|
Microwave semiconductor
tradeoffs
Updated May 18,
2013
Click here
to go to our page on MMIC suppliers
Click
here to learn about semiconductor starting material
Let's start with a Microwaves101
rule of thumb:
Any microwave semiconductor house that doesn't invest in new technology,
is going to go out of business in the long run. By long run, we
mean five years.
At just about every meeting involving
an empty suit, someone will ask "what's the difference between
a SiGe HBT and a GaAs pHEMT MMIC?" Plenty! You can look like
an expert and make your friends and enemies jealous of your knowledge
if you study our pages carefully.
Attention corporate spies, the
information compiled here is widely known throughout the universe,
so don't think we are giving away any proprietary foundry information
here, from any sources. We just know what we scrape off the web
Attention MMIC and discrete
semiconductor foundries... any one of these topics is fair game
for you to sponsor on your own private
Microwaves101 page! And we'll become your new best friend, we
promise! Attention MMIC nerds! Contact
us if you want to write about one of these topics, so we can
speed up the process of making this into a more useful resource!
Here are the semiconductor technologies
support microwave frequencies:
Click
here to go to our page on antimonide-based compound semiconductors
(ABCS)
Click
here to go to our page on gallium arsenide semiconductors
Click
here to go to our page on gallium nitride semiconductors
Click
here to go to our page on indium phosphide semiconductors
Click
here to go to our page on silicon semiconductors for microwaves
Click
here to go to our page on LDMOS
For tons of information on material
properties of all semiconductors, check out the Ioffe
Institute's web site, if they don't have it, it hasn't been measured.
Horizontal or vertical?
Before we get too far into this
subject, let's discuss the difference between vertical and
horizontal semiconductors. HBTs (heterojunction bipolar transistors)
and PIN diodes are vertical structures, each of the regions are
grown in layers using some type of epitaxy. FETs (field effect transistors)
of all kinds are horizontal structures. When we talk about vertical
structures, where the "magic" takes place is referred
to as the junction. For horizontal transistors (FETs)
it's called the channel. So don't talk about the "junction
temperature" of a HEMT (high electron mobility transistor,
a type of FET), or you will sound like an idiot!
What's a compound semiconductor?
A compound semiconductor is one
where the crystal lattice uses two or more types of atoms. This
is the case of gallium arsenide, gallium nitride and silicon germanium.
Binary, ternary, or quaternary?
These terms refer to the number
of elements in a crystal lattice. Many compound semi's are binary,
like GaAs and SiGe. Some are ternary, like InGaAs.
Here's a reference to quaternary semiconductors, thanks to Tyler:
From Wikipedia:
“AlGaInP is used in manufacture of light-emitting diodes of high-brightness red, orange, green, and yellow color, to form the heterostructure emitting light. It is also used to make diode lasers.”
|