Performance Msm Uv Detector Test

Ultraviolet (UV) detectors have been much studied because of its important applications in many fields. ZnO is an n-type semiconductor with a large exciton binding energy of 60 meV and wide band gap energy of 3.37 eV at room temperature. The band gap can be modulated by varying the Al composition. These properties make it a potentially useful photonic material for ultraviolet photodetectors.At first, AZO thin films doped with different concentrations of Al can be prepared by RF sputtering method on quartz substrates and Si substrates, respectively. And then, Au interdigital metal electrodes can be made by vacuum evaporation technology. Finally, MSM structure UV detector can be gained by packaging system. The structure and performances of the detectors were studied by testing.The AZO thin films were prepared on the quartz substrate by changing the ratio of sputtering gases and keeping other process conditions, the effect of oxygen in sputtering process can be studied by testing the performance of the detectors. So was the effect of oxygen in testing process. The results showed that reducing appropriately the oxygen/argon ratio in the sputtering process and the presence of oxygen in the testing process can improve the light-dark current ratio and the detector response time. Comparing the doped Al 5at% and the doped Al 30at% of the detectors, the results were found that: the light-dark current ratio was nearly four orders of magnitude, and the detector response time of the doped Al 30at% was significantly smaller than that of the doped Al 5at%. At the same bias voltage, the photocurrent increased as the irradiance increasing and the response time decreased as the irradiance increased.The AZO thin films were prepared on the Si substrate. Through the CV characteristic curve of the detector, it can be found that on Si substrate, metal Au electrode and the AZO films forms Schottky contacts. At 5V bias voltage, the light-dark current ratio which doped with Al 30at% was 10:1, the response time was less than 1ms, and the fall time was 2ms. The test of the spectral response found that detectors fabricated on Si substrate increased response the Si detector in ultraviolet. When the bias voltage was greater than the punch-through voltage, we found that the detector capacitance decreases with the increasing frequency, and increases with the increasing temperature. The linear of between the resistance and the voltage got more obvious as the increasing frequency.