Surface roughness control by energy shift in deep X-ray lithography

Previous studies show that the surface roughness of the sidewall generated by deep X-ray lithography (DXL) is a function of the photon energy of X-rays. Present study demonstrates and reveals the ideas of controlling surface roughness by tuning irradiation photon energy on the sidewall using the developing temperature. The ideas are resulted from two observations (1) X-rays of higher energy induce photoelectrons of higher energy in the resist and the corresponding scattering distance is nearly a square function of electron energy [1], and (2) high-energy X-rays are expected to induce more surface roughness and this effect has been observed by different laboratory [2].