Abstract
ABSTRACT The resist has the critical effect on the lithography process in semiconductor manufacturing. The performance of resist is relied on the irradiation sensitivity, etching resistance, purity and thermal stability. This study wants to investigate the material characteristics of existing I-line resist, of which spiking with various amounts of poly(4-vinylphenol)polymer. The structure of the modified resist is characterized by ultraviolet visible spectrometry(UV/VIS)and gel permeation chromatography(GPC). The resist layer, coating onto the wafer, is characterized by various methods, including n&k analyzer, Nanospec, Fourier transform infrared(FTIR), thermogravimetric analysis(TGA),and differential scanning calorimetry(DSC). Therefore, the film properties in terms of viscosity, thickness and uniformity, spectrum of vibration, and thermal stability are fully evaluated. The resist exposure parameters, namely A,B,and C,at 365 nm are determined by the absorbance measurement. The extracted parameters are further used in the resist profile simulation by PROLITH/2 software to investigate the resolution, linearity of line width, and swing effect. It is shown that the modified resist can improve the resolution and linearity for dense lines, enhance the thermal stability. In addition, the swing effects can reduced by up to 35 and 31 percent for dense and isolated lines, respectively. The result demonstrats the polymer structure is still similar, regardless of the polymer modification. In addition, the gravimetric method is applied to evaluate the feasibility of open-focused microwave digestion efficiency for bottom anti=reflective coating(BARC), deep ultra-violet photoresist(DUV/PR),and I-line photoresist(PR) samples. The suitable digestion recipe is developed to destroy the complex matrix and determine the trace metals by inductively coupled plasma-mass spectrometer(ICP-MS). The detection limit of the method implies ICP-MS is suitable for multi-element determination at sub-ppb level. The lithographic sample throughout can achieve up to 3.5 samples per hour for mulyi-element analysis. By following the establishd microwave digestion method, the UV/VIS spectrometric and gravimetric methods are also implemented to evaluate the open-focused microwave digestion efficiencies of modified I-line resist samples. Moreover, the reactive ion etcher, n&k analyzer, and Nanospec are used to evaluate the etching resistance for various modified resists. The result indicates the polymer modification can slightly degrade the digestion efficiency and enhance plasma etching resistance for the resist.