提高压电微探针表面信息读取电荷灵敏度的方法

Methods of Improving Charge Sensitivity of Piezoelectric Microprobe in Surface Data Reading

分析了基于原子力显微镜(AFM)探针阵列的超高密度信息存储中压电方式读取纳米数据坑的电荷灵敏度,从探针结构设计的角度指出通过改进上电极钝化层的设计可以使电荷灵敏度提高约50%;在读取电路中引入直流偏置电压,通过提高锆钛酸铅(PZT)薄膜的等效横向压电系数d31进一步提高电荷灵敏度.利用硅片悬臂梁上溶胶-凝胶法制备的PZT薄膜,基于正压电效应实验验证了施加直流偏置电压对d31的提高作用.直流偏压从0 V增加到10 V时,等效横向压电系数d31从-48 pC/N提高到-120 pC/N.

The piezoelectric charge sensitivity of nano-scaled data reading in atomic force microscopy（AFM） probe-array- based ultrahigh density data storage was studied. The sensitivity can be increased by two ways. Firstly, the sensitivity can be increased 50% by improving the design of passivation layer on the upper electrode. Secondly, the effective transverse piezo- electric coefficient of lead zirconate titanate（PZT） thin film d31 can be increased by introducing a direct current（DC） bias voltage in data readout circuit, which will further the increase of the sensitivity. Based on direct piezoelectric effect, sol-gel derived PZT thin films prepared on Si wafer cantilever have been used to validate the effect of DC bias voltage on d31. Effective transverse piezoelectric coefficient d31 was enhanced from -48 pC/N to -120 pC/N by increasing DC bias voltage from 0Vto 10V.