Mobility enhancement in graphene transistors on low temperature pulsed laser deposited boron nitride

• Published in: Applied physics letters Vol. 107; no. 20
• Main Authors: Uddin, Md Ahsan, Glavin, Nicholas, Singh, Amol, Naguy, Rachel, Jespersen, Michael, Voevodin, Andrey, Koley, Goutam
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 16-11-2015
• Subjects: ANNEALING; Applied physics; Boron nitride; BORON NITRIDES; Carrier density; CARRIERS; Chemical synthesis; CHEMICAL VAPOR DEPOSITION; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPARATIVE EVALUATIONS; CRYSTAL STRUCTURE; DEPOSITS; DIELECTRIC MATERIALS; Dielectric properties; Doping; ELECTRON MOBILITY; ENERGY BEAM DEPOSITION; FIELD EFFECT TRANSISTORS; GRAPHENE; LASER RADIATION; LASERS; Low temperature; Organic chemistry; PHONONS; PULSED IRRADIATION; Pulsed laser deposition; Pulsed lasers; PULSES; Semiconductor devices; Silicon dioxide; SILICON OXIDES; SUBSTRATES
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4936191

Low temperature pulsed laser deposited (PLD) ultrathin boron nitride (BN) on SiO2 was investigated as a dielectric for graphene electronics, and a significant enhancement in electrical transport properties of graphene/PLD BN compared to graphene/SiO2 has been observed. Graphene synthesized by chemical vapor deposition and transferred on PLD deposited and annealed BN exhibited up to three times higher field effect mobility compared to graphene on the SiO2 substrate. Graphene field effect transistor devices fabricated on 5 nm BN/SiO2 (300 nm) yielded maximum hole and electron mobility of 4980 and 4200 cm2/V s, respectively. In addition, significant improvement in carrier homogeneity and reduction in extrinsic doping in graphene on BN has been observed. An average Dirac point of 3.5 V and residual carrier concentration of 7.65 × 1011 cm−2 was observed for graphene transferred on 5 nm BN at ambient condition. The overall performance improvement on PLD BN can be attributed to dielectric screening of charged impurities, similar crystal structure and phonon modes, and reduced substrate induced doping.