Low yields driving calls for EUV pellicles

[Fred Chen]

There were statements to the effect that some chips made by EUV have suffered low yield, due to no pellicles:

EUV Pellicles Finally Ready

Yield rises with mask protection; multiple sources will likely reduce costs.

semiengineering.com

..Samsung and TSMC initially moved into EUV production without pellicles, simply because these components weren’t ready. The results are mixed. Using EUV, chipmakers have produced a multitude of chips, although the yields have ranged anywhere from satisfactory to poor, according to multiple sources in the equipment industry. This depends on the chip size, design and vendor, sources said.
...
Not surprisingly, chipmakers are taking yield hits on some chips, namely the larger dies, according to sources in the equipment business...in some cases, customers are pushing back, demanding that their foundry partners use EUV pellicles for select chips, sources added.

Pellicles would dictate an extensive re-qual, as doses, throughput, imaging are all affected significantly.

 

[Scotten Jones]

Pellicles are available now and in fact are being used on some layers in production today. ASML is also introducing a new higher transmission pellicle. This is old news.

 

[Fred Chen]

~90% transmission (single-pass) results in ~20% effective power loss, so they're still targeting higher transmission.

 

[Scotten Jones]

You took a post from another web site, copied it and posted it here. The post implies that pellicles aren't available or aren't being used, I simply pointed out that pellicles are available and are being used on some layers.

Now you are trying to change the conversation by saying they are still targeting higher transmission. Yes they are and in my comment I mentioned that ASML is introducing a higher transmission pellicle.

Pellicle use is a tradeoff between throughput and yield, and the yield impact is layer specific. Contact and via layers aren't very defect sensitive, interconnect layers are.

You also mention that ~90% pellicle transmission results on ~20% loss in overall power transmission, that is true but the impact on throughput is a lot less. Taking into account all the factors that impact throughput, the effect is closer to 10%.

 

[Fred Chen]

This might be relevant supplementary information: https://bits-chips.nl/artikel/asml-readies-next-gen-euv-pellicle-for-production/

At the time of that article (Oct 2020), the one-way transmission was still 83%. That was with polysilicon; by going to the silicide they are getting to 90%. They are also getting improved thermal stability.

Mitsui is expected to take over the pellicle production, if not started already.