How to overcome the challenge of ultra-precision dimensional control in semiconductor equipment precision parts processing?
Publish Time: 2026-01-26
In the semiconductor manufacturing field, the performance of equipment directly determines the process precision and yield of chips. Supporting core equipment such as high-end lithography machines, etching machines, and ion implanters are a series of precision parts with geometric precision reaching the micrometer or even sub-micrometer level. The critical dimensional tolerance requirements for some semiconductor equipment precision parts processing are controlled within ±0.5 micrometers, equivalent to 1/140th the diameter of a human hair. Faced with such an extreme challenge, ultra-precision dimensional control has become a core bottleneck in semiconductor equipment component manufacturing.1. Material Selection and Pre-treatment: Suppressing Deformation from the SourceThe first step in ultra-precision machining is ensuring the stability of the material itself. Semiconductor equipment parts often use special materials such as Invar steel, silicon carbide ceramics, ultra-low expansion glass, or high-purity stainless steel, which have extremely low coefficients of thermal expansion and excellent long-term dimensional stability. However, these materials often retain residual stress after casting, forging, or machining, which is easily released during subsequent processing, leading to micro-deformation. Therefore, multiple rounds of stress-relief annealing or cryogenic treatment are necessary to bring the internal structure of the material to equilibrium, laying the physical foundation for subsequent high-precision machining.2. Ultra-precision Machining Technology: Micron-level "Sculpting"Traditional machining methods can no longer meet the requirements for nanometer-level surface finishes and geometric tolerances. Modern semiconductor precision parts commonly employ ultra-precision CNC machine tools, equipped with air hydrostatic guides, linear motor drives, and nanometer-level grating feedback systems to achieve "zero friction and zero hysteresis" motion control. The process path is highly customized for different characteristics:Planar surfaces or mirror bases are machined using single-point diamond turning, directly producing optical-grade surfaces;Complex internal cavities or micro-hole structures use micro-electrical discharge machining or laser-assisted milling to avoid mechanical stress;Key mating surfaces are finished through multi-stage grinding and magnetorheological polishing, controlling roundness and parallelism to the sub-micron level.3. Constant Temperature and Clean Environment: Isolation from External InterferenceTemperature fluctuations of 0.5℃ can cause thermal deformation of several micrometers. Therefore, ultra-precision machining workshops generally maintain a constant temperature of 20±0.1℃ and employ marble bases, active vibration isolation platforms, and ISO Class 5 or higher clean environments to effectively isolate vibration, dust, and airflow disturbances. Equipment requires several hours of preheating before startup to ensure the entire machine reaches thermal equilibrium. This "laboratory-grade" environment is the fundamental guarantee of dimensional repeatability accuracy.4. Online Measurement and Closed-Loop Compensation: Real-Time Error Correction"Inaccurate measurement leads to inaccurate production." Today, advanced production lines have achieved integrated machining and measurement. Machine tools integrate non-contact laser probes, white light interferometers, or capacitive sensors to scan the workpiece contour in real time during machining, feeding the data back to the CNC system to dynamically adjust the tool path and form real-time closed-loop compensation. After machining, the parts undergo full inspection by a high-precision coordinate measuring machine or optical profilometer to ensure that every key feature meets the drawing requirements.
Semiconductor equipment precision parts processing is not achieved through a single technological breakthrough, but rather through the synergistic evolution of four major systems: materials, processes, environment, and measurement. As the semiconductor industry races towards 2nm and below, the precision ceiling for equipment components continues to be pushed. Each breakthrough beyond the micrometer limit represents a crucial step for China's high-end manufacturing to climb to the top of the global value chain—because in this silent competition, precision is the core competitive advantage.
