In this paper, a fabrication method of suspended silicon microfluidic channels and various shapes of microstructures of desired thickness in (100)-Si wafers using single photolithography step is presented. The fabrication method uses wafer bonding with silicon nitride (Si3N4) as intermediate layer, local oxidation of silicon (LOCOS), and complementary metal oxide semiconductor (CMOS) process compatible wet anisotropic etching. The etching process is performed in two steps in non-ionic surfactant Triton-X-100 [C14H22O(C2H4O)n] added and pure tetramethyl ammonium hydroxide (TMAH) solutions. The surfactant added TMAH is used to define the shape of the structures, whereas pureTMAH is employed for their release. ©EDA Publishing/DTIP 2009.