유연소자 응용을 위한 그래핀 트랜지스터의 전기적 특성

Abstract

The synthesis, fabrication and electrical characteristics of graphene field effect transistor (GFET) have been reported. For the growth of graphene, thermal chemical vapor deposition (CVD) method was used. The Cu foil and H2/CH4 gas mixture was used to synthesize graphene as the catalysis and the precursors, respectively. After synthesis, graphene was transferred on both rigid silicon substrate and flexible stainless steel (STS) substrate and back-gate (BG) GFETs and top-gate GFETs were fabricated and their electrical characteristics were measured. The advantages of STS are much better durable, tolerating high temperature, dimensional stability than plastic substrate, etc. STS was needed additional planarization process to reduce its rough surface for GFET. First, on the SiO2/Si substrate, the BG GFET with width of 300 um and length of 200 um showed the on/off current ratio of ~3.72, maximum point of transconductance of 56 uS at gate bias (Vg) of 24V, electron mobility of 2180 cm2/V•s, and hole mobility of 1020 cm2/V•s, respectively. The Top-gate (TG) GFET with width of 6 um and length of 4 mm on SiO2/Si substrate showed the on/off current ratio of ~2.8, maximum point of transconductance of 120 uS at gate bias (Vg) of 1.2V, electron mobility of 680 cm2/V•s, and hole mobility of 190 cm2/V•s, respectively. Next, on the STS substrate, the TG GFET with 6um width and 4um length showed the on/off current ratio of ~3.6, maximum point of transconductance of 48 uS at gate bias (Vg) of 1.9V, electron mobility of 190 cm2/ V•s, and hole mobility of 40 cm2/ V•s, respectively.