Epitaxial graphene on SiC

Transcription

1 Epitaxial graphene n SiC A rute twards high-perfrmance electrnic devices Albert García

2 Outline 1. GPNT: a brief intrductin 2. Graphene n SiC 3. Back-gated graphene 4. Cnclusins

3 Outline 1. GPNT: a brief intrductin 2. Graphene n SiC 3. Back-gated graphene 4. Cnclusins

4 GPNT: Activity and lcatin GPNT is a startup cmpany devted t prduce and distribute epitaxial graphene grwn n SiC. MICROELECTRONICS INSTITUTE OF BARCELONA (IMB) CVD and epitaxial graphene n SiC since 2007 INSTITUTE OF NANOSCIENCE OF ARAGON (INA) R&D in nanscience and nantechnlgy (2003) ARAGON MATERIALS SCIENCE INSTITUTE (ICMA) Investigatin and applicatins f new materials

5 GPNT: Available facilities Centrtherm Jipelec Fast ramp up. Up t 1900ºC. 4 wafers (Centrtherm) and 2 wafers (Jipelec) Ar, H 2, CH 4, SiH 4. Standard characterizatin Selected samples Optical micrscpy AFM Raman spectrscpy Lithgraphy PPMS TEM

6 Outline 1. GPNT: a brief intrductin 2. Graphene n SiC 3. Back-gated graphene 4. Cnclusins

7 Epitaxial graphene n SiC: Key aspects Silicn carbide Grwth mechanism Wide bandgap semicnductr ( ev) with superir prperties: high breakdwn electric field, gd thermal cnductivity Graphitizatin takes place via the sublimatin f Si atms at high temperatures (>1500ºC) Mre than 250 plytypes f SiC have been fund. Si face c-plane (0001) Frmatin f terraces SiC is a plar crystal C face c-plane (0001) - Optimized grwth High vacuum P. Sutter, Nature Materials 8 (2009) 171

8 Epitaxial graphene n SiC: Si face Optical micrscpy AFM R q <0.3 nm Number f terraces Width ( m) Raman D G 2D

9 Epitaxial graphene n SiC: Si face Optical micrscpy AFM R q <0.3 nm Number f terraces Width ( m) Raman DC Transprt Mapping 2D peak Quantum Hall effect 0.04 Lngitudinal Hall 0.03 T = 2 K T (K) n e (cm -2 ) µ e (cm 2 V -1 s -1 ) R xx (h/e 2 ) R xy (h/e 2 ) B (T) 0.0

10 Epitaxial graphene n SiC: C face Optical micrscpy AFM Phase Raman D G 2D Anistrpic grwth f lng islated graphene ribbns n the C face f graphite-capped 6H -SiC Camara, N et al (2009) Physical Review B - Cndensed Matter and Materials Physics, 80 (12) Intensity (a.u.) Raman Shift (cm -1 ) Anistrpic grwth FWHM 2D (cm -1 ) I 2D /I G <30 3 Almst free standing graphene

11 Outline 1. GPNT: a brief intrductin 2. Graphene n SiC 3. Back-gated graphene 4. Cnclusins

12 Back-gated graphene transistrs Graphene-based devices may require the expsure f graphene: i. e. gas and chemical sensing. SEM S. Rumyantsev et al., Nan. Lett. 12, 2294 (2012) Bttm-gated EG n SiC B. Juault et al., Appl. Phys. Lett. 100, (2012) SiC is an active substrate. Avid cmplex dielectric interfacing. Graphene surface available fr functinalizatin.

13 Frmatin f a buried layer In implantatin (n-type/p-type dpant) N ins 340 µm 4H-SiC, Semi-insulating ρ > 10 8 Ω cm 2

14 Frmatin f a buried layer In implantatin (n-type/p-type dpant) Activatin prcess Cncentratin (atms/cm 3 ) E=200 kev D=6E14 cm -2 T=400 ºC Depth (nm) 340 µm N-implanted (gate electrde) 4H-SiC, Semi-insulating ρ > 10 8 Ω cm 2

15 Frmatin f a buried layer In implantatin (n-type/p-type dpant) Activatin prcess FFT 340 µm N-implanted (gate electrde) 4H-SiC, Semi-insulating ρ > 10 8 Ω cm 2

16 Results in-implanted graphene Crystal damage: additinal treatment required Optical micrscpy AFM R q <0.2 nm 10 Number f terraces Width ( m) URL: Raman D G 2D DC Transprt Intensity (a.u.) Raman Shift (cm -1 ) Mapping FWHM 2D Full cverage 65% mnlayer T (K) n e (cm -2 ) µ e (cm 2 V -1 s -1 ) R xx (h/e 2 ) Quantum Hall effect 0.14 Lngitudinal 0.12 Hall 0.10 T = 2 K R xy (h/e 2 ) B (T) 0.0

17 Outline 1. GPNT: a brief intrductin 2. Graphene n SiC 3. Back-gated graphene 4. Cnclusins

18 Cnclusins 1. High-quality graphene was grwn n SiC (Si and C faces). 2. Fully cverage n Si-face. 3. Almst free-standing graphene islands n C-face. 4. In implantatin allws t define a buried gate.

19 Thank yu fr yur attentin Executive Manager Alejandr Rdríguez Executive President Javier Palacis Develpment scientist Ana Ballestar Develpment scientist Luis Serran Develpment scientist Albert García Scientific Advisr Jsé María De Teresa Scientific Advisr M. Ricard Ibarra Scientific Advisr Philippe Gdignn