TY - JOUR
AU1 - Kim, Dae-Jin
AU2 - Kim, Yong-Kee
AU3 - Ryu, Je-Kil
AU4 - Kim, Hyun-Jung
AB - The contaminants on a bare wafer or a patterned wafer can seriously impact the yield of manufacturing devices in semiconductor fabrication. In very large scale integrated circuit (VLSI) technology, as the device density increases, particularly for flat panel displays, the importance of cleaning also increases. The removal of particles and the Photoresist (PR) layer on a silicon wafer was investigated by a line beam of a KrF excimer laser in a cleanroom condition. This paper reports the effects of a high-energy laser beam onto the electrical, structural and morphological properties of the wafer and introduces a practical line beam laser cleaning method for particle removal and PR stripping. The removal of particles and the PR layer on a silicon wafer was performed using a KrF excimer laser in the cleanroom condition. The results of surface morphology were observed using a scanning electron microscope (SEM) and atomic force microscopy (AFM). The crystallization of the silicon wafer was observed by X-ray diffraction (XRD) studies. The electrical properties of the silicon wafer before and after laser irradiation were characterized by Hall measurements. The compositions of the PR covered wafers were determined by energy dispersive X-ray diffraction (EDX). The carrier concentration and resistivity of the bare silicon wafer were 1.4×1015 cm-3 and 17.7 Ω·cm, respectively, before laser irradiation. The carrier concentration of the silicon wafers after laser irradiation was in the range of 1.1×1015–1.6×1015 cm-3, and the resistivity was in the range of 17.0–18.2 Ω·cm. The carrier concentration and resistivity of the bare silicon wafers were not changed even after high-energy laser irradiation of up to 600 mJ/cm2. After 6-pulse laser irradiation, the PR layer of 0.82 µm thickness was stripped perfectly with an energy density of 300 mJ/cm2 without the aid of any chemical or solvent. The ablation rates were 0.06 µm/pulse for 100 mJ/cm2, 0.10 µm/pulse for 200 mJ/cm2 and 0.13 µm/pulse for 300 mJ/cm2. Dry laser cleaning technology shows that particles and organic compounds, like PR, on the bare silicon wafer can be effectively removed without any damage to the silicon substrate. 
TI - Dry Cleaning Technology of Silicon Wafer with a Line Beam    for Semiconductor Fabrication by KrF Excimer Laser
JF - Japanese Journal of Applied Physics
DO - 10.1143/JJAP.41.4563
DA - 2002-07-01
UR - https://www.deepdyve.com/lp/iop-publishing/dry-cleaning-technology-of-silicon-wafer-with-a-line-beam-for-d0KGU5pO7z
SP - 4563
VL - 41
IS - 7R
DP - DeepDyve
ER -