原子层沉积技术制备氧化锌薄膜及其性能的研究

发布时间：2018-01-09 08:12

本文关键词：原子层沉积技术制备氧化锌薄膜及其性能的研究　出处：《北京交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：氧化锌(ZnO)作为第三代半导体材料,由于其禁带宽度大,可以广泛的应用于制造蓝绿光和紫外光的光电器件,同时还具有电子漂移饱和速度高、介电常数小等特点,因此,成为当下半导体材料的研究热点。而原子层沉积技术(ALD)是近些年发展起来的薄膜制备技术,由于该技术制备的薄膜性能优异、厚度可控且保型性好,也越来越受到人们的关注。本文利用自主研制原子层沉积设备在蓝宝石衬底上沉积新型半导体材料ZnO薄膜,并通过对薄膜晶型与形貌的测试,完成对ALD技术所制备ZnO薄膜性能的分析。 1、采用热型ALD技术制备ZnO薄膜时,首先研究了锌源脉冲时间对ZnO薄膜性能的影响,实验中均得到了单一(002)晶向的薄膜。实验中还发现薄膜的厚度以及生长速率与锌源脉冲时间并无直接的联系,但是随着锌源脉冲时间的增加,薄膜结晶性能得到改善,粗糙度有所降低,载流子浓度从5.5×1019/cm3增加到7.6×1019/cm3,导电性得到增强。 2、采用热型ALD技术制备ZnO薄膜时,其次我们研究了生长的循环周期数对ZnO薄膜性能的影响。实验中发现,通过增加生长的循环周期数,可以使薄膜晶粒尺寸明显增大,结晶性得到了很大的改善。当循环周期数为1000时,晶粒尺寸可达到50纳米,约是200循环的2.5倍,因此可以通过控制生长的循环周期数来调节ZnO薄膜的晶粒尺寸。 3、针对常规ALD的技术难点和问题,首次提出可变电场调制的原子层沉积技术(E-PEALD)的概念,并从理论上分析E-PEALD技术对反应物的作用模式。 4、采用E-PEALD技术制备ZnO薄膜时,我们研究了所施加的电场方向对ZnO薄膜性能的影响,实验中发现,可通过控制所施加电场的方向来调节ZnO薄膜的晶向。同时还研究了所施加电场的强度对ZnO薄膜性能的影响,在电场方向为(Zn-/O+)时,可通过增大电场强度来提高薄膜在(002)晶向的单晶性。
[Abstract]:Zinc oxide (ZnO) as the third generation semiconductor material, because of its wide band gap, it can be widely used in the manufacture of blue-green light and ultraviolet light optoelectronic devices, but also has high electron drift saturation speed. Because of its small dielectric constant, ALD has become a hot research topic in semiconductor materials, and ALD (Atomic layer deposition) is a new thin film preparation technology developed in recent years. The film prepared by this technology has excellent properties, controllable thickness and good shape preservation. In this paper, ZnO thin films are deposited on sapphire substrates with atomic layer deposition equipment, and the crystal shape and morphology of the films are tested. The properties of ZnO films prepared by ALD were analyzed. 1. The effect of pulse time of zinc source on the properties of ZnO thin films was studied by thermal ALD technique. The thickness and growth rate of the films are not directly related to the pulse time of zinc source, but with the increase of the pulse time of zinc source. The crystalline properties of the films were improved, the roughness was decreased, the carrier concentration was increased from 5.5 脳 10 19 / cm 3 to 7.6 脳 10 19% cm 3, and the conductivity was enhanced. 2. When ZnO thin films were prepared by thermal ALD, the effect of cycle number on the properties of ZnO thin films was studied. When the cycle number is 1000, the grain size can reach 50 nm, which is about 2.5 times that of 200 cycles. Therefore, the grain size of ZnO films can be adjusted by controlling the cycle number of growth. 3. Aiming at the technical difficulties and problems of conventional ALD, the concept of E-PEALDD, which is a variable electric field modulated atomic layer deposition technique, is proposed for the first time. The action mode of E-PEALD on reactants is analyzed theoretically. 4. When ZnO thin films were prepared by E-PEALD, we studied the effect of the applied electric field direction on the properties of ZnO thin films. The crystal direction of ZnO thin films can be adjusted by controlling the direction of applied electric field, and the influence of the applied electric field intensity on the properties of ZnO thin films is also studied, when the electric field direction is Zn-r / O). By increasing the electric field intensity, the single crystal properties of the thin films in the crystal direction of (002) can be improved.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304

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