Introduction

In modern semiconductor manufacturing processes, the precision and reliability of wafer processing equipment directly determine the yield and efficiency of chip manufacturing. The wafer transfer system, as the core hub connecting various process modules, its performance directly affects the smoothness of the entire production line and product consistency. This article will conduct an in-depth analysis of the design principles, technical features and application scenarios of the wafer transfer system and its key subsystems - ceramic chip forks, wafer alignment stations, wafer calibrators and air flotation rotation shafts.

I. Wafer Transfer System: The "Transporter" in Semiconductor Manufacturing

System Overview

The wafer transfer system is a key subsystem in semiconductor production equipment, responsible for safely and efficiently transferring wafers between different process modules. Modern wafer transfer systems typically adopt a modular design, integrating multiple precision components to ensure extremely high positioning accuracy and stability during high-speed movement.

Core technical indicators

Positioning accuracy: ±0.5μm (The industry-leading level can reach ±0.1μm)

Transmission speed: Up to 300mm/s at most

Compatibility: Supports 200mm/300mm wafer sizes

Shockproof design: Active vibration reduction technology is adopted to ensure stability under high-speed movement

Innovative design case

The technological accumulation in the research and development of precision moving parts has provided important support for the structural optimization of the wafer transfer system. By adopting new composite materials and optimizing the mechanical structure, the overall performance and reliability of the system have been significantly enhanced.

Ii. Ceramic Chip Forks: The "Precision Tweezers" for Wafer Handling

Material Properties and selection

As a key component that directly contacts the wafer, the material selection of ceramic chip forks is of vital importance:

Alumina (Al₂O₃) : High hardness and excellent wear resistance

Silicon nitride (Si₃N₄) : High toughness and good thermal stability

Silicon carbide (SiC) : Ultra-high hardness and excellent chemical stability

Key points of structural design

1. Clamping force control: An elastic deformation design is adopted to ensure uniform distribution of the clamping force

2. Thermal expansion compensation: Special structural design offsets dimensional changes caused by temperature variations

3. Surface treatment: Ultra-precision polishing, with surface roughness Ra<0.1μm

Application Challenges and Solutions

Wafer damage risk: Reduce the risk by optimizing the clamping points and contact area

Static electricity accumulation problem: Use anti-static coating or grounding design

Extended lifespan: Regular maintenance and surface regeneration techniques

Iii. Wafer Alignment Table: The Source of Precision

Alignment principles and techniques

Modern wafer alignment stations adopt a combination of multiple alignment technologies:

Optical alignment: High-precision positioning based on machine vision

Mechanical alignment: Sub-micron level adjustment is achieved by using a micro-motion platform

Laser interference alignment: Ultra-high precision measurement technology

Key performance parameters

Industry standards for typical parameter values

The accuracy of the X/Y axis is ±0.5μm ±1μm

The accuracy of the θ axis is ±0.005° ±0.01°

Align the time <5 seconds <10 seconds

The load-bearing capacity is 5kg and 3kg

Innovative design direction

Multi-station alignment: Integrating multiple alignment stations to enhance efficiency

Intelligent compensation: Real-time compensation algorithm based on AI

Modular design: Easy to maintain and upgrade

Iv. Wafer Calibrator: The "Ruler" of the Microscopic World

Calibration principles and methods

The wafer calibrator ensures the precise position of the wafer in the following ways:

1. Reference point identification: Detect the edge or marking point of the wafer

2. Position calculation: Based on coordinate system transformation algorithm

3. Error compensation: Adjust the transmission path in real time

Technical challenges

Micro-mark recognition: Requires an ultra-high resolution imaging system

Dynamic calibration: Maintaining accuracy during high-speed motion

Environmental adaptability: Resistant to interference such as vibration and temperature changes

Typical application scenarios

Before the photolithography process: Ensure that the wafer is precisely aligned with the mask

Etching process: Maintain the accuracy of pattern transfer

Measuring equipment: As the benchmark for high-precision measurement

V. Air Flotation Rotating Shaft: The "Joint" of Ultra-Precise Motion

Working principle

The air-flotation rotating shaft is realized by using gas bearing technology:

Non-contact support: Eliminates mechanical friction

Ultra-low vibration: Damping characteristics of gas films

High-precision rotation: Angle control can reach ±0.001°

Key technical parameters

Rotational accuracy: ±0.001° (industry-leading)

Load capacity: 5-20kg (depending on the model)

Rotational speed range: 0-300rpm (adjustable)

Service life: >10,000 hours (under normal use)

Maintenance and upkeep

Regular cleaning: Prevent particle contamination from affecting performance

Air pressure monitoring: Maintain a stable working air pressure

Lubrication inspection: Although there is no contact, the auxiliary system needs maintenance

Vi. System Integration and Collaborative Work

Interface design between components

The precise coordination among various subsystems is the key to the overall performance:

Mechanical interface: High-precision locating pins and reference surfaces

Electrical interface: Standardized signal transmission protocol

Software interface: Unified control instruction set

Typical workflow

The wafer transfer system receives wafers

2. Precise clamping with ceramic disc forks

3. Adjust the Angle of the air flotation rotating shaft

4. The wafer alignment table is precisely positioned

5. The wafer calibrator verifies the position

6. Transfer to the next process module

System optimization direction

Intelligent control: Predictive maintenance based on AI

Modular design: Convenient for quick replacement and upgrade

Energy efficiency optimization: Reduce overall energy consumption

Conclusion

The wafer transfer system and its key sub-components represent the highest technical level of semiconductor manufacturing equipment. From the precise clamping of the ceramic disc fork to the ultra-precise movement of the air flotation rotating shaft, each component embodies the outstanding achievements of modern engineering technology. As the semiconductor process nodes continue to shrink, the design of these key components will face more challenges, while also nurturing new opportunities for technological innovation.