【摘要】 研究了Au,In,N i/Au三种不同金属膜与N掺杂p型ZnO的接触特性,发现N i/Au双层膜更适合作为其欧姆电极材料,并比较了不同气氛和不同温度退火对N i/Au电极的影响。发现在O2中退火电极性能发生蜕变,而在N2中退火性能得到改善。指出即使在N2中退火,退火温度的选择也是至关重要的,本实验在400℃,氮气气氛下退火150 s,得到了较好的欧姆接触特性。更多还原

【Abstract】 ZnO is a direct wide-band-gap（3.37 eV） semiconductor.It has attracted considerable attention as a potential candidate material for gas sensors,transparent electrode and surface acoustic wave deices,especially for ultraviolet light-emitting diodes（LEDs） and laser diodes（LDs）.However,for ultimately fabricating ZnO-based optoelectronic devices,the performance of the contacts to ZnO is attracting more and more attention.This is because a good ohmic contact allows lower operating voltage and minimizes dissipation of power,while a poor ohmic property leads to poor device performance and eventually device failure.Compared with that to n-type ZnO,the fabrication of ohmic contacts to p-type ZnO is more difficult since the work function of p-type ZnO is higher than that of single metal.The contact properties of Au,In,Ni/Au to N-doped p-type ZnO films grown by MBE method were re-（ported.） The zinc（Zn） source was supplied by evaporating metal zinc with 99.999 9% through a Knudsen effusion cell.NO gas activated by an Oxford Applied Research r.f.（13.56 MHz） plasma source with a power of 300 W was used as both N and O source.Compared with Au and In contacts,Ni/Au contact is more suitable to form（stable） ohmic contact to p-type ZnO.The contacts behavior of Ni/Au after annealing under N₂ and O₂ ambient were given.It was found Ni/Au contact gave a degenerative behavior after rapid thermal annealing（RTA）（under） O₂ ambient at the（temperature） of 300 ℃ for 150 s,while an improved contact behavior was obtained（after） RTA under N₂ in the same temperature for 150 s.The dependence of Ni/Au contact on the annealing（temperature）（under） N₂ gas（ambient） was investigated.With the increase of the annealing temperature,the resistances of Ni/Au contacts decrease firstly and then increase.In this experiment,after RTA at 400 °C under N₂ for 150 s,the Ni/Au contact gives a better ohmic characteristic,and the contact resistivity is about 0.8 Ω·cm².更多还原