Review How are Wafers Aligned Within the Nanometer Scale?

[kiba99]

In order to get accurate photolithography, the wafer have to be aligned within nanometer or even sub nanometer scales. How is wafer alignment done so accurately?

Some online references say that it is a fiducial based system, just like in PCB alignment, but are the "vision cameras" literally SEMs, given that alignment needs to be so precise?

 

[nopiano]

Are you lost?

I think you meant to go here…

https://www.reddit.com/r/hardware/comments/sz4t6i

View: https://www.reddit.com/r/hardware/comments/sz4t6i/how_are_wafers_aligned_within_the_nanometer_scale/

 

[Gray]

Straight in at number 1 in the chart of best ever1st posts.
Sets a high bar.

 

[bigboss]

Usually a spammer puts a random question, and then few weeks later the spammer registers as another spammer to post a dodgy link.

 

[Tinman1952]

In order to get accurate photolithography, the wafer have to be aligned within nanometer or even sub nanometer scales. How is wafer alignment done so accurately?

A bloody big magnifying glass and a very steady hand..........? 🤔