Technology node and wavelength relation for double patterning

[VLSI_Learner]

I was reading double patterning. And came to know that dividing the mask into two for lithography is basically called double patterning. But there are some reasons for doing this. One reason was sited like this: (can't remember the proper wording but trying to write what I remember and understood)

"The UV light that is used for lithography has certain wavelength. And the technology node is too small as compared to the wavelength of the UV light. And hence proper lithography result can't be achieved."

I really didn't get what the technology nodes mean and what relation technology nodes bear with UV light wavelength. Please explain this with proper examples.

 

[Subhash]

Hope this will be of your help:
https://www.techdesignforums.com/practice/guides/double-patterning/

 

[VLSI_Learner]

Still not clear what technology node means here? And here also there is mention that if the minimum width of any particular layer is just a few fraction of the wavelength of UV light, lithography result is not achieved as expected, most of the time the layer boundary gets burred or the drawn layer differs. But still I don't have the clear explanation of the relation between the UV light wavelength and drawing layer's width.
Please some help.

 

[Subhash]

Please find the link of the videos about Double Patterning:
Part 1: https://youtu.be/d5uoklMx63I
Part 2: https://youtu.be/YDnIYmQ_Ll4

I will try to get you the "EXACT" meaning for Technology node, though my understanding in my words might not explain it correct.