Physical vapour depos­ition

PVD is the abbreviation of physical vapor deposition. PVD is the technology of material evaporation deposition in vacuum state. Vacuum chamber is the necessary condition to avoid the reaction of evaporated material and air. PVD coating is used to prepare new products with additional value and characteristics, such as brilliant color, wear resistance and friction reduction. The PVD process is used to form the coating by condensing most of the metal materials and combining them with gases, such as nitrogen. The matrix material is transformed from solid state to gas state, and is ionized by heat energy as received in the arc process, or by kinetic energy as in the sputtering process. PVD technology is environmentally friendly and pollution-free. In general, Huicheng vacuum focuses on PVD coating.

The term "phys­ical vapour depos­ition" (PVD) cov­ers spe­cific pro­cesses used in thin film tech­no­logy. In all cases, it refers to vacuum-based coat­ing pro­cesses that use phys­ical meth­ods to deposit thin films on a sub­strate.

Of the vari­ous types, sput­ter­ing is one of the most eco­nomic depos­ition meth­ods which is used as a stand­ard coat­ing tech­nique in many indus­tries. One of the main reas­ons for pop­ular­ity of sput­ter­ing is the fact that this method allows for a mul­ti­tude of dif­fer­ent mater­i­als to be depos­ited on a wide vari­ety of sub­strates.

Sput­ter­ing pro­cesses are used in dif­fer­ent applic­a­tions such as fin­ish­ing sur­faces in the semi­con­ductor industry, pro­du­cing polar­iz­a­tion fil­ters in the optical industry or coat­ing large area sur­faces in archi­tec­tural glass industry.

Not only do we sup­ply our cus­tom­ers with coat­ing sys­tems, we also develop and pro­duce sput­ter­ing tar­gets and we have a great deal of ex­per­tise from our more than quarter a cen­tury of exper­i­ence in this area.

In all PVD pro­cesses, the mater­ial from which the thin film will be pro­duced is ini­tially in solid form and nor­mally loc­ated some­where in the pro­cess cham­ber, e.g. at the tar­get in sput­ter­ing. Vari­ous meth­ods are used to vapor­ize the mater­ial (for example, using a short, power­ful laser pulse, with an arc, or by ion or elec­tron bom­bard­ment) which then con­denses in the form of a thin film on the sub­strate sur­face.

In thermal vapour depos­ition, the mater­ial that pro­duces the film is heated by an elec­tric heater until it is released into the gas phase. Molecu­lar beam epi­taxy and ion beam sput­ter­ing depos­ition are also coun­ted among the group of PVD meth­ods. The res­ult­ing films are extremely pure and very uni­form. They also adhere excel­lently to the sub­strate. PVD coat­ings offer an envir­on­ment­ally friendly altern­at­ive to the con­ven­tional elec­tro­chem­ical pro­cesses for many applic­a­tions.

Sputtering is another way of physical vapor deposition technology. The sputtering process is the technology that the target material is bombarded out by ion bombardment. Inert gas, such as argon, is charged into the vacuum cavity. By using high voltage, glow discharge is generated to accelerate the ion to the target surface. Argon ion bombards (sputters) the target material from the surface and deposits it on the workpiece in front of the target. Other gas bodies, such as nitrogen and acetylene, are usually used to react with the target material sputtered out to form a thin compound Membrane. Sputtering technology can prepare many kinds of coatings, and has many advantages in decorative coatings (such as Ti, Cr, Zr and carbonitride). Because of its very smooth coating, sputtering technology is also widely used in the field of Tribology in the automobile market (for example, CrN, Cr2N and many kinds of diamond (DLC) coatings). High energy ions bombard the target, extract atoms and transform them into gas state. A large number of materials can be sputtered by magnetron sputtering technology.

Advantages of sputtering technology:
+Target material adopts water cooling to reduce thermal radiation
+Almost any metal material can be sputtered as a target without decomposition
+Insulating materials can also be sputtered by RF or if power supply
+It is possible to prepare oxide (reactive sputtering)
+Good coating uniformity
+The coating is very smooth (without droplets)
+The cathode (up to 2m long) can be placed at any position, which improves the flexibility of equipment design

Disadvantages of sputtering technology:
-Lower deposition rate compared with arc technology
-Compared with the arc, the plasma density is lower (~ 5%), the coating adhesion and the coating density are lower

