Date: 22/02/2012

Is Germanium a potential candidate to work along with Silicon in future computers?

Silicon is an excellent material in many aspects such as environment, cost, and physical properties. Is there any drawback! Yes, the mobility of electrons is not as good as other semiconductor materials to use in high frequency applications. So the speed is the limit. Germanium, though known for reliability issues matches in performance with another RF semiconductor material Gallium Arsenide for high speed and optoelectronics needs. Researched looking at Germanium as an alternative when the VLSI geometry is shrinking further.

Germanium is looked at for another important research-trend. The trend is by using photons instead of electrons as media of data inside the processor chips supports faster-computing and faster-communications at low power. The question is how to do that on the present silicon chips, whose manufacturing process is well established. The emission of light from silicon is proving to be very challenging. The challenge is to find a material, which can convert electrons into photons and can be fabricated on the present silicon chips. It's not going to be pure photonics but a combination of electronics and photonics in a single device. The Germanium is again a preferred material for photon generation.

As per the latest media reports, an U.S. based company called APIC Corp has said to have achieved breakthrough in using Germanium to produce laser light and stream it inside the chip. Indian born IIT alumni Dr. Birendra (Raj) Dutta is heading this company. To know more on his companies visit www.photonic-corp.com/ and www.apichip.com.

The Silicon based CMOS reaching this far is great, but moving further, Silicon may not get same preference. Even with the present technology of chip-making chip-experts will always look for other semiconductor materials such as Germanium or any high electron mobility material. Graphene is also found to be very interesting candidate.

Well, the path ahead in nano-VLSI is far different than the path it has traveled in past 2/3 decades.

Here is a link comparing properties of Silicon, Germanium and Gallium Arsenide:
http://www.siliconfareast.com/sigegaas.htm

The trend is to look at every material to make the devices smaller and faster and rugged. There is also opportunity for chip developers to fabricate chips using a process far cheaper than the present one.