ZnO基紫外探测器的制作与研究

Fabrication and Study of ZnO UV Photodetetor

利用新型的等离子体辅助金属有机化学气相沉积(P-MOCVD)系统在蓝宝石、硅等衬底上生长出具有单一c轴取向、高阻的ZnO薄膜,利用添加的等离子体发生装置,进行氮掺杂获得高阻ZnO薄膜。利用ZnO的宽禁带与高光电导特性,结合MSM(金属-半导体-金属)结构器件响应度高、速度快、随偏压变化小、工艺简单、易于单片集成等优点,制作了ZnO基紫外探测器,器件规格为80 μm×100μm,电极为叉指式电极。测试中采用500 W的氙灯做测试光源,探测器的Ⅰ-Ⅴ特性曲线显示;正向偏压下探测器的暗电流及光照电流与外加偏压呈线性增长。不同波长下的响应曲线显示:探测器对紫外波段有响应,响应峰值在375nm附近。

We present the results of UV photodetectors fabricated on ZnO epitaxial films grown on c-plane sapphire substrates by plasma assisted MOCVD. The ZnO films with single c-axis orientation and high resistivity are ob- tained. With plasma apparatus, we also obtain high resistivity ZnO films doped with N. Considering the high photo- conductive characteristics of ZnO, and characteristics of device with MSM structute, such as high responsivity, high speed, little change with bias, simple fabrication technic, easy for monolithic integration, we fabricate the ZnO UV photodetector. The size of the device is 80μm×100μm, the electrode is interdigital. Measurements are performed using a 500 W Xe-arc lamp as light source. Based on the I-V characteristics of ZnO MSM IDT devices, we can con- clude that the dark current and illuminated current of the photodetector linearly increase with the increase of the bias. The curve of the spectra-photoresponse of the IDT photodetector indicates that the detector is in response to the ultraviolet wave range and that the peak value is about 375 nm.