Humidity control is an indispensable condition for the production of dust-free workshop. Relative humidity is a commonly used environmental control condition during the operation of the clean room. Typical target relative humidity in semiconductor clean rooms and cleanrooms is controlled in the approximate range of 30 to 50% with tolerances within a narrow range of ± 1%, such as lithography or DUV ) Area is even smaller and can relax to within ± 5% elsewhere. The company is located in:

   In recent years, to maintain the air treatment process within the scope of these provisions, the Tianjin Purification Project will introduce you to a series of factors that may affect the overall performance of the clean room. These include:

  1, bacterial growth;

  2, the staff feel comfortable at room temperature range;

  3, there is static charge;

  4, metal corrosion;

  5, water vapor condensation;

  6, the degradation of lithography;

  7, water absorption. The company is located in:

   Bacteria and other biological contaminants (molds, viruses, fungi, mites) can actively multiply in environments with relative humidity above 60%. Some flora grows when the relative humidity is above 30%. When the relative humidity is in the range of 40% to 60%, the effects of bacteria and respiratory infections can be minimized. The company is located in:

  Relative humidity in the range of 40% to 60% is also a moderate range of human comfort. Excessive humidity can make people feel nauseous, while humidity below 30% can make people feel dry, chapped skin, respiratory discomfort and emotional discomfort. The company is located in:

  High humidity actually reduces the dust-free workshop, electrostatic charge accumulation on the surface of the clean room, lower humidity is more suitable for the accumulation of charge and become potential destructive sources of electrostatic discharge. Static charges begin to dissipate rapidly when the relative humidity exceeds 50%, but they can persist on insulators or ungrounded surfaces for a long time when the relative humidity is less than 30%. The company is located in:

  Relative humidity of 35% to 40% can be used as a satisfactory compromise between semiconductor dust-free workshop, clean room generally use additional control devices to limit the accumulation of electrostatic charge. The company is located in:

  The speed of many chemical reactions, including the corrosion process, will accelerate as the relative humidity increases. All surfaces exposed to the clean room, the air surrounding the cleanroom, are quickly covered with at least one layer of monolayer water. When these surfaces are composed of a thin metal coating that can react with water, high humidity can accelerate the reaction. Fortunately, some metals, such as aluminum, can form a protective oxide with water and prevent further oxidation reactions; in the other case, copper oxide, for example, is not protective and therefore, In high-humidity environments, copper surfaces are more susceptible to corrosion. The company is located in:

  In relatively high relative humidities, the concentrated capillary-shaped capillary force forms a bond between the particles and the surface, increasing the adhesion of the particles to the siliceous surface. Relative humidity less than 50% is not important, but when the relative humidity is about 70%, it becomes the main force of adhesion between particles. The company is located in:

  So far, the most pressing need for proper control of cleanrooms in semiconductor cleanrooms has been the sensitivity of photoresists. Because of its sensitivity to relative humidity, it has the strictest level of control over the relative humidity. The company is located in:

  In fact, relative humidity and temperature are key to photoresist stability and precise dimensional control. Even at constant temperature, the viscosity of the photoresist will rapidly decrease with increasing relative humidity. Of course, changing the tack will change the thickness of the protective film formed by the fixed component coating. A 3% variation in relative humidity will change the protective thickness by 59.2A. The company is located in:

In addition, under high relative humidity conditions, the photoresist swells more heavily after the baking cycle due to moisture absorption. Photoresist adhesion can also be negatively affected by higher relative humidity; lower relative humidity (about 30%) makes photoresist adhesion much easier, even without the need for polymerization modifiers such as hexamethyldisilazane Azide (HMDS).