| Summary: | 碩士 === 國立成功大學 === 資源工程學系 === 85 === ABSTRACT Chemomechanical
polishing (CMP) for planarization has become one of the most
rapidly growing segments of the semiconductor manufacturing
market.Application of CMP for the planarization of interlayer
dielectric as well as polysilicon and tungsten metal studs was
pioneered by IBM and had been used in the fabrication of very
large scale integrated circuits since 1985.CMP is carried out by
pressing a rotating wafer against a moving polishing pad on
which a suitable slurry is dispensed. For oxide polishing, the
slurry consists of silica particles dispersed in an aqueous
solution. The oxide surface is chemically modified and this
modified layer can be removed by mechanical action. The speed
of the marble surface reaction to acid is very fast. We can
observe the marble surface before and after acid etching and
polishing process by means of infrared spectroscope. Under the
acid circumstance, the oxalic acid will react with the marble
surface and produces fine calcite particles attached on the
surface. After a long time of polishing, this reaction will
cause etching pores. In mechanical polishing condition, oxalic
acid solution has the function of erosion and can remove the
scraps. CMP under alkaline condition, sodium silicate solution
has the function of gelation, and forms a film on the marble
surface which filling the pores and cracks on the marble
surface, instead of planarization. α-serum is a kind of Na-
Si organic substance co-precipitated from oxalic acid and sodium
silicate. This serum is formed in the range of pH from 1.43 to
3.50 and the particle''s size is distributed between 5μm ~100μ
m.. It can dissolve in water, but can''t dissolve in alcohol. α-
serum will offer a chemical reaction in the polishing of marble
under acid condition. By means of mechanical polishing, it can
promote the function of planarization, in the mean time, the
chemical reaction can also remove the scraps caused by
mechanical polishing. For polishing of the white marble, the
largest brightness after mechanical polishing is only 82, but
the brightness after CMP of α-serum is above 95. It can also
shorten the duration of polishing time. In the polishing
experiment, the infusion of chemical polishing after the initial
period of mechanical polishing will change the abrasion rate and
appear the difference between mechanical polishing and chemical
polishing. The variation of line regression rate of brightness
can explain the quantity of both mechanical and chemical
polishing.
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