Preparation and characterization of reactively sputtered conducting Rh oxide thin films

反应溅射导电Rh氧化物薄膜的制备及表征

基本信息

批准号：
11650311
负责人：
ABE Yoshio
金额：
$ 1.73万
依托单位：
Kitami Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Rh oxide thin films were prepared by reactively sputtering a Rh metal target in Ar and O_2 mixed gas atmosphere. Influences of sputtering parameters and post-deposition annealing on crystal structure, chemical bonding state and electrical properties of the deposited thin films were studied by X-ray diffraction, X-ray photoelectron spectroscopy and four-point probe method.Conducting RhO_2 thin films were deposited at low substrate temperatures below 100℃, low sputtering power and low sputtering gas pressure using pure O_2 gas. The as-deposited RhO_2 thin films were poorly crystallized and resistivity of about 300 μΩcm was obtained. In order to improve the crystallinity of the films and reduce resistivity, the as-deposited RhO_2 thin films were annealed in oxygen atmosphere. It was found that the crystal grain size of the RhO_2 thin films increased and the resistivity decreased with increasing annealing temperature. The minimum resistivity of 80 μΩcm and positive temperature coefficient of resistivity (TCR), which indicate metallic conduction characteristics, were obtained for the RhO_2 thin films after annealing at 600-700℃ for 1 hour. The minimum resistivity obtained in this study is almost the same with that reported for bulk RhO_2. The RhO_2 thin films were stable up to 700℃ and thermally decomposed to Rh_2O_3 above 750℃. The resistivity of the Rh_2O_3 thin films was larger than 1mΩcm and negative TCR was observed, which indicate semiconducting characteristics of Rh_2O_3.Low resistivity conducting oxides of platinum group metals, such as RuO_2 and IrO_2, are considered to be promising material for capacitor electrodes of dynamic random access memory (DRAM) and ferroelectric RAM (FeRAM). RhO_2 is thought to be applicable to the electronic devices because thin films of RhO_2 with low resistivity (80 μΩcm) were prepared.

在Ar和O_2混合气体气氛中反应溅射Rh金属靶材制备了Rh氧化物薄膜，利用X-研究了溅射参数和沉积后退火对沉积薄膜的晶体结构、化学键合状态和电学性能的影响。采用射线衍射、X射线光电子能谱和四点探针法，在低于100℃的低基体温度、低溅射功率和低电压条件下沉积了导电RhO_2薄膜。在纯O_2气体压力下沉积的RhO_2薄膜结晶不良,电阻率约为300 μΩcm。为了提高薄膜的结晶度并降低电阻率,对沉积态RhO_2薄膜进行了退火。结果发现，随着退火温度的升高，RhO_2薄膜的晶粒尺寸增大，电阻率降低，电阻率最低为80℃。 RhO_2薄膜在600-700℃退火1小时后获得了μΩcm和正电阻率温度系数(TCR)，表明了金属的导电特性，本研究获得的最小电阻率与报道的几乎相同。块状RhO_2薄膜在700℃下仍保持稳定，在750℃以上热分解为Rh_2O_3。 Rh_2O_3薄膜大于1mΩcm并且观察到负TCR，这表明Rh_2O_3具有半导体特性。RuO_2和IrO_2等铂族金属的低电阻率导电氧化物被认为是动态随机存取存储器电容器电极的有前途的材料（ DRAM）和铁电RAM（FeRAM）被认为适用于电子设备，因为薄膜制备了低电阻率(80μΩcm)的RhO_2。