, such as wafer cleaning and etching, a large amount of electronic special gases or chemicals are used. Most of these materials are highly corrosive. Therefore, the pipelines, pump valves, storage containers and other components or linings used for transportation and storage The material is required to have outstanding chemical corrosion resistance and low precipitation, which can ensure that the highly corrosive chemicals in the chip manufacturing process will not pollute the ultra-clean environment.
Material: PTFE, PFA, PVDF, ETFE, PEI
9. Gas filter element
The special gas filter element for semiconductor manufacturing process is used to remove impurities and improve the purity, thus ensuring the yield rate of chip manufacturing. Generally, materials with high temperature resistance, corrosion resistance and low precipitation are selected.
The filter element is made of PTFE, and the skeleton support material is made of high-purity PFA.
10. Bearings, guide rails and other components
Semiconductor processing equipment components such as bearings, guide rails, etc., require continuous operation at low temperature to high temperature, low wear and friction, stable dimensions, and excellent plasma erosion resistance and exhaust characteristics.
Material: Polyimide PI
11. Semiconductor package test socket
The test socket is a device that electrically connects the direct circuit of each semiconductor component to the test instrument. Different test sockets are used to test various microchips specified by integrated circuit designers. The material used for the test socket should meet the requirements of good dimensional stability, mechanical strength, less burr formation, durability, and easy processing within a wide temperature range.
Material: PEEK, PAI, PI, PEI, PPS
12. Semiconductor packaging release film
ETFE film has heat resistance, chemical resistance, light transmission, non-adhesiveness, and the surface of the product after release is smooth and pollution-free, and is widely used in semiconductor packaging release film.
13. IC tray (IC TRAY)
IC trays are packaging trays used by semiconductor packaging and testing companies for their chip (IC) packaging and testing. IC trays are used as chip packaging to protect chips from damage and facilitate automatic inspection and installation. Therefore, materials are required to have low water absorption, temperature resistance, dimensional stability, and recyclability.
Material: PPO, PSU, ABS, PP, PEI
The above are the application cases of plastics in the semiconductor field that I have learned. If you have a deeper insight into this, welcome to exchange and discuss!