Lithium Niobate (LiNbO3) Thin Film
Lithium Niobate (LiNbO3) thin film is a core material for integrated photonics and surface acoustic wave devices, playing an irreplaceable role in high-performance optical modulators, waveguides, sensors, and RF filters due to its excellent electro-optic, acoustic-optic, and nonlinear optical properties. It features high refractive index, broad transparency window, strong electro-optic coefficient, and good chemical stability, enabling efficient optical signal modulation and low-loss transmission. However, the surface quality of LiNbO3 thin films directly impacts optical loss, modulation efficiency, and device reliability, especially in high-frequency and high-power applications, which demand superior surface roughness, flatness, and integrity.
Hemei Company possesses systematic expertise in processing advanced optical films and crystal materials. Targeting the material characteristics of LiNbO3 thin films, Hemei has developed a polishing and planarization solution that achieves high surface precision while minimizing sub-surface damage. This process covers the entire surface treatment workflow from epitaxial film preparation to post-device integration, ensuring it meets the stringent requirements for atomic-level smooth surfaces, low scattering loss, and excellent optical uniformity demanded by high-speed optical communication, quantum optics, and RF systems.
Application Requirements
The objectives for polishing and surface treatment of LiNbO3 thin films include:
Reducing surface roughness (Ra) to < 0.5 nm to minimize transmission loss in waveguides and insertion loss in modulators.
Achieving total thickness variation (TTV) of ≤ 1 μm to ensure consistency in optical and electric field distribution.
Obtaining a damage-free surface with no sub-surface defects, meeting the requirements for high modulation efficiency and long device lifetime.
Controlling thickness uniformity (TTV) within a specific micrometer-range.
To achieve these goals, Hemei's process employs customized bonding systems and multi-step polishing procedures to ensure geometric accuracy and surface integrity during processing.
System Specifications
Hemei's modular polishing system supports processing LiNbO3 thin films of various sizes and shapes. Core systems include:
HSM-L/LP Series lapping Equipment: For initial material removal and thickness control.
HSM-CMP Series Chemical Mechanical Polishing (CMP) System: For achieving ultra-smooth, damage-free surfaces.
Key subsystems include:
Wafer/Crystal-specific Bonding Unit (WB)
SJ/ASJ Series Precision Polishing Fixtures
C-ASJ Drive Head High-Speed Polishing System
Processing Flow
Bonding and Mounting: The LiNbO3 thin film is temporarily bonded to a carrier plate using the WB unit, then mounted onto the polishing fixture.
Rough and Intermediate Polishing: Controlled lapping is performed on the HSM-L equipment to remove the processing damage layer.
Fine Polishing: The HSM-CMP system performs the final polish. Parameters like pressure, rotation speed, and slurry flow are adjusted in real-time to achieve nanometer-level surface smoothness.
Typical Results
Surface roughness (Ra) reduced to < 0.5 nm.
Total thickness variation (TTV) ≤ 1 μm.
Damage-free surface with no sub-surface defects.
Controllable material removal rate of 0.05 - 0.2 μm/min.
Hemei Company provides a complete and controllable polishing and planarization solution for Lithium Niobate thin films. This solution stably delivers atomic-level surface quality and excellent photoelectric performance, robustly supporting the industrial application and performance enhancement of LiNbO3 thin films in cutting-edge fields such as high-speed optical communication, integrated photonic chips, microwave photonics, sensing, and quantum information processing.
