172nm and the Application Fields of Ion Plating Technology
1.1 Application Fields of Ion Plating Technology
Ion plating technology is closely related to the development of human society and daily life. Thin film products prepared by plasma-enhanced technology are widely used in information display devices such as televisions, computers, and mobile phones, as well as in semiconductor devices, optoelectronic devices, optical devices, energy utilization, surface hardening of materials, wear resistance, corrosion resistance, oxidation resistance, and many other fields. With the modernization of national defense, the development of high-tech manufacturing, and the improvement of people's living standards, higher performance requirements are being placed on thin film products. Especially in the future era of cloud computing, intelligent economy, and the Internet, many devices are developing toward miniaturization, integration, and intelligence, which will impose even higher demands on thin film preparation technology. Among these, the preparation technology for high-precision films at the 172 nm level has become one of the core requirements for certain high-end devices.
1.2 New Requirements of Modern Science and Technology for Thin Film Products
Special Functions High-end products require parts to have various special surface functions, such as photothermal conversion, photoelectric conversion, thermoelectric conversion, photomagnetic storage, light reflection, light transmission, light filtering, electrical conductivity, insulation, high hardness, high wear resistance, low friction, etc. Some also need to possess brilliant and colorful decorative characteristics.
Diversification of Composition To meet the new performance requirements of high-tech products in different fields, the composition of thin films has evolved from pure metal films to a variety of inorganic compound films and polymer organic films. Table 1-1 lists various thin film materials and their application ranges that meet the needs of different fields today. Among them, composite film materials compatible with the 172 nm thickness specification are seeing a year-by-year increase in application proportion in precision electronic devices.
Table 1-1 Various Thin Film Materials and Their Application Ranges
| Application Category | Coating Materials | Substrate Materials | Application Range |
|---|---|---|---|
| High hardness, wear resistance | TiN, ZrN, HfN, TaN, NbN, CrN, CBN, Si₃N₄, TiC, ZrC, Cr₇C₃, SiC, Ti(C,N), Ti(B,N), Ti(Al,N), β-C₃N₄, diamond, etc. | High-speed steel, die steel, cemented carbide, cermet, etc. | Machining tools, molds, mechanical parts |
| High temperature resistance, oxidation resistance | Al, W, Ti, Ta, Mo, Al₂O₃, Si₃N₄, Ni-Cr, BN, MCrAlY, etc. | Stainless steel, heat-resistant alloys, copper, aluminum alloys, etc. | Turbine blades, exhaust pipes, nozzles, aerospace components, atomic energy heat-resistant components |
| Corrosion resistance | TiN, TiC, Al₂O₃, Cd, Al, Ti, Cr, Cr₇C₃, Ni-Cr-Fe, Cr-Ni-P-B (amorphous), etc. | Steel, stainless steel, non-ferrous metals, etc. | Aircraft, ships, automobiles, chemical pipelines, fasteners surface protection |
| Decorative beautification | TiN, TiC, TaN, TiAC, ZrN, Cr₇C₃, Al₂O₃, Al, Ag, Ti, Au, Cu, Ni, Cr, Ni-Re, TaN, Te-N, Al-TaSi, Ni-CrAl | Steel, brass, aluminum, stainless steel, plastic, ceramics, glass, paper foil, etc. | Jewelry, watches, lamps, glasses, hardware parts, automotive accessories, electrical parts |
| Conductive films | Au, Mo, W, MoSi₂, WSi₂, TaSi₂, Ti-Si, Ag-Si, Al, Ni, Al₂O₃, Au-Pb, etc. | Silicon wafer, ceramics, plastic, glass, alloy strip | Thin-film resistors and leads, electron emission devices, tunnel devices, etc. (including 172 nm precision conductive films) |
| Dielectric films | SiO₂, Al₂O₃, AlN, Al₂O₃-BaTiO₃, TiO₂, ZnO, AlN, LiNbO₂, etc. | Silicon wafer, ceramics, plastic, glass | Surface passivation, interlayer insulation, capacitors, electrothermal elements, etc. |
