难熔夹层金属提高NiSi薄膜热稳定性的新思路

The Novel Thought about Employing a Thin Interlayer Metal for Thermal Stability of NiSi

首次给出了一种具有规律性的能用来提高镍硅化物热稳定性的方法。依据此方法,摸索出在Ni中分别以夹层金属掺入Pt、Mo、Zr、W金属来提高NiSi硅化物的热稳定性。概括总结了掺入难熔金属M后形成的三元镍硅化物Ni(M)Si热稳定性能。实验结果表明,Ni(M)Si硅化物薄膜四种镍硅化物薄膜有相同的热稳定性。以Ni/W/Ni/Si样品为例,经650～800℃快速热退火后,薄层电阻率保持较小值,小于3Ω/□。XRD衍射、Raman光谱和AFM分析表明,Ni(M)Si薄膜界面平整,该薄膜中只存在低阻NiSi相,而没有高阻NiSi_2相生成,从而将NiSi薄膜的低阻温度窗口的上限从700℃提高到800℃,使形成高阻NiSi_2相的最低温度提高到850℃。研制的高压Ni(M)Si/Si肖特基硅器件在650～800℃温度跨度范围内保留了NiSi/Si肖特基相近的整流特性,肖特基势垒高度分布在0.61～0.71 eV区间内,由此表明Ni(M)Si硅化物是令人满意的互连和接触材料。

A novel method with reqularity was put forward to improve the thermal stability of NiSi film for the first time. According to the way, adding a thin W,Pt, Mo, and Zr interlayer within the nickel film was first reported to effectively improve the thermal stability of nickel monosilicide. The results showed that four kinds of Ni（M）Si films had the same good thermal stability. After rapid thermal annealing （RTA） at temperatures ranging from 650 ℃ to 800 ℃, the sheet resistance of formed Ni（M）Si samples was less than 3Ω/□, and its value was also lower than that of nickel monosilicide without the interlayer. X-ray diffraction （XRD）, Raman spectra and AFM results all revealed that only the NiSi phase exists in these samples, but the high resistance NiSi2 phase does not. Fabricated Ni （M）Si/Si Schottky barrier diodes with the guard ring structure displayed good quality, with the barrier height being located generally between 0. 61 eV and 0. 71 eV and the ideality factor approaching unity, which shows that Ni（M）Si is a satisfactory local connection and contact material.