Complete Applications of Granite Precision Bases in the Semiconductor Industry
I. Core Material Advantages of Granite Bases in Semiconductor Manufacturing
Semiconductor manufacturing processes reach nanometer-level precision, requiring extreme standards for thermal deformation, vibration, flatness, and cleanroom compatibility of the base. Natural black granite (Jinan Green / Indian Black) is the optimal alternative to metal, cast iron, and ceramics:
Extremely Low Coefficient of Thermal Expansion
The thermal expansion coefficient is only 0.5~1.0×10⁻⁶/℃, about 1/3 of cast iron and 1/5 of steel; under a temperature fluctuation of ±0.1℃ in a cleanroom, the base deformation is <0.1nm, eliminating lithography and inspection offsets. Natural Strong Vibration Absorption and Damping The dense internal micropores provide inherent vibration damping characteristics, with a vibration attenuation rate >90%. It can absorb vibrations from linear motors, air bearings, and cutting spindles, ensuring nanometer-level positioning stability.
Ultra-High Rigidity Permanent Flatness Precision
With a density of 3100kg/m³ and high compressive strength, it remains undeformed under long-term loads; after precision machining, the flatness can reach Grade 000 (≤0.5μm/m), serving as the installation datum for air bearings and linear motors.
Cleanroom Compatibility
Water absorption <0.13%, rust-proof, corrosion-resistant, and does not easily generate metal dust; excellent insulation (resistivity >10¹³Ω·m) prevents electron beam and wafer electrostatic interference.
Wear-Resistant and Stress-Free Deformation
Natural stone has no internal stress and will not creep over long-term use; after embedding threaded inserts and copper sleeves, it can be repeatedly disassembled and reassembled without precision degradation.
Real Photos of Semiconductor Equipment Granite Bases
Precision Granite Machine Tool Bases
II. Segmented Application Scenarios Across the Semiconductor Full Industry Chain
- Lithography Equipment (Highest Precision Scenarios)
(1) EUV/DUV Lithography Machine Stage Base
The core load-bearing base of the entire machine, supporting the XY air-bearing stage, grating scales, and laser interferometry systems; granite isolates workshop vibrations and offsets equipment thermal deformation, enabling 0.1nm-level step-and-scan wafer positioning, making it a core essential component for advanced process lithography machines.
(2) Laser Direct Writing / Electron Beam Lithography (EBL) Base
Electron beam lithography is extremely sensitive to vibration and static electricity: the insulating properties of granite prevent electron beam scattering, and strong damping suppresses motor vibrations, supporting the writing of micro-nano circuit patterns below 10nm.
(3) Coating and Developing Equipment Positioning Platform
Supports wafer carriers to ensure uniform coating, eliminating lithography photoresist thickness unevenness caused by table deformation, thereby improving exposure yield. - Wafer Processing Equipment
(1) Wafer Dicing Machine / Cutter Base
High-speed diamond cutting spindles generate intense vibrations, which granite rapidly absorbs; micron-level flatness supports the flat fixation of 6/8/12-inch wafers, significantly reducing cutting edge chipping and offset defects, improving chip yield by over 10%.
(2) CMP Chemical Mechanical Polishing Platform
Under high polishing pressure and continuous friction, the high rigidity of granite prevents deformation, ensuring global wafer flatness and preventing local over-polishing or under-polishing of silicon wafers.
(3) Etching and Thin Film Deposition Equipment Load Platform
As a precision motion datum inside the vacuum chamber, it is corrosion-resistant and free of metal precipitation, making it suitable for high-cleanliness vacuum environments. - Wafer Inspection and Metrology Equipment (Metrology Stage)
(1) Optical Defect Inspection (AOI) and Electron Beam Inspection (EBI) Base
Supports high-precision optical lenses and displacement stages; even tiny vibrations can cause image blurring and defect misjudgment. As a reference table, granite stabilizes the imaging datum.
(2) 3D Profiler / Film Thickness Measurement Platform - Nanometer-scale height and thickness measurement, relying on a constant granite plane reference to eliminate measurement errors caused by temperature drift.
- (3) Semiconductor CMM / Wafer Dimension Inspection Tool
- Large-size granite platform, used for precision inspection of geometric tolerances of silicon wafers, carriers, and photomasks.
- Advanced Packaging Equipment
Die Bonder and Wire Bonder Base: Chip micro-solder point positioning accuracy within ±1μm, granite vibration damping avoids bonding offset, reducing the offset defect rate from 0.3% to 0.01%;
Flip Chip and Bonding Equipment Base: Low thermal deformation under high-temperature bonding conditions, ensuring precise alignment between the chip and the substrate;
Post-packaging Appearance Inspection Platform: Stable reference for visual inspection of mass-packaged components. - Supporting Precision Motion Units (Air Bearing Platform Core)
The granite plate in your picture with copper inserts and threaded mounting holes is exactly the base of an air bearing motion platform:
Semiconductor equipment extensively uses air bearing guides to achieve frictionless ultra-precision motion, and air bearing stages must be installed on granite bases; if the base slightly deforms, the air bearing gap becomes unbalanced, directly leading to positioning failure. Granite provides an absolutely flat and stable mounting reference, suitable for the pre-embedded installation of linear motors, grating scales, and limit sensors.
III. Typical Process Requirements for Semiconductor-Specific Granite Bases
Material: High-density black granite (Jinan Green / Indian Black) selected, free of cracks and loose pores;
Precision Grade: 00/000 grade, flatness 0.5~1μm/m, perpendicularity and parallelism at micron level;
Machined Structure: Embedded stainless steel threaded sleeves, copper-inlaid wear-resistant guide rails, vacuum suction grooves, wafer positioning countersinks, wiring slots (completely matching the structure in your image);
Surface Treatment: Fine-ground mirror finish, no dust precipitation; vacuum sealing and anti-static treatment available;
Cleanroom Compatibility: Dust-free cleaning and passivation treatment before shipment, compatible with Class 100/1000 cleanrooms.
