Inductively coupled plasma etching to fabricate sensing window for polymer waveguide biosensor application

► We designed and fabricated an improved sensing window based on the ICP method. ► The sensitivity of the sensor was enhanced by a factor of 2.8 in theory. ► The etching rate of P(MMA-GMA) was twice as fast as that of SU-8 2005. ► The parameters were optimized to minimize the surface roughness in the etched area. ► The sensor presented a higher sensitivity than the conventional waveguide sensor.