Transparent P-type Conductive Ternary Oxide Films Prepared by Reactive Sputtering Method

反应溅射法制备透明P型导电三元氧化物薄膜

• 批准号: 16560270
• 负责人: TSUBOI Nozomu
• 金额: $ 2.43万
• 依托单位: Niigata University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16560270/
• 关键词: delafossite; CuAlO_2; transparent conductive oxide; p-type oxide; thin films; reactive sputtering; sputtering; oxide electronics; レーザアニール

Cu-Al-O films were prepared on quarts substrates at 500〜700℃ by sputtering alternately the Cu and the Al targets on atomic-layer-scale under Ar-diluted O_2(5〜20%) gas atmosphere, and then annealed at 1050℃ under the nitrogen atmosphere. The [Cu]/[Al] ratio was controlled by changing Cu and Al deposition periods. Composition of as-deposited films corresponded to the slightly oxygen-rich region of the CuO-CuAl_2O_4-Al_2O_3 system. Films as-deposited at 500℃ had amorphous structure, while films as-deposited at 700℃ had CuAl_2O_4 and CuO phases. After thermal annealing, the film composition approached to the Cu_2O-CuAlO_2-Al_2O_3 system line, causing noticeable appearance of CuAlO_2 delafossite phase along with absences of the CuAl_2O_4 and CuO phases. Cu-rich and Al-rich annealed films had additionally Cu_2O phase and amorphous Al_2O_3 phase, respectively. All annealed films exhibited p-type conductivity. The annealed films with [Cu]/[Al]【approximately equal】1 had the absorption edge corresponding to the energy gap of CuAlO_2. These results indicate the change of Cu ion from di-valence to mono-valence through the annealing process, which results the preparation of transparent conductive films dominated by CuAlO_2. We also tried to irradiate the as-deposited films in order to crystallize the amorphous structure to CuAlO_2 delafossite structure by using a KrF laser in the power range of 10〜10^3 mJcm^<-2>. However, we observed no changes of the amorphous structure. At the power more than about 10^2 mJcm^<-2>, laser ablation of the films was observed.

在500 ~ 700℃，Ar稀释的O_2（5 ~ 20%）气氛下，以原子层尺度交替溅射Cu和Al靶，在石英衬底上制备Cu-Al-O薄膜，然后在1050℃氮气气氛下退火。[Cu]/[Al]比值通过改变Cu和Al沉积周期来控制。沉积态薄膜的成分对应于CuO-CuAl_2 O_4-Al_2O_3系统的微富氧区。500℃沉积的薄膜为非晶态结构，700℃沉积的薄膜为CuAl_2O_4和CuO相。热处理后，薄膜的成分接近Cu_2 O-CuAlO_2-Al_2O_3系线，沿着出现CuAlO_2铜铁矿相，而CuAl_2O_4和CuO相消失。富Cu和富Al退火膜分别含有Cu_2O相和非晶Al_2O_3相。所有退火的薄膜表现出p型导电性。[Cu]/[Al]约为1的退火膜具有与CuAlO_2的能隙相对应的吸收边。结果表明，在退火过程中，Cu离子由二价态转变为一价态，从而形成了以CuAlO_2为主的透明导电膜。我们还尝试用功率范围为10 ~ 10^3 mJcm ↑ [2]的KrF激光辐照沉积态薄膜，使非晶结构晶化为CuAlO_2铜铁矿结构<-2>。然而，我们没有观察到无定形结构的变化。在大于约10^2 mJcm^2的功率下<-2>，观察到膜的激光烧蚀。