Browsing by Author "Hsiao, LT"

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Evaluation of impurity migration and microwave digestion methods for lithographic materials
(1999)
Ko, FH
;
Hsiao, LT
;
Chou, CT
;
Wang, MY
;
Wang, TK
In the section of incoming quality (IQC) or quality reliability analysis (QRA) of advanced semiconductor fabrication company, it is inevitable to regulate the strict standard for the incoming materials to ensure the reliability. In our radioactive tracer study, it is interestingly found the various amounts of metal and trace element impurities in the lithographic materials may migrate into the substrate. Based on the complex organic matrix in lithographic materials such as bottom anti-reflective coating (BARC), I-line resist and DUV resist, it is not easy to direct determine the multi-elements by the instrumentation. In this work, the lithographic materials are first decomposed by the close-vessel and open-focused microwave oven, and the digest is evaporated to incipient dryness. After adding water, the sample solutions are used either for evaluating the completeness of the digestion process by UV-VIS spectrometer, or for the determination of eleven elements using inductively coupled plasma mass spectrometry (ICP-MS). In addition, the digestion efficiency is also evaluated by the weight of total dry residual after various digestion recipes. By the complementary digestion method, the method detection limits for analytes can be achieved at lower than ng/g level. For evaluation of data accuracy, the results obtained by the two independent degestion methods are in good agreement. Moreover, the spiking recovery tests for all the elements are of 70 to 130%. According to the microcontamination control limit predicted by the SIA roadmap, the established method can meet the requirements for the quality control of lithographic materials in the future ten years.
Film characterization and evaluation of process performance for the modified electron beam resist
(2000)
Ko, FH
;
Ting, JH
;
Chou, CT
;
Hsiao, LT
;
Huang, TY
The modification of the electron beam resist by spiking with various amounts of poly(styrene-co-maleic anhydride) copolymer is performed. The characterization of resist solutions by gel permeation chromatography (GPC) and viscosity measurement reveals the main polymer chain in the resist is unchangeable, irrespective of the amount of modification. In addition, the spiking copolymer exists in original form. The viscosity of the resist increases with the amount of spiking polymer. Our thermal analysis results show that the resists are mainly decomposed in two regions (280 and 544 degrees C). The mass loss at 280 degrees C is significant higher than at 544 degrees C. The spectra of Fourier transform infrared red (FTIR) spectrometer indicate the extent of carbonate group decomposition decreases with temperature for resists. The plasma etching experiment indicates the promotion of etching resistance of the resist film is due to modification, while the resolution, sensitivity and contrast are not degraded. Owing to the polymer aggregation effect, the stripping performance of the resist film can achieve better after copolymer modification.