TY - JOUR
T1 - Nanogap CMOS-MEMS Pirani Gauge Based on Titanium-Nitride Heating Element for Broad-Range Vacuum Characterization
AU - Garg, Manu
AU - Singh, Pushpapraj
AU - Chiu, Yi
N1 - Publisher Copyright:
© 1963-2012 IEEE.
PY - 2024/2/1
Y1 - 2024/2/1
N2 - This article presents a titanium-nitride composite (TiN-C)-based complementary metal-oxide-semiconductor microelectromechanical system (CMOS-MEMS) Pirani gauge integrated into the back-end-of-line (BEOL) layers. A microbeam architecture is utilized as the sensing element consisting of a stack of TiN and SiO2. The structure utilizes the sandwiched (TiN/AlCu/TiN) metal line configuration to craft the suspended sensing element having a nanogap from the substrate. TiN serves as the heating element in the sensing element, while SiO2 provides mechanical support to the structure. Gauges with lengths varying from 60 to 90~mu text{m} are proposed, while the width is kept the same, i.e., 4~mu text{m}. Since the BEOL-integrated MEMS devices are prone to suffer from residual stress, an optical profilometer analysis is performed to quantify the effective value of the suspended gap. Furthermore, temperature profiles of the proposed designs are evaluated using COMSOL Multiphysics. Finally, the fabricated gauges are tested for pressure-dependent response from 1 to 10^{{6}} Pa and a performance comparison is established. In the monolithic CMOS-MEMS implementation, a lower detection limit of 15.5, 12.3, 10.3, and 8.3 Pa is obtained for different gauge lengths, while the upper detection range is the same, i.e., 10^{{6}} Pa.
AB - This article presents a titanium-nitride composite (TiN-C)-based complementary metal-oxide-semiconductor microelectromechanical system (CMOS-MEMS) Pirani gauge integrated into the back-end-of-line (BEOL) layers. A microbeam architecture is utilized as the sensing element consisting of a stack of TiN and SiO2. The structure utilizes the sandwiched (TiN/AlCu/TiN) metal line configuration to craft the suspended sensing element having a nanogap from the substrate. TiN serves as the heating element in the sensing element, while SiO2 provides mechanical support to the structure. Gauges with lengths varying from 60 to 90~mu text{m} are proposed, while the width is kept the same, i.e., 4~mu text{m}. Since the BEOL-integrated MEMS devices are prone to suffer from residual stress, an optical profilometer analysis is performed to quantify the effective value of the suspended gap. Furthermore, temperature profiles of the proposed designs are evaluated using COMSOL Multiphysics. Finally, the fabricated gauges are tested for pressure-dependent response from 1 to 10^{{6}} Pa and a performance comparison is established. In the monolithic CMOS-MEMS implementation, a lower detection limit of 15.5, 12.3, 10.3, and 8.3 Pa is obtained for different gauge lengths, while the upper detection range is the same, i.e., 10^{{6}} Pa.
KW - Complementary metal-oxide-semiconductor microelectromechanical systems (CMOS-MEMSs)
KW - Joule heating
KW - MEMS
KW - Pirani gauge
KW - monolithic integration
KW - vacuum detection
UR - http://www.scopus.com/inward/record.url?scp=85181835219&partnerID=8YFLogxK
U2 - 10.1109/TED.2023.3341885
DO - 10.1109/TED.2023.3341885
M3 - Article
AN - SCOPUS:85181835219
SN - 0018-9383
VL - 71
SP - 1214
EP - 1219
JO - IEEE Transactions on Electron Devices
JF - IEEE Transactions on Electron Devices
IS - 2
ER -