Browsing by Author "Lin, I-Kai"

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Analysis of Relationship between Inorganic Gases and Fine Particles in Cleanroom Environment
(2010-06-01)
Lin, I-Kai
;
Bai, Hsunling
;
Wu, Bi-Jun
;
環境工程研究所
;
Institute of Environmental Engineering
The concentrations and characteristics of major components in inorganic gases and fine particles were measured at the photo and etch cleanroom areas in a Taiwan semiconductor factory. The results showed that the major inorganic gases, as expressed in terms of volume concentration, were NH(3) and HF at 7-10 and 4-6 ppbv, respectively. The average PM(2.5) mass concentration were 17.52 and 18.23 mu g/m(3) at the photo and etch areas, respectively, with species of Na(+), NH(4)(+), Cl(-) and SO(4)(2-) had the highest concentrations in the PM(2.5) mass. And the inorganic species account for 56% and 62% of the particulate mass, respectively, at the photo and etch areas. Relatively stronger correlations were observed between NH(4)(+) and SO(4)(2-) with the correlation coefficient R(2) of 0.62 and 0.82, respectively, at the photo and etch areas; this indicates their common source was possibly from the gas to particle formation process. And NH(3) was found to co-exist with HF at the etch area due to their common source as process chemicals (NH(4)OH and HF) in the wet bench. In the predominant NH(3)-rich environment, ammonia is the basic neutralizing agent to form the ammonium aerosol in a cleanroom.
Comparison of cleanroom samplers for inorganic airborne molecular contaminants
(2008-03-01)
Lin, I-Kai
;
Bai, Hsunling
;
Liu, Cheng-Chang
;
Wu, Bi-Jun
;
環境工程研究所
The performances of inorganic airborne molecular contaminants (AMCs) via silica gel tubes, impingers, and diffusion denuder sampler (DDS) were compared in a cleanroom. The results showed silica gel tubes were not applicable for cleanroom sampling due to high blanks. While with optimal sampling conditions both impingers and DDS have much better performances, of which DDS has the lowest detection limits of the method for HF, HCl, HNO2, HNO3, SO2, and NH3 gases to be 0.15, 0.11, 0.13, 0.03, 0.07, and 0.42 mu g/m(3), respectively. Results indicated no significant difference for the HF and SO42- concentrations made by the DDS and impingers.
Metal Corrosion of Al-Si-Cu Pattern Wafer Due to Chloride Ion Contaminants
(2012-02-01)
Wu, Bi-Jun
;
Bai, Hsunling
;
Lin, I-Kai
;
Liu, Hsiang-Hsing
;
環境工程研究所
Chloride ions (Cl-) induce metal corrosion of integrated circuits and cause wafer scrap events in the clean room environment. In this study, Al-Si-Cu pattern wafers were designed to monitor critical Cl- concentration which leads to metal corrosion effects in a simulated airborne molecular contamination (AMC) mini-environment. The simulated Cl- contamination was generated by HCl permeation tube in a mini-environment; meanwhile, the HCl concentrations in the mini-environment and the real fab were monitored by a real-time Ion Mobility Spectrometry (IMS) instrument. The exposed Al-1%Si-0.5%Cu pattern wafers were analyzed by the surface scanner, the optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) analyzer. The critical HCl concentration where metal corrosion defects could be occurred and found on the wafer surface was around 2.9-4.7 ppbv for simulated mini-environment exposure within 1 hour, and 2.9-4.2 ppbv for real fab ambient air exposure within only 10 minutes. The results indicated that the Al-Si-Cu pattern wafer with TiW barrier layer is more sensitive than the Al-Cu pattern wafer with TiN barrier layer. It also proved that the permeation tube method can be served as a stable Cl- simulated source, which can control the simulated mini-environment to be within similar to 4% error in ppbv levels.
Surface Deposition of Ionic Contaminants on Silicon Wafers in a Cleanroom Environment
(2009-05-01)
Lin, I-Kai
;
Bai, Hsunling
;
Wu, Bi-Jun
;
環境工程研究所
;
Institute of Environmental Engineering
The adsorption and desorption behaviors of ionic micro-contaminants on the silicon wafers in a cleanroom environment were investigated in this study. The experimental measurements showed that the surface density of ionic contaminants was significantly affected by both the exposure time and the properties of contaminants. The rate parameters of a kinetic model for surface deposition were determined by numerical optimization of fitting the experimental data on surface and ambient concentrations of airborne molecular contaminants (AMCs). Subsequently, the time-dependent deposition velocity and sticking coefficient of ionic species were obtained. The results showed that F(-), Cl(-), NO(3)(-), SO(4)(2-), Na(+), NH(4)(+), K(+), and Mg(2+) were the major ionic microcontamination species on the wafer surfaces, with the adsorption rate constant and the sticking coefficient of K(+) ion being larger than those of other ionic contaminants. After the determination of sticking coefficients, the allowable wafer exposure durations and the maximum ambient concentrations of ionic species were exemplified based on the guideline recommended by the International Technology Roadmap for Semiconductors (ITRS).