DUV vs EUV (aka VUV) in semiconductor manufacturing

[Bob Eisenman]

So....Reuters posted a recent story about China's new 7nm chip (Kirin 9000s) produced using DUV, where EUV (banned in China by US sanctions) is generally reported as the most logical path of the future for 5-7 nm chip manufacturing.

https://www.reuters.com/technology/huaweis-new-chip-breakthrough-likely-trigger-closer-us-scrutiny-analysts-2023-09-05/

So...I wondered what DUV and EUV stood for? 

Google'ing and Wikipedia finds some meaning:

DUV (deep ultraviolet)

EUV (extreme ultraviolet)

"What does EUV stand for? EUV stands for 'extreme ultraviolet'. It refers to the light's wavelength. The deep ultraviolet (DUV) light used in chip production has wavelengths of 248 and 193 nm, whereas the light used in EUV lithography has a wavelength of 13.5 nm."

OK....my college science courses came to mind where a picture of the color spectrum with the nm (nanometer) of wavelength listed below came to mind. I looked at a chart to refresh my memory.

https://images.app.goo.gl/keQf6iVBHTS85iue9

The 248-193 nm fit into memory but the EUV (aka VUV) was a new term.

Wikipedia describes EUV light at this link:

https://en.m.wikipedia.org/wiki/Extreme_ultraviolet_lithography

Vacuum UV (aka EUV) is 4 to 40 times shorter in wavelength than 400 nm UV light. The shorter the wavelength of light the more 'energetic' each photo is. When electrons transition to lower energy electron orbitals the energy difference between the two levels denotes the nm value (energy/photon) of the emitted photon. The electron orbitals for EUV (remember the periodic table of elements and electron filling by orbital type and spin up/down ?) for VUV (vacuum ultra violet) is:

"It uses extreme ultraviolet (EUV) wavelengths near 13.5 nm, using a laser-pulsed tin (Sn) droplet plasma (Sn ions in the ionic states from Sn IX to Sn XIV give photon emission spectral peaks around 13.5 nm from 4p⁶4dⁿ - 4p⁵4dⁿ⁺¹ + 4d^n-14f ionic state transitions"

Sn is the atomic symbol for Tin (atomic #50)

https://images.app.goo.gl/fwFCiBAZD6et58fy9

p stands for p type orbital (dumbbell in x y or z orientation (6 total electrons)

https://images.app.goo.gl/KFjpoPNyYzBFqbmN8

d stands for d type orbital (10 total electrons)

https://images.app.goo.gl/cnQCBVbwLegZAmvB9

This stuff is quantum theory and it became more complicated with 'orbital hybridizations' with fused geometries. Anything below the 3rd or 4th row of the periodic table was confusing.

Ultraviolet	200 nm - 400nm  (3 - 6 eV)	7x1014 -  1.5x1015	Divided at 300 nm by atmospheric (ozone) cutoff. Appreciable solar flux causes sunburn.
Vacuum UV (EUV)	10 nm -  200 nm  (6 - 120 eV)	1.5x1015 - 3x1016	Very strong absorption in matter, hence very difficult to observe."

So .... Getting back to the China chip called Kirin 9000s. The chip is a 7nm (chip dimension) made with improvements in DUV lithography developed by China's chip manufactures.

The EUV (aka VUV vacuum UV) lithography technology that is sanctioned against use by China (defense industry concerns?) EUV lithography is described by the orbital theory model for Tin described above in my best plagiarized form. Most web sources point to the future of 5-7 nm chip manufacture as being produced by the EUV lithography approach.

Somewhere...as written in the next url news link.... 5g wireless and the phone industry market fits into the marketing strategy for DUV lithography produced chips (for phones (Mate 60 Pro) at the 7 nm level.

https://asiatimes.com/2023/08/huaweis-new-phone-juices-chinese-chip-stocks/