抗反射涂层颜色

精确测量抗反射涂层厚度的最常见方法是使用椭圆偏振技术，它可以观察偏振光的反射方式。

测量抗反射涂层的一种简单方法是通过观察薄膜颜色。^[Henrie2004]

四个覆盖有氮化硅薄膜的多晶硅片。颜色的差异完全是由于薄膜的厚度造成的。绿色硅片具有非常厚的薄膜，因此不会出现在下图的颜色图表中。

薄膜的颜色受到厚度和折射率的影响，因此薄膜颜色只是厚度的粗略指导。有多个表用于确定二氧化硅或氮化硅膜的膜厚度，如下所示。制作薄膜标准是很常见的，这样可以通过将样品与标准进行比较来快速检测工艺条件的变化。

在法向入射光的荧光照明下，折射率约为 2.05 的氮化硅薄膜的颜色与薄膜厚度的函数关系。该图表仅供参考，因为商业生产中薄膜颜色会受到制绒和折射率变化的影响。（使用 BYU 小程序生成的图）

荧光灯下二氧化硅 (SiO2) 薄膜的色卡^{[Pliskin1964]}

Film Thickness (µm)	Colour and Comments
0.05	Tan
0.07	Brown
0.10	Dark violet to red violet
0.12	Royal Blue
0.15	Light blue to metallic blue
0.17	Metallic to very light yellow green
0.20	Light gold to yellow; slightly metallic
0.22	Gold with slight yellow orange
0.25	Orange to melon
0.27	Red violet
0.30	Blue to violet blue
0.31	Blue
0.32	Blue to blue green
0.34	Light green
0.35	Green to yellow green
0.36	Yellow green
0.37	Green yellow
0.39	Yellow
0.41	Light orange
0.42	Carnation pink
0.44	Violet red
0.46	Red violet
0.47	Violet
0.48	Blue violet
0.49	Blue
0.50	Blue green
0.52	Green (broad)
0.54	Yellow green
0.56	Green yellow
0.57	"Yellowish" (actually at times appears to be light creamy gray or metallic)
0.58	Light orange or yellow to pink borderline
0.60	Carnation pink
0.63	Violet red
0.68	"Bluish" (actually appears more like a mixture between violet red and blue green and looks grayish)
0.72	Blue green to green (quite broad)
0.77	"Yellowish"
0.80	Orange (rather broad for orange)
0.82	Salmon
0.85	Dull, light red violet
0.86	Violet
0.87	Blue violet
0.89	Blue
0.92	Blue green
0.95	Dull yellow green
0.97	Yellow to "yellowish"
0.99	Orange
1.00	Carnation pink
1.02	Violet red
1.05	Red violet
1.06	Violet
1.07	Blue violet
1.10	Green
1.11	Yellow green
1.12	Green
1.18	Violet
1.19	Red Violet
1.21	Violet red
1.24	Carnation pink to salmon
1.25	Orange
1.28	"Yellowish"
1.32	Sky blue to green blue
1.40	Orange
1.45	Violet
1.46	Blue violet
1.50	Blue
1.54	Dull yellow green

 

References

1. J. Henrie et al., “Electronic color charts for dielectric films on silicon,” Optics Express, vol. 12, pp. 1464–1469, 2004. https://doi.org/10.1364/OPEX.12.001464
2. W.A. Pliskin and E.E. Conrad, “Nondestructive determination of thickness and refractive index of transparent films,” IBM Journal of Research Devices, vol. 8, pp. 43–51, 1964. http://portal.acm.org/citation.cfm?id=1662391