Self-assembly process, patterning, and characterization of well-aligned single-walled carbon nanotube (SWNT) films are presented in this letter. The dc current in an ac dielectrophoresis of an SWNT solution was measured and used to control the self-assembly process to get an oriented, compact SWNT film 15-20 nm thick. The film was further patterned to form submicron beams by focused ion beams, or lithography and oxygen plasma etching. The Young's modulus of the film ranged from 350 to 830 GPa. The electrical resistivity was about 8.7× 10-3cm. The temperature coefficient of resistance was -1.2%/K.