What is a transistor made of?

Answer 1

a specially treated microscopic piece of silicon

Answer 2

By far, the majority of transistors are made of silicon. There are a bunch of different kinds of transistors too. The original transistor was a bipolar junction transistor (BJT). The MOSFET is a special kind of transistor that is probably lots more popular than the BJT.

First, you have the silicon. Different impurities such as boron, phosphorus, and arsenic are used to make the silicon P type or N type. But it doesn't stop there. There is also glass (silicon dioxide), which is used as an insulator. This keeps the electricity from going where we don't want it to go.

Even the glass can have impurities such as boron and phosphorus intentionally added so that it behaves how we want. Other common insulators used in transistors are silicon nitride or oxynitride.

There's even another kind of silicon called polysilicon because it's not a single crystal like the crystalline silicon used in the transistor. Polysilicon is like lots of tiny crystals jumbled together.

Next, you have metal. We have to have a way to connect the silicon to the wires coming out of the package. There's titanium, tungsten, aluminum, nickel, silver, and even gold. And yes, you'll probably find all of those metals in a single MOSFET package.

The package that holds the transistor is made of plastic, usually an epoxy called a molding compound. The MOSFET is attached to a metal base called a leadframe, usually made of copper and plated with nickel. The industry is moving away from lead based solders, and is now using silver solders to attach the MOSFET to the leadframe. Or, they can use a silver epoxy instead of solder.

So there you have it, and probably more than you really asked for. Silicon, plastic, metal, and glass, all working together to switch electricity on and off.

Answer 3

There are many kinds of transistors, and many materials "processes" transistors can be made on.


Transistors are made from doping a semiconductor to create P and N type regions in the material "process". In a pure silicon crystal, boron can be diffused into the material to create a P-type region, and Phosphorus doped into the material to create an N-type region.

Some transistors don't have P regions, they use the shottky junctions between a metal and an N-type material to get the transistor action.

Some transistors (MOSFETS) use an insulating layer of SiO2 which an electric field from a charged gate inverts the semiconductor type (P to N, or N to P) under the gate to create a conductive path between the other two terminals (source and drain).

Processes can include:

Silicon (by far the most common)
GaAs (used for high frequency applications)
SiGe

There are many other semiconductors that can be used to make transistors.

Answer 4

Jess said "The oldest transistor is probable the triode vacuum tube."

Bollocks.

Make your mind up. Do you want to talk about transistors or vacuum tubes? They're completely different animals.

Answer 5

Mostly silicon, plus a little germanium, go look on wikipedia.

Answer 6

typically silicon or germanium

Answer 7

Sugar and spice and......what was the question again?