InSb薄膜的制备及其光电特性研究

Study on Preparation and Optoelectronic Characteristics of InSb Thin Films

摘要: 针对Si基光电探测器在中红外波段响应受限，以及高质量InSb薄膜传统制备方法与Si基集成工艺兼容性不足的问题，本研究采用直流磁控溅射及InSb-Zn双靶共溅射工艺，在p型Si(111)和n型Si(100)衬底上分别制备InSb薄膜和Zn掺杂InSb薄膜，考察了溅射功率、工作气压、衬底温度及沉积时间等工艺参数对薄膜生长、晶体结构和表面形貌的影响，并进一步构建了p-Si/n-InSb和n-Si/p-InSb(Zn)异质结构器件。由实测膜厚与沉积时间计算得到，样品3~6的平均沉积速率分别为14.01、11.04、5.67和7.53 Å/s；在工作气压1.0 Pa、衬底温度300℃和沉积时间5 min条件下，溅射功率由40 W提高至60 W时，薄膜平均沉积速率提高约32.8%。p-Si/n-InSb器件的反向与正向电阻之比约为5，表现出一定的整流特征；室温下，在近红外和中红外波段红外光辐照条件下均检测到光生电压，最高开路光电压约为68 mV。在本实验光源条件下，近红外辐照产生的光电压整体高于中红外辐照。研究结果表明，采用磁控溅射在Si衬底上直接制备InSb薄膜并构筑InSb/Si异质结构具有可行性，可为低成本、Si基兼容红外光电器件的制备提供实验依据。

Abstract: To address the limited mid-infrared response of Si-based photodetectors and the challenges associated with integrating conventional high-quality InSb thin-film fabrication processes with Si-based technologies, InSb and Zn-doped InSb thin films were deposited on p-type Si(111) and n-type Si(100) substrates, respectively, using direct-current magnetron sputtering and InSb–Zn dual-target co-sputtering. The effects of sputtering power, working pressure, substrate temperature, and deposition time on the film growth behavior, crystal structure, and surface morphology were investigated. On this basis, p-Si/n-InSb and n-Si/p-InSb(Zn) heterostructure devices were fabricated. Based on the measured film thicknesses and deposition times, the average deposition rates of Samples 3~6 were calculated to be 14.01, 11.04, 5.67, and 7.53 Å/s, respectively. Under otherwise identical conditions of a working pressure of 1.0 Pa, a substrate temperature of 300˚C, and a deposition time of 5 min, increasing the sputtering power from 40 to 60 W resulted in an approximately 32.8% increase in the average deposition rate. The p-Si/n-InSb device exhibited a reverse-to-forward resistance ratio of approximately 5, indicating discernible rectifying behavior. At room temperature, photovoltages were detected under infrared irradiation in both the near-infrared and mid-infrared wavelength ranges, with a maximum open-circuit photovoltage of approximately 68 mV. Under the specific illumination conditions employed in this study, the photovoltage generated under near-infrared irradiation was generally higher than that obtained under mid-infrared irradiation. These results demonstrate the feasibility of directly depositing InSb thin films on Si substrates by magnetron sputtering and constructing InSb/Si heterostructures, providing an experimental basis for the development of low-cost, Si-compatible infrared optoelectronic devices.