Research On Slicing Mechanism And Technology With Fixed Diamond Wire Saw For Semiconductor Ceramics

With the development of semiconductor industry, semiconductor ceramic material such as single silicon, gallium arsenide and silicon carbide, etc, is extensive used in this field. On one hand, for increasing the yield of chips and decreasing the cost of every unit, the chips'diameter increases continuously; on the other hand, the reticule width becomes thinner to increase the integration level of Integrated Circuit, which meet the requirements of modern chips and other logic chips. These new situations put forward new requirements to the manufacturing technology of single silicon. The slicing is an important process for manufacturing Integrated Circuit. This paper researched the slicing technology of fixed abrasive wire, which has the advantages including narrow cutting kerfs, high cutting efficiency, good slicing quality, little environmental pollution, processing ability for large diameter work piece and super hard material. The relationship between processing parameters and processing quality was revealed by deep and systematic experimental research and theoretical analysis for this slicing technology, the measures to obtain high process quality was put forward, which provided scientific basis and technical support to semiconductor ceramic material's high quality and efficient slicing. The main work is as follows:(1)Slicing mechanism of fixed diamond wire saw was studied.The hardness of single silicon and the cracks' generation, extension and characteristics at normal temperature was studied by Vickers hardness tester. The slicing mechanism was researched binding experiment results.(2)The relationships between the vibration, fracture of the wire saw and the processparameters were researched, and the process parameters'scope was defined. The effect factors of wire sawing process were analyzed, the wire saw's vibration model was built and the relationship between process parameters, including linear velocity of wire saw, the work piece feed rate and the tension force, and vibration of wire saw was studied. The fracture of wire saw, such as formation cause, the relationship with process parameters and the conditions to form was researched. All of the above initially defined the process parameters' scope for the experimental study.(3)The process for slicing single silicon and gallium arsenide by fixed diamond wire saw was studied.A single factor experiment for slicing single silicon and gallium arsenide was designed and carried on, which used linear velocity of wire saw, the work piece feed rate and the tension force as the factors. The effects of the process parameters to the surface quality of single silicon and gallium arsenide was researched based on this experiment. An orthogonal test was designed by Taguchi method, through which an orthogonal optimum for process parameters was made. Influence of characteristic parameters of surface quality and process parameters was analyzed, based on which the best process parameters' scope was defined.(4)The working mechanism of cutting fluid was revealed by analyzing and contrasting different cutting fluid.The accelerator was introduced into the cutting process. The cutting surface quality under different situations such as the water and the accelerator was compared. The evidence showed that the accelerator can improve the surface quality greatly than the water. The ratio of the accelerator was researched, and the best ratio was got.(5)The simulation study of the slicing process and 3-D surface topography was carried on.Simulation study of single abrasive slicing single silicon was made, which simulated the slicing process of single abrasive, chip shape and crack damages on the surface of single silicon was analyzed. The wire saw model was built though the study of saw abrasive's distribution; the simulation study of 3D topography of the slicing surface was carried on, from which the simulation value of surface roughness could be obtained.(6)The damage layer of slicing was researched.The damage layer of slicing surface for the single silicon and gallium arsenide was detected by X-ray diffractometer, by which thickness of surface damage layer under different process parameters was obtained and the influence between process parameters and the thickness of surface damage layer was studied; the thickness of surface damage layer was predicted by neuron algorithm.