VLSI 2018: Samsung’s 2nd Gen 7nm, EUV Goes HVM – WikiChip Fuse
This WikiChip fuse article which appeared several days ago is a pretty nice short review of Samsung's 7nm presentations from both VLSI 2018 and ISSCC 2018. It also seems to provide a pretty balanced look at Samsung's 7nm situation. Most of the VLSI 2018 stuff was covered here at SemiWiki already. So I'll just list a number of points from the 5-page article, many probably already known:
1. Samsung referred to 7LPP as the "2nd generation" 7nm, the first being 7LPE, which practically never happened but was developed at one point.
2. Fin pitch 27 nm, Gate pitch 54 nm, Metal pitch 36 nm.
3. EUV single exposure for contact, metal, >25% mask reduction consequently. (Note: previously EUV for fin layer has been corrected)
4. 6.75 tracks for high density standard cells and 7.5 tracks for high performance standard cells. High-density cell 112.79 MTr/mm[SUP]2[/SUP].
5. A reported advantage of EUV was "pattern fidelity." This is only applicable to nonlinear 2D patterns, and can be attributed to high k1.
6. Another reported advantage of EUV was bidirectionality, or the use of 2D patterns. This allows serial via reduction, and less IR drop. However, as we know from many analyses, they can only keep this benefit for sufficiently large pitches. Ironically, the 7LPP EUV designs actually looked more like 1.5D while the triple-patterned 10LPP looked like 'true' 2D.
7. They reported a very tight CD distribution (1nm 3s) which looks like a very high dose (>50 mJ/cm[SUP]2[/SUP]) being used (literature reports 3-4 nm 3s at 50 mJ/cm[SUP]2[/SUP] or lower). The dimension also looks pretty large, most likely 2x-nm scale since there was comparison with SADP.
8. Other tricks to enhance density include special constructs (T-shape, single dummy gate).
9. Readiness assessment: official line is to ramp late this year through early next year, though unofficially it could delay to maybe even 2020. Different answers from different Samsung personnel. Mask inspection still not ready, as well as photoresist. No pellicles used for now because of low transmission. Without many pieces ready, Samsung's position looks highly experimental, as if they are playing guinea pig. But during this time, 8LPP, the backup basically, has much in common with 7LPP.
This WikiChip fuse article which appeared several days ago is a pretty nice short review of Samsung's 7nm presentations from both VLSI 2018 and ISSCC 2018. It also seems to provide a pretty balanced look at Samsung's 7nm situation. Most of the VLSI 2018 stuff was covered here at SemiWiki already. So I'll just list a number of points from the 5-page article, many probably already known:
1. Samsung referred to 7LPP as the "2nd generation" 7nm, the first being 7LPE, which practically never happened but was developed at one point.
2. Fin pitch 27 nm, Gate pitch 54 nm, Metal pitch 36 nm.
3. EUV single exposure for contact, metal, >25% mask reduction consequently. (Note: previously EUV for fin layer has been corrected)
4. 6.75 tracks for high density standard cells and 7.5 tracks for high performance standard cells. High-density cell 112.79 MTr/mm[SUP]2[/SUP].
5. A reported advantage of EUV was "pattern fidelity." This is only applicable to nonlinear 2D patterns, and can be attributed to high k1.
6. Another reported advantage of EUV was bidirectionality, or the use of 2D patterns. This allows serial via reduction, and less IR drop. However, as we know from many analyses, they can only keep this benefit for sufficiently large pitches. Ironically, the 7LPP EUV designs actually looked more like 1.5D while the triple-patterned 10LPP looked like 'true' 2D.
7. They reported a very tight CD distribution (1nm 3s) which looks like a very high dose (>50 mJ/cm[SUP]2[/SUP]) being used (literature reports 3-4 nm 3s at 50 mJ/cm[SUP]2[/SUP] or lower). The dimension also looks pretty large, most likely 2x-nm scale since there was comparison with SADP.
8. Other tricks to enhance density include special constructs (T-shape, single dummy gate).
9. Readiness assessment: official line is to ramp late this year through early next year, though unofficially it could delay to maybe even 2020. Different answers from different Samsung personnel. Mask inspection still not ready, as well as photoresist. No pellicles used for now because of low transmission. Without many pieces ready, Samsung's position looks highly experimental, as if they are playing guinea pig. But during this time, 8LPP, the backup basically, has much in common with 7LPP.
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