Ultrasonic Spray Coating in Semiconductor Industry

Ultrasonic spray coating for semiconductor industry is a precision thin-film deposition technology that uses high-frequency ultrasonic energy to atomize semiconductor materials (such as photoresists and conductive materials) into fine, uniform droplets. These droplets are then precisely sprayed onto the substrate surface using a carrier gas, resulting in high-quality, uniform thin-film coatings. This technology offers advantages such as high efficiency, high precision, low material loss, and thin, uniform coatings. It is widely used in semiconductor manufacturing, new energy, and glass coatings, replacing traditional spray methods.

 

Photoresist spraying is a key process technology for achieving uniform photoresist coating in precision manufacturing applications such as semiconductors and display panels. It is particularly suitable for coating non-planar substrates (such as 3D chips and MEMS devices) or large substrates (such as OLED panels), addressing the limitations of traditional spin coating in specific applications.

The essence of photoresist atomization spraying is to transform liquid photoresist into uniform micron-scale (or even nanometer-scale) droplets through physical atomization. These droplets are then delivered to the substrate surface using precisely controlled airflow and pressure. Ultimately, the droplets spread, fuse, and bake onto the substrate to form a continuous, uniform photoresist film.

 

Ultrasonic atomization spraying is a key technology in precision manufacturing fields such as photoresist coating and functional thin film preparation. Its core approach is to use high-frequency ultrasonic vibrations to transform liquid materials (such as photoresists, metal precursors, and biological reagents) into uniform droplets at the micrometer or even nanometer scale. These droplets are then transported to the substrate surface via precise airflow, ultimately forming a continuous, uniform film. Compared to pressure atomization and electrostatic atomization, ultrasonic atomization offers advantages over pressure atomization and electrostatic atomization, resulting in its widespread application in applications requiring extremely high material stability and coating precision, due to its lack of mechanical shear and highly controllable droplet size.

 

Working Principle

1. Ultrasonic Atomization:

The core of the device is the ultrasonic nozzle, which contains a transducer that converts electrical energy into high-frequency mechanical vibrations.

2. Liquid Atomization:

As liquid (solution, sol, or suspension) flows through the nozzle, the vibrating atomizer generates vibrations. When the vibration amplitude exceeds the liquid's surface tension, the liquid is broken into micron-sized droplets.

3. Carrier Gas Delivery:

The atomized droplets are then evenly transported to the substrate surface by a predetermined amount of carrier gas (such as air).

4. Thin Film Deposition:

Droplets are deposited on the substrate, forming a continuous thin film coating.

Advantages in Semiconductor Applications

High Precision and Uniformity:

The ability to deposit ultra-thin and uniform thin film coatings is crucial for applications in semiconductor manufacturing, such as photoresists, conductive films, and insulating films, which require extremely high precision.

Reduced Material Loss:

Compared to traditional spraying, ultrasonic spraying produces virtually no droplet bounce or excess splashing, increasing material utilization several times, making it particularly suitable for coating expensive materials.

Soft Spraying:

The spraying process is gentle and does not damage the substrate, making it suitable for fragile semiconductor materials and electronic components.

Diversified Nozzles:

Nozzles of varying widths, lengths, shapes, and flow rates can be selected to meet specific application requirements, enabling uniform coating of localized or large areas.