Final answer:
To calculate optimal resist thickness for novolak resist at 365 nm exposure, use the formula t = (m*λ)/(2*n), taking into account the thin-film interference and the resist material's refractive index.
The specific optimal thickness depends on the lithography requirements.
The correct answer is: a) Resist thickness is not related to exposure wavelength.
Step-by-step explanation:
The assignment of good and bad resist thicknesses for novolak resist at 365 nm exposure in photolithography involves understanding the relationship between resist thickness and exposure wavelength.
Thin-film interference is a phenomenon that can provide insights into optimal thicknesses. The constructive and destructive interference of light waves that occur when reflecting off thin films inform which thicknesses will best achieve the desired lithography results.
Optimal resist thickness can be calculated using the formula t = (m*λ)/(2*n), where t is the thickness of the resist, m is an integer (for constructive interference) or a half-integer (for destructive interference), λ is the wavelength of the light used, and n is the refractive index of the resist material.
For instance, for a novolak resist with a refractive index of 1.40 (assuming this value is accurate for the example), and using a 365 nm wavelength, the optimal thickness for destructive interference would be calculated by setting m to 0.5, 1.5, 2.5, etc.
However, a specific optimal value for t would depend on the specific context and requirements of the lithography process, including the desired properties of the photoresist after exposure.