Plasma has frequently been used by the industry as a last step surface preparation technique in an otherwise predominant wet-etched process. Recent research of the chemistry of plasma led to a great understanding of plasma processes. It is by controlling the plasma conditions and gas mixtures, ultra-fast plasma cleaning and etching is possible. With enhanced organic removal rates, plasma processes become more desirable as an environmentally sound alternative to traditional solvent or acid dominated process, not only as a cleaning tool, but also as a patterning and machining tool. In this paper, improvement in the processing of nanogap fabrication using O2 plasma is discussed including the parameters for PR patterning with two times limited in the O2 plasma process. For applications that have not been possible with limited usefulness, plasma processes are now approaching the realm of possibility. We introduce this work to fabricate and characterize the nanogap device fabrication using O2 plasma technique for biosensor fabrication. In this review, two masks designs are proposed. The first mask is for the lateral nanogap and the second mask is for a gold pad electrode pattern, and the lateral nanogap is introduced in the fabrication process using silicon, and gold as an electrode. Conventional photolithography technique is used to fabricate this nanogap (NG) based on the plasma etching technique. The increase in etching time when we apply the O2 plasma means an increase in the amount of etching, while in the case of reducing the time of etching means reducing the amount of etching, as shown in the results.