PMID- 29239861
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20191120
IS  - 1361-6528 (Electronic)
IS  - 0957-4484 (Linking)
VI  - 29
IP  - 6
DP  - 2018 Feb 9
TI  - Capacitance-voltage analysis of electrical properties for WSe(2) field effect 
      transistors with high-k encapsulation layer.
PG  - 065703
LID - 10.1088/1361-6528/aaa1d7 [doi]
AB  - Doping effects in devices based on two-dimensional (2D) materials have been 
      widely studied. However, detailed analysis and the mechanism of the doping effect 
      caused by encapsulation layers has not been sufficiently explored. In this work, 
      we present experimental studies on the n-doping effect in WSe(2) field effect 
      transistors (FETs) with a high-k encapsulation layer (Al(2)O(3)) grown by atomic 
      layer deposition. In addition, we demonstrate the mechanism and origin of the 
      doping effect. After encapsulation of the Al(2)O(3) layer, the threshold voltage 
      of the WSe(2) FET negatively shifted with the increase of the on-current. The 
      capacitance-voltage measurements of the metal insulator semiconductor (MIS) 
      structure proved the presence of the positive fixed charges within the Al(2)O(3) 
      layer. The flat-band voltage of the MIS structure of Au/Al(2)O(3)/SiO(2)/Si was 
      shifted toward the negative direction on account of the positive fixed charges in 
      the Al(2)O(3) layer. Our results clearly revealed that the fixed charges in the 
      Al(2)O(3) encapsulation layer modulated the Fermi energy level via the field 
      effect. Moreover, these results possibly provide fundamental ideas and guidelines 
      to design 2D materials FETs with high-performance and reliability.
FAU - Ko, Seung-Pil
AU  - Ko SP
AD  - School of Electrical Engineering, Korea University, Seoul, 02841, Republic of 
      Korea.
FAU - Shin, Jong Mok
AU  - Shin JM
FAU - Jang, Ho Kyun
AU  - Jang HK
FAU - You, Min Youl
AU  - You MY
FAU - Jin, Jun-Eon
AU  - Jin JE
FAU - Choi, Miri
AU  - Choi M
FAU - Cho, Jiung
AU  - Cho J
FAU - Kim, Gyu-Tae
AU  - Kim GT
LA  - eng
PT  - Journal Article
PL  - England
TA  - Nanotechnology
JT  - Nanotechnology
JID - 101241272
EDAT- 2017/12/15 06:00
MHDA- 2017/12/15 06:01
CRDT- 2017/12/15 06:00
PHST- 2017/12/15 06:00 [pubmed]
PHST- 2017/12/15 06:01 [medline]
PHST- 2017/12/15 06:00 [entrez]
AID - 10.1088/1361-6528/aaa1d7 [doi]
PST - ppublish
SO  - Nanotechnology. 2018 Feb 9;29(6):065703. doi: 10.1088/1361-6528/aaa1d7.