TY - JOUR
T1 - Evaluation of electrical characteristics of the copper-metallized SPDT GaAs switches at elevated temperatures
AU - Wu, Yun Chi
AU - Chang, Edward Yi
AU - Lin, Yueh Chin
AU - Hsu, Li Han
PY - 2008/9/1
Y1 - 2008/9/1
N2 - Copper-metallized AlGaAs/InGaAs pseudomophic high-electron mobility transistor single-pole-double-throw (SPDT) switches utilizing platinum (Pt, 70 nm) as the diffusion barrier have been studied and demonstrated. As compared with the Au-metallized switches, the Cu-metallized SPDT switches exhibited comparable performance with insertion loss less than 0.5 dB, return loss larger than 20 dB, isolation larger than 35 dB, and the input power for 1-dB compression (input P1 dB) of 28.3 dBm at 2.5 GHz. In order to evaluate the temperature-dependent impact on dc and RF characteristics of the coppermetallized switches for high-temperature applications, the switches have been tested at different temperatures. The device exhibits low thermal threshold coefficients (δVth/δT) of -0.25 mV/K from 300 K to 500 K, good microwave performance at 380 K with insertion loss less than 0.5 dB, isolation higher than 40 dB, and the input power for 1-dB compression (input P1 dB) of 28.45 dBm at 2.5 GHz. To test the thermal stability of the Pt diffusion barrier, these switches were annealed at 250°C for 20 h. After the annealing, the switches showed no degradation of the dc characteristics. In addition, after a high temperature storage life environment test at 150°C, these copper-metallized switches remained capable of excellent power handling. To test the operation reliability of the copper-metallized switches, the copper-metallized switches were subjected to ON/OFF (control voltage = +3/0 V exchange) stress test for 24 h at room temperature. The devices maintained excellent RF characteristics after the stress test. Consequently, it is successfully demonstrated through these tests that copper metallization using Ft as the diffusion barrier could be applied to the GaAs monolithic microwave integrated circuit switch fabrication with good RF performance, high-temperature characteristics, and reliability.
AB - Copper-metallized AlGaAs/InGaAs pseudomophic high-electron mobility transistor single-pole-double-throw (SPDT) switches utilizing platinum (Pt, 70 nm) as the diffusion barrier have been studied and demonstrated. As compared with the Au-metallized switches, the Cu-metallized SPDT switches exhibited comparable performance with insertion loss less than 0.5 dB, return loss larger than 20 dB, isolation larger than 35 dB, and the input power for 1-dB compression (input P1 dB) of 28.3 dBm at 2.5 GHz. In order to evaluate the temperature-dependent impact on dc and RF characteristics of the coppermetallized switches for high-temperature applications, the switches have been tested at different temperatures. The device exhibits low thermal threshold coefficients (δVth/δT) of -0.25 mV/K from 300 K to 500 K, good microwave performance at 380 K with insertion loss less than 0.5 dB, isolation higher than 40 dB, and the input power for 1-dB compression (input P1 dB) of 28.45 dBm at 2.5 GHz. To test the thermal stability of the Pt diffusion barrier, these switches were annealed at 250°C for 20 h. After the annealing, the switches showed no degradation of the dc characteristics. In addition, after a high temperature storage life environment test at 150°C, these copper-metallized switches remained capable of excellent power handling. To test the operation reliability of the copper-metallized switches, the copper-metallized switches were subjected to ON/OFF (control voltage = +3/0 V exchange) stress test for 24 h at room temperature. The devices maintained excellent RF characteristics after the stress test. Consequently, it is successfully demonstrated through these tests that copper metallization using Ft as the diffusion barrier could be applied to the GaAs monolithic microwave integrated circuit switch fabrication with good RF performance, high-temperature characteristics, and reliability.
KW - Copper metallization
KW - Platinum
KW - Pseudomophic high-electron mobility transistor (PHEMT)
KW - Single-pole-double-throw (SPDT)
KW - Switch
KW - Temperature
UR - http://www.scopus.com/inward/record.url?scp=54949131376&partnerID=8YFLogxK
U2 - 10.1109/TDMR.2008.2002493
DO - 10.1109/TDMR.2008.2002493
M3 - Article
AN - SCOPUS:54949131376
VL - 8
SP - 621
EP - 628
JO - IEEE Transactions on Device and Materials Reliability
JF - IEEE Transactions on Device and Materials Reliability
SN - 1530-4388
IS - 3
M1 - 4655597
ER -