Printing Chips

batty writes :"Nature has this article about a process that uses a quartz die and a laser to mechanically print features onto chips instead of photo-etching them. The article mentions engraving a silicon wafer with features only 10 nanometres in size, as opposed to 130 nanometres using photlithography, and the process is quicker, simpler, and more environmentally friendly than current processes. Which is nice."

Comments

OutStripping Moores Law

[rugwuk]

The author of this article from Princeton was reported in the BBC as saying he thinks he can outstrip Moores Law with this new technology!

Same

[Anonymous Coward]

From this Nature article

With a transparent quartz die and a laser pulse, Stephen Chou and colleagues at Princeton University in New Jersey imprint features only 10 millionths of a millimeter (10 nanometers) wide onto a silicon wafer2. The best photolithography can reproduce features about 130 nanometers wide.

From previous BBC article

Professor Chou's process, described in the scientific journal Nature, involves a simple mechanical printing of the features of the chip.

A quartz die is pressed against the silicon, which is melted briefly by a laser.

Re:In terms of CPU lingo

[rjw57]

Quantum effects are what make semiconductors work :). However below a certain size the wave-particle duality stats to make you wires into waveguides...

Re:But how do you make the mold

[joshv]

This is really interesting, an exact copy of the comment I posted to this same story four days ago...

Enterprising young ACs.

-josh

Re:In terms of CPU lingo

[Anonymous Coward]

>That's the funny thing about reality.

Quantum mechanics is NOT reality. It is a DESCRIPTION that matches empirical data, just as in ancient times, astronomers used "epicycles" to explain the puzzling pathways of the planets and stars when they thought the earth was at the center of the universe. Did it matter to ship navigators whether or not the astronmers were correct? Most of the time, the theory of epicycles was an adequate explanation for their needs.

I do not believe in the reality of particle-wave duality, but it does provide the most adequately useful DESCRIPTION to date so that people are able to invent things on top of it.

Re:stamping process is not useful for mass product

[waferbuster]

The idea of stamping an entire wafer at once, and getting the pattern correct is pretty heady stuff, considering the inherent difficulty in getting the overlay on a single field correct. The primary showstopper for stamping the entire wafer at once is obviously going to be the ability to get overlay to the underlying pattern *perfectly* over the entire area of the wafer. Let's say the quartz stamper is in perfect condition (no particles, and no residue from previous stampings, and no broken impression teeth). Raising the temperature of the stamper by even a miniscule amount will cause the stamper to expand, creating more than enough X and Y scaling error to prevent all but the centermost chips from even being *close* to matching the underlying pattern. Hence no continuity layer to layer and no usable chips except in the center of the wafer.

Also, let's say that the stamper can do 1 stamp per minute (aggressive, but ya gotta make some assumptions). How do you determine when the first little imprinter point snaps off, and every subsequent stamp creates a dead die. If it happens during the first several hundred wafers patterned, and the stamper isn't changed for thousands of stamps, there's going to be an awful lot of non-yielding die at end of line. That's a real bummer, because nobody buys the chips that fail sort/etest for anything more challenging than pretty keychains/ornaments.

Another problem is going to be that the surface of a wafer is *not* flat. Run a wafer through a diffusion furnace, and it warps like an album left in the sun (ok, so I'm dating myself... but the analogy is valid). Let's assume that the wafer bows up at the edges, relative to the center. If you try to press the entire wafer at once, you are going to get excessive pressures at the edges, while the center of the wafer isn't yet touched by the stamper. As a result, the center of the wafer isn't going to get any pattern, and so the center of the wafer won't yield usable die. Bummer.

Another issue is that *all* wafers end up with particles on the surface, be it aluminum, stainless steel, tantalum, or just plain old dust. What happens to the little imprinter fingers when you try to press them into a hunk of steel? I'll give you a hint, it'll be like holding your fingers out straight and punching a bowling ball... your fingers are gonna break. How well are your fingers going to be at pressing anything after that? On the wafer scale, any stamper which hits a die that has a surface defect will result in that die being defective on all subsequent pressings. More keychain ornaments, but less working chips and much less profitable.

In closing, let's consider one other little issue. In patterning, the goal is to have the sidewalls as nearly perpendicular to the surface as possible. A cross section view of a line should look like a skyscraper, with vertical sides, and not like a pyramid/trapezoid. In order to stamp and be able to extract the stamper from the imprinted surface without ripping off teeth, the impresser has to be tapered to minimize friction effects. Etchers and implanters really don't do well with tapered sidewalls on the pattern... you lose resolution of the resultant structures/implants.