Development of novel micromachining technique using proton microbeam and range shifters

Sakai, Takuro; Yasuda, Ryo; Iikura, Hiroshi  ; Sato, Takahiro; Ishii, Yasuyuki

We report a unique micromachining technique using proton microbeam and range shifters. The combination of these devices enables rapid fabrication of 3D microstructures. The range shifters are used to control the depth profile of energetic particle beams in materials. This device is an essential technique in particle cancer therapy. In this work, we have demonstrated fabrication of 3D structures made from UV/EB curable resin using the scanning proton microbeam. The height of the structures depends on the penetration depth of the proton beam that is controlled by the range shifters. Five different polymer films are used as the range shifters. Optical microscopy and scanning electron microscopy have been used to characterize the fabricated samples. The results show that the control of proton beam depth is successful and degradation caused by straggling is tolerable. In conclusion, this new technique is very promising to fabricate 3D structures.