Metrologia e Qualidade - MEQ 7

Title  :

SURFACE QUALITY EVALUATION OF DIAMOND TURNED SEMICONDUCTOR CRYSTAL BY MEANS OF ATOMIC FORCE MICROSCOPY

Abstract :
The possibility of fabricating high quality components from brittle materials has been made possible by achieving material removal in the ductile mode. It is known that plastic behavior in brittle materials take place prior to the onset of fracture when the cut is restricted below critical cutting depth value. The surface integrity of any mechanical component, finished by means of mechanical material removal process, is considered to be critical for its performance. The importance of assessing surface integrity of mechanically finished brittle materials such as semiconductor crystals is strongly justified by the optical and electronic applications. In this paper, the use of AFM for the evaluation of diamond turned monocrystalline silicon surface finish is presented. (100) oriented monocrystalline silicon was single point diamond turned under conditions that lead to a ductile regime. 3-D image was used for the characterization of surface quality. The cut grooves can be clearly seen, regularly spaced and running parallel with cutting direction which confirm the absence of chatter vibration. A machined surface with the maximum peak-to-valley roughness of 25 nm can be generated at feedrate in the range of 1.5 and 2.0 mm/rev. The surface roughness measured is in the range of 2 nm Ra. This surface finish is slightly better than the polished samples used in the diamond turning tests. A closer examination at higher magnifications of the machined surface indicated that no microcracks are present. In this case single point diamond turning has achieved fully ductile material removal. The results demonstrate that the AFM is more suitable for the assessment of the of diamond machined surfaces because of the better accuracy of the surface roughness and evaluation of microtopography of the surface generated.
Autores :
Jasinevicius, Renato Goulart
da Silva, H. A.T
Montanari, L.
Tsukamoto, R.
Duduch, J. G.
Trabalho Completo :


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