Smiconductor Thin Film Deposition Equipment

Thin film deposition equipment, one of the three core equipment of the semiconductor production line.

I.What is thin film deposition

II. Detailed Introduction of PVD,CVD and ALD

III. Two important PECVD introductions in the industry

IV. Global Semiconductor Thin Film Deposition Equipment Market

I.What is thin film deposition

To put it simply: film deposition is to "lay" the chip.

The more precise and layered the chip, the greater the demand for "film".

The better the chip, the more stickers there are.

Professionally: Classification of thin film deposition equipment Thin film deposition refers to the deposition of thin film materials to be treated on silicon wafers and other substrates, and the deposited thin film materials are mainly silica, silicon nitride, polysilicon and other non-metals and copper and other metals, and the deposited film can be amorphous, polycrystalline or monocrystalline.

It includes CVD (chemical vapor deposition), PVD (physical vapor deposition), and ALD (atomic layer deposition), among which ALD belongs to the branch of CVD.

Why do we say that the more precise and the more layers the chip, the greater the demand for "film"?

Chip manufacturing is like putting a film on a mobile phone, but this "film" is nano-level, and it needs to be pasted with dozens or even hundreds of layers! As the chip process becomes more and more sophisticated and the structure becomes more and more complex, the demand for "film" has also increased significantly.

The more advanced the process, the more layers of the film

In the CMOS production line of the 90nm process, about 40 thin film deposition processes are required, involving 6 materials; In the FinFET production line of the 3nm process, the thin film deposition process has increased to 100 and the types of materials are close to 20. Each layer of "film" is crucial, and without any layer, the chip may not work properly.

The more complex the structure, the more difficult it is to apply the film

Taking memory chips as an example, from 2D NAND to 3D NAND, the structure has changed from flat to three-dimensional, and the number of layers has increased significantly, just like a single-story bungalow to a skyscraper. Each layer requires precise "coating", which naturally increases the demand for thin film deposition equipment.

Therefore, thin film deposition equipment is the "film master" of chip manufacturing, and the more precise and layered the chip, the more inseparable it is.

II. PVD,CVD

PVD(Physical Vapor Deposition)

Physical vapor deposition is a technology that uses physical mechanisms to perform thin film deposition, and the process does not involve chemical reactions.

It mainly includes evaporation, sputtering, arc plasma coating, ion coating, molecular beam epitaxial coating and other categories. Evaporation: refers to a coating technology in which the evaporated material is heated by evaporation sources such as resistance, electron beam, high-frequency induction, arc and laser in a high vacuum chamber to reach the melting and gasification temperature, so that the atoms or molecules of the evaporated material are vaporized and escaped from its surface to form a vapor stream, which is incident on the surface of the substrate to be evaporated and condensed to form a solid film.Vacuum evaporation is currently the mainstream process of OLED panels.

Sputtering: usually refers to magnetron sputtering, which refers to the use of charged particles to accelerate in the electric field with a certain kinetic energy, in a vacuum state of 1.3×10-3Pa is filled with inert gas, and between the substrate (anode) and the metal target (cathode) is added with high-voltage direct current, due to the electrons generated by glow discharge (glowdischarge) to excite the inert gas, produce plasma, blast out the atoms of the metal target, and deposit on the substrate.

Sputter coating is the most widely used PVD.

Molecular Beam Epitaxy (MBE): It is a special vacuum coating process that grows thin films layer by layer along the crystal axis of the substrate material. MBE can prepare single crystal films with dozens of atomic layers, as well as alternating thin films with different components and doping to form ultra-thin layer quantum microstructure materials.

Ion plating: a combination of vacuum evaporation and sputter coating, the material to be plated is partially ionized in the discharge space after vaporization, and then the ions to be plated are attracted by the electrode to the substrate to be deposited into a film.

Due to its complexity, ion plating has a limited range of applications.

All in all, during the PVD process, only the material form changes, and no chemical reaction is involved, which is a pure physical change. PVD is an essential key process for depositing ultra-pure metal and transition metal nitride films in the whole process of semiconductor manufacturing.

2.CVD(Chemical Vapor Deposition)

Deposition of dielectric and semiconductor film CVD is a coating process that deposits solid films on the surface of a substrate through a vapor phase chemical reaction, which is a chemical reaction.

CVD reaction precursors are generally silane, phosphorus, borane, ammonia, oxygen and other gas raw materials, and the products are generally nitride, oxide, nitrogen oxide, carbide, polysilicon and other solid films, and the reaction conditions are generally high temperature, high pressure, plasma, etc.

The CVD film formation process generally includes eight steps:

Reactive gas transport to the sedimentary area;

membrane precursor formation;

membrane precursors diffuse to the surface of the matrix;

membrane precursor adhesion;

membrane precursors diffuse to the membrane growth area;

surface chemical reaction, the film precipitates and gradually grows, and finally forms a continuous film and generates by-products at the same time;

By-products are removed from the surface of the matrix;

By-products are removed from the reaction chamber. With the continuous progress of the process, the demand for grooves and deep hole filling has given birth to new CVD technologies, and the current mainstream applied technologies are LPCVD, PECVD, and the future development direction is HDPCVD, SACVD.

Two important PECVD introductions in the industry:

According to the frequency of plasma generation, the plasma used in PE CVD can be divided into two types: radio frequency plasma and microwave plasma

.

At present, the RF frequency frequency used in the industry is generally 13.56MHz. Among them, RF plasma coupling methods are usually divided into two types: capacitive coupling (CCP) and inductive coupling (ICP).

