氮分压对氮化锆薄膜颜色的影响规律研究

CIElab颜色空间坐标是氮化锆薄膜非常关键的技术指标,而氮分压对氮化锆薄膜颜色坐标有较大的影响。应用中频反应磁控溅射技术沉积氮化锆薄膜,通过对炉内分压强和氮化锆薄膜颜色的测量,绘制了氮分压对CIE颜色坐标L*,a*,b*值的影响曲线。发现随炉内氮分压的增大,薄膜颜色坐标a*,b*值呈环形曲线、L*值呈单调下降的变化趋势。并使用金属自由电子气模型对颜色变化趋势进行了理论分析。发现颜色坐标的变化是由于随氮分压增加,自由电子浓度降低引起等离子体频率降低造成的。对薄膜的X射线衍射谱(XRD)以及电阻率测量结果的分析表明,在氮分压较大时,颜色坐标L*的明显下降变化是由于Zr3N4等的禁带宽度小于可见光谱的极限造成的。

Effect of Nitrogen Partial Pressure on Color of ZrN

CIE 1976 LAB color space coordinate is an important technical index of ZrN film,and nitrogen partial pressure has a critical effect on ZrN film color coordinate.Mid-frequency reactive magnetron sputtering is adopted to deposite ZrN layer,and through measuring the color of ZrN films and nitrogen partial pressure,the curves of CIE L*,a* and b* values of ZrN films versus nitrogen partial pressure are obtained.The results show that the curve of a* and b* values is a loop curve and L* values decrease with the rise of nitrogen partial pressure.The theoretical analysis is given by metal free-electron model.As the nitrogen partial pressure increases,the variation of color coordinate is caused by decrease of free electrons number of the films and decrease of plasma frequency.The results of X-ray diffraction(XRD) and resistivity measurement indicate that the distinct decrease of L* value at high nitrogen partial pressure is caused by that band gap of Zr3N4 is less than limit of visible light.