讨论下sio2在镀膜时冲o2的问题

guangang · *发表于* 2009-4-13 12:56:27

充不充对吸收和折射率基本上没太大区别,对附着性和飘移有一点影响

AR_coating · *发表于* 2009-4-14 01:57:09

14# guangang

O2 can make sure the film is fully oxidized.
Too much O2 cause the tooling factor changes, film packing density decreases, refractive index decreases. The adhesion might also get worse.
Not enough O2 can't fully oxidize the film, so you can't get a reliable film if the film is exposed in air for a long time.

tianguosky1 · *发表于* 2009-4-14 08:08:22

14楼的，能不能给出结论的合理解释，谢谢！！！

AR_coating · *发表于* 2009-4-15 01:07:26

16# tianguosky1

Too much O2 increases the chamber pressure, if your crystal is not located at the same height of the substrate, the tooling factor changes.

Too much O2 increases the voids inside the SiO2 film, let's say, you want N_SiO2=1.45, now you can get 90% SiO2, the left 10% is void, which is Air, so the final film's refractive index decreases (0.9*1.45+0.1*1=1.405).

Less O2 causes the film not fully oxidized, after a long time expose in the air, the O2 in the air may gradually oxidize the film and change the refractive index.