PMMA-Assisted Plasma Patterning of Graphene

Figure 5

PMMA ribbon (∼56 nm width) patterns on graphene/silicon dioxide (a) before and (b, c, d) after exposure to oxygen plasma (8 Watts, 30 mTorr, 1 sccm, 2 minutes). (a, b) Light microscope images. (c, d) Scanning electron microscope (SEM) images. Three-terminal electrical measurements (I_ds−V_g) are performed in different graphene nanoribbon (“gnr”) devices in (e) air conditions and in (f) distilled water with a semiconductor analyzer. A backside gate electrode is used for measurements in air and a top gate electrode for measurements in water.