Because of the more chaotic purification process, the temperature fluctuation range is becoming smaller and smaller. For example, in the lithographic exposure process produced by large scale integrated circuits, the mask data is a requirement that the difference between the thermal expansion coefficients of glass and silicon is getting smaller and smaller. The temperature of a silicon wafer with a diameter of 100 microns rises to a certain extent, and the aluminum material causes a linear expansion of 0.24 um, so it must have a stable temperature of ±0.1 degrees, and the required humidity value is generally lower because of human sweat. The latter products will be polluted, especially if they are afraid of sodium semiconductor plants, which should not exceed 25 degrees.
High humidity creates more problems. When the relative humidity exceeds 55%, the inner wall of the condenser will be, if there is an accurate equipment or circuit, it can cause various kinds of troubles. Relative humidity is 50% anti-rust. In addition, in high-humidity air, it is difficult to remove water by a dust resistor that is chemically adsorbed on the surface of the wafer. The higher the relative humidity, the adhesion is removed, and if the relative humidity is less than 30%, the difficulty of electrostatic adsorption on the surface of the particles is very simple, and many semiconductor devices that simply break down occur. About the optimum temperature range for wafer production of 35-45%.
The pressure required in purifying the aluminum chamber:
In most clean rooms, in order to avoid contamination from the outside, the internal pressure (static pressure) that needs to be adhered to is higher than the external pressure (static pressure). To adhere to the pressure difference should meet the following general guidelines:
1. The clean space pressure is higher than the pressure in the non-clean space.
2. A high level of cleaning is higher than the pressure in a clean room with a low level of pressure in an adjacent space.
3, similarities clean room opening, high level of cleanliness of the room.
Depending on the fresh air, the pressure difference that is adhered to, the fresh air can leak the pressure difference from the gap to compensate.