Deeply cultivating precision motion control: Innovative practice of core components in wafer manufacturing process of Huzhou Prime Semiconductor

On the precision track of semiconductor manufacturing, the efficient circulation of every wafer and the precise alignment at the micron level are inseparable from the technical support of core moving components. Huzhou Pulim Semiconductor Co., Ltd., rooted in Changxing, Huzhou, has been deeply engaged in the research and development of core equipment components for wafer manufacturing processes. Focusing on core scenarios such as wafer handling, high-precision alignment, and ultra-smooth rotation, it has created a full-chain product matrix centered around ceramic fork, wafer alignment table, air-bearing rotary shaft, and precision motion stage, laying a solid foundation for precision and efficiency for semiconductor manufacturing enterprises.

Ceramic wafer fork: a lightweight and high-precision carrier for wafer handling

As the core end-effector component of wafer handling robots, the ceramic fork developed by Prim utilizes high-performance engineering ceramic materials for integral molding, achieving ultimate lightweight while ensuring structural rigidity. Its overall weight is reduced by more than 40% compared to traditional metal forks. This material characteristic not only significantly reduces the inertial impact during high-speed transfer, but also maintains an extremely low particle precipitation rate in Class 1 clean room environments, fully adapting to the non-contact picking and placing requirements of 6-12 inch wafers. The surface of the fork is specially polished at the nanoscale, with no sharp edges or corners, effectively preventing scratches on the back of the wafer and edge chipping issues. Coupled with a customized flexible limiting structure, the slip rate of the wafer is controlled within 0.1% in high-speed transmission scenarios, and the transmission efficiency is improved by more than 30% compared to the industry's conventional solutions. It can seamlessly interface with the AMHS automatic material transmission system in semiconductor factories.

Wafer alignment stage: core support for sub-micron level alignment

For the high-precision alignment requirements of processes such as lithography, probe testing, and wafer bonding, Prim's wafer alignment stage integrates machine vision recognition and multi-axis collaborative control technology to establish a dual-layer alignment system of "coarse alignment + fine alignment". In the coarse alignment stage, three remotely distributed reference marks on the wafer are identified to quickly complete the preliminary position matching of the wafer. In the fine alignment stage, it can automatically complete the sampling calculation of more than 20 alignment marks, and combined with sub-pixel positioning algorithms, it ultimately achieves a recognition accuracy better than 0.3 micrometers. The telecentric optical imaging system equipped on the alignment stage can effectively eliminate the reflective interference from the metal plating on the wafer surface. Even in complex imaging scenarios of ultra-thin translucent wafers, it can stably extract the mark contours. Coupled with multi-point average calibration and real-time temperature drift compensation functions, the entire alignment process can be completed in milliseconds, with the alignment success rate consistently maintained at over 99%. This significantly reduces the overlay error in multi-layer lithography processes and directly contributes to improving chip manufacturing yield.

Air float rotary shaft: frictionless and ultra-smooth rotating core

The air-bearing rotary shaft independently developed by Prim utilizes gas static pressure technology to form a uniform rigid gas film between the moving parts and the fixed support surface, completely eliminating the friction loss of traditional mechanical contact rotary structures. The entire shaft system is driven by a frameless direct-drive motor, paired with a high-resolution circular grating as an angle feedback component, achieving nanometer-level axial and radial rotation precision, with a repeatability of up to 0.61 arc seconds. Thanks to the non-contact air-bearing support characteristics, the air-bearing rotary shaft operates almost vibration-free and noiselessly, without the need for lubrication maintenance, fully meeting the cleanliness requirements of semiconductor cleanrooms. This component can be widely applied in processes such as wafer thinning, wafer inspection, and laser etching, maintaining high motion stability even in long-term continuous operation scenarios, avoiding accuracy degradation caused by mechanical wear, and significantly extending the full life cycle of the equipment.

Precision motion stage design: a motion control hub adaptable to all scenarios

The design of Prim's precision motion stage is centered around the core principles of "high rigidity, high response, and high stability". It can flexibly construct motion solutions for single-axis and multi-axis combinations according to different process requirements. The base of the motion stage is made of high-stability mineral casting material, effectively suppressing external vibration interference. Coupled with optimized linear motor drive and a fully closed-loop grating feedback system, the repeatability and positioning accuracy consistently reach the submicron level. For different process scenarios, the team can customize and adjust the travel, load, and dynamic response parameters of the motion stage: the motion stage for wafer transfer scenarios focuses on high-speed and smooth start-stop, while the motion stage for high-precision inspection scenarios emphasizes long-term position holding accuracy. The entire design process, from structural mechanics simulation, component selection to control algorithm debugging, is completed autonomously, enabling rapid response to differentiated customization needs of semiconductor equipment manufacturers.

From wafer handling and transportation to high-precision alignment, and then to smooth rotation and precise displacement control, the four core technological components of Huzhou Pulim Semiconductor have formed a complete technological closed loop that works in synergy. With continuously iterative precision motion technology, they inject solid underlying momentum into the independent development of China's semiconductor equipment industry.