Photo-reactive materials that are used to transfer circuit patterns on a photomask to a wafer.
It is coated on a wafer before the exposure.
Typically it is classified into two kind: positive and negative.
Resolution Resolving Power
The distance between two points that can be optically distinguished to be separate is called "resolution" or "resolving power" and in the microscopy field this is expressed by the following equation;
R=k × λ / 2NA
λ; the wavelength of the light source,
NA: Numerical aperture of the lens, constant
k: about 0.61 for ordinary optical microscope
Resolution Enhancement Techniques
Technologies to improve pattern transfer resolution by using either masks of PSM and OPC or immersion method
A photomask used in a stepper is typically called "Reticle".
Before steppers were introduced, a reticle was not used directly to expose wafers which were exposed with masks that are made with a reticle.
Sheet resistance: This simulated resistor connects to a Solar cell in series in the equivalent circuit and the value of this resistor is desirable to be as low as possible.
Shunt resistance: This simulated resistor connects to a Solar cell in parallel in the equivalent circuit and the value of this resistor is desirable to be as high as possible.
Reticle SMIF Pod
SMIF type storage case for a photomask