多晶金刚石薄膜日盲紫外探测器件的电极制备

Electrode Preparation of Solar Blind UV Detector Based on Polycrystalline Diamond Films

通过在直流等离子体喷射化学气相沉积(DC-PJCVD)法生长的多晶金刚石薄膜上制备Au叉指电极,构建了金属-半导体-金属(MSM)结构的日盲紫外探测器件。研究了不同光刻工艺对制备的金刚石探测器件性能的影响。结果表明,lift-off光刻工艺所制备的器件性能明显优于湿法光刻工艺器件,其I_(light)提高了4.4倍,光暗电流比提高了6.8倍,在25 V电压下响应度提高了9倍,达到了0.15 A/W。在此基础上通过lift-off光刻工艺制备了Au、Ti、Ti/Au和Ag四种不同金属的叉指电极,对比了不同金属电极制备的金刚石紫外探测器件的性能差异。其中Ag电极由于存在势垒隧穿效应引起的增益,在四种电极中性能表现最佳,在25 V偏压下其I_(light)高达0.21μA,响应度提升到0.78 A/W,性能与已有报道的器件性能相当。与普通Au电极制备的器件相比,其光电流提高了5.2倍,光暗电流比提升了7倍,响应度提高了5.2倍。

A metal-semiconductor-metal(MSM)structure solar blind UV detector was constructed by preparing interdigital Au electrode on polycrystalline diamond films grown by DC plasma jet chemical vapor deposition(DC-PJCVD).The effects of different photolithography processes on the performance of the diamond detector were studied,and the results show that the performance of the device prepared by lift-off photolithography is significantly better than that prepared by wet procedure photolithography.The photocurrent of the device is increased by 4.4 times,the light-dark current ratio is increased by 6.8 times,and the responsivity is increased by 9 times to 0.15 A/W at 25 V.On this basis,the interdigitated electrodes of Au,Ti,Ti/Au and Ag were prepared by lift-off photolithography.The performance differences of diamond UV detectors prepared by different metal electrodes were compared.The Ag electrode has the best performance among the four electrodes due to the gain caused by the barrier tunneling effect.At 25 V bias,the light current is 0.21μA,and responsivity increases to 0.78 A/W.Compared with common Au electrode,the photocurrent,lightdark current ratio and responsivity are increased by 5.2 times,7 times and 5.2 times respectively.