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To meet the ultra-high precision manufacture demands of spherical surfaces and aspherical surfaces in an optical system of Deep Ultra Violet (DUV) and Extreme Ultra Violet (EUV), a series of motion-precision control methods in bonnet-polishing were proposed. Firstly, the temperatures of main operation units were finely controlled to allow the motion-precision of polishing to be to 50 m. Then, the coordinates transmitting method was used to guarantee the two-dimension unity between measured data and operating data to be 0.30-0.70 mm. Furthermore, the convergence efficiency of surface-error in fine polishing was improved by bonnet removal estimation method and feedback correction method. Finally, the vertical position accuracy between bonnet and work piece was improved to 10 m by probing-correction method. The experiment results on a actual polishing by using motion-precision control methods indicate that the surface machining accuracy is 0.8 nm (RMS) in polishing a flat with a diameter of 280 mm, and that is 1.1 nm (RMS) in polishing a concave with a diameter of 160 mm. The proposed methods realize ultra-high precision polishing for spherical surfaces and aspherical surfaces, and they are also suitable for other contact small tool computer controlled polishing. , 2015, Chinese Academy of Sciences. All right reserved.

To enlarge the grain size and decrease the effect of the defect between the grain boundaries on a p-Si film transistor,a phase modulated excimer laser crystallization technique is used to fabricate the uniform p-Si film with a large grain size.First,an energy window for super lateral growth is determined by measuring the grain size of p-Si film fabricated with different laser energy intensities.Then,the spatial distribution of the input laser is modulated by a phase mask with a period of 1 073 nm and an artificially controlled lateral temperature gradient is induced on the a-Si film,which leads the a-Si to be melten and crystallized into p-Si grains by super lateral growth.Finally,the characteristics of the prepared p-Si film are measured and compared with those of the a-Si film and the p-Si film fabricated by super lateral growth technique.The results show that the grain size of the p-Si film is 228.24 nm,which is ten times of that fabricated by super lateral growth under the same processing parameters;the electrical resistivity of the prepared sample is 18.9 Ω·m,which is lower by an order magnitude than that prepared by super lateral growth.Furthermore,the distribution of the grain is more uniform than that fabricated by other techniques.The reported technique can increase the electrical characteristics of the p-Si film greatly and is suitable for the fabrication of high quality p-Si devices.

A flexible mechanism which was considered as a key component of the moving mirror supporting in a Michelson interferometer based Fourier-transform spectrometer was researched.The flexible mechannism with double compensation rods was created on the basis of the flexible mechannism with a single compensation rod.By use of the finite element analysis softwares PATRAN and NASTRAN,the mechanism was simulated and the corresponding results were compared with the best theoretical calculation of the flexible mechannism with the single compensation rod.A simplified model was also fabricated according to the structral specifications from simulation calculation.Furthermore,the model was also tested and error analysis was conducted.It is shown that the vertical coupling displacement of the moving mirror introduced by this flexible mechannism with double compensation rods has been decreased by 93.2%.The results of error analysis indicate that the length tolerence of the flexible segment is a critical factor that would result in coupling displacement of the moving mirror.Therefore,it points out that when a supporting mechanism with high precision is machined for the moving mirror,the tolerences related to the flexible segments must be strictly controlled in fabrication.

To ensure high-precision calibration of gear measuring instruments,the international standard ISO / TR 10064-5:2005 recommends a Double-Ball Artifact(DBA) as calibration reference.The DBA employs a high-precision sphere to replace the involute and uses an error compensation technique to obtain a high-precision involute to realize the involate traceability.The theoretical issues relating to the DBA are discussed to provide a theoretical basis for the design and application of the DBA.The error of measurement principle of DBA and its calculation function are given under the conditions of ideal installation and with installed errors for the electronic generative metrology.According to the optimized arc thoughts,the formula of the optimized center distance between the two balls is derived by the least square method.Finally,the error compensation method is described.The DBA software is designed based on the above theory and a DBA is developed with a parameter of module in 2.268 1 mm,number of teeth in 40,and a pressure angle in 20 °.