非晶Ga2O3薄膜的制备及其深紫外光电性能的研究

STUDY ON PREPARATION AND DEEP ULTRAVIOLET PHOTOELECTRIC PROPERTIES OF AMORPHOUS Ga2O3 FILMS

张立冬

11930057

硕士

材料工程

陈朗

2021-05-18

2021-06-11

南方科技大学

深圳

近年来，深紫外探测器由于其在军事和民用领域的巨大的应用前景受到了广泛的关注，以Ga2O3为代表的宽禁带半导体材料禁带宽度为4.5-4.9 eV，由于具有固有的深紫外吸收特性，且稳定性高，抗干扰能力强，被认为是最理想的深紫外探测材料之一。但是以往研究多数集中在β-Ga2O3薄膜材料，对于非晶Ga2O3深紫外探测器的研究尚处于初始阶段。非晶Ga2O3与β-Ga2O3相比，所需制备的温度更低、制备设备及工艺更为简单，更适合大尺寸生长，但非晶Ga2O3薄膜材料因为具有更多的内部缺陷而制约着器件光电探测器性能的提升。因此，探究生长工艺对非晶薄膜内部缺陷的影响规律，探寻最佳生长条件具有重要意义。本论文制备出了非晶Ga2O3薄膜，然后通过改变薄膜生长参数来调控薄膜内部缺陷，最终制备出基于氧化镓薄膜的深紫外探测器。本文利用脉冲激光沉积技术(Pulsed Laser Deposition，PLD)，在α-Al2O3 (0006) 衬底上生长非晶Ga2O3薄膜，通过调节生长参数，研究温度与氧压对非晶Ga2O3结构与形貌的影响，当生长温度在450 ℃以下时，制备的Ga2O3薄膜呈非晶形态，且随着氧气分压的增加，其透过光谱呈现蓝移的趋势。通过对制备的非晶薄膜进行高氧退火处理，研究了退火温度对薄膜内部缺陷和光电吸收特性的影响。退火后0.13 Pa，1.3 Pa和13 Pa氧压条件下氧化镓薄膜的O 1s结合能峰位分别对应为531.1 eV，531.2 eV和531.35 eV，经过高氧退火处理后的薄膜内部氧空位减少。通过紫外光刻技术制备出基于非晶Ga2O3薄膜的金属-半导体-金属型(Metal-Semiconductor-Metal，MSM) 光电探测器，并对器件进行性能测试，包括暗黑暗下和深紫外光下的I-V关系和瞬态光响应速度等性能。研究发现升高氧压和退火处理均可提升探测器的信噪比，最高可以达到104的水平

In recent years, deep ultraviolet detectors have received extensive attention due to their huge application prospects in military and civilian fields. The wide band gap semiconductor material represented by Ga2O3 has a band gap of 4.5-4.9 eV. Due to its inherent deep ultraviolet absorption characteristics, high stability and strong anti-interference ability, gallium oxide is considered to be one of the most ideal deep ultraviolet detection materials. However, most previous researches focused on β-Ga2O3 thin film materials, and the research on amorphous Ga2O3 deep ultraviolet detectors is still in the initial stage. Compared with β-Ga2O3, the preparation temperature of amorphous Ga2O3 material is lower, the preparation equipment and process are simpler, and it is more suitable for large-scale production. But amorphous Ga2O3 thin film materials have more internal defects, which restricts the improvement of device photodetector performance. Therefore, it is of great significance to explore the influence of the growth process on the internal defects of the amorphous film and the optimal growth conditions. In this thesis, amorphous Ga2O3 thin films were prepared, and then the internal defects of the film were adjusted by changing the film growth parameters, and finally deep ultraviolet detectors based on amorphous gallium oxide films were prepared. In this thesis, pulsed laser deposition technology (PLD) is used to grow amorphous Ga2O3 film on α-Al2O3 (0006) substrate, and the influence of temperature and oxygen pressure on the structure and morphology of amorphous Ga2O3 were studied by adjusting the growth parameters. When the growth temperature is below 450 ℃, the prepared Ga2O3 film is amorphous, and as the oxygen partial pressure increases, its transmission spectrum shows a blue shift trend. Through the high-oxygen annealing treatment of these prepared amorphous films, the effect of annealing temperature on the internal defects and photoelectric absorption characteristics of the film were studied. After annealing, the O 1s binding energy peaks of gallium oxide films under oxygen pressures of 0.13 Pa, 1.3 Pa and 13 Pa correspond to 531.1 eV, 531.2 eV and 531.35 eV, respectively. The oxygen vacancies in the film are reduced after annealing at high oxygen pressure. Metal-Semiconductor-Metal (MSM) photodetectors based on amorphous Ga2O3 thin films were fabricated by ultraviolet lithography technology. Performance tests have been performed on devices, including the I-V relationship under dark and deep ultraviolet light and transient light response speed. The study found that increasing the oxygen pressure and annealing treatment can improve the signal-to-noise ratio of the detector, up to a level of 104.

非晶Ga2O3薄膜 PLD 深紫外光电探测器 氧空位

amorphous Ga2O3 thin film PLD deep ultraviolet photodetector oxygen vacancy

中文

独立培养

南方科技大学

张立冬. 非晶Ga2O3薄膜的制备及其深紫外光电性能的研究[D]. 深圳. 南方科技大学,2021.