<< Chapter < Page Chapter >> Page >
SSPD_Chapter 1_Part 11_continuation describes the crystal structure and its crystalline parameters.

SSPD_Chapter 1_ Part 11_Solid State of Matter continued_Silicon, Germanium and GaAs crystal structures

1.11.5. SILICON AND COMPOUND SEMICONDUCTORS.

Before the advent of Solid State Technology, i.e. before 1950, semiconductor was used as two terminal point contact diode and photodiode. With the invention of Bipolar Junction Transistor, Germanium rose to the position of eminence because of its unusually high mobility of electron = 3900 cm 2 /(V-sec) [Table 1.10]. But with the invention of Integrated Circuit Chips it yielded ground to Silicon.

Today Silicon has become the staple of the Post- Industrial Society just as Iron became the staple of the Industrial Society.

Why Silicon has become the material of choice and the most studied semiconductor in Computer Era? It is primarily because of Silicon-dioxide layer which can easily be formed by oxidation either in dry Oxygen or in steam. Oxidation is the key process in I.C.Technology. SiO 2 acts as passivating layer as well as a shielding layer during diffusion. As we know that Silicon is a 3-D orderly arrangement of Silicon atoms which is abruptly terminated at the surface boundary of the crystal. This abrupt termination of orderly arrangement leaves many covalent bonds incomplete. These incomplete bonds are known as dangling bonds. These dangling bonds cause surface states and these surface states tend to trap or release mobile carriers. This random release or trapping of mobile carriers cause 1/f noise or flicker noise. Passivation of the surface states minimizes the flicker noise, stabilizes the electrical characteristics of the device and provides a protective layer to the underlying device. Since SiO 2 is a perfect insulator it is used for isolation of devices which considerably reduces the parasitic effects. Conventionally reversed biased diode is used which eats away a lot of the real estate on the Silicon Surface and gives rise to severe parasitic effects. The real estate is saved as well as parasitics are minimized by the use of SiO 2 as isolation layer as well as the substrate as it is done in Silicon - on - Insulator (SOI) Technology.

The second reason for the popularity of Silicon is easy and cheap availability. It is obtained from silica and silica comprises 25% of Earth’s crust. Silicon is second most abundant after oxygen.

But Silicon is most unsuitable for photonics because of indirect band-gap and its accompanying non-radiative transitions though in recent years Silicon has been suitably modified to obtain photonic circuits on Silicon Substrate. Because of the unsuitability of Silicon, we have had to opt for Compound Semiconductors and its alloy as shown in Table(1.25).

Table(1.25) give the compound semiconductors which have application in Photonics.

Table. 1.25. Compound Semiconductors for Photonics application.

Element IV-IV compounds. III-Vcompounds II-VIcompounds IV-VIcompounds
Si SiC AlAs CdS PbSe.
Ge AlSb CdSe
BN CdTe
GaAs ZnS
GaP ZnSe
GaSb ZnTe
InAs
InP
InSb

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Solid state physics and devices-the harbinger of third wave of civilization. OpenStax CNX. Sep 15, 2014 Download for free at http://legacy.cnx.org/content/col11170/1.89
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Solid state physics and devices-the harbinger of third wave of civilization' conversation and receive update notifications?

Ask