Nano resolution imaging technique with a near-field scanning microwave microscope

We demonstrated a near-field scanning microwave microscope (NSMM) with a nano spatial resolution using a hybrid tip. In order to understand the function of the probe, we fabricated the hybrid tip with a flat shaped shoulder and a reduced length of the tapered part using a conventional chemical etching technique. Two different NSMM images were observed for patterned Cr films on glass substrates and analyzed as a function of the apex and the cone angle of the tapered part. The hybrid tips were coupled to a high quality dielectric resonator at an operating frequency f = 4.46 GHz. By using the hybrid tip, we demonstrated an improved high contrast NSMM image of lambda phage DNA on a glass substrate.