Knowledge | 2022-09-14
Filtering coating process commonly clean method ultrasonic cleaning method
In the process of detector manufacturing, many cleaning techniques are involved, such as substrate cleaning during chip fabrication, epitaxial growth, substrate cleaning before coating processing, and the cleaning of optical elements such as filters. With the development of technology, the production of semiconductor devices is becoming more and more demanding of cleanliness. Complex new cleaning systems and equipment are also in use. In the fields of optical instruments, precision machinery, and electronic machinery, there is a growing need for precision industrial cleaning. The cleaning and treatment of the substrate is an essential step in both semiconductor film growth and device fabrication based on the semiconductor film. The semiconductor substrate is the base of epitaxy growth and subsequent process, the process of substrate preparation including clean treatment and so on, its quality directly affects the epitaxy and subsequent process, the substrate becomes the starting point of the Photoelectron Device Process, the cleaning of the substrate is divided into chemical cleaning and physical cleaning. Different substrate materials have different cleaning methods and processes, different application fields of the same materials, and different requirements for cleaning, cleaning methods are not the same, even if the same material is for the same purpose, cleaning methods also vary.
The cleanliness of the substrate is one of the key factors affecting the quality of the coated components, which can ensure the high cleanliness of the surface of the components before coating and reduce the impurities in the film, it is very important to clean the components before coating. Before the substrate enters the coating chamber, no matter what the coating requirements, it should be carefully pre-plating treatment (that is, cleaning treatment), to achieve the goal of oil, decontamination, and dehydration, which is an important measure to improve the film firmness.
The main mechanism of ultrasonic cleaning is ultrasonic cavitation, the second-order effect of ultrasonic cavitation, and the impact of high-speed micro-jet generated by ultrasonic cavitation on the solid-liquid interface, it is a high-speed, high-quality, and easy-to-realize automatic cleaning technology to promote the chemical and physical reaction effect of cleaning solution and remove pollutants. Ultrasonic cleaning technology is one of the most ideal technologies to make the substrate surface meet the requirements of the required cleanliness. Compared with other cleaning methods, ultrasonic cleaning has the advantages of a high cleaning rate, less residue, short cleaning time, and a good cleaning effect. To achieve a better ultrasonic cleaning effect, according to the different types of pollutants, it is necessary to select the appropriate ultrasonic frequency and different cleaning media. The frequency of ultrasonic cleaning of the filter substrate before the coating is usually in the range of (20-80) kHz. The ultrasonic cleaning medium can be selected according to the following criteria. The surface tension is small, and the attenuation of the ultrasonic wave is small, so the oil dissolves the ability to be big, the harmless matter, chooses deionizes the water, the neutral cleaner, isopropanol, acetone, and so on. In the process of ultrasonic cleaning of the filter before coating, to achieve a better cleaning effect, the medium is often heated to a certain extent.
In the process of cleaning the optical filter before coating, some chemical reagents such as cleaning agents are used to wipe, ultrasonic cleaning, and vapor cleaning to meet the cleaning requirements of the optical filter substrate before coating. Green, efficient and low-cost cleaning technology is a trend, but also the cleaning industry as a whole trend.