Study on PSZT thin films for microforce sensors

Pb_1-xSr_x (Zr_0.53Ti_0.47) O₃ (PSZT) thin films have been fabricated on Pt/Ti/SiO₂/Si substrates by a sol-gel method combined with a rapid thermal annealing process. It is shown that the introduction of Sr²⁺ into the PZT thin films favors the growth of (111) orientation. The orientation ratio of (111) is increased from 0.304, 0.475 to 0.849 with the increase of the x value. The dielectric measurement results indicates that the addition of Sr²⁺ in the PZT thin films greatly improves the dielectric properties of the PZT thin films. Two kinds of the PSZT0.03 thin films with thickness of 1.68 um and 2.19 um were fabricated and tested for the same structure size, and the spring constant of 11.72 N/m and 4.87 N/m is obtained, respectively. The PSZT thin films with x=0, 0.03, 0.08 have an spring constant of 13.73 N/m, 11.72 N/m and 8.16 N/m, respectively. Three kinds of the PSZT thin films for the microforce sensors were tested in quasi static state, the sensing sensitivity of the three kinds of microforce sensors are 0.017 pc/uN, 0.033 pc/uN, and 0.011 pc/uN, respectively. The sensing sensitivity of the microforce sensors is 0.033 pc/uN and 0.077 pc/uN while thickness of PSZT0.03 thin films is 1.68 um and 2.19 um.