多组分掺杂ZnO薄膜的微观结构及电学性能研究

Microstructure and electrical roperty of(Bi,Cr,Sb,Mn,Co)-doped ZnO thin films grown by RF magnetron sputtering

采用射频磁控溅射法在Si(111)衬底上制备多组分掺杂ZnO薄膜,研究了衬底温度和氧分压对Bi、Cr、Sb、Mn和Co掺杂ZnO薄膜的晶体结构、表面形貌及电学性能的影响。结果表明:随着衬底温度的升高,ZnO(002)衍射峰相对强度先增强后减弱;薄膜表面粗糙度先减小后增大。随着氧分压的增大,ZnO的(101)、(102)和(103)衍射峰消失,薄膜呈优异的(002)择优取向生长。在衬底温度为300℃、氧分压为50%时,Bi、Cr、Sb、Mn和Co所引起的缺陷和氧过剩引起的本征缺陷,共同形成受主态的复合缺陷,导致晶界势垒激增。此时,薄膜有最优化的压敏电压、非线性常数和漏电流,分别达到7.05V、20.83和0.58μA/mm^2。

（Bi,Cr,Sb,Mn,Co）-doped ZnO thin films deposited on silicon（111） substrates were grown by radio frequency （RF） magnetron sputtering technique. The effects of both substrate temperature and oxygen partial pressure on the crystal structure, surface morphology and electrical properties of ZnO films were investigated. The results showed that with the increase of the substrate temperature, both the surface roughness and the c-axis（002） orientation of films tended to first decrease and then increased. When the temperature was 300℃ ,both the c-axis（002） orientation and surface roughness became best. With the increase of the oxygen partial pressure, the ZnO（101）, （102）, （103） diffraction peaks disappeared, the c-axis（002） orientation was excellent. When the temperature was 300℃ and oxygen partial pressure was 50%, both the segregation of Bi,Co, Sb, Mn,Co and the excess oxygen in the grain boundary caused the composite defects of acceptor states, which leaded to the grain boundary barrier surging. The films, as a result, showed the best nonlinear voltage, nonlinear coefficient and leakage current density, and reached 7.05V, 20.83 and 0.58μA/mm^2 , respectively.