Answer by Mira Zaslove:
Gallium-Arsenide (GaAs) is a compound semiconductor of Gallium (Ga) and Arsenic (As). Gallium is rarer than gold. Arsenic isn't rare, but yeah, it's poisonous.
GaAs is a faster conveyor of current than silicon. And, GaAs IC's consume less power. But GaAs is significantly more expensive and harder to come by than silicon. Behind oxygen, silicon is the most frequent chemical in the earth’s crust. Sand has a high percentage of silicon. Silicon is cheap and plentiful. And silicon wafers are the standard today.
The need for GaAs didn't go away. It's still alive and kicking. GaAs devices are fast, allow for greater flexibility, less noise, and are used in weak-signal amplification applications. GaAs is commonly associated with ultra-high RF, fast electronic switching, LEDs, and solar. GaAs is also highly resistant to radiation damage, which lends GaAs to satellite and space applications.
Analysts predict thewill reach $650M+ by 2017. Primarily due to demand for handsets and LEDs in lighting and automotive. Solar cells for high-concentration photovoltaics (HCPV) will also add to the development of the GaAs substrate market.
GaAs cells are relatively insensitive to heat. According to a recent NASA tech brief when considering GaAs as a photovoltaic:, GaAs produces more total energy and runs 10°C degrees cooler than silicon. Factoring in the efficiency advantage, GaAs solar panels collected over 50% more total energy greater than competing silicon-based solar panels.
The primary reason GaAs has not been further pursued in larger scale fabs is the high cost and it's inconsistent processes. For all its advantages, gallium arsenide is more costly than silicon. It's also toxic, and requires expensive precautions. It's unlikely, therefore, that the alloy will ever take over the semiconductor market.
GaAs is also being squeezed by newer high voltage compound semiconductor materials like GaN and SiC. There are a large number of RF Si foundries that have high capacities available such as Taiwan Semiconductor (TSMC), Tower/JAZZ Semiconductor.
As Si technologies squeeze GaAs from the lower frequency and power applications side, other compound semiconductors such as GaN and SiC are squeezing GaAs from the high frequency, high power side where it has always excelled.
No large mainstream tier 1 semiconductor companies (Intel, Samsung, Global Foundries, or the like) run GaAs. I've never heard of GaAs production lines running on 300mm wafer sizes. I'm not even sure it can be done. Most of the GaAs fabs I've seen ran 100mm or 150mm wafer sizes, which yield lower die levels than 200mm and 300mm fabs, further increasing time and costs for large scale production.
Once a company has set up its fab and manufacturing process for silicon, they are extremely unlikely to undertake a major and risky change to GaAs. Fabs are large and complicated. Silicon is cheap, plentiful, and a pure element. The tremendousavailable to the silicon industry at the 300mm level have also reduced the adoption of GaAs.