Photolithography

Pagina 1

C  light is not used for the deposition, D photoresists are polymers, thus not made of silicon A  it is the opposite, pressure is higher, in order to prevent external air to come inside C  the environment is not sterile (clean is not sterile) E  light is NOT always yellow, but only where there is photolithography False because the cleaning process does not increase the adhesion of the photoresist. Moreover, oxidation is not removed by any cleaning procedure. A  In general, not true for every photoresist, but only for the negative photoresist, where the crosslinking is initialized by light. D  In general, positive resist require positive mask to be transferred A  the area’s coverage is controlled by the quantity of material D  the higher the velocity, the lower the thickness It is true that the oven provides uniform temperature, but in this case, hotplates are better because they provide a gradient of temperature which is better if you want to remove the solvent B  not realistic. The pattern is not made of chrome metal-absorbing film C  it is the opposite, in fact D is correct C  UV LEDs are able to be monochromatic, but LED in UV range are not powerful enough. Lamps are used and they provide are wide spectrum  filters required D  the area is missing. The dose is radiance (power over cm^2) multiplied by the exposure time (J over cm^2) A  only true for the shadow printing B  it increases with higher power (shorter wavelength) A  not always, it depends on the application B  not ideal, because the lift-off solution (etchant) won’t properly remove the material. If you have an overcut, the etchant cannot reach the photoresist, and thus it cannot be lifted off