Ultra‑precision coating is a technique for controllably depositing thin films at the atomic or molecular scale on ultra‑smooth substrates, with thickness‑control accuracy required to reach the subnanometer level; in EUV multilayer mirrors, the thickness of individual layers can even be less than 1 nm. When film growth enters this regime, environmental factors such as temperature, humidity, particulates, and micro‑vibrations cease to be mere background conditions and instead become process variables that directly influence the formation of the film’s microstructure. Jice (Nanjing) Technology Co., Ltd. Independently developed High-Precision Environmental Control System UPECS , for the vacuum deposition process The substrate during loading, transfer, and post‑plating processing stages The need for microenvironmental consistency, with device-level regulation provided: Temperature stability up to ±0.002°C, humidity stability up to ±0.1%RH, and cleanliness class ISO 1; it can also be configured with process‑integrated modules for micro‑vibration suppression, magnetic shielding, and pressure stabilization, with operating noise ≤45 dB.

Temperature: Ensures consistent thermal history of the substrate throughout the entire process cycle.

In both evaporation coating and magnetron sputtering, the substrate temperature during deposition is primarily determined by the kinetic energy of particles reaching the substrate, plasma radiation, and thermal radiation from the evaporation source—these constitute the core process parameters within the deposition chamber of the coating equipment. However, the substrate’s handling and transfer prior to entering the deposition chamber, as well as its thermal exposure in post‑coating processing areas, impart to the substrate a… Initial thermal state ; If this state cannot be reproduced due to fluctuations in ambient temperature, the subsequent deposition process loses a traceable reference, thereby exacerbating film‑thickness variations and stress nonuniformities. The high‑precision environmental control system UPECS establishes a stable ambient temperature field in the substrate loading, transfer, and post‑deposition processing zones through closed-loop airflow circulation and a high‑accuracy PID algorithm, ensuring consistent thermal exposure conditions for the substrates during these non‑deposition periods. Reduce, at the source, fluctuations in membrane-layer performance caused by initial temperature drift. 。

Humidity: The Invisible Culprit Behind Interface Defects

The effects of humidity on coating processes are primarily manifested in the substrate surface condition and the chamber atmosphere. Under high-humidity conditions, a layer of water molecules adsorbs onto the substrate surface; once introduced into the plasma environment, this adsorbed water dissociates to produce… Hydrogen and oxygen active groups , which interferes with the chemical processes at the etching–growth interface, leading to interfacial defects and reduced adhesion. Moreover, low-humidity environments are prone to generating static electricity, causing particles to adhere to the substrate surface. The high-precision environmental control system UPECS maintains humidity stability within ±0.1% RH, ensuring that the substrate remains in a consistently stable, low-humidity environment throughout loading and transfer, thereby minimizing the introduction of interfacial disturbances caused by adsorbed moisture during subsequent processing steps.

Cleanliness: Particles are defects.

Ultra-precise coating has extremely low tolerance for particulate contamination. A single particle… The size is comparable to or greater than the total thickness of the film layer. Particles landing on the substrate during deposition become macroscopic defects or scattering centers within the coating, directly impacting the laser‑induced damage threshold, optical transmittance, and even the structural integrity of the film. EUV multilayer coatings, high‑reflectivity mirrors, and optical filters are particularly sensitive to such defects. The ultra‑precise environmental control system UPECS achieves ISO Class 1 cleanliness at critical process stations, maintaining the concentration of particles ≥0.1 μm at a level below 10 particles/m³. At the critical stage when the substrate is exposed to the external environment Reduce particulate contamination to a controllable level.

Microvibrations and Atmospheric Pressure: Stabilizing the Growth Interface

During sputtering and evaporation, even minute vibrations of the substrate holder or wafer stage can disrupt the relative geometry between the deposition beam and the substrate, degrading film thickness uniformity and interface roughness. Ion-beam sputtering and atomic layer deposition are particularly sensitive to vibration because… The beam spot size of the ion beam, the beam‑positioning accuracy, and the pulse timing of ALD. It places extremely stringent demands on mechanical stability. The high-precision environmental control system, UPECS, integrates micro‑vibration suppression into its airflow management and structural design, thereby providing a stable mechanical environment for coating equipment.

of magnetron sputtering Deposition working pressure The vacuum and gas‑supply systems of the coating equipment itself play a decisive role, directly influencing the plasma state and the density of the deposited film. UPECS focuses on… Air pressure stability in the loading/transfer area If the ambient pressure in which the substrate is exposed prior to entering the deposition chamber fluctuates, its surface adsorption state becomes irreproducible, introducing variability at the onset of deposition. UPECS can be equipped with a pressure‑control module to maintain stable pressure in critical regions. Certain coating processes also require magnetic shielding to prevent external magnetic fields from interfering with the ion beam or plasma; UPECS’s magnetic‑shielding unit can provide this capability.

Process‑customized environmental control capabilities

Different coating methods exhibit varying sensitivities to environmental parameters. Evaporation coating places greater emphasis on the substrate throughout the entire process cycle. Thermal history reproducibility ; Magnetron sputtering affects particle cleanliness and Consistency of the substrate’s surface condition prior to entering the deposition chamber Highly sensitive; atomic layer deposition is extremely sensitive to vibration, humidity, and chemical contamination, while ion-beam sputtering demands exceptionally low levels of vibration and electromagnetic interference. UPECS employs a modular architecture that integrates the main cabinet, intelligent control system, airflow circulation system, clean filtration system, cooling/heating system, and localized gas‑bath modules into a deeply interconnected whole. Functional units such as temperature and humidity stability range, cleanliness class, air pressure control, micro‑vibration resistance, and magnetic shielding can all be configured on demand, precisely tailored to the specific requirements of particular coating equipment in Substrate Transport and Processing Stage Environmental control requirements.

Historical curves of environmental parameters can be queried and exported, providing data support for process traceability and optimization in coating operations. In high-end optical coating and semiconductor thin-film deposition applications, environmental control has evolved from a mere ancillary engineering feature to a critical process capability that determines film‑layer performance. The Jice ultra‑precision environmental control system, UPECS, sets the benchmark with temperature stability as tight as ±0.002°C, humidity stability at ±0.1% RH, and ISO Class 1 cleanliness, while offering customizable features such as micro‑vibration resistance and magnetic shielding, thereby establishing a repeatable, traceable environment for ultra‑precise coating equipment. Substrate Transport and Processing Microenvironment , enabling nanoscale film thickness and interface quality to become stable process outputs.