EUV Is Late—And It Hurts

Who’s in control of design depends largely on the progress of new tools.

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Most chip architects and engineers couldn’t give a whit about the difference between deep ultraviolet and extreme ultraviolet lithography. It’s traditionally been a problem that foundries had to wrestle with, and that was their problem. Even DFM has been slow to catch on because what’s done in a foundry is of little interest up front.

 

The separation of those two worlds worked fine above 65nm. Architects and foundries had little in common other than their goal to get chips out the door, and architects typically dictated what needed to be done. At 45nm they became much more equal in their say of what could be done. And at 28nm and 22nm, it’s about to turn into a completely different kind of relationship, where the foundry rules dictate what’s has to be done at the architecture level to get a chip out the door on time.

 

The problem this time is the inability to etch fine enough lines with deep ultraviolet lithography. At 193nm, it doesn’t come close to providing the granularity needed at 32nm or 28nm, depending upon who’s defining the next process node. Immersion lithography doesn’t solve it either. That means the short-term solution is double patterning, which adds significantly to the mask cost, the time it takes to churn out wafers, and the overall cost of devices.

 

It may take three to five years before we see EUV, which uses a 13.5nm wavelength. Until then, expect the fabs to be far more in control of designs, dictating what can be used, how it can be laid out, and what the parameters will be for defect density. And expect to see more and more companies hanging back a generation or two on the Moore’s Law road map until this gets resolved.

 

Seeing the light was supposed to be a good thing. Now it turns out there are different kinds of light, and not all of them are equal.

 

–Ed Sperling


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