Product Code: ICAL08_P147

Laser Removal of Nanosized Particles from a Silicon Wafer using Green Laser
Authors:
HOON JEONG, Korea Institute of Industrial Tech; Cheonansi South Korea
Jae Dong Song, Kitech; Cheonan South Korea
Ji Young Baek, Kitech; Cheonan South Korea
Kang Won Lee, Kitech; Cheonan South Korea
Myong Hwa Lee, Kitech; Cheonan South Korea
Sang Bum Kim, Kitech; Cheonan South Korea
Kyung Soo Kim, Kitech; Cheonan South Korea
Presented at ICALEO 2008

As semiconductor device technology moves toward higher densities and smaller dimensions, a wafer surface cleaning of sub-100 nm sized particles becomes one of the most important processes. This paper presents the laser removal of nanosized particles from a silicon wafer. We collected the 100 nm sized NaCl particles on a silicon wafer by using scanning mobility particle sizer(SMPS). The collected NaCl particles were removed by irradiation of a 532 nm green laser which from 2nd harmonic generation of Nd:YAG laser. The silicon wafer surfaces were measured by a scanning electron microscopy(SEM) and the number of NaCl particles before and after laser irradiation were compared each other. Over 90% particle removal efficiency was found at output energy of 200 mJ/cm2 and pulse duration of 5 ns. We confirmed that laser cleaning processes are induced by fast thermal expansion of NaCl particles and/or silicon wafer surfaces irradiated by laser.