Research On Preparation Of ZnO Waveguide Layer By Magnetron Sputtering And The Love Wave Senor

The energy of the Love wave is mainly distribute in the waveguide layer,and the Love wave,which has small coupling between the substrate surface and the waveguide layer load,does not exist the displacement component of the substrate normal vector.Therefore,the love wave device has been widely studied and applied in the fields of the electronic devices,the sensors,the biological analysis chips and so on.The growth of the waveguide layer is related to the quality factors such as the internal defects,the grain size and the crystal orientation.It is the key technology that affects the final performance of the device.In order to improve the performance of the Love wave device,a scheme of preparation of ZnO waveguide layer in the Love wave device has been prepared by the magnetron sputtering,and the Love wave device was used for the humidity sensor.In the technique of preparation of ZnO waveguide by the magnetron sputtering,the sputtering temperature is an important factor affecting the quality of the waveguide layer.In order to study the influence of deference sputtering temperatures on the ZnO waveguide layer and the performance of Love wave device,a set of Love wave devices with ZnO waveguide layer were prepared at the sputtering power of 120 W,the sputtering pressure of 1.2Pa,the deference temperatures and the sputtering time of 200 min.The crystallographic orientation and the microstructure of ZnO waveguide layer were analyzed by various characterization tools,and the response characteristics of Love wave device with ZnO waveguide layer were analyzed by the network analyzer.The experimental results show that at 25? to 150?,the overall quality of ZnO waveguide layer increases as the increase of sputtering temperature.When the sputtering temperature is greater than 150?,the overall quality of the ZnO waveguide layer decreases.Compared with other sputtering temperatures,the(002)preferred orientation of ZnO waveguide layer prepared at 150? is the best,the internal defects and the internal stress is minimum.The insertion loss of Love wave device with ZnO waveguide layer is 17.7 dB.The Love wave device with ZnO waveguide layer prepared at a sputtering temperature of150? was used as the humidity sensor and a measurement system was designed to analyze its important characteristics.The measurement results show that the Love wave humidity sensor has good repeatability.At the measurement chamber temperature of 25?,the sensor has a high sensitivity of 6.43 KHz / RH and the test limit of 0.00015%RH/Hz in the relative humidity of 20% to 80% range.The quality sensitivity of the sensor is 178.68cm2 / g,and thesensor has a small hysteresis.