By: tarlinian (tarlinian.delete@this.gmail.com), July 1, 2022 5:50 pm
Room: Moderated Discussions
Eric P (eric.delete@this.nospam.com) on July 1, 2022 5:26 pm wrote:
> > I think the notch is still there. It seems to be in the Intel image.
>
> > In the 1st and 2nd image it looks to be around 5 o'clock.
>
> > In the 3rd image just above (and in the middle of) the "ra" in semiaccurate
>
> Thank you for pointing that out. I was referring to the flat section (segment of a circle), like
> on the TSMC logo. I didn’t notice the V notch before but I agree the Intel wafers do have a V notch.
> Even the Samsung and TSMC wafers seem to have a V notch at 6 o’clock, but it is less clear due
> to lighting highlights. I guess this V notch is now used to indicate the crystal orientation.
I have usually heard the feature you describe on smaller wafers referred to as a "flat" in order to differentiate it from the fiducial notch you see on 300 mm wafers and many 200 mm wafers. From what I've heard, those fiducial features obviously caused even more issues with edge related effects.
> > I think the notch is still there. It seems to be in the Intel image.
>
> > In the 1st and 2nd image it looks to be around 5 o'clock.
>
> > In the 3rd image just above (and in the middle of) the "ra" in semiaccurate
>
> Thank you for pointing that out. I was referring to the flat section (segment of a circle), like
> on the TSMC logo. I didn’t notice the V notch before but I agree the Intel wafers do have a V notch.
> Even the Samsung and TSMC wafers seem to have a V notch at 6 o’clock, but it is less clear due
> to lighting highlights. I guess this V notch is now used to indicate the crystal orientation.
I have usually heard the feature you describe on smaller wafers referred to as a "flat" in order to differentiate it from the fiducial notch you see on 300 mm wafers and many 200 mm wafers. From what I've heard, those fiducial features obviously caused even more issues with edge related effects.