Developments of the Physical and Electrical Properties of NiCr and NiCrSi Single-Layer and Bi-Layer Nano-Scale Thin-Film Resistors.
In this study, commercial-grade NiCr (80 wt % Ni, 20 wt % Cr) and NiCrSi (55 wt % Ni, 40 wt % Cr, 5 wt % Si) were used as targets and the sputtering method was used to deposit NiCr and NiCrSi thin films on Al₂O₃ and Si substrates at room temperature under different deposition time. X-ray diffraction patterns showed that the NiCr and NiCrSi thin films were amorphous phase, and the field-effect scanning electronic microscope observations showed that only nano-crystalline grains were revealed on the surfaces of the NiCr and NiCrSi thin films. The log (resistivity) values of the NiCr and NiCrSi thin-film resistors decreased approximately linearly as their thicknesses increased. We found that the value of temperature coefficient of resistance (TCR value) of the NiCr thin-film resistors was positive and that of the NiCrSi thin-film resistors was negative. To investigate these thin-film resistors with a low TCR value, we designed a novel bi-layer structure to fabricate the thin-film resistors via two different stacking methods. The bi-layer structures were created by depositing NiCr for 10 min as the upper (or lower) layer and depositing NiCrSi for 10, 30, or 60 min as the lower (or upper) layer. We aim to show that the stacking method had no apparent effect on the resistivity of the NiCr-NiCrSi bi-layer thin-film resistors but had large effect on the TCR value.
Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan. eveflora818@gmail.com.
Huan-Yi
HY
Cheng
Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan. ycc@mail.ee.nsysu.edu.tw.
Ying-Chung
YC
Chen
Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan. insist256@hotmail.com.
Chi-Lun
CL
Li
Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung 804, Taiwan. sunnyrain516@hotmail.com.
Pei-Jou
PJ
Li
Institute of Microelectronics, National Cheng-Kung University, No.1, University Road, Tainan City 701, Taiwan. mphoung@eembox.ncku.edu.tw.
Mau-Phon
MP
Houng
Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81141, Taiwan. cfyang@nuk.edu.tw.
Cheng-Fu
CF
Yang
Bi-layer; sheet resistance; sputtering method; thin-film resistor; value of temperature coefficient of resistance (TCR value)