Masks
Lithographic Masks
In most MEMS activities, the lithography process is of particular importance. A micro or nano chip pattern is transferred onto a substrate/substrate using a process called photolithography. First, the substrate (wafer) is coated with a thin layer of a light-sensitive organic material called photoresist. Each area of the photoresist that is illuminated changes its solubility. The mask with the desired pattern is then aligned with the substrate and a light source such as Deep UV is illuminated. Finally, the substrate is placed in the solvent and the resulting image is developed and inspected like photographic film. The mask works by selectively exposing the photoresist layer that covers the wafer surface.
A mask is made of a transparent glass such as Fused Silica, Quartz or Soda lime glass (the kind used in making laboratory slides) on which a thin layer of chromium is deposited. The deposited chromium prevents the passage of light and is covered with a layer of photoresist (usually positive).
Parts of the photoresist are exposed by a mask writing device. By developing the photoresist of the mask and dipping the mask in a chromium remover solution, the parts of the chromium not protected by the photoresist are removed, revealing the transparent glass underneath. In this way, light will pass through this part with the pattern created by the chromium.
Rasa Company has the following services and activities in the field of mask production and manufacturing:
-Preparation of raw masks in different dimensions (based on order, for more information, contact the laboratory supervisor at 021-64545463 ext. 114)
-Creation of a pattern on the mask (to create a pattern, the mask software file with the specified conditions, for more information, contact the laboratory supervisor at 021-64545463 ext. 114)
-Mask design (if you are not interested in mask design, Rasa Company provides a mask design service, for more information, contact the laboratory supervisor at 021-64545463 ext. 114)
