TY - JOUR
T1 - Metal-contact improvement in a multilayer WSe2transistor through strong hot carrier injection
AU - Lee, Kookjin
AU - Kim, Yeonsu
AU - Kim, Doyoon
AU - Lee, Jaewoo
AU - Lee, Hyebin
AU - Joo, Min Kyu
AU - Cho, Young Hoon
AU - Shin, Jinwoo
AU - Ji, Hyunjin
AU - Kim, Gyu Tae
N1 - Funding Information:
This work is supported by a grant to the Terahertz Electronic Device Research Laboratory funded by Defense Acquisition Program Administration and the Agency for Defense Development (UD180025RD). Also, all authors in this work thank Ben Kaczer, who is working at imec for discussing and giving advice.
Publisher Copyright:
©
PY - 2021/1/20
Y1 - 2021/1/20
N2 - Hot carrier injection (HCI), occurring when the horizontal electric field is strongly applied, usually affects the degradation of nanoelectronic devices. In addition, metal contacts play a significant role in nanoelectronic devices. In this study, Schottky contacts in multilayer tungsten diselenide (WSe2) field-effect transistors (FETs) by hot carrier injection (HCI), occurring when a high drain voltage is applied, is investigated. A small number of hot carriers with high energy reduces the Schottky barrier height and improves the performance of FETs effectively rather than damaging the channel. Thermal annealing at the end of the fabrication process increases device performance by causing interfacial reactions of the source/drain electrodes. HCI causes a significant enhancement in the local asymmetry, especially in the subthreshold region. The subthreshold swing (SS) of the thermally annealed FETs is significantly improved from 9.66 to 0.562 V dec-1 through the energy of HCI generated by a strong horizontal electric field. In addition, the contact resistances (RSD), also called series resistances, extracted by a four-probe measurement and a Y-function method were also improved by decreasing to a 10th through the energy of HCI. To understand the asymmetrical characteristics of the channel after the stress, we performed electrical analysis, electrostatic force microscopy (EFM), and Raman spectroscopy.
AB - Hot carrier injection (HCI), occurring when the horizontal electric field is strongly applied, usually affects the degradation of nanoelectronic devices. In addition, metal contacts play a significant role in nanoelectronic devices. In this study, Schottky contacts in multilayer tungsten diselenide (WSe2) field-effect transistors (FETs) by hot carrier injection (HCI), occurring when a high drain voltage is applied, is investigated. A small number of hot carriers with high energy reduces the Schottky barrier height and improves the performance of FETs effectively rather than damaging the channel. Thermal annealing at the end of the fabrication process increases device performance by causing interfacial reactions of the source/drain electrodes. HCI causes a significant enhancement in the local asymmetry, especially in the subthreshold region. The subthreshold swing (SS) of the thermally annealed FETs is significantly improved from 9.66 to 0.562 V dec-1 through the energy of HCI generated by a strong horizontal electric field. In addition, the contact resistances (RSD), also called series resistances, extracted by a four-probe measurement and a Y-function method were also improved by decreasing to a 10th through the energy of HCI. To understand the asymmetrical characteristics of the channel after the stress, we performed electrical analysis, electrostatic force microscopy (EFM), and Raman spectroscopy.
KW - Schottky barrier
KW - WSe
KW - field-effect transistor
KW - hot carrier injection
KW - metal contacts
UR - http://www.scopus.com/inward/record.url?scp=85099657716&partnerID=8YFLogxK
U2 - 10.1021/acsami.0c18319
DO - 10.1021/acsami.0c18319
M3 - Article
C2 - 33410320
AN - SCOPUS:85099657716
SN - 1944-8244
VL - 13
SP - 2829
EP - 2835
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 2
ER -