| Microelectronic devices – semiconductor films | Si, a-Si, Au-ZnS, GaAs, CdSe, CdS, PbS, InSb, Ge, Pb-Sn-Te, etc. | Silicon wafer, ceramics, plastic, glass | Light-emitting diodes, thin-film transistors, optoelectronic devices, magnetoelectric devices, sensors, etc. |
| Superconducting films | Pb-Bi-Pb-Au, Nb₃Ge, V₃Si, Pb-In-Au, PbO/In₂O₃ | - | Superconducting devices |
| Magnetic materials & recording media | γ-Fe₂O₃, Co-Ni, Co-Cr, MnBi, GdCo, GdFe, TbFe, Ni-Co-P, Co-Zr-Nb amorphous, Y₃Fe₅O₁₂, etc. | Alloys, plastics, etc. | Magnetic recording, magnetic heads, magnetoresistive devices, optical disks, etc. |
| Display device films | ZnO, Y₂O₃, Ag, Cu, Al, SiO₂, Al₂O₃, Si₃N₄, etc. | Glass, plastic, etc. | Fluorescent tubes, plasma displays, liquid crystal displays |
| Optics & optical communication | Si₃N₄, Al, Ag, Au, TiO₂, ZnO, SnO₂, GdFe, TbFe, InAs, InSb, PbS, diamond, etc. | Plastic, glass, ceramics, etc. | Protective, reflective, anti-reflective films, optical switches, frequency conversion, optical memory, optical sensors, etc. |
| Solar energy utilization | Au-ZnS, Ag-ZnS, CdS-Cu₂S, SnO₂, etc. | Stainless steel, plastic, glass | Photovoltaic cells, transparent conductive films, etc. |
| Lubrication, low friction | Au, Ag, Pb, Cu-Au, Pb-Sn, MoS₂, MoSe₂, MoTe₂, WS₂, MoS, MS₂, BN, MoS₂-graphite, Ag-MoS₂, DLC, etc. | High-temperature alloys, structural metals, bearing steel, etc. | Ultra-high vacuum, room temperature, ultra-low temperature, jet engine bearings, satellite bearings, aerospace high-temperature rotating parts |
| Packaging | Cr, Al, SiO₂, Al₂O₃, TiN, etc. | Paper, plastic, metal, etc. | Metallization of packaging materials, high barrier protection |
As shown in Table 1-1, thin film materials are diverse in composition, offer a full range of special functions, and have wide application fields, playing an important role in all sectors of the national economy. Functional films with a thickness of 172 nm, thanks to their combination of precision and stability, have become an important choice in the field of precision manufacturing.
Film thickness at nanometer to micrometer scale As high-tech products become increasingly intelligent and integrated, the integration density of modern microelectronic devices continues to rise. It is now required to integrate 1,000,000 transistors per 1 mm² on a microelectronic chip. The size of transistor components is extremely small, requiring each functional layer to be thinner and thinner - only at the nanometer to micrometer level. Chip conductor line widths have reached 5–7 nm, and some high-precision devices have achieved precise preparation of functional films at the 172 nm level, with development now heading toward 3 nm. This can only be achieved using thin-film integrated circuit technology. At present, ion plating technology is the optimal choice for preparing thin-film integrated circuits.
Excellent film microstructure and crystal structure To produce thin film products with excellent performance, the film must possess superior microstructure and crystal structure. Depending on the application, films may be required to have single-crystal, polycrystalline, or amorphous structures, as well as dense, columnar, or multilayer nano-scale microstructures. Among these, 172 nm thick multilayer nanofilms exhibit excellent structural stability and performance consistency in optoelectronic devices.
High density and defect-free film As high-tech products move toward lighter, smaller, thinner, finer, more integrated, and more intelligent designs, the films must be extremely dense and free of defects.
High film-substrate adhesion There is no metallurgical bonding between the film and substrate - only an "adhered layer" - therefore, the smaller and thinner the device, the higher the required adhesion between the film and the substrate. High adhesion is also required for hard coatings on tools and dies.
1.3 Types of Coating Technologies
1.3.1 Early Thin Film Preparation Technologies
The technology for obtaining solid thin films has a long history, initially relying mainly on thermal energy, and later evolving to plasma-enhanced technologies.
