Researchers uncover the fastest semiconductor yet
Researchers claim to have built a rhenium-based semiconductor that could switch on femtosecond timescales—up to a million times faster than today’s gigahertz silicon electronics—raising the prospect of radically faster computing and novel applications like infrared rectification or ultra‑high‑speed optical interfaces. Commenters probe whether the extreme rarity and production limits of rhenium make such devices commercially infeasible, noting that material cost per chip is tiny but large new demand could send prices soaring and require complex recycling and deposition processes. Many expect any real impact to come only if similar properties can be replicated in more abundant materials and integrated into existing manufacturing flows, drawing parallels to earlier hype cycles around graphene and carbon nanotubes that stalled at mass production.
Performance Potential and Architectural Limits
- Material promises femtosecond-scale switching, implying up to a million‑fold speedup over GHz electronics.
- Commenters note CPUs couldn’t simply scale clocks by 10⁶: DRAM latency would dominate, so only very small on‑chip memories could keep up.
- Likely early uses would be in specialized, high‑speed interfaces (e.g., optical regeneration, networking ASICs) rather than general CPUs.
- With such speed, even very simple in‑order cores might outperform today’s complex designs if memory constraints are addressed.
Rhenium Scarcity, Cost, and Market Dynamics
- Rhenium is among the rarest elements; annual global production is tiny and largely a byproduct of other mining.
- One side argues that chips use microscopic amounts and even grams per chip would be a small cost adder compared to processing and IP.
- Others emphasize that if demand scaled to consumer volumes, supply constraints would likely drive prices from ~$1–10/g up to orders of magnitude higher.
- Some expect higher prices would incentivize better extraction and recycling; others think geological limits cap production, making widespread use unrealistic.
Manufacturing and Integration Challenges
- Deposition processes waste much more material than ends up on wafers; for expensive elements, full recycling becomes mandatory and complex.
- Finding compatible substrates and reliable deposition chemistries for such compounds is non‑trivial.
- The article itself notes the material is not necessarily compatible with current semiconductor hardware, so applications would differ from traditional logic.
Alternative Materials and Future Prospects
- The key scientific value is seen as identifying structural/electronic properties that enable this “transport regime,” enabling search for earth‑abundant analogues.
- Comparisons made to prior paths: germanium → silicon, gallium arsenide, and hafnium‑based dielectrics show that exotic materials can become standard over decades.
Context from Graphene, Nanotubes, and Safety
- Discussion recalls past hype for graphene and carbon nanotubes: lab demos succeeded, mass production and yield did not.
- Nanotubes/graphene raise asbestos‑like toxicity concerns; fabs already handle worse hazards but added controls would increase cost.
- Overall sentiment: impressive science, but commercialization hinges on new materials, process breakthroughs, and realistic economics.