Study On And Fabrication Of Chemical Mechanical Polishing Tester With Electrochemical Testing System

As an essential process in the IC chip manufacture, Chemical-mechanical polishing (CMP) is recognized as the exclusive technology to achieve gloable planarization. There is no doubt that the electrochemical behaviors of metal appear to play an important role in CMP, which could be used to investigate the material removal mechanism and provide the theoretical support for the accuracy control of CMP process. With the fast development of IC industry, more and more researchers both at home and abroad have focused on the research of CMP material removal mechanism. However, Chinese research institutes have to import such expensive equipments, because there is no CMP tester with electrochemistry test system at home. Therefore, the present study is to develop a kind of special-purpose CMP tester with electrochemical system.In this dissertation, the movement mechanism of CMP machine was studied to optimize and confirm the structure parameters and movement parameters of tester. It is indicated that the optimal nonuniformity of wafer surface and material removal rate can be obtained under the wafer and the pad rotating in the same direction with the equal rotational speed. The function of stepless pressure regulation and stepless speed regulation through the driving mechanism and pressurized structure were realized creatively avoiding pneumatics and hydraulics to reduce the cost. For the requirement of the CMP process, the resistance-strain force sensor and data acquisition & analysis system with VB language have been developed, which can be used to control the polishing pressure measurement including the data automatic acquisition, dynamical show & subsequent analysis, the pressure curve drawing, saving and chart exporting. The PS-168C electrochemical measuring system has been also applied to the CMP tester successfully to investigate the electrochemical behaviors. Finally the polarization curves under CMP process conditions of aluminum have been measured and the influence of polishing pressure to the open circuit potential in Al CMP has been explored, which results indicate that chemical machinery polishing tester with electrochemical testing system designed run steadily and reliably, with a higher practical value, supply a domestic gap.