3.ALD(Atomic Layer Deposition)

ALD has precise film thickness control capabilities, excellent thickness uniformity and consistency of deposited films, and its step coverage capacity is very strong, making it suitable for film growth in deep groove structures. ALD plays an important role in multiple processes such as SADP, HKMG, and copper metal interconnect diffusion barrier layers.

ALD principle: through the pulse of the gas-phase precursor through alternating penetration into the reactor and forming a film layer by layer on the substrate surface in the mode of a single atomic layer, the reaction steps include:

precursor A enters the reaction chamber and is adsorbed on the surface of the matrix;

Rinse the reaction chamber with inert gas and clean the remaining precursor A;

Precursor B enters the reaction chamber and adsorbs on the surface of the matrix, reacts chemically with precursor A to form the target film;

The inert gas flushes the reaction chamber to remove the by-products generated by the chemical reaction from the reaction chamber and completes the deposition of atomic layer thin films. This cycle allows for the deposition of thin films at the atomic level.

III. What is thin film deposition equipment?

Thin film deposition is a key equipment for semiconductors. As the name suggests, it is mainly responsible for the deposition of the dielectric layer and the metal layer in each process step.

Vacuum and pressure control system composition: mechanical pump, molecular pump, vacuum valve, vacuum gauge, etc.

Function: Provide a stable vacuum environment for the deposition process, reduce the impact of nitrogen, oxygen and water vapor on the quality of the film. Low vacuum is extracted by dry pump to avoid oil contamination of the substrate. The molecular pump is used to extract high vacuum, which has a strong ability to remove water vapor and ensure the cleanliness of the reaction chamber.

Importance: The vacuum environment is fundamental to film deposition, directly affecting the purity and uniformity of the film.

The composition of the deposit system: RF power supply, water cooling system, substrate heater, etc.

Function: RF power supply: ionizes the reaction gas, generates plasma, and promotes chemical reactions. Water Cooling System: Provides cooling for the pump and reaction chamber, preventing equipment from overheating and triggering alarms in case of overtemperature. Cooling water lines are insulated to avoid electrical interference.

Substrate heater: Heats the substrate to remove surface impurities and improve the adhesion of the film to the substrate. Importance: The sedimentation system is the core of film deposition and directly affects the quality and performance of the film.

Gas and flow control system composition: gas cylinder, gas cabinet, mass flow meter, gas transmission pipeline, etc.

Function:

Gas source: Reaction gas (such as silane, ammonia, nitrogen, etc.) is provided by gas cylinders.

Gas Delivery: Gas is transported to the process chamber through a gas cabinet.

Flow control: Mass flow meters are used to precisely control gas flow to ensure stable proportions and flow rates of reactive gases.

Importance: Gas flow control directly impacts the composition, thickness, and uniformity of the film.

Reaction chamber system composition: reaction chamber, substrate tray, gas distributor, electrode, etc.

Functions:

(1) Reaction chamber: Provides reaction space for thin film deposition, usually made of high-temperature and corrosion-resistant materials.

Substrate tray: Secure the substrate and ensure it is evenly heated.

Gas distributor: evenly distribute the reaction gas to ensure the uniformity of film deposition.

(4) Electrode: In processes such as PECVD, it is used to generate plasma.

Importance: The reaction chamber is the core area of film deposition, and its design directly affects the quality and performance of the film.

5.Control system composition: PLC (programmable logic controller), sensor, human-machine interface (HMI), etc.

Functions:

(1) Automatic control: realize the automatic operation of each system of the equipment through PLC.

(2) Parameter monitoring: Real-time monitoring of key parameters such as temperature, pressure, and gas flow.

(3) Fault alarm: trigger the alarm and automatically stop the machine under abnormal circumstances.

Importance: The control system ensures stable operation of the equipment, improving process consistency and reliability.

Cleaning and maintenance system composition: cleaning gas (such as NF₃, CF₄), cleaning pipeline, exhaust gas treatment device, etc.

Function:

Chamber cleaning: Regularly remove sediment in the reaction chamber to avoid contamination.

Exhaust gas treatment: Treat harmful gases generated during the reaction process to ensure environmental protection and safety.

Important: Cleaning and maintenance systems extend the life of the equipment and ensure the stability and consistency of film deposition.

IV.International market for thin film deposition equipment

According to SEMI measurement data, lithography machines, etching machines, and thin film deposition equipment account for about 24%, 20%, and 20% of the semiconductor equipment market respectively.

Thin film deposition equipment is one of the three core equipment of the semiconductor production line, and its market size will continue to grow with the progress of the process.

The global thin film deposition equipment market size was around USD 20 Billion in 2022. The market is expected to grow to $30 billion by 2026, with a compound annual growth rate (CAGR) of about 8-10%.

Growth Drivers:

Advanced process requirements: As semiconductor processes evolve to 3nm, 2nm and below nodes, the number and complexity of thin film deposition processes have increased significantly. For example, the thin film deposition process of the 3nm process is 2.5 times higher than that of the 90nm process.

Memory chip upgrades: From 2D NAND to 3D NAND, the number of thin film deposition layers has increased significantly. The number of stacked layers of 3D NAND has grown from 32 to more than 200, and the demand for thin film deposition equipment has skyrocketed.

3. Emerging applications driven: The demand for high-performance chips in emerging technologies such as 5G, artificial intelligence, Internet of Things, and autonomous driving continues to grow, driving the expansion of the thin film deposition equipment market.

4. Market segment share: CVD equipment: accounts for about 60% of the thin film deposition equipment market, which is the largest segment. PVD equipment: accounts for about 25% of the thin film deposition equipment market. ALD equipment: accounts for about 15% of the thin film deposition equipment market, but it is growing the fastest, with a CAGR of more than 15% in the next FIVE YEARS.