Vacuum Evaporation Coating Technology This technology uses a heat source to evaporate a solid material, allowing the vapor atoms to transport in high vacuum and deposit on the substrate surface to form a film. It belongs to the physical vapor deposition (PVD) category and can achieve preliminary preparation of 172 nm-level films.
Chemical Vapor Deposition (CVD) Technology This technology uses thermal energy to thermally decompose introduced inorganic gases into active atoms, which then chemically react on a heated substrate surface to deposit a film.
Polymer Organic Polymerization Technology Organic monomer gases polymerize into high-molecular-weight polymers under high temperature, high pressure, and the action of an initiator.
1.3.2 Ion Plating Technology
Since 1963, when American scientist D.M. Mattox introduced gas discharge into evaporation coating, numerous ion plating technologies that utilize various gas discharge methods to obtain high-performance film particles have emerged. The technology has evolved from plasma-enhanced coating using solid sources to using gaseous sources, with gaseous sources expanding from inert gases and inorganic compound gases to organic gases. Many new coating techniques and processes that cleverly utilize electric fields, magnetic fields, and arc discharges to excite and enhance plasma have appeared, providing thin film researchers with diverse means to prepare special-function thin films required in various fields. Among these, the preparation of high-precision 172 nm-level films has become an important application direction of this technology.
The concept of ion plating has expanded from evaporation-type ion plating to a broader field. Any coating technology that uses plasma energy during gas discharge is now called ion plating technology. Modern ion plating technology includes evaporation-type ion plating, magnetron sputtering ion plating, arc discharge ion plating within PVD, as well as plasma-enhanced chemical vapor deposition and plasma-enhanced polymerization, and can be classified into three major categories:
Plasma-Enhanced Physical Vapor Deposition (PEPVD)
Plasma-Enhanced Chemical Vapor Deposition (PECVD)
Plasma-Enhanced Polymerization (PEP)
Table 1-2 Various Modern Ion Plating Technologies and Their Characteristics
| Coating Technology | Technology Type | Film Particle Source | Discharge Type | Discharge Technology | Reaction Mechanism |
|---|---|---|---|---|---|
| Evaporation-type ion plating | PEPVD | Thermal evaporation | Glow/arc discharge | DC glow, RF glow, hot filament arc, cold cathode arc | Metal ions + high-energy atoms → synthesis of new structure films (can prepare 172 nm films) |
| Magnetron sputtering ion plating | PEPVD | Cathode sputtering | Glow discharge | DC glow, RF glow, microwave glow | Metal ions + high-energy atoms → synthesis of new structure films |
| Plasma-enhanced chemical vapor deposition | PECVD | Inorganic gas | Glow/arc discharge | DC glow, RF glow, microwave glow, hot filament arc | Inorganic gas ions + high-energy active radicals → synthesis of new structure films |
| Plasma-enhanced polymerization | PEP | Organic monomer gas | Glow/arc/corona discharge | DC glow, RF glow, microwave glow, corona discharge | Organic monomers + active groups → plasma polymerization into polymer films |
Key points summarized from Table 1-2:
All modern ion plating technologies are performed in various gas discharges.
PEPVD film particles come from evaporation or sputtering of solid materials; PECVD particles come from inorganic gases; PEP particles come directly from introduced organic gases.
Discharge modes include glow discharge and arc discharge, with PEPVD, PECVD, and PEP technologies all trending toward arc discharge.
Plasma-enhanced polymerization is a technology that has emerged in recent years.
Plasma is the fourth state of matter, possessing energy several orders of magnitude higher than solids, liquids, and gases. Plasma-enhanced polymerization technology that utilizes plasma energy to produce high-molecular-weight polymers has been widely applied extensively in the preparation of modern high-end organic thin film products.
Thanks to the development of various new plasma-energy-enhanced coating technologies and processes, in recent years, generations of superior special-function thin film materials have been developed - urgently needed in fields such as semiconductor integrated circuits, information display devices, optical films, conductive films, insulating films, medical materials, and barrier films - creating enormous economic value. In particular, the scalable preparation technology for 172 nm-level functional films has strongly driven the rapid development of the precision electronics industry.
