Effective energy densities in KrF excimer laser reformation as a sidewall smoothing technique
Resource
The Journal of Vacuum Science and Technology B 26 (1): 110-116
Journal
Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
Journal Volume
26
Journal Issue
1
Pages
110-116
Date Issued
2008
Author(s)
Abstract
Profile transformation of sidewalls and roughness reduction by KrF excimer laser reformation at different illumination conditions are presented. The effective energy density derived from a finite element model of heat transfer is used to characterize the molten depth of Si during high energy laser illumination at normal and oblique incidence. The operation range of laser reformation as a sidewall smoothing technique, including incident angles and energy densities, is determined by the effective energy density. Using an energy density higher than 1.4 J/cm2 at the incident angle of 75° is recommended for a minimal residual roughness, acceptable sidewall profile transformation, and a practical interval-height ratio. The upper bound of scattering loss after laser reformation at different effective energy densities is also calculated.
SDGs
Type
journal article