There are many forms of sputtering technology. Here we will explain some of them. These sputtering technologies can be realized on the vacuum coating equipment of vacuum production.
+Magnetron sputtering uses a magnetic field to maintain the plasma in front of the target, strengthen the ion bombardment and improve the plasma density.
+UBM sputtering is the abbreviation of unbalanced magnetron sputtering. The enhanced magnetic field coil is used to enhance the plasma density near the workpiece. A more compact coating can be obtained. Higher energy is used in the UBM process, so the temperature will rise accordingly.
+The closed field sputtering uses the magnetic field distribution to confine the plasma in the closed field. The loss of the target material to the vacuum chamber is reduced and the plasma is closer to the workpiece. A compact coating can be obtained and the vacuum chamber can be kept relatively clean.
+Twin target sputtering (DMS) is a technique for the deposition of insulator coatings. Alternating current (AC) acts on two cathodes instead of using direct current (DC) between the cathodes and the vacuum chamber. This enables the target to have a self-cleaning function. Twin target magnetron sputtering is used for high-speed deposition such as oxide coating.
+Hipims + (high power pulsed magnetron sputtering) uses high pulse power supply to improve the ionization rate of sputtering materials. The coatings prepared by hipims + have the advantages of arc technology and sputtering technology. Hipims + is a compact coating with good adhesion, and it is also a smooth and defect free coating at the atomic level.

High power pulsed magnetron sputtering (HIPIMS) technology

Under the condition of low frequency and low duty cycle, the target was sputtered by hipims technology with very short pulse voltage. During the time of applying voltage, the magnetron target generates MW level pulse energy, while maintaining low average power. High density ions are produced in the plasma.

Arc evaporation is a way of physical vapor deposition. The application of PVD in hard coating starts from the arc technology. The arc technology originated from electric welding. The evaporated solid metal (target) is placed in the vacuum chamber to generate glow discharge, and then it runs on the target surface. The target evaporates in a very small range, about several microns in size. The arc motion is controlled by the magnetic field. The plasma formed by the evaporated metal ions will be deposited on the surface of the workpiece. These workpieces rotate in the vacuum cavity. The coating prepared by the arc is usually used for the surface coating of tools and parts, such as tin, AlTiN, AlCrN, TiSiN, TiCN, crcn and CrN. The evaporated metal is ionized and accelerated into the electric field at the same time. In the arc process, the evaporated material is highly ionized, and the deposited coating has excellent adhesion.

Advantages of arc technology:
+High deposition rate (~ 1-3 μ M / h)
+High dissociation rate, good adhesion and compact coating
+When the target is cooled, the coated workpiece is heated less, so that it can be deposited below 100 ° C
+Metals with multiple components can be evaporated, and the remaining solid target components remain unchanged
+The cathode can be placed in any position (horizontal, vertical, upper and lower), and the equipment design is flexible

Main disadvantages of arc technology:
-Limited target material
-Only metals (excluding oxides) can be used, so that the evaporation temperature will not be low
-Due to the high current density, some target materials are splashed out by evaporation in the form of small droplets

Electromagnetic Filtering Cathode Technology (EFC)

The combination of pulsed electromagnetic field and fixed magnetic field scans the entire target surface so that the target surface is evenly etched. The unique electromagnetic power supply can output in both positive and negative directions, control the uniform scaling of arc spot on the target surface, reduce the generation of large particles. And the coating is dense and smooth. 

Characteristic:

• Coatings of new metal compounds or nitride films (nitrogen atmosphere)
• Coatings of amorphous carbon, nano diamond and carbon nanotubes nanoparticles
• Coatings of thermoelectric thin film with thermoelectric material target

Electron beam evaporation

Body with longitudinal beam scanning

A system with a spray gun and a full digital beam sweeper for thick layers of single, multi pocket and large capacity crucibles.

The customized electron gun source with crucible turret system is used for special applications and extends the product time between source maintenance.

Ion assisted evaporation（IAD）

Ion source technology can provide lower process temperature, shorter process time and enhanced film performance for applications in Photonics and optoelectronics.

HCMS series E-beam evaporation optical coater adopts advanced electron gun evaporation and ion assisted deposition (IAD) technology to deliver thin film deposition and etch capabilities for precision optics, optoelectronics and semiconductor applications to customers around the globe. 

From deposition of multilayer dielectrics and metals, to TCOs or whole range of compounds, it can be configured just the way you need for directional coating, enhanced thickness uniformities and the tightest optical, mechanical and environmental specifications. 

HCVAC brings you the complete solution including processes and substrate handling knowhow on a platform with proven production reliability for the best ever cost of ownership.

For most medium carbon alloy structural steel parts, its hardness is much lower than that of hard film. Only a few microns thick PVD film is deposited, which is difficult to effectively improve its wear resistance, fatigue strength and plastic deformation resistance. After nitriding, nitrogen compound and diffusion layer are formed on the surface of steel, which improves the surface hardness of parts. Nitriding parts are more suitable for PVD coating than non nitriding parts.

