Figure 3

Process flow for the deposition of insulator. (a) Uniform \(\hbox {Al}_2\hbox {O}_3\) film over the sample after ALD. (b) Coating of sample with photoresist layer. (c) Insulator pattern defined by optical lithography. (d) Exposed SLG channel and contacts after wet etching of \(\hbox {Al}_2\hbox {O}_3\). (e) Patterned \(\hbox {Al}_2\hbox {O}_3\) film after removal of excess photoresist.