In recent years, large-scale and ultra-large-scale integrated circuits have developed rapidly, and the research and development and production technology related to the semiconductor field are also developing rapidly. In the field of semiconductors, large-scale integrated circuit manufacturing process can not be separated from lithography and etching technology, is an important process in fine line graphics processing, which is an important raw material is irradiated photosensitive material-photoresist, also known as photoresist.

Photoresist is divided into positive glue and reverse glue. Its distinction is based on different development and chemical reaction mechanisms. The insoluble substance formed after illumination is negative glue. On the contrary, the soluble substance formed after illumination is positive glue. The photoresist has the following important parameter characteristics:

①   Resolution: the ability to distinguish the graphical features of silicon wafers, the higher the resolution, the higher the dimensional accuracy of the semiconductor produced.

②   Sensitivity: Photoresist to produce a good pattern requires a certain wavelength of energy light. The sensitivity of the photoresist is particularly important for shorter wavelength ultraviolet light.

③   Viscosity/Viscosity: Viscosity/viscosity is a parameter that measures the flow characteristics of photoresist. High viscosity will produce a thick photoresist; the smaller the viscosity, the more uniform the thickness of the photoresist produced. Simply put, the smaller the viscosity, the better the fluidity, and the better the photoresist produced.

④   Adhesion: Adhesion characterizes the adhesion of the photoresist to the substrate. Insufficient adhesion can cause deformation of the silicon wafer surface pattern, and adhesion is particularly important in the subsequent process.

⑤   Corrosion resistance: in the subsequent etching process of photoresist, it is necessary to protect the surface of the substrate, and the photoresist is required to have certain corrosion resistance, heat stability and resistance to ion bombardment.

In the photoresist production process, a suitable production workshop is particularly important, which needs to have the following characteristics:

①   The staff of the workshop felt the room temperature within a comfortable range. If the humidity in the workshop is too high, it will make people feel stuffy, and if it is too low, it will make the respiratory tract uncomfortable, thus affecting the work.

②   Static charge control: when the humidity is less than 30% RH, static electricity will exist in the insulator for a long time, and the semiconductor production workshop will generally use additional humidity control and anti-static devices to limit the accumulation of static charge.

③   If the humidity in the workshop is not well controlled, it is easy to cause metal corrosion in the workshop and accelerate the aging of the equipment.

④   Adhesion is affected by the humidity of the workshop. In the production equipment with high humidity, the capillary of concentrated water type forms a connecting bond between the particles and the surface, which increases the adhesion between the colloidal particles and the silicon wafer. When the humidity is controlled at 70% RH, this effect is particularly obvious.

⑤   Relative humidity and temperature have a great influence on the stability of the photoresist. Photoresists are extremely sensitive to relative humidity and play a significant role in precise dimensional control for subsequent production.

It can be seen that the control of relative humidity and temperature is very important. The temperature and humidity sensor HTU21D is often used in the temperature and humidity control of the production workshop, which is extremely important for the production of products with harsh manufacturing environment.

Advantages:

Fully interchangeable, no recalibration required

Rapid recovery after long-term saturation

Suitable for lead-free reflow soldering and other automated assembly methods

Separate identification, meet strict traceability requirements