Chemical Vapour Deposition (CVD)
CVD is a well-established technique for deposition of a wide variety of films with different compositions and thicknesses down to a single layer of atoms.

Highlights

• Substrate sits directly on electrode which can be heated up to 1200˚C
• Gas injected into process chamber via “showerhead” gas inlet in the top electrode 
• Solid/liquid precursor delivery system for novel processes such as 2D materials MOCVD, ZnO nanowire CVD etc.
• Automatic load lock to transfer sample directly on to a hot table and save time on heating and cooling.
• Plasma enhancement options for lower temperature deposition or plasma assisted conversion or functionalization as well as chamber cleaning.
• Wide range of processes possible in the same chamber

In-depth diagram of CVD system chamber

PECVD is the abbreviation of plasma assisted chemical vapor deposition. Sometimes PECVD is also written. E stands for enhancement. In the PVD process, the coating material is obtained by evaporation in the solid form; in the PACVD process, the coating material is obtained by evaporation in the gas form, and the gas, such as hmdso (hexamethyldimethylsilyl ether), is about 200 under the action of plasma When cracking occurs at º C, non reactive gases, such as argon, can make ions deposit on the workpiece surface and form a very thin coating. Diamond like carbon (DLC) coating is a good example of PACVD technology, which is usually used in tribology and automobile industry.

Plasma assisted chemical vapor deposition (PACVD) is used to deposit DLC coating. Through plasma excitation and ionization, chemical reactions in the process can be activated. With this process, we can use pulse glow or high frequency discharge to deposit at a low temperature of about 200 ° C. the DLC coating produced by PACVD has the characteristics of low friction coefficient and expandable surface hardness.

Atomic layer deposition (ALD) is a method that can deposit materials on the substrate surface layer by layer in the form of single atomic film, so as to form a full coverage film on the substrate surface with complex morphology. Atomic layer deposition is similar to ordinary chemical deposition, but in the process of atomic layer deposition, the chemical reaction of a new atomic film is directly related to the previous layer, so only one layer of atoms is deposited in each reaction. In the ALD process, different reaction precursors are alternately sent into the reaction chamber in the form of gas pulses. Therefore, it has the characteristics of self limiting growth, and the thickness of the film can be accurately controlled. The prepared film has uniform thickness, excellent consistency and high step coverage, which is especially suitable for the film growth in deep groove structure, It has irreplaceable applications for the demand of accurate film-forming on the surface of multi-dimensional structures. Since ALD equipment can realize high aspect ratio, excellent step coverage of extremely narrow groove opening and accurate film thickness control, ALD is one of the essential core equipment in the manufacturing of advanced logic chips, DRAM and 3D NAND with complex structure and accurate film thickness requirements.

Focused-ion rapid etch (FIR etch) technology

HCVAC systems, although designed for coating deposition, already have what you need to use them for cleaning and etching as well. Argon (Ar) ions, from a plasma generated with a hot filament plasma source, can be accelerated towards and around the products loaded in the chamber. This ion bombardment etches or cleans the surface. The combination of the plasma source and ARC technology is what enables

focused-ion rapid etch (FIR etch).

Improved productivity and performance due to more efficient and powerful etching

Increased plasma density on the table

Plasma steering provides excellent uniformity

Reactive Ion Etching（RIE）
Reactive Ion Etching (or RIE) is a simple operation and an economical solution for general plasma etching. A single RF plasma source determines both ion density and energy.

Highlights

Multiple choices of etch processes:

• Chemical etching – isotropic, fast rate
• Ion induced etching – anisotropic, medium rate
• Physical etching – anisotropic, slow rate
• Wide applications in semiconductor de-processing and failure analysis

With microwave PACVD technology, the gases and precursors are activated with microwave frequencies to generate the plasma, not with pulsed bias. Without the need for a bias voltage, non-conductive coatings and coatings on non-conductive materials become possible. In addition, the remote microwave plasma generator means the product load has less influence on the deposition process, leaving more process

parameters, such as bias voltage, available to tune the coating characteristics.

Remote plasma generator, so coating properties depend less on the product load in the chamber

Enables coatings such as DLC on non-conductive products such as plastic or glass

Can be used with a wider range of precursor gases (such as C2H2, HMDSO and O2) to make coatings such as SiO2

Improved process repeatability (for DLC) for a mixed load of products that is typical for jobcoaters.

Uniform plasma distribution over the height of the system

Bias voltage available to tune coating properties

Microwave technology opens a window for new etching and activation processes