I keep reading on how people on the last gen node are faring, and besides power it seems there are no clear way forward.
1. Pellicle — is ready, but appeared to be a mixed blessing for productivity, and yields
2. Tool cleaning, and other maintenance — an unavoidable fixed cost. Fabs seem to be trying to improvise there, but in the end it will still be needed, even if fully automated.
3. Mask repair, inspection, and other mask servicing — besides costing a fortune, EUV mask will eventually die, and die invariably faster than DUV masks. EUV masks inherently require more care.
4. Reticle — EUV reticle does not match DUV systems which will be doing metal, needing to shoot multiple exposures into the size of DUV reticle, necessitating stitching essentially the same layer. Since EUV reticle is a mirror itself, there is a limit to how much it can be increased in size. 3500 will likely reach a feasible reticle size maximum for its NA.
5. Material handling — EUV is one more vacuum process, and getting wafers in, and out of vacuumed tools inherently takes more time.
6. Particles — have no idea what's the actual rate, but I believe it's much trickier to fight in a vacuum system. In vacuum, every minuscule amount of volatiles will try to deposit on your wafer.
7. Multiple exposures — seem to be already being used for 3nm, so big hopes for single exposure seem to been misplaced.
8. Future resists — it seems the industry will go for ALD deposited resists, or PSCAR. These will inherently require more complex, and lengthy coating, and developing process.
So, with all this in mind, does this leave a chance for 157i to come back from the grave?
1. Pellicle — is ready, but appeared to be a mixed blessing for productivity, and yields
2. Tool cleaning, and other maintenance — an unavoidable fixed cost. Fabs seem to be trying to improvise there, but in the end it will still be needed, even if fully automated.
3. Mask repair, inspection, and other mask servicing — besides costing a fortune, EUV mask will eventually die, and die invariably faster than DUV masks. EUV masks inherently require more care.
4. Reticle — EUV reticle does not match DUV systems which will be doing metal, needing to shoot multiple exposures into the size of DUV reticle, necessitating stitching essentially the same layer. Since EUV reticle is a mirror itself, there is a limit to how much it can be increased in size. 3500 will likely reach a feasible reticle size maximum for its NA.
5. Material handling — EUV is one more vacuum process, and getting wafers in, and out of vacuumed tools inherently takes more time.
6. Particles — have no idea what's the actual rate, but I believe it's much trickier to fight in a vacuum system. In vacuum, every minuscule amount of volatiles will try to deposit on your wafer.
7. Multiple exposures — seem to be already being used for 3nm, so big hopes for single exposure seem to been misplaced.
8. Future resists — it seems the industry will go for ALD deposited resists, or PSCAR. These will inherently require more complex, and lengthy coating, and developing process.
So, with all this in mind, does this leave a chance for 157i to come back